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Sample records for beta-adrenergic receptor sensitivity

  1. Beta adrenergic receptors in human cavernous tissue

    Energy Technology Data Exchange (ETDEWEB)

    Dhabuwala, C.B.; Ramakrishna, C.V.; Anderson, G.F.

    1985-04-01

    Beta adrenergic receptor binding was performed with /sup 125/I iodocyanopindolol on human cavernous tissue membrane fractions from normal tissue and transsexual procedures obtained postoperatively, as well as from postmortem sources. Isotherm binding studies on normal fresh tissues indicated that the receptor density was 9.1 fmoles/mg. with a KD of 23 pM. Tissue stored at room temperature for 4 to 6 hours, then at 4C in saline solution for 19 to 20 hours before freezing showed no significant changes in receptor density or affinity, and provided evidence for the stability of postmortem tissue obtained within the same time period. Beta receptor density of 2 cavernous preparations from transsexual procedures was not significantly different from normal control tissues, and showed that high concentrations of estrogen received by these patients had no effect on beta adrenergic receptor density. Displacement of /sup 125/iodocyanopindolol by 5 beta adrenergic agents demonstrated that 1-propranolol had the greatest affinity followed by ICI 118,551, zinterol, metoprolol and practolol. When the results of these displacement studies were subjected to Scatfit, non- linear regression line analysis, a single binding site was described. Based on the relative potency of the selective beta adrenergic agents it appears that these receptors were of the beta 2 subtype.

  2. Mood states, sympathetic activity, and in vivo beta-adrenergic receptor function in a normal population.

    Science.gov (United States)

    Yu, Bum-Hee; Kang, Eun-Ho; Ziegler, Michael G; Mills, Paul J; Dimsdale, Joel E

    2008-01-01

    The purpose of this study was to examine the relationship between mood states and beta-adrenergic receptor function in a normal population. We also examined if sympathetic nervous system activity is related to mood states or beta-adrenergic receptor function. Sixty-two participants aged 25-50 years were enrolled in this study. Mood states were assessed using the Profile of Mood States (POMS). Beta-adrenergic receptor function was determined using the chronotropic 25 dose isoproterenol infusion test. Level of sympathetic nervous system activity was estimated from 24-hr urine norepinephrine excretion. Higher tension-anxiety, depression-dejection, and anger-hostility were related to decreased beta-adrenergic receptor sensitivity (i.e., higher chronotropic 25 dose values), but tension-anxiety was the only remaining independent predictor of beta-adrenergic receptor function after controlling for age, gender, ethnicity, and body mass index (BMI). Urinary norepinephrine excretion was unrelated to either mood states or beta-adrenergic receptor function. These findings replicate previous reports that anxiety is related to decreased (i.e., desensitized) beta-adrenergic receptor sensitivity, even after controlling for age, gender, ethnicity, and body mass index.

  3. Beta-adrenergic receptor sensitivity, autonomic balance and serotonergic activity in practitioners of Transcendental Meditation

    International Nuclear Information System (INIS)

    Hill, D.A.

    1989-01-01

    The aim of this thesis was to investigate the acute autonomic effects of the Transcendental Meditation Program (TM) and resolve the conflict arising from discrepant neurochemical and psychophysiological data. Three experimental investigations were performed. The first examined beta 2 -adrenergic receptors (AR's) on peripheral blood lymphocytes, via [I 125 ]iodocyanopindolol binding, in 10 male mediating and 10 age matched non-meditating control subjects, to test the hypothesis that the long-term practice of TM and the TM Sidhi Program (TMSP) reduces end organ sensitivity to adrenergic agonists. The second investigated respiratory sinus arrhythmia (an indirect measure of cardiac Parasympathetic Nervous System tone), and skin resistance (a measure of Sympathetic Nervous System tone) during periods of spontaneous respiratory apneusis, a phenomenon occurring during TM that is known to mark the subjective experience of transcending. The third was within subject investigation of the acute effects of the TMSP on 5-hydroxytryptamine (5-HT) activity. Platelet 5-HT was assayed by high pressure liquid chromatography with electrochemical detection, plasma prolactin (PL) and lutenizing hormone (LH) by radioimmunoassay, tryptophan by spectrofluorimetry, and alpha-1-acid glycoprotein (AGP, a modulator of 5-HT uptake) by radial immunodiffusion assay

  4. Developmental changes of beta-adrenergic receptor-linked adenylate cyclase of rat liver

    International Nuclear Information System (INIS)

    Katz, M.S.; Boland, S.R.; Schmidt, S.J.

    1985-01-01

    beta-Adrenergic agonist-sensitive adenylate cyclase activity and binding of the beta-adrenergic antagonist(-)-[ 125 I]iodopindolol were studied in rat liver during development of male Fischer 344 rats ages 6-60 days. In liver homogenates maximum adenylate cyclase response to beta-adrenergic agonist (10(-5) M isoproterenol or epinephrine) decreased by 73% (P less than 0.01) between 6 and 60 days, with most of the decrease (56%; P less than 0.01) occurring by 20 days. beta-adrenergic receptor density (Bmax) showed a corresponding decrease of 66% (P less than 0.01) by 20 days without subsequent change. Binding characteristics of stereospecificity, pharmacological specificity, saturability with time, and reversibility were unchanged with age. GTP-, fluoride-, forskolin-, and Mn2+-stimulated adenylate cyclase activities also decreased during development, suggesting a decrease of activity of the catalytic component and/or guanine nucleotide regulatory component of adenylate cyclase. These results indicate that the developmental decrease of beta-adrenergic agonist-sensitive adenylate cyclase activity may result from decreased numbers of beta-adrenergic receptors. Developmental alterations of nonreceptor components of the enzyme may also contribute to changes of catecholamine-sensitive adenylate cyclase

  5. Characterization of beta-adrenergic receptors in synaptic membranes from rat cerebral cortex and cerebellum

    International Nuclear Information System (INIS)

    Lautens, L.

    1986-01-01

    Beta-adrenergic receptor ligand binding sites have been characterized in synaptic membranes from rat cerebral cortex and cerebellum using radioligand binding techniques. The equilibrium and kinetic properties of binding were assessed. The binding sites were non-interacting and exhibited two states of agonist binding which were sensitive to guanyl nucleotide. Synaptic membranes from cerebral cortex contained an equal number of beta 1 - and beta 2 -receptors; membranes from cerebellum possessed more beta 2 -than beta 1 -receptors. Photoaffinity labeling experiments revealed two different beta-adrenergic receptor polypeptides, R 1 and R 2 (and possibly a third, R 3 ) in synaptic membranes. The ratios of incorporation of photoaffinity label into R 1 : 2 were approximately 1:1 (cerebral cortex) and 5:1 (cerebellum). Photoaffinity labeling of R 1 and R 2 was inhibited equally well by both agonist and antagonist in synaptic membranes from cerebellum; whereas agonist was a less potent inhibitor in membranes from cerebral cortex. Both subtypes of beta-adrenergic receptors exhibited the same apparent molecular weight in synaptic membranes from cerebral cortex. The beta-adrenergic receptors in synaptic membranes from cerebral cortex and cerebellum were glycoproteins which exhibited the same apparent molecular weight after exposure to endoglycosidase F. The partial proteolytic digest maps of photoaffinity labeled beta-adrenergic receptors from rat cerebral cortex, cerebellum, lung and heart were compared

  6. Reduced beta-adrenergic receptor activation decreases G-protein expression and beta-adrenergic receptor kinase activity in porcine heart.

    OpenAIRE

    Ping, P; Gelzer-Bell, R; Roth, D A; Kiel, D; Insel, P A; Hammond, H K

    1995-01-01

    To determine whether beta-adrenergic receptor agonist activation influences guanosine 5'-triphosphate-binding protein (G-protein) expression and beta-adrenergic receptor kinase activity in the heart, we examined the effects of chronic beta 1-adrenergic receptor antagonist treatment (bisoprolol, 0.2 mg/kg per d i.v., 35 d) on components of the myocardial beta-adrenergic receptor-G-protein-adenylyl cyclase pathway in porcine myocardium. Three novel alterations in cardiac adrenergic signaling as...

  7. Anxiety and beta-adrenergic receptor function in a normal population.

    Science.gov (United States)

    Kang, Eun-Ho; Yu, Bum-Hee

    2005-06-01

    Many studies have shown a close relationship between anxiety and beta-adrenergic receptor function in patients with anxiety disorders. This study examined the relationship between beta-adrenergic receptor function and anxiety levels in a normal population. Subjects for this study included 36 men and 44 women between the ages of 20 and 40 years whose Body Mass Index (BMI) was between 18 and 26. All of them were healthy subjects who had no previous history of medical or psychiatric illnesses. The authors measured the Spielberger State-Trait Anxiety Inventory (STAI), Beck Depression Inventory (BDI), and Chronotropic 25 Dose (CD25) of isoproterenol, previously developed to assess in vivo beta-adrenergic receptor sensitivity. We also examined correlations between log normalized CD25 and mood states. The mean of CD25 was 2.64+/-1.37 mug and the mean of CD25 in men was significantly higher (i.e., lower beta-adrenergic receptor sensitivity) than that of women (3.26+/-1.35 vs. 2.14+/-1.17 microg; t = 3.99, p anxiety (r = -0.344, p = 0.002), trait anxiety (r = -0.331, p = 0.003), and BDI (r = -0.283, p = 0.011). CD25 was positively correlated with BMI (r = 0.423, p anxiety, and BMI. The sensitivity of beta-adrenergic receptors increased as anxiety levels became higher in a normal population. Thus, the relationship between anxiety and beta-adrenergic receptor function in healthy subjects may be different from that of patients with anxiety disorders.

  8. Characterization of beta-adrenergic receptors through the replicative life span of IMR-90 cells

    International Nuclear Information System (INIS)

    Scarpace, P.J.

    1987-01-01

    Beta-adrenergic receptor number and receptor affinity for isoproterenol were assessed at various in vitro ages of the human diploid fibroblast cell line IMR-90. From population doubling level (PDL) 33 to 44, there was a positive correlation between beta-adrenergic receptor density and PDL. Beta-adrenergic receptors, assessed by Scatchard analysis of [ 125 I]-iodocyanopindolol (ICYP) binding, increased from 15 fmol/mg protein at PDL 33 to 36 fmol/mg protein at PDL 44. In contrast, from PDL 44 to 59, there was a negative correlation between beta-adrenergic receptor density and PDL. Receptor density declined to 12 fmol/mg protein at PDL 59. When the density of beta-adrenergic receptors was expressed as receptor per cell, the findings were similar. Receptor agonist affinity for isoproterenol was determined from Hill plots of [ 125 I]-ICYP competition with isoproterenol. There was no change in the dissociation constant for isoproterenol with in vitro age. In humans, serum norepinephrine concentrations increase with age. This increase in serum norepinephrine may be partially responsible for the decreased beta-adrenergic receptor-agonist affinity observed with age in human lymphocytes and rat heart and lung. The present findings are consistent with the hypothesis that the decreases in receptor agonist affinity in rat and man with age are secondary to increases in catecholamine concentrations

  9. Beta-adrenergic receptors of lymphocytes in children with allergic respiratory diseases

    International Nuclear Information System (INIS)

    Bittera, I.; Gyurkovits, K.; Falkay, G.; Eck, E.; Koltai, M.

    1988-01-01

    The beta-adrenergic receptor binding sites on peripheral lymphocytes in children with bronchial asthma (n = 16) and seasonal allergic rhinitis (n = 8) were examined in comparison with normal controls (n = 18) by means of 124 I-cyanopindolol. The number of beta-adrenergic receptors was significantly lower in the asthmatic group (858 +/- 460/lymphocyte) than in the controls (1564 +/- 983/lymphocyte). The value (1891 +/- 1502/lymphocyte in children with allergic rhinitis was slightly higher than that in healthy controls. Of the 24 patients suffering from allergic diseases of the lower or upper airways, the bronchial histamine provocation test was performed in 21; 16 gave positive results, while 5 were negative. No difference in beta-adrenergic receptor count was found between the histamine-positive and negative patients. Neither was there any correlation between the number of beta-adrenergic receptors and the high (16/24) and low (8/24) serum IgE concentrations found in allergic patients. The significant decrease in beta-adrenergic receptor count in asthmatic children lends support to Szentivanyi's concept. Further qualitative and quantitative analysis of lymphocyte beta-adrenergic receptors may provide an individual approach to the treatment of bronchial asthma with beta-sympathomimetic drugs

  10. Beta-Adrenergic Receptor Blockers in Hypertension: Alive and Well.

    Science.gov (United States)

    Frishman, William H

    Beta-adrenergic receptor blockers (β-blockers) are an appropriate treatment for patients having systemic hypertension (HTN) who have concomitant ischemic heart disease (IHD), heart failure, obstructive cardiomyopathy, aortic dissection or certain cardiac arrhythmias. β-Blockers can be used in combination with other antiHTN drugs to achieve maximal blood pressure control. Labetalol can be used in HTN emergencies and urgencies. β-Blockers may be useful in HTN patients having a hyperkinetic circulation (palpitations, tachycardia, HTN, and anxiety), migraine headache, and essential tremor. β-Blockers are highly heterogeneous with respect to various pharmacologic properties: degree of intrinsic sympathomimetic activity, membrane stabilizing activity, β 1 selectivity, α 1 -adrenergic blocking effects, tissue solubility, routes of systemic elimination, potencies and duration of action, and specific properties may be important in the selection of a drug for clinical use. β-Blocker usage to reduce perioperative myocardial ischemia and cardiovascular (CV) complications may not benefit as many patients as was once hoped, and may actually cause harm in some individuals. Currently the best evidence supports perioperative β-blocker use in two patient groups: patients undergoing vascular surgery with known IHD or multiple risk factors for it, and for those patients already receiving β-blockers for known CV conditions. Copyright © 2016 Elsevier Inc. All rights reserved.

  11. Species differences in the localization and number of CNS beta adrenergic receptors: Rat versus guinea pig

    International Nuclear Information System (INIS)

    Booze, R.M.; Crisostomo, E.A.; Davis, J.N.

    1989-01-01

    The localization and number of beta adrenergic receptors were directly compared in the brains of rats and guinea pigs. The time course of association and saturability of [125I]cyanopindolol (CYP) binding to slide-mounted tissue sections was similar in rats (Kd = 17 pM) and guinea pigs (Kd = 20 pM). The beta-1 and beta-2 receptor subtypes were examined through the use of highly selective unlabeled receptor antagonists, ICI 118,551 (50 nM) and ICI 89,406 (70 nM). Dramatic species differences between rats and guinea pigs were observed in the neuroanatomical regional localization of the beta adrenergic receptor subtypes. For example, in the thalamus prominent beta-1 and beta-2 receptor populations were identified in the rat; however, the entire thalamus of the guinea pig had few, if any, beta adrenergic receptors of either subtype. Hippocampal area CA1 had high levels of beta-2 adrenergic receptors in both rats and guinea pigs but was accompanied by a widespread distribution of beta-2 adrenergic receptors only in rats. Quantitative autoradiographic analyses of 25 selected neuroanatomical regions (1) confirmed the qualitative differences in CNS beta adrenergic receptor localization, (2) determined that guinea pigs had significantly lower levels of beta adrenergic receptors than rats and (3) indicated a differential pattern of receptor subtypes between the two species. Knowledge of species differences in receptor patterns may be useful in designing effective experiments as well as in exploring the relationships between receptor and innervation patterns. Collectively, these data suggest caution be used in extrapolation of the relationships of neurotransmitters and receptors from studies of a single species

  12. beta-Adrenergic and cholinergic receptors in hypertension-induced hypertrophy

    International Nuclear Information System (INIS)

    Vatner, D.E.; Kirby, D.A.; Homcy, C.J.; Vatner, S.F.

    1985-01-01

    Perinephritic hypertension was produced in dogs by wrapping one kidney with silk and removing the contralateral kidney 1 week later. Mean arterial pressure rose from 104 +/- 3 to 156 +/- 11 mm Hg, while left ventricular free wall weight, normalized for body weight, was increased by 49%. Muscarinic, cholinergic receptor density measured with [ 3 H]-quinuclidinyl benzilate, fell in hypertensive left ventricles (181 +/- 19 fmol/mg, n = 6; p less than 0.01) as compared with that found in normal left ventricles (272 +/- 16 fmol/mg, n = 8), while receptor affinity was not changed. The beta-adrenergic receptor density, measured by binding studies with [ 3 H]-dihydroalprenolol, rose in the hypertensive left ventricles (108 +/- 10 fmol/mg, n = 7; p less than 0.01) as compared with that found in normal left ventricles (68.6 +/- 5.2 fmol/mg, n = 15), while beta-adrenergic receptor affinity decreased in the hypertensive left ventricles (10.4 +/- 1.2 nM) compared with that found in the normal left ventricles (5.0 +/- 0.7 nM). Plasma norepinephrine levels were similar in the two groups, but myocardial norepinephrine levels were depressed (p less than 0.05) in dogs with hypertension. Moderate left ventricular hypertrophy induced by long-term aortic banding in dogs resulted in elevations in beta-adrenergic receptor density (115 +/- 14 fmol/mg) and decreases in affinity (10.4 +/- 2.2 nM) similar to those observed in the dogs with left ventricular hypertrophy induced by hypertension. Thus, these results suggest that perinephritic hypertension in the dog induces divergent effects on cholinergic and beta-adrenergic receptor density. The increased beta-adrenergic receptor density and decreased affinity may be a characteristic of left ventricular hypertrophy rather than hypertension

  13. Human myometrial adrenergic receptors: identification of the beta-adrenergic receptor by [3H]dihydroalprenolol binding

    International Nuclear Information System (INIS)

    Hayashida, D.N.; Leung, R.; Goldfien, A.; Roberts, J.M.

    1982-01-01

    The radioactive beta-adrenergic antagonist [ 3 H] dihydroalprenolol (DHA) binds to particulate preparations of human myometrium in a manner compatible with binding to the beta-adrenergic receptor. The binding of DHA is rapid (attaining equilibrium in 12 minutes), readily reversible (half time = 16 minutes), high affinity (K/sub D/ = 0.50 nM), low capacity (Bmax = 70 fmoles/mg of protein), and stereoselective ([-]-propranolol is 100 times as potent as [+] -propranolol in inhibiting DHA binding). Adrenergic agonists competed for DHA binding sites in a manner compatible with beta-adrenergic interactions and mirrored β 2 pharmacologic potencies: isoproterenol > epinephrine >> norepinephrine. Studies in which zinterol, a β 2 -adrenergic agonist, competed for DHA binding sites in human myometrial particulate indicated that at least 87% of the beta-adrenergic receptors present are β 2 -adrenergic receptors. Binding of DHA to human myometrial beta-adrenergic receptors provides a tool which may be used in the examination of gonadal hormonal modification of adrenergic response in human uterus as well as in the analysis of beta-adrenergic agents as potentially useful tocolytic agents

  14. Concanavalin a increases beta-adrenergic and glucocorticoid receptors in porcine splenocytes

    International Nuclear Information System (INIS)

    Kelley, K.N.; Westly, H.J.

    1986-01-01

    We identified specific glucocorticoid and beta-adrenergic receptors on porcine splenocytes. There are 2000 to 4000 glucocorticoid receptors per cell with a K /SUB D/ of 2 to 4 nM and 1000 beta-adrenergic receptors with a K /SUB D/ of 0.3 to 0.6 nM. When splenocytes were incubated with concanavalin A (Con A), there was an approximate 2-fold increase in both gluococorticoid and beta-adrenergic receptors with no change in binding affinity. Incubation of splenocytes with cortisol as low as 40 nM (13 ng/ml) inhibited proliferation in response to Con A. This inhibitory effect of cortisol was not due to cytotoxic effects of glucocorticoids. At maximal physiologic concentrations (400 nM; 135 ng/ml), cortisol caused reductions in Con A activation of thymocytes and peripheral blood mononuclear cells. When eight wk old pigs were restrained, there was an increase in plasma cortisol, atrophy of thymus and reduction in skin test responses to phytohemagglutinin. On the basis of the data, we suggest that physiologic concentrations of stress asociated hormones affect functional activities of porcine lymphoid cells. Since activated splenocytes display increased numbers of receptors for these hormones, perhaps glucocorticoids or catecholamines normally function in vivo to suppress clonal expansion of antigen activated and autoreactive T lymphocytes

  15. {beta}-adrenergic receptor density and adenylate cyclase activity in lead-exposed rat brain after cessation of lead exposure

    Energy Technology Data Exchange (ETDEWEB)

    Chang, Huoy-Rou [I-Shou University, Department of Biomedical Engineering, Dashu Shiang, Kaohsiung County (Taiwan); Tsao, Der-An [Fooyin University of Technology, Department of Medical Technology (Taiwan); Yu, Hsin-Su [Taiwan University, Department of Dermatology, College of Medicine (Taiwan); Ho, Chi-Kung [Kaohsiung Medical University, Occupational Medicine (Taiwan); Kaohsiung Medical University, Graduate Institute of Medicine, Research Center for Occupational Disease (Taiwan)

    2005-01-01

    To understanding the reversible or irreversible harm to the {beta}-adrenergic system in the brain of lead-exposed rats, this study sets up an animal model to estimate the change in the sympathetic nervous system of brain after lead exposure was withdrawn. We address the following topics in this study: (a) the relationship between withdrawal time of lead exposure and brain {beta}-adrenergic receptor, blood lead level, and brain lead level in lead-exposed rats after lead exposure was stopped; and (b) the relationship between lead level and {beta}-adrenergic receptor and cyclic AMP (c-AMP) in brain. Wistar rats were chronically fed with 2% lead acetate and water for 2 months. Radioligand binding was assayed by a method that fulfilled strict criteria of {beta}-adrenergic receptor using the ligand [{sup 125}I]iodocyanopindolol. The levels of lead were determined by electrothermal atomic absorption spectrometry. The c-AMP level was determined by radioimmunoassay. The results showed a close relationship between decreasing lead levels and increasing numbers of brain {beta}-adrenergic receptors and brain adenylate cyclase activity after lead exposure was withdrawn. The effect of lead exposure on the {beta}-adrenergic system of the brain is a partly reversible condition. (orig.)

  16. [Density of beta-adrenergic receptors and left ventricular mass in patients with primary essential hypertension].

    Science.gov (United States)

    Gajek, J; Zyśko, D; Spring, A

    2000-08-01

    Left ventricular hypertrophy (LVH) is one of the more important risk factors for sudden death. There are multiple factors for development of LVH in patients with hypertension. Sympathetic nervous system may play a key role causing afterload increase and neurohumoral mechanisms activation. The aim of the study was to determine beta-adrenergic receptors density and its relations to left ventricular mass in hypertensive subjects. The study was carried out in 63 patients (23 women and 40 men), mean age 43.3 +/- 11.6 yrs with primary hypertension: stage I--42 pts and stage II--21 pts. The control group consisted of 26 healthy persons matched for age and sex. We evaluated the density of beta-adrenergic receptors using 125I-cyanopindolol radioligand labeling method. Left ventricular dimensions were assessed by echocardiography (Hewlett-Packard 77010 CF) and left ventricular mass index (LVMI) was calculated. Systolic and diastolic blood pressure and LVMI was significantly higher in hypertension group 156.7 +/- 12.5 vs. 119.8 +/- 8.8 mmHg, p < 0.0001, 95.9/5.5 vs. 78.8 +/- 6.5 mmHg, p < 0.0001, 126.5 +/- 41.9 vs. 93.1 +/- 19.9 g/m2, p < 0.001 respectively. Beta-adrenergic receptors density was 40.7 +/- 29.9 fmol/ml in the hypertensive vs. 37.2 +/- 17.8 fmol/ml in control group (p = NS). There was no correlation between beta-adrenergic receptors density and LVMI. There was a statistically significant positive correlation between LVMI and systolic and diastolic blood pressure (r = 0.44, p < 0.05; r = 0.60, p < 0.01 respectively). 1. Beta-adrenergic receptors density was unchanged in patients with hypertension and did not correlate with LVMI. 2. A high positive correlation between blood pressure values and LVMI, but only in stage II hypertension was revealed.

  17. Determination of beta-adrenergic receptor blocking pharmaceuticals in united states wastewater effluent

    Energy Technology Data Exchange (ETDEWEB)

    Huggett, D.B.; Khan, I.A.; Foran, C.M.; Schlenk, D

    2003-02-01

    This is the first report of beta-adrenergic receptor antagonist pharmaceuticals in United States wastewater effluent. - Beta adrenergic receptor antagonists ({beta}-Blockers) are frequently prescribed medications in the United States and have been identified in European municipal wastewater effluent, however no studies to date have investigated these compounds in United States wastewater effluent. Municipal wastewater effluent was collected from treatment facilities in Mississippi, Texas, and New York to investigate the occurrence of metoprolol, nadolol, and propranolol. Propranolol was identified in all wastewater samples analyzed (n=34) at concentrations {<=}1.9 {mu}g/l. Metoprolol and nadolol were identified in {>=}71% of the samples with concentrations of metoprolol {<=}1.2 {mu}g/l and nadolol {<=}0.36 {mu}g/l. Time course studies at both Mississippi plants and the Texas plant indicate that concentrations of propranolol, metoprolol, and nadolol remain relatively constant at each sampling period. This study indicates that {beta}-Blockers are present in United States wastewater effluent in the ng/l to {mu}g/l range.

  18. Norepinephrine signaling through beta-adrenergic receptors is critical for expression of cocaine-induced anxiety.

    Science.gov (United States)

    Schank, Jesse R; Liles, L Cameron; Weinshenker, David

    2008-06-01

    Cocaine is a widely abused psychostimulant that has both rewarding and aversive properties. While the mechanisms underlying cocaine's rewarding effects have been studied extensively, less attention has been paid to the unpleasant behavioral states induced by cocaine, such as anxiety. In this study, we evaluated the performance of dopamine beta-hydroxylase knockout (Dbh -/-) mice, which lack norepinephrine (NE), in the elevated plus maze (EPM) to examine the contribution of noradrenergic signaling to cocaine-induced anxiety. We found that cocaine dose-dependently increased anxiety-like behavior in control (Dbh +/-) mice, as measured by a decrease in open arm exploration. The Dbh -/- mice had normal baseline performance in the EPM but were completely resistant to the anxiogenic effects of cocaine. Cocaine-induced anxiety was also attenuated in Dbh +/- mice following administration of disulfiram, a dopamine beta-hydroxylase (DBH) inhibitor. In experiments using specific adrenergic antagonists, we found that pretreatment with the beta-adrenergic receptor antagonist propranolol blocked cocaine-induced anxiety-like behavior in Dbh +/- and wild-type C57BL6/J mice, while the alpha(1) antagonist prazosin and the alpha(2) antagonist yohimbine had no effect. These results indicate that noradrenergic signaling via beta-adrenergic receptors is required for cocaine-induced anxiety in mice.

  19. Determination of beta-adrenergic receptor blocking pharmaceuticals in united states wastewater effluent

    International Nuclear Information System (INIS)

    Huggett, D.B.; Khan, I.A.; Foran, C.M.; Schlenk, D.

    2003-01-01

    This is the first report of beta-adrenergic receptor antagonist pharmaceuticals in United States wastewater effluent. - Beta adrenergic receptor antagonists (β-Blockers) are frequently prescribed medications in the United States and have been identified in European municipal wastewater effluent, however no studies to date have investigated these compounds in United States wastewater effluent. Municipal wastewater effluent was collected from treatment facilities in Mississippi, Texas, and New York to investigate the occurrence of metoprolol, nadolol, and propranolol. Propranolol was identified in all wastewater samples analyzed (n=34) at concentrations ≤1.9 μg/l. Metoprolol and nadolol were identified in ≥71% of the samples with concentrations of metoprolol ≤1.2 μg/l and nadolol ≤0.36 μg/l. Time course studies at both Mississippi plants and the Texas plant indicate that concentrations of propranolol, metoprolol, and nadolol remain relatively constant at each sampling period. This study indicates that β-Blockers are present in United States wastewater effluent in the ng/l to μg/l range

  20. Synthesis of the sup 11 C-labelled. beta. -adrenergic receptor ligands atenolol, metoprolol and propanolol

    Energy Technology Data Exchange (ETDEWEB)

    Antoni, G.; Ulin, J.; Laangstroem, B. (Uppsala Univ. (Sweden). Dept. of Organic Chemistry)

    1989-01-01

    The {sup 11}C-labelled {beta}-adrenergic receptor ligands atenolol 1, metoprolol 2 and propranolol 3 have been synthesized by an N-alkylation reaction using (2-{sup 11}C)isopropyl iodide. The labelled isopropyl iodide was prepared in a one-pot reactor system from ({sup 11}C)carbon dioxide and obtained in 40% radiochemical yield within 14 min reaction time. The total reaction times for compounds 1-3, counted from the start of the isopropyl iodide synthesis and including purification were 45-55 min. The products were obtained in 5-15% radiochemical yields and with radiochemical purities higher than 98%. The specific activity ranged from 0.4 to 4 GBq/{mu}mol. In a typical experiment starting with 4 GBq around 75 MBq of product was obtained. (author).

  1. Food restriction prevents an age-associated increase in rat liver beta-adrenergic receptors

    Energy Technology Data Exchange (ETDEWEB)

    Dax, E.M.; Ingram, D.K.; Partilla, J.S.; Gregerman, R.I.

    1989-05-01

    In male Wistar rats fed ad libitum (24% protein, 4.5 Kcal/gm), the (/sup 125/I)iodopindolol binding capacity of the beta-adrenergic receptors in liver of 24-month-old animals is 3-4 times greater than that of 6-month-old counterparts. In rats fed the same diet, on alternate days from weaning, the receptor capacity did not increase significantly between 6 and 24 months (10.20 +/- 0.55 vs 9.20 +/- 0.72 fmol/mg) or between 24 and 30 months. This was not due to acute dietary deprivation, as rats food-restricted for only 2 weeks, at 23.5 months of age, also showed elevated receptor capacities compared to 6-month-old ad libitum fed animals. Moreover, intermittent feeding produced no significant effects among 6-month-old animals, whether restricted since weaning or for two weeks prior to sacrifice. Many biochemical parameters that decrease with aging in rats fed ad libitum are prevented by dietary restriction. Our results demonstrate that a reproducible biochemical process that increases with aging is also prevented with dietary restriction. The age-related, liver beta-receptor increase may be a potentially reliable marker for studying biochemical perturbations that modify life span.

  2. Food restriction prevents an age-associated increase in rat liver beta-adrenergic receptors

    International Nuclear Information System (INIS)

    Dax, E.M.; Ingram, D.K.; Partilla, J.S.; Gregerman, R.I.

    1989-01-01

    In male Wistar rats fed ad libitum (24% protein, 4.5 Kcal/gm), the [ 125 I]iodopindolol binding capacity of the beta-adrenergic receptors in liver of 24-month-old animals is 3-4 times greater than that of 6-month-old counterparts. In rats fed the same diet, on alternate days from weaning, the receptor capacity did not increase significantly between 6 and 24 months (10.20 +/- 0.55 vs 9.20 +/- 0.72 fmol/mg) or between 24 and 30 months. This was not due to acute dietary deprivation, as rats food-restricted for only 2 weeks, at 23.5 months of age, also showed elevated receptor capacities compared to 6-month-old ad libitum fed animals. Moreover, intermittent feeding produced no significant effects among 6-month-old animals, whether restricted since weaning or for two weeks prior to sacrifice. Many biochemical parameters that decrease with aging in rats fed ad libitum are prevented by dietary restriction. Our results demonstrate that a reproducible biochemical process that increases with aging is also prevented with dietary restriction. The age-related, liver beta-receptor increase may be a potentially reliable marker for studying biochemical perturbations that modify life span

  3. Characterization of phosphorylated beta-adrenergic receptors from desensitized turkey erythrocytes

    International Nuclear Information System (INIS)

    Rebar, R.; Crooke, S.T.; Stadel, J.M.

    1986-01-01

    Catecholamine-induced desensitization of turkey erythrocyte (TE) adenylate cyclase results in a 40-50 percent decrease in agonist stimulated cyclase activity. Desensitization is accompanied by decreased mobility on SDS-PAGE of beta-adrenergic receptor (BAR) proteins photoaffinity labeled with [ 125 I]-p-azidobenzylcarazolol compared to control. Using a low crosslinked gel, the M/sub r/ = 42,000 band of BAR from desensitized TE was further resolved into a doublet compared to a single M/sub r/ = 38,000 band for control. The formation of the doublet appears to correlate with the amount of adenylate cyclase desensitization. Preincubating TE for 20 hr at 37 0 C with 32 P-/sub i/ labels BAR. 32 P-BAR was partially purified by affinity chromatography over alprenolol-Sepharose. Limited digest peptide maps of 32 P-BAR using papain identified a unique peptide (M/sub r/ = 2800) from BAR of desensitized TE which was absent in control. This unique 32 P-peptide was found only in the upper band of the doublet of BAR from desensitized TE. These data indicate that BAR is not uniformly phosphorylated following agonist-induced desensitization of TE and identify a peptide of BAR which is a site of phosphorylation correlating with desensitization of TE adenylate cyclase

  4. Characterization of beta-adrenergic receptors and adenylate cyclase activity in rat brown fat

    International Nuclear Information System (INIS)

    Baresi, L.A.; Morley, J.E.; Scarpace, P.J.

    1986-01-01

    Catecholamines stimulate thermogenesis in rat brown fat through a mechanism which involves binding to the beta-adrenergic receptor (BAR), stimulation of adenylate cyclase (AC) and culminating with uncoupling of mitochondrial respiration from ATP synthesis. The authors characterized BAR, AC and cytochrome (cyt) c oxidase in CDF (F-344) interscapular brown fat. Scatchard analysis of [ 125 ]Iodopindolol binding yields a straight line consistent with a single class of antagonist binding sites with 41.8 +/- 12.0 fmol BAR/mg protein and a K/sub d/ of 118 +/- 15 pM. Binding was both specific and stereospecific. Competition with 1-propranolol (K/sub d/ = 6.7 nM) was 15 times more potent than d-propranolol (K/sub d/ = 103 nM). Competition with isoproterenol (K/sub d/ = 79 nM) was 10 times more potent than epinephrine (K/sub d/ = 820 nM) which was 35 times more potent than norepinephrine (K/sub d/ = 2.9 x 10 -5 M) suggesting predominate beta 2 -type BAR. Cyt c oxidase activity was assessed in brown fat mitochrondrial preparations. The ratio of BAR to cyt c activity was 959 +/- 275 nmol BAR/mol cyc c/min. Isoproterenol (0.1 mM) stimulated AC activity was 24 times GTP (0.1 mM) stimulated AC (98.5 vs 40.7 pmol cAMP/min/mg). NaF-stimulated AC was nine times basal activity (90.5 vs 11.3 pmol cAMP/min/mg). These data demonstrate the presence of a beta- 2 -type BAR coupled to adenylate cyclase in rat brown fat

  5. Structural derivatives of pindolol: relationship between in vivo and in vitro potencies for their interaction with central beta-adrenergic receptors

    International Nuclear Information System (INIS)

    Tejani-Butt, S.M.; Brunswick, D.J.

    1987-01-01

    Although (-)- 125 I-iodopindolol (IPIN) can be used to label beta-adrenergic receptors in the central nervous system (CNS) in vivo, use of this ligand for receptor imaging studies in humans may be limited due to its relatively poor penetration into the CNS. A series of derivatives related to pindolol was therefore studied in an effort to determine the factors that might influence the penetration and interaction of these compounds with central beta-adrenergic receptors in vivo. Evaluation of the ability of these derivatives to displace the binding of IPIN in the brain upon systemic administration provides an assessment of whether the derivatives penetrate and interact with central beta-adrenergic receptors in vivo. Multiple regression analyses showed that the most important factor which influences the ability of the pindolol derivatives to penetrate into the brain and interact with beta-adrenergic receptors in vivo is the affinity of the derivatives for binding to beta-adrenergic receptors in vitro. Both lipophilicity and the molecular weights of the derivatives are important secondary factors which influence their in vivo potency. 15 references, 4 figures, 1 table

  6. Structural derivatives of pindolol: relationship between in vivo and in vitro potencies for their interaction with central beta-adrenergic receptors

    Energy Technology Data Exchange (ETDEWEB)

    Tejani-Butt, S.M.; Brunswick, D.J.

    1987-08-24

    Although (-)-/sup 125/I-iodopindolol (IPIN) can be used to label beta-adrenergic receptors in the central nervous system (CNS) in vivo, use of this ligand for receptor imaging studies in humans may be limited due to its relatively poor penetration into the CNS. A series of derivatives related to pindolol was therefore studied in an effort to determine the factors that might influence the penetration and interaction of these compounds with central beta-adrenergic receptors in vivo. Evaluation of the ability of these derivatives to displace the binding of IPIN in the brain upon systemic administration provides an assessment of whether the derivatives penetrate and interact with central beta-adrenergic receptors in vivo. Multiple regression analyses showed that the most important factor which influences the ability of the pindolol derivatives to penetrate into the brain and interact with beta-adrenergic receptors in vivo is the affinity of the derivatives for binding to beta-adrenergic receptors in vitro. Both lipophilicity and the molecular weights of the derivatives are important secondary factors which influence their in vivo potency. 15 references, 4 figures, 1 table.

  7. Reduced number of alpha- and beta-adrenergic receptors in the myocardium of rats exposed to tobacco smoke

    Energy Technology Data Exchange (ETDEWEB)

    Larue, D.; Kato, G.

    1981-04-09

    The concentration of alpha- and beta-adrenergic receptors--as measured by specific (/sup 3/H)WB-4101 and (-)-(/sup 3/H)dihydroalprenolol binding--was diminished by 60% below control values in the hearts of rats exposed to tobacco smoke. These changes in receptor numbers took place almost immediately after tobacco smoke exposure and were rapidly reversible after termination of the exposure. The dissociation constant, KD, for (/sup 3/H)WB-4101 was identical in exposed (KD . 0.34 +/- 0.09 nM) and control (KD . 0.35 +/- 0.07 nM) hearts but was significantly different in the case of (-)-(3H)dihydroalprenolol binding (exposed, KD . 2.83 +/- 0.30 mM vs. control KD . 5.22 +/- 0.61 nM). For beta-receptor binding there was no significant difference between exposed and control animals in the Ki values for (-)-epinephrine, (-)-norepinephrine, (-)-alprenolol, (+/-)-propranolol or timolol. (-)-Isoproterenol, however, was found to bind with lower affinity in exposed compared with control hearts. For alpha-receptor binding there was no significant difference between control and 'smoked' animals in the Ki values for (-)-epinephrine, (-0)-norepinephrine or phentolamine. The decrease in alpha- and beta-adrenergic receptor concentration may be related to the phenomenon of receptor desensitization resulting from a release of catecholamines in rats exposed to tobacco smoke.

  8. Differential effects of beta-adrenergic receptor blockade in the medial prefrontal cortex during aversive and incidental taste memory formation.

    Science.gov (United States)

    Reyes-López, J; Nuñez-Jaramillo, L; Morán-Guel, E; Miranda, M I

    2010-08-11

    The medial prefrontal cortex (mPFC) is a brain area crucial for memory, attention, and decision making. Specifically, the noradrenergic system in this cortex is involved in aversive learning, as well as in the retrieval of these memories. Some evidence suggests that this area has an important role during taste memory, particularly during conditioned taste aversion (CTA), a model of aversive memory. Despite some previous evidence, there is scarce information about the role of adrenergic receptors in the mPFC during formation of aversive taste memory and appetitive/incidental taste memory. The goal of this research was to evaluate the role of mPFC beta-adrenergic receptors during CTA acquisition/consolidation or CTA retrieval, as well as during incidental taste memory formation using the model of latent inhibition of CTA. The results showed that infusions in the mPFC of the beta-adrenergic antagonist propranolol before CTA acquisition impaired both short- and long-term aversive taste memory formation, and also that propranolol infusions before the memory test impaired CTA retrieval. However, propranolol infusions before pre-exposure to the taste during the latent inhibition procedure had no effect on incidental taste memory acquisition or consolidation. These data indicate that beta-adrenergic receptors in the mPFC have different functions during taste memory formation: they have an important role during aversive taste association as well as during aversive retrieval but not during incidental taste memory formation. Copyright (c) 2010 IBRO. Published by Elsevier Ltd. All rights reserved.

  9. Postsynaptic alpha-adrenergic receptors potentiate the beta-adrenergic stimulation of pineal serotonin N-acetyltransferase.

    OpenAIRE

    Klein, D C; Sugden, D; Weller, J L

    1983-01-01

    The role played by postsynaptic alpha-adrenergic receptors in the stimulation of pineal N-acetyltransferase (EC 2.3.1.5) and [3H]melatonin production was investigated in the rat. In vivo studies indicated that phenylephrine, an alpha-adrenergic agonist, potentiated and prolonged the effects of isoproterenol, a beta-adrenergic agonist. Similar observations were made in organ culture with glands devoid of functional nerve endings. In addition, a combination of 1 microM prazosin, an alpha 1-adre...

  10. Evidence that shock-induced immune suppression is mediated by adrenal hormones and peripheral beta-adrenergic receptors.

    Science.gov (United States)

    Cunnick, J E; Lysle, D T; Kucinski, B J; Rabin, B S

    1990-07-01

    Our previous work has demonstrated that presentations of mild foot-shock to Lewis rats induces a suppression of splenic and peripheral blood lymphocyte responses to nonspecific T-cell mitogens. The present study demonstrated that adrenalectomy prevented the shock-induced suppression of the mitogenic response of peripheral blood T-cells but did not attenuate the suppression of splenic T-cells. Conversely, the beta-adrenergic receptor antagonists, propranolol and nadolol, attenuated the shock-induced suppression of splenic T-cells in a dose-dependent manner but did not attenuate suppression of the blood mitogen response. These data indicate that distinct mechanisms mediate the shock-induced suppression of T-cell responsiveness to mitogens in the spleen and the peripheral blood. The results indicate that the peripheral release of catecholamines is responsible for splenic immune suppression and that adrenal hormones, which do not interact with beta-adrenergic receptors, are responsible for shock-induced suppression of blood mitogenic responses.

  11. Beta-Adrenergic Receptor Activation during Distinct Patterns of Stimulation Critically Modulates the PKA-Dependence of LTP in the Mouse Hippocampus

    Science.gov (United States)

    Gelinas, Jennifer N.; Tenorio, Gustavo; Lemon, Neal; Abel, Ted; Nguyen, Peter V.

    2008-01-01

    Activation of Beta-adrenergic receptors (Beta-ARs) enhances hippocampal memory consolidation and long-term potentiation (LTP), a likely mechanism for memory storage. One signaling pathway linked to Beta-AR activation is the cAMP-PKA pathway. PKA is critical for the consolidation of hippocampal long-term memory and for the expression of some forms…

  12. (-)[125I]-iodopindolol, a new highly selective radioiodinated beta-adrenergic receptor antagonist: measurement of beta-receptors on intact rat astrocytoma cells

    International Nuclear Information System (INIS)

    Barovsky, K.; Brooker, G.

    1980-01-01

    (-)-Pindolol, one of the most potent beta-adrenergic receptor antagonists, was radioiodinated using chloramine-T oxidation of carrier-free Na 125I and separated from unreacted pindolol to yield 2200 Ci/mmole (-)-[125I]-iodopindolol ((-)-[125I]-IPin). Mass and ultraviolet spectra confirmed that the iodination occurred on the indole ring, presumably at the 3 position. The binding of radiolabeled (-)-[125I]-IPin to beta-adrenergic receptors has been studied using intact C6 rat astrocytoma cells (2B subclone) grown in monolayer cultures. Binding of (-)[125IPin was saturable with time and concentration. Using 13 pM (-)-[125I]IPin, binding equilibrium was reached in 90 min at 21-22 degrees C. The reverse rate constant was 0.026 min-1 at 21 0 C. Specific binding (expressed as 1 microM(-)-propranolol displaceable counts) of (-)-[125I]-IPin was 95% of total binding. Scatchard analysis of (-)-[125I]-I]Pin binding revealed approximately 4300 receptors/cell and a dissociation constant of 30 pM. This was in excellent agreement with the kinetically determined dissociation constant of 35 pM. Displacement by propranolol and isoproterenol showed that (-)-[125I]-IPin binding sites were pharmacologically and stereospecifically selective. These results indicate that (-)-[125I]-IPin, a pure (-)-stereoisomer, high specific activity radioligand, selectively binds to beta-adrenergic receptors in whole cells with a high percentage of specific binding and should therefore be useful in the study and measurement of cellular beta-adrenergic receptors

  13. Dissociation between cardiomyocyte function and remodeling with beta-adrenergic receptor blockade in isolated canine mitral regurgitation.

    Science.gov (United States)

    Pat, Betty; Killingsworth, Cheryl; Denney, Thomas; Zheng, Junying; Powell, Pamela; Tillson, Michael; Dillon, A Ray; Dell'Italia, Louis J

    2008-12-01

    The low-pressure volume overload of isolated mitral regurgitation (MR) is associated with increased adrenergic drive, left ventricular (LV) dilatation, and loss of interstitial collagen. We tested the hypothesis that beta1-adrenergic receptor blockade (beta1-RB) would attenuate LV remodeling after 4 mo of MR in the dog. beta1-RB did not attenuate collagen loss or the increase in LV mass in MR dogs. Using MRI and three-dimensional (3-D) analysis, there was a 70% increase in the LV end-diastolic (LVED) volume-to-LV mass ratio, a 23% decrease in LVED midwall circumferential curvature, and a >50% increase in LVED 3-D radius/wall thickness in MR dogs that was not attenuated by beta1-RB. However, beta1-RB caused a significant increase in LVED length from the base to apex compared with untreated MR dogs. This was associated with an increase in isolated cardiomyocyte length (171+/-5 microm, P<0.05) compared with normal (156+/-3 microm) and MR (165+/-4 microm) dogs. Isolated cardiomyocyte fractional shortening was significantly depressed in MR dogs compared with normal dogs (3.73+/-0.31 vs. 5.02+/-0.26%, P<0.05) and normalized with beta1-RB (4.73+/-0.48%). In addition, stimulation with the beta-adrenergic receptor agonist isoproterenol (25 nM) increased cardiomyocyte fractional shortening by 215% (P<0.05) in beta1-RB dogs compared with normal (56%) and MR (50%) dogs. In summary, beta1-RB improved LV cardiomyocyte function and beta-adrenergic receptor responsiveness despite further cell elongation. The failure to attenuate LV remodeling associated with MR could be due to a failure to improve ultrastructural changes in extracellular matrix organization.

  14. Uncoupling of the beta-adrenergic receptor as a mechanism of in vitro neutrophil desensitization

    International Nuclear Information System (INIS)

    Galant, S.P.; Britt, S.

    1984-01-01

    Human leukocytes have been useful in studying desensitization phenomena to beta-adrenergic agonists in a number of clinical conditions. In the present in vitro study the authors have explored the mechanism for beta-adrenergic desensitization and have compared conditions for homologous and heterologous desensitization, using the intact PMN model. PMN preincubated with isoproterenol (10 -4 M), washed thoroughly, then restimulated, desensitized rapidly so that within 10 min 80% of control isoproterenol-induced cyclic AMP stimulation is lost. Cells washed free of isoproterenol recover full responsiveness in 1 to 2 hr. The estimated isoproterenol desensitization EC 50 in cells washed and then restimulated is 1 x 10 -5 M, and EC 50 in unwashed cells that are restimulated is 9 x 10 -8 M. Rank-order potency studies of catecholamine desensitization show isoproterenol > epinephrine > norepinephrine, a beta-2 pattern. Isoproterenol-induced desensitization results in a small reduction in [ 3 H]DHA binding sites, which becomes statistically significant (p 50 of 6.6 +/- 2.6 x 10 - (M, which is significantly different (p 50 of 38.1 +/- 9.1 x 10 -1 M found when cells are previously desensitized with isoproterenol for 10 min. GTP does not affect the EC 50 of desensitized cells. Finally, prolonged (3 hr) isoproterenol preincubation results in a small but significant (p 1 (59.3% +/- 7.4), suggesting heterologous desensitization. These studies suggest that the human PMN is a suitable model to study both homologous and heterologous desensitization in vitro. 22 references. 6 figures. 3 tables

  15. [Beta]-Adrenergic Receptors in the Insular Cortex are Differentially Involved in Aversive vs. Incidental Context Memory Formation

    Science.gov (United States)

    Miranda, Maria Isabel; Sabath, Elizabeth; Nunez-Jaramillo, Luis; Puron-Sierra, Liliana

    2011-01-01

    The goal of this research was to determine the effects of [beta]-adrenergic antagonism in the IC before or after inhibitory avoidance (IA) training or context pre-exposure in a latent inhibition protocol. Pretraining intra-IC infusion of the [beta]-adrenergic antagonist propranolol disrupted subsequent IA retention and impaired latent inhibition…

  16. Differential modulation of Beta-adrenergic receptor signaling by trace amine-associated receptor 1 agonists.

    Directory of Open Access Journals (Sweden)

    Gunnar Kleinau

    Full Text Available Trace amine-associated receptors (TAAR are rhodopsin-like G-protein-coupled receptors (GPCR. TAAR are involved in modulation of neuronal, cardiac and vascular functions and they are potentially linked with neurological disorders like schizophrenia and Parkinson's disease. Subtype TAAR1, the best characterized TAAR so far, is promiscuous for a wide set of ligands and is activated by trace amines tyramine (TYR, phenylethylamine (PEA, octopamine (OA, but also by thyronamines, dopamine, and psycho-active drugs. Unfortunately, effects of trace amines on signaling of the two homologous β-adrenergic receptors 1 (ADRB1 and 2 (ADRB2 have not been clarified yet in detail. We, therefore, tested TAAR1 agonists TYR, PEA and OA regarding their effects on ADRB1/2 signaling by co-stimulation studies. Surprisingly, trace amines TYR and PEA are partial allosteric antagonists at ADRB1/2, whereas OA is a partial orthosteric ADRB2-antagonist and ADRB1-agonist. To specify molecular reasons for TAAR1 ligand promiscuity and for observed differences in signaling effects on particular aminergic receptors we compared TAAR, tyramine (TAR octopamine (OAR, ADRB1/2 and dopamine receptors at the structural level. We found especially for TAAR1 that the remarkable ligand promiscuity is likely based on high amino acid similarity in the ligand-binding region compared with further aminergic receptors. On the other hand few TAAR specific properties in the ligand-binding site might determine differences in ligand-induced effects compared to ADRB1/2. Taken together, this study points to molecular details of TAAR1-ligand promiscuity and identified specific trace amines as allosteric or orthosteric ligands of particular β-adrenergic receptor subtypes.

  17. [Studies on the relationship between beta-adrenergic receptor density on cell wall lymphocytes, total serum catecholamine level and heart rate in patients with hyperthyroidism].

    Science.gov (United States)

    Gajek, J; Zieba, I; Zyśko, D

    2000-08-01

    Hyperthyreosis mimics the hyperadrenergic state and its symptoms were though to be dependent on increased level of catecholamines. Another reason for the symptoms could be the increased density or affinity of beta-adrenergic receptors to catecholamines. The aim of the study was to examine the elements of sympathetic nervous system, thyroid hormones level and their influence on heart rate control in patients with hyperthyreosis. The study was carried out in 18 women, mean age 48.9 +/- 8.7 yrs and 6 men, mean age 54.2 +/- 8.7 yrs. The control group consisted of 30 healthy persons matched for age and sex. We examined the density of beta-adrenergic receptors using radioligand labelling method with 125I-cyanopindolol, serum total catecholamines level with radioenzymatic assay kit, the levels of free thyroid hormones using radioimmunoassays and thyreotropine level with immunoradiometric assay. Maximal, minimal and mean heart rate were studied using Holter monitoring system. The density of beta-adrenergic receptors in hyperthyreosis was 37.3 +/- 21.7 vs 37.2 +/- 18.1 fmol/mg in the control group (p = NS). Total catecholamines level was significantly decreased in hyperthyreosis group: 1.5 +/- 0.89 vs 1.9 +/- 0.73 pmol/ml (p < 0.05). There was significantly higher minimal, maximal and mean heart rate in hyperthyreosis group (p < 0.0001, p < 0.0001 and p < 0.05 respectively). There was a weak inverse correlation between minimum heart rate and triiodothyronine level (r = -0.38, p < 0.05). An inverse correlation between triiodothyronine and catecholamines level (r = -0.49, p < 0.05) was observed. Beta-adrenergic receptors density is unchanged and catecholamines level is decreased in hyperthyreosis when compared to normal subjects. There is no correlation between minimal heart rate and adrenergic receptors density or catecholamines level in hyperthyreosis.

  18. Distribution of beta-adrenergic receptors in failing human myocardium. Implications for mechanisms of down-regulation

    International Nuclear Information System (INIS)

    Murphree, S.S.; Saffitz, J.E.

    1989-01-01

    The density of beta-adrenergic receptors is reduced in crude membranes prepared from failing human myocardium. We used quantitative autoradiography of radioligand binding sites in intact tissue slices to determine whether the total tissue content of receptors is reduced and to characterize the transmural distribution of receptors in cardiac myocytes and the coronary vasculature in hearts obtained from nine cardiac transplant patients with severe congestive failure. Binding of [125Iodo]cyanopindolol to transmural slices of human myocardium was rapid, saturable, stereoselective, and displaceable by agonists and antagonists with an appropriate rank order of potency. Binding isotherms in four normal and nine failing ventricles showed a significant reduction in the total tissue content of beta-receptors in failing myocardium (38.3 +/- 2.0 fmol/mg protein) compared with normal tissue (52.4 +/- 1.7 fmol/mg protein, p = 0.038). In the normal ventricles, the greatest receptor density was observed autoradiographically in myocytic regions of the subendocardium. Receptor density of the coronary arterioles was approximately 70% of that in adjacent myocytic regions. The density of binding sites in both myocytic regions and arterioles was diminished in all regions of the failing ventricles, but down-regulation was due primarily to a selective reduction of beta-receptors of subendocardial myocytes (63 +/- 5% of subepicardial receptor density vs. 115 +/- 6% in controls, p less than 0.0001). These observations indicate that down-regulation occurs nonuniformly in the transmural distribution and thus is likely not related simply to elevated circulating catecholamine levels

  19. Activation of Cyclic AMP Synthesis by Full and Partial Beta-Adrenergic Receptor Agonists in Chicken Skeletal Muscle Cells

    Science.gov (United States)

    Young, R. B.; Bridge, K. Y.

    2003-01-01

    Several beta-adrenergic receptor (bAR) agonists are known to cause hypertrophy of skeletal muscle tissue. Accordingly, five bAR agonists encompassing a range in activity from strong to weak were evaluated for their ability to stimulate CAMP accumulation in embryonic chicken skeletal muscle cells in culture. Two strong agonists (epinephrine and isoproterenol), one moderate agonist (albuterol), and two weak agonists known to cause hypertrophy in animals (clenbuterol and cimaterol) were studied. Dose response curves were determined over six orders of magnitude in concentration for each agonist, and values were determined for their maximum stimulation of CAMP synthesis rate (Bmax) and the agonist concentration at which 50% stimulation of CAMP synthesis (EC50) occurred. Bmax values decreased in the following order: isoproterenol, epinephrine, albuterol, cimaterol, clenbuterol. Cimaterol and clenbuterol at their Bmax concentrations were approximately 15-fold weaker than isoproterenol in stimulating the rate of CAMP synthesis. When cimaterol and clenbuterol were added to culture media at concentrations known to cause significant muscle hypertrophy in animals, there was no detectable effect on stimulation of CAMP synthesis. Finally, these same levels of cimaterol and clenbuterol did not antagonize the stimulation of CAMP by either epinephrine or isoproterenol.

  20. Beta adrenergic receptors in dog heart characterised in vivo by sup 11 C-CGP 12117 and positron emission tomography

    Energy Technology Data Exchange (ETDEWEB)

    Seto, Mikito [Kanazawa Univ. (Japan). School of Medicine

    1989-06-01

    Beta adrenergic receptors in the dog heart were demonstrated in vivo using a potent antagonist, {sup 11}C-CGP 12117 (Kd=0.2 nmol/kg, in vitro), and positron emission tomography (PET). {sup 11}C-CGP at a high specific radioactivity (approximately 500 Ci/mmol) was intravenously injectd in dogs. Axial transverse slices of the heart were obtained. The concentration of {sup 11}C-CGP 12177 in the myocardium rapidly increased and then remained nearly constant for about 30 minutes, before decreasing slowly. Designing a new method to distinguish specific receptor binding from the total ligand concentration in the heart measured by PET, beta adrenoceptor density in the dog myocardium (Bmax) was found to be 113 pmol/cm{sup 3}. Displacement and pre-saturation studies were performed to demonstrate the specifity of {sup 11}C-CGP 12177 binding for noradrenaline binding sites. The bolus injection of unlabeled CGP 12177 25 min following {sup 11}C-CGP 12177 injection led to a rapid decrease in the myocardial ligand concentration and a rapid fall in the heart rate. Both the pharmacological effect of CGP 12177 and the binding inhibition of radioligand were synchronous with the increasing amount of antagonist injected for displacement. In experiments of presaturation with an excessive dose of unlabeled antagonist injection 10 min before {sup 11}C-CGP 12177 injection, the heart/blood radioligand concentration ratio as a function of time was significantly lower than that in the control study. Thus, specific receptor binding of {sup 11}C-CGP 12177 for noradrenaline binding sites in the living heart was proved by PET, which might be the ideal method to study the physiologically active form of receptors in vivo. (author).

  1. Ultrastructural characterization of noradrenergic- and beta-adrenergic receptor-containing profiles in the lateral nucleus of the amygdala

    Directory of Open Access Journals (Sweden)

    Claudia Farb

    2010-10-01

    Full Text Available Norepinephrine (NE is thought to play a key role in fear and anxiety, but its role in amygdala-dependent Pavlovian fear conditioning, a major model for understanding the neural basis of fear, is poorly understood. The lateral nucleus of the amygdala (LA is a critical brain region for fear learning and regulating the effects of stress on memory. To understand better the cellular mechanisms of NE and its adrenergic receptors in the LA, we used antibodies directed against dopamine beta-hydroxylase (DβH, the synthetic enzyme for NE, or against two different isoforms of the beta-adrenergic receptors (βARs, one that predominately recognizes neurons (βAR 248 and the other astrocytes (βAR 404, to characterize the microenvironments of DβH and βAR. By electron microscopy, most DβH terminals did not make synapses, but when they did, they formed both asymmetric and symmetric synapses. By light microscopy, βARs were present in both neurons and astrocytes. Confocal microscopy revealed that both excitatory and inhibitory neurons express βAR248. By electron microscopy, βAR 248 was present in neuronal cell bodies, dendritic shafts and spines, and some axon terminals and astrocytes. When in dendrites and spines, βAR 248 was frequently concentrated along plasma membranes and at post-synaptic densities of asymmetric (excitatory synapses. βAR 404 was expressed predominately in astrocytic cell bodies and processes. These astrocytic processes were frequently interposed between unlabeled terminals or ensheathed asymmetric synapses. Our findings provide a morphological basis for understanding ways in which NE may modulate transmission by acting via synaptic or non-synaptic mechanisms in the LA.

  2. Beta-adrenergic receptors are critical for weight loss but not for other metabolic adaptations to the consumption of a ketogenic diet in male mice

    Directory of Open Access Journals (Sweden)

    Nicholas Douris

    2017-08-01

    Conclusions: The response of β-less mice distinguishes at least two distinct categories of physiologic effects in mice consuming KD. In the liver, KD regulates peroxisome proliferator-activated receptor alpha (PPARα-dependent pathways through an action of FGF21 independent of the SNS and beta-adrenergic receptors. In sharp contrast, induction of interscapular brown adipose tissue (BAT and increased energy expenditure absolutely require SNS signals involving action on one or more β-adrenergic receptors. In this way, the key metabolic actions of FGF21 in response to KD have diverse effector mechanisms.

  3. Pet measurements of postsynaptic muscarinic and beta adrenergic receptors in the heart

    International Nuclear Information System (INIS)

    Syrota, A.

    1991-01-01

    There is ample evidence from both experimental and clinical studies that changes in β-adrenergic and muscarinic receptor density can be associated with such cardiac diseases as congestive heart failure, myocardial ischemia and infarction, cardiomyopathy, diabetes, or thyroid-induced muscle disease. Changes in B-adrenergic density also have been shown in the denervated transplanted heart. These alterations of cardiac receptors have been demonstrated in vitro on homogenates from samples collected mainly during surgery or post mortem. Recent developments of Positron Emission Tomography (PET) techniques and of radioligands suitable for cardiac receptor binding studies in vivo have made possible both the imaging and the measurement of receptor density. From these studies, important information is now available concerning physiologic and pathologic conditions, as well as alterations induced by treatment. For the investigation of myocardial B-adrenergic receptors we have used [ 11 C] CGP 12177, a potent hydrophilic antagonist of the 3-adrenergic receptor. The quantification of myocardial muscarinic receptors in vivo has been obtained with [ 11 C] MQNB, a nonmetabolized hydrophilic antagonist of the muscarinic receptor. Receptor density and affinity have been measured by a kinetic, nonequilibrium approach in an experimental protocol that provides sufficient data to determine values for all parameters from a single experiment

  4. [H-3]dihydroalprenolol binding to beta adrenergic receptors in multiple sclerosis brain

    NARCIS (Netherlands)

    Zeinstra, E; Wilczak, N; De Keyser, J

    2000-01-01

    By using immunocytochemistry we previously reported the absence of beta(2) adrenergic receptors on astrocytes in multiple sclerosis (MS) white matter. Here, we measured beta(1) and beta(2) adrenergic receptor concentrations in postmortem brain sections of six MS patients and six controls by using

  5. Beta-Adrenergic Receptors and Mechanisms in Asthma: The New Long-Acting Beta-Agonists

    Directory of Open Access Journals (Sweden)

    Robert G Townley

    1996-01-01

    Full Text Available The objective is to review β-adrenergic receptors and mechanisms in the immediate and late bronchial reaction in asthma and the new long-acting β-agonist. This will be discussed in light of the controversy of the potential adverse effect of regular use of long-acting β-agonists. We studied the effect of formoterol on the late asthmatic response (LAR and airway inflammation in guinea-pigs. Formoterol suppressed the LAR, antigen-induced airway inflammation and hyperresponsiveness, although isoproterenol failed to inhibit these parameters. β-Adrenergic hyporesponsiveness, and cholinergic and a- adrenergic hyperresponsiveness have been implicated in the pathogenesis of asthma. A decrease in β-adrenoreceptor function can result either from exogenously administered β-agonist or from exposure to allergens resulting in a late bronchial reaction. There is increasing evidence that eosinophils, macrophages, and lymphocytes which are of primary importance in the late bronchial reaction are also modulated by β2- adrenoreceptors. In functional studies of guinea-pig or human isolated trachea and lung parenchyma, PAF and certain cytokines significantly reduced the potency of isoproterenol to reverse methacholine- or histamine-induced contraction. The effect of glucocorticoids on pulmonary β-adrenergic receptors and responses suggests an important role for glucocorticoids to increase β-adrenergic receptors and responsiveness.

  6. Myocardial slice: a physiological approach to beta-adrenergic ([3H] CGP-12177) receptor binding in hamster and guinea pig heart.

    Science.gov (United States)

    Watson-Wright, W M; Armour, J A; Johnstone, D E; Wilkinson, M

    1989-08-01

    A new technique is described for the characterization and quantification of beta-adrenergic receptors in biologically viable slices of myocardium from the hamster right ventricle using the hydrophilic radioligand, [3H]CGP-12177 (CGP). Binding was stereospecific, saturable, of high affinity, reversible, displaceable by appropriate drugs, and highly positively correlated with increasing tissue concentrations. Bmax for CGP binding to myocardial slices from 50-day-old male Golden Syrian hamsters was 3.28 +/- 0.15 fmol/mg wet weight, while Kd was 0.21 +/- 0.02 nM. Freezing resulted in a close to 50% loss of receptor number with no apparent change in affinity. The slice preparation may be utilized to detect in vivo changes in myocardial cell surface receptors, as evidenced by the fact that the number of receptors in slices from ischemic guinea pigs was increased (Bmax = 15.5 +/- 1.25 fmol/mg wet wt) compared with sham-operated controls (Bmax = 10.4 +/- 0.38 fmol/mg wet wt). The minimal tissue disruption associated with this procedure, as well as its speed, simplicity, and relatively low cost, suggest that the myocardial slice preparation provides an important methodology for the study of beta-adrenergic receptor binding in the semiintact myocardium.

  7. The use of (125I) iodocyanopindolol as a specific probe for beta-adrenergic receptors in differentiating cultured rat skeletal muscle

    International Nuclear Information System (INIS)

    Schonberg, Michael; Morris, S.A.; Krichevsky, Alexander; Bilezikian, J.P.

    1983-01-01

    In order to examine more precisely the role of beta-adrenergic receptors in the process of differentiation the new radioligand iodocyanopindolol was used, and found to be a very useful probe to identify beta receptors. Binding charcteristics conformed to those expected for a physiologically relevant beta receptor. L 6 E 9 cells grown in horse serum, which allows differentiation exhibit increased beta receptor density in intact cells as a function of age. In contrast, cells grown in fetal calf serum, which does not allow differentiation, exhibit constant beta receptor density. In broken cells, however, both differentiating and non-differentiating cells show an increase in beta receptors. These results suggest that the process of differentiation is associated with an unmasking of beta receptors which are increasing but cryptic in undifferentiated cells. (author)

  8. Beta-Adrenergic Receptor Polymorphisms and Cardiac Graft Function in Potential Organ Donors

    Science.gov (United States)

    Khush, K.K.; Pawlikowska, L.; Menza, R.L.; Goldstein, B.A.; Hayden, V.; Nguyen, J.; Kim, H.; Poon, A.; Sapru, A.; Matthay, M.A.; Kwok, P.Y.; Young, W.L.; Baxter-Lowe, L.A.; Zaroff, J.G.

    2012-01-01

    Prior studies have demonstrated associations between β-adrenergic receptor polymorphisms and left ventricular dysfunction—an important cause of allograft non-utilization for transplantation. We hypothesized that βAR polymorphisms predispose donor hearts to LV dysfunction after brain death. 1,043 organ donors managed from 2001-2006 were initially studied. The following βAR single nucleotide polymorphisms were genotyped: β1AR 1165C/G (Arg389Gly), β1AR 145A/G (Ser49Gly), β2AR 46G/A (Gly16Arg), and β2AR 79C/G (Gln27Glu). In multivariable regression analyses, the β2AR46 SNP was significantly associated with LV systolic dysfunction, with each minor allele additively decreasing the odds for LV ejection fractiondonor management period: donors with the GG and AA genotypes had ORs of 2.64 (95% CI 1.52-4.57) and 2.70 (1.07-2.74) respectively for requiring >10 mcg/kg/min of dopamine compared to those with the CC and GG genotypes. However, no significant associations were found between βAR SNPs and cardiac dysfunction in 364 donors managed from 2007-2008, perhaps due to changes in donor management, lack of power in this validation cohort, or the absence of a true association. βAR polymorphisms may be associated with cardiac dysfunction after brain death, but these relationships require further study in independent donor cohorts. PMID:22994654

  9. Functional characterization of the beta-adrenergic receptor subtypes expressed by CA1 pyramidal cells in the rat hippocampus.

    Science.gov (United States)

    Hillman, Kristin L; Doze, Van A; Porter, James E

    2005-08-01

    Recent studies have demonstrated that activation of the beta-adrenergic receptor (AR) using the selective beta-AR agonist isoproterenol (ISO) facilitates pyramidal cell long-term potentiation in the cornu ammonis 1 (CA1) region of the rat hippocampus. We have previously analyzed beta-AR genomic expression patterns of 17 CA1 pyramidal cells using single cell reverse transcription-polymerase chain reaction, demonstrating that all samples expressed the beta2-AR transcript, with four of the 17 cells additionally expressing mRNA for the beta1-AR subtype. However, it has not been determined which beta-AR subtypes are functionally expressed in CA1 for these same pyramidal neurons. Using cell-attached recordings, we tested the ability of ISO to increase pyramidal cell action potential (AP) frequency in the presence of subtype-selective beta-AR antagonists. ICI-118,551 [(+/-)-1-[2,3-(dihydro-7-methyl-1H-inden-4-yl)oxy]-3-[(1-methylethyl)amino]-2-butanol] and butoxamine [alpha-[1-(t-butylamino)ethyl]-2,5-dimethoxybenzyl alcohol) hydrochloride], agents that selectively block the beta2-AR, produced significant parallel rightward shifts in the concentration-response curves for ISO. From these curves, apparent equilibrium dissociation constant (K(b)) values of 0.3 nM for ICI-118,551 and 355 nM for butoxamine were calculated using Schild regression analysis. Conversely, effective concentrations of the selective beta1-AR antagonists CGP 20712A [(+/-)-2-hydroxy-5-[2-([2-hydroxy-3-(4-[1-methyl-4-(trifluoromethyl)-1H-imidazol-2-yl]phenoxy)propyl]amino)ethoxy]-benzamide methanesulfonate] and atenolol [4-[2'-hydroxy-3'-(isopropyl-amino)propoxy]phenylacetamide] did not significantly affect the pyramidal cell response to ISO. However, at higher concentrations, atenolol significantly decreased the potency for ISO-mediated AP frequencies. From these curves, an apparent atenolol K(b) value of 3162 nM was calculated. This pharmacological profile for subtype-selective beta-AR antagonists

  10. An investigation into the receptor-regulating effects of the acute administration of opioid agonists and an antagonist on beta adrenergic receptors in the rat cerebral cortex

    International Nuclear Information System (INIS)

    Roper, I.

    1987-01-01

    Past and current research indicated that biochemical deviations which might be involved in the etiology and pathophysiology of depression, included abnormalities or imbalances in the noradrenergic, serotonergic, hormonal and possibly in the endogenous opioid, dopaminergic, histaminergic, cholinergic and trace amine systems. In order to investigate a possible link between the noradrenergic system and opioids, it was decided to test the acute effects of opioid administration on cortical beta adrenoceptor numbers and affinity. As these receptors have been most consistently downregulated by antidepressant treatment, they may be involved in the mechanism of antidepressant action of these agents. It was decided to investigate beta adrenoceptor-regulatory effects of opioid treatment. Naloxone was tested alone, with a view to suppressing any possible endogenous opioid influences upon beta receptor status and revealing an effect which would possibly be the opposite of that brought about by the administration of opioid agonists. Naloxone was administered together with morphine to demonstrate that any beta receptor up- or downregulation which might be measured, had indeed been opioid-receptor mediated. It was found that the acute administration of four different mu opioid agonists, naloxone and naloxone plus morphine, did not cause any statistically significant alterations in cortical beta adrenergic receptor numbers or affinity in the rat. A radioactive ligand, the beta adrenoceptor-labelling compound referred to as DHA (L-dihydroalprenolol HCI) was used in this study

  11. Effects of thyroid hormone on. beta. -adrenergic responsiveness of aging cardiovascular systems

    Energy Technology Data Exchange (ETDEWEB)

    Tsujimoto, G.; Hashimoto, K.; Hoffman, B.B.

    1987-03-01

    The authors have compared the effects of ..beta..-adrenergic stimulation on the heart and peripheral vasculature of young (2-mo-old) and older (12-mo-old) rats both in the presence and absence of triiodothyronine (T/sub 3/)-induced hyperthyroidism. The hemodynamic consequences of T/sub 3/ treatment were less prominent in the aged hyperthyroid rats compared with young hyperthyroid rats (both in intact and pithed rats). There was a decrease in sensitivity of chronotropic responsiveness to isoproterenol in older pithed rats, which was apparently reversed by T/sub 3/ treatment. The number and affinity of myocardial ..beta..-adrenergic receptor sites measured by (/sup 125/I)cyanopindolol were not significantly different in young and older control rats; also, ..beta..-receptor density increased to a similar extent in both young and older T/sub 3/-treated rats. The ability of isoproterenol to relax mesenteric arterial rings, markedly blunted in older rats, was partially restored by T/sub 3/ treatment without their being any change in isoproterenol-mediated relaxation in the arterial preparation from young rats. The number and affinity of the ..beta..-adrenergic receptors measured in the mesenteric arteries was unaffected by either aging or T/sub 3/ treatment. The data suggest that effects of thyroid hormone and age-related alterations of cardiovascular responsiveness to ..beta..-adrenergic stimulation are interrelated in a complex fashion with a net result that the hyperkinetic cardiovascular manifestations in hyperthyroidism are attenuated in the older animals.

  12. Repeated stressor exposure enhances contextual fear memory in a beta-adrenergic receptor-dependent process and increases impulsivity in a non-beta receptor-dependent fashion.

    Science.gov (United States)

    Camp, Robert M; Johnson, John D

    2015-10-15

    Memory formation is promoted by stress via the release of norepinephrine and stimulation of beta-adrenergic receptors (β-ARs). Previous data demonstrate that repeated stressor exposure increases norepinephrine turnover and β-AR signaling within the amygdala, which led to the hypothesis that some stress-induced behavioral changes are likely due to facilitated associative learning. To test this, Fischer rats were exposed to chronic mild stress for four days. On day 5, subjects (including non-stressed controls) were injected with the beta-blocker propranolol or vehicle prior to conditioning in an operant box (animals receive two mild foot shocks) or passive avoidance apparatus (animals received a foot shock upon entry into the dark chamber). Twenty-four hours later, subjects were returned to the operant box for measurement of freezing or returned to the passive avoidance apparatus for measurement of latency to enter the dark chamber. Subjects were also tested in an open field to assess context-independent anxiety-like behavior. Animals exposed to chronic stress showed significantly more freezing behavior in the operant box than did controls, and this exaggerated freezing was blocked by propranolol during the conditioning trial. There was no effect of stress on behavior in the open field. Unexpectedly, retention latency was significantly reduced in subjects exposed to chronic stress. These results indicate that chronic exposure to stress results in complex behavioral changes. While repeated stress appears to enhance the formation of fearful memories, it also results in behavioral responses that resemble impulsive behaviors that result in poor decision-making. Copyright © 2015 Elsevier Inc. All rights reserved.

  13. Effect of Increased Cyclic AMP Concentration on Muscle Protein Synthesis and Beta-Adrenergic Receptor Expression in Chicken Skeletal Muscle Cells in Culture

    Science.gov (United States)

    Young, R. B.; Vaughn, J. R.; Bridge, K. Y.; Smith, C. K.

    1998-01-01

    Analogies of epinephrine are known to cause hypertrophy of skeletal muscle when fed to animals. These compounds presumably exert their physiological action through interaction with the P-adrenergic receptor. Since the intracellular signal generated by the Beta-adrenergic receptor is cyclic AMP (cAMP), experiments were initiated in cell culture to determine if artificial elevation of cAMP by treatment with forskolin would alter muscle protein metabolism and P-adrenergic receptor expression. Chicken skeletal muscle cells after 7 days in culture were treated with 0.2-30 micrometers forskolin for a total of three days. At the end of the treatment period, both the concentration of cAMP and the quantity of myosin heavy chain (MHC) were measured. Concentration of cAMP in forskolin-treated cells increased up to 10-fold in a dose dependent manner. In contrast, the quantity of MHC was increased approximately 50% above control cells at 0.2 micrometers forskolin, but exhibited a gradual decline at higher levels of forskolin so that the quantity of MHC in cells treated with 30 micrometers forskolin was not significantly different from controls. Curiously, the intracellular concentration of cAMP which elicited the maximum increase in the quantity of MHC was only 40% higher than cAMP concentration in control cells.

  14. Beta-adrenergic receptors in the lateral nucleus of the amygdala contribute to the acquisition but not the consolidation of auditory fear conditioning.

    Science.gov (United States)

    Bush, David E A; Caparosa, Ellen M; Gekker, Anna; Ledoux, Joseph

    2010-01-01

    Beta-adrenergic receptors (βARs) have long been associated with fear disorders and with learning and memory. However, the contribution of these receptors to Pavlovian fear conditioning, a leading behavioral model for studying fear learning and memory, is still poorly understood. The aim of this study was to investigate the involvement of βAR activation in the acquisition, consolidation and expression of fear conditioning. We focused on manipulations of βARs in the lateral nucleus of the amygdala (LA) because of the well-established contribution of this area to fear conditioning. Specifically, we tested the effects of intra-LA microinfusions of the βAR antagonist, propranolol, on learning and memory for auditory Pavlovian fear conditioning in rats. Pre-training propranolol infusions disrupted the initial acquisition, short-term memory (STM), and long-term memory (LTM) for fear conditioning, but infusions immediately after training had no effect. Further, infusion of propranolol prior to testing fear responses did not affect fear memory expression. These findings indicate that amygdala βARs are important for the acquisition but not the consolidation of fear conditioning.

  15. Covalent labeling of the beta-adrenergic ligand-binding site with para-(bromoacetamidyl)benzylcarazolol. A highly potent beta-adrenergic affinity label

    International Nuclear Information System (INIS)

    Dickinson, K.E.; Heald, S.L.; Jeffs, P.W.; Lefkowitz, R.J.; Caron, M.G.

    1985-01-01

    Para-(Bromoacetamidyl)benzylcarazolol (pBABC) was synthesized and found to be an extremely potent affinity label for beta-adrenergic receptors. Its interaction with mammalian (rabbit and hamster lung) and nonmammalian (turkey and frog erythrocyte) beta-adrenergic receptors was similar, displaying EC 50 values of 400-900 pM for inhibiting 125 I-cyanopindolol binding to these receptors. pBABC reduced the number of beta-adrenergic receptors in frog erythrocyte membranes, without any change in the affinity of the remaining sites for [ 125 I]iodocyanopindolol. pBABC has been radioiodinated. As assessed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis, this affinity probe specifically labeled the beta-adrenergic peptide of a purified preparation of hamster lung, with high efficiency (approximately 40%) and with a pharmacological specificity characteristic of an interaction at the beta 2-adrenergic receptor ligand-binding site. Comparison of the proteolyzed products derived from purified receptor labeled with [ 125 I]pBABC and with the photoaffinity agent [ 125 I]p-azidobenzylcarazolol suggested that covalent labeling of the beta-adrenergic receptor by these probes occurs at similar domains of the beta-adrenergic receptor

  16. Regulation of the beta-adrenergic receptor-adenylate cyclase complex of 3T3-L1 fibroblasts by sodium butyrate

    International Nuclear Information System (INIS)

    Stadel, J.M.; Poksay, K.S.; Nakada, M.T.; Crooke, S.T.

    1986-01-01

    Mouse 3T3-L1 fibroblasts contain beta-adrenergic receptors (BAR), predominantly of the B 1 subtype. Incubation of these cells with 2-10 mM sodium butyrate (SB) for 24-48 hr results in a switch in the BAR subtype from B 1 to B 2 and promotes a 1.5 to 2.5 fold increase in total BAR number. Other short chain acids were not as effective as SB in promoting changes in BAR. BAR were assayed in membranes prepared from the 3T3-L1 cells using the radiolabeled antagonist [ 125 I]-cyanopindolol and the B 2 selective antagonist ICI 118.551. BAR subtype switch was confirmed functionally by measuring cellular cAMP accumulation in response to agonists. The structure and amount of the alpha subunits of the guanine nucleotide regulatory proteins N/sub s/ and N/sub i/ were determined by ADP-ribosylation using 32 P-NAD and either cholera toxin or pertussis toxin for labeling of the respective subunits. Preincubation of cells with 5 mM SB for 48 hr resulted in a 2-3 fold increase in the labeling of the alpha subunits of both N/sub s/ and N/sub i/. A protein of M/sub r/ = 44,000 showed enhanced labeling by cholera toxin following SB treatment of the cells. These data indicate SB concomitantly regulates expression of BAR subtype and components of the adenylate cyclase in 3T3-L1 cells

  17. The Role of Beta-Adrenergic Receptors in the Regulation of Circadian Intraocular Pressure Rhythm in Mice.

    Science.gov (United States)

    Tsuchiya, Shunsuke; Higashide, Tomomi; Toida, Kazunori; Sugiyama, Kazuhisa

    2017-07-01

    To investigate whether the elimination of β1- and β2-adrenergic receptors alters the diurnal intraocular pressure (IOP) rhythm in mice. β1-/β2-adrenergic receptor double-knockout and C57BL/6J mice were anesthetized intraperitoneally, with their IOPs measured via microneedle method. After entrainment to a 12-h light-dark (LD) cycle (light phase 6:00-18:00), IOPs were measured every 3 h from 9:00 to 24:00 (group 1, β1-/β2-adrenergic receptor double-knockout mice, n = 11; C57BL/6J, n = 15). The IOP measurements at 15:00 and 24:00 under a 12-h LD cycle and in the constant darkness (1 day and 8 days after exposure to darkness, respectively) were performed in another group of β1-/β2-adrenergic receptor double-knockout mice (group 2, n = 12). IOP variance throughout the day and mean IOP differences among time points were evaluated using a linear mixed model. β1-/β2-adrenergic receptor double-knockout and C57BL/6J mice showed biphasic IOP curves, low during the light phase and high during the dark phase; the fluctuation was significant (P adrenergic receptor double-knockout mice group. IOP curves of β1-/β2-adrenergic receptor double-knockout and C57BL/6J were nearly parallel, and the IOPs of β1-/β2-adrenergic receptor double-knockout mice were significantly higher than those of C57BL/6J mice (P adrenergic receptors did not disturb the biphasic diurnal IOP rhythm in mice.

  18. Effect of cardiopulmonary bypass on beta adrenergic receptor-adenylate cyclase system on surfaces of peripheral lymphocytes.

    Science.gov (United States)

    Luo, A; Tian, Y; Jin, S

    2000-01-01

    The experimental results showed that the level of CAMP, the ratio of cAPM to cGMP, IL-2R expression and IL-2 production in vitro in lymphocytes immediate and 2 weeks after cardiopulmonary bypass (CPB) were significantly lower than those before anesthetics in the patients undergoing cardiac surgery with CPB. These findings suggested that CPB could cause serious damage to adrenergic beta receptor-adenylate cyclase system on circulating lymphocytes surfaces, which might be one of the mechanisms resulting in immunosuppression after open heart surgery with CPB.

  19. Beta-adrenergic blockade for the treatment of hyperthyroidism.

    Science.gov (United States)

    Geffner, D L; Hershman, J M

    1992-07-01

    To review the clinical and biochemical effects of beta-adrenergic blocking drugs on hyperthyroidism. Studies published since 1972 were identified through a computerized search of MEDLINE and extensive searching of the bibliographies of the articles identified. Based on an understanding of the differences in beta-blocker metabolism in euthyroid and hyperthyroid patients, we reviewed the differences in pharmacokinetics and metabolic and clinical outcomes during their use in hyperthyroidism, as reported in the articles reviewed. beta Blockers have been used to modify the severity of the hyperadrenergic symptoms of hyperthyroidism for the past 20 years. The clinical efficacy of these agents is affected by hyperthyroid-induced alterations in their gastrointestinal absorption, hepatic metabolism, and renal excretion. The mechanisms whereby these clinical changes are effected is unknown. The agents differ in their beta 1 cardioselectivity, membrane-stabilizing activity, intrinsic sympathomimetic activity, and lipid solubility. They do not appear to alter synthesis or secretion of thyroid hormone by the thyroid gland. Their effects on thyroxine metabolism are contradictory. Decreased thyroxine to triiodothyronine conversion is caused by some, but not all, beta blockers, and this appears to correlate with membrane-stabilizing activity. There does not appear to be any alteration in catecholamine sensitivity during beta-adrenergic blockade. The principal mechanism of action of beta blockers in hyperthyroidism is to antagonize beta-receptor-mediated effects of catecholamines. beta Blockers are effective in treating hypermetabolic symptoms in a variety of hyperthyroid states. Used alone, they offer significant symptomatic relief. They are also useful adjuvants to antithyroid medications, surgery, and radioactive iodide treatment in patients with Graves' disease and toxic nodular goiters.

  20. Role of alpha- and beta-adrenergic receptors in cardiomyocyte differentiation from murine-induced pluripotent stem cells.

    Science.gov (United States)

    Li, Xiao-Li; Zeng, Di; Chen, Yan; Ding, Lu; Li, Wen-Ju; Wei, Ting; Ou, Dong-Bo; Yan, Song; Wang, Bin; Zheng, Qiang-Sun

    2017-02-01

    Induced pluripotent stem cell (iPSC)-derived cardiomyocytes are a promising source of cells for regenerative heart disease therapies, but progress towards their use has been limited by their low differentiation efficiency and high cellular heterogeneity. Previous studies have demonstrated expression of adrenergic receptors (ARs) in stem cells after differentiation; however, roles of ARs in fate specification of stem cells, particularly in cardiomyocyte differentiation and development, have not been characterized. Murine-induced pluripotent stem cells (miPSCs) were cultured in hanging drops to form embryoid bodies, cells of which were then differentiated into cardiomyocytes. To determine whether ARs regulated miPSC differentiation into cardiac lineages, effects of the AR agonist, epinephrine (EPI), on miPSC differentiation and underlying signalling mechanisms, were evaluated. Treatment with EPI, robustly enhanced miPSC cardiac differentiation, as indicated by increased expression levels of cardiac-specific markers, GATA4, Nkx2.5 and Tnnt2. Although β-AR signalling is the foremost signalling pathway in cardiomyocytes, EPI-enhanced cardiac differentiation depended more on α-AR signalling than β-AR signalling. In addition, selective activation of α 1 -AR signalling with specific agonists induced vigorous cardiomyocyte differentiation, whereas selective activation of α 2 - or β-AR signalling induced no or less differentiation, respectively. EPI- and α 1 -AR-dependent cardiomyocyte differentiation from miPSCs occurred through specific promotion of CPC proliferation via the MEK-ERK1/2 pathway and regulation of miPS cell-cycle progression. These results demonstrate that activation of ARs, particularly of α 1 -ARs, promoted miPSC differentiation into cardiac lineages via MEK-ERK1/2 signalling. © 2016 John Wiley & Sons Ltd.

  1. Deletion of Nhlh2 results in a defective torpor response and reduced Beta adrenergic receptor expression in adipose tissue.

    Directory of Open Access Journals (Sweden)

    Umesh D Wankhade

    2010-08-01

    Full Text Available Mice with a targeted deletion of the basic helix-loop-helix transcription factor, Nescient Helix-Loop-Helix 2 (Nhlh2, display adult-onset obesity with significant increases in their fat depots, abnormal responses to cold exposure, and reduced spontaneous physical activity levels. These phenotypes, accompanied by the hypothalamic expression of Nhlh2, make the Nhlh2 knockout (N2KO mouse a useful model to study the role of central nervous system (CNS control on peripheral tissue such as adipose tissue.Differences in body temperature and serum analysis of leptin were performed in fasted and ad lib fed wild-type (WT and N2KO mice. Histological analysis of white (WAT and brown adipose tissue (BAT was performed. Gene and protein level expression of inflammatory and metabolic markers were compared between the two genotypes.We report significant differences in serum leptin levels and body temperature in N2KO mice compared with WT mice exposed to a 24-hour fast, suggestive of a defect in both white (WAT and brown adipose tissue (BAT function. As compared to WT mice, N2KO mice showed increased serum IL-6 protein and WAT IL-6 mRNA levels. This was accompanied by slight elevations of mRNA for several macrophage markers, including expression of macrophage specific protein F4/80 in adipose, suggestive of macrophage infiltration of WAT in the mutant animals. The mRNAs for beta3-adrenergic receptors (beta3-AR, beta2-AR and uncoupling proteins were significantly reduced in WAT and BAT from N2KO mice compared with WT mice.These studies implicate Nhlh2 in the central control of WAT and BAT function, with lack of Nhlh2 leading to adipose inflammation and altered gene expression, impaired leptin response to fasting, all suggestive of a deficient torpor response in mutant animals.

  2. Beta-adrenergic receptors support attention to extinction learning that occurs in the absence, but not the presence, of a context change

    Directory of Open Access Journals (Sweden)

    Marion Emma André

    2015-05-01

    Full Text Available The noradrenergic (NA-system is an important regulator of cognitive function. It contributes to extinction learning(EL, and in disorders where EL is impaired NA-dysfunction has been postulated. We explored whether NA acting on beta-adrenergic-receptors (β-AR, regulates EL that depends on context, but is not fear-associated. We assessed behaviour in an ‘AAA’ or ‘ABA’ paradigm: rats were trained for 3 days in a T-maze(context-A to learn that a reward is consistently found in the goal arm, despite low reward probability. This was followed on day 4 by EL(unrewarded, whereby in the ABA-paradigm, EL was reinforced by a context change (B, and in the AAA-paradigm, no context change occurred. On day 5, re-exposure to the A-context (unrewarded occurred. Typically, in control ‘AAA’ animals EL occurred on day 4 that progressed further on day 5. In control ‘ABA’ animals, EL also occurred on day 4, followed by renewal of the previously learned (A behavior on day 5, that was followed (in day 5 by extinction of this behavior, as the animals realised that no food reward would be given.Treatment with the β-AR-antagonist, propranolol, prior to EL on day 4, impaired EL in the AAA-paradigm. In the ‘ABA’ paradigm, antagonist treatment on day 4, had no effect on extinction that was reinforced by a context change (B. Furthermore, β-AR-antagonism prior to renewal testing (on day 5 in the ABA-paradigm, resulted in normal renewal behavior, although subsequent extinction of responses during day 5 was prevented by the antagonist. Thus, under both treatment conditions, β-AR-antagonism prevented extinction of the behavior learned in the ‘A’ context.β-AR-blockade during an overt context change did not prevent EL, whereas β-AR were required for EL in an unchanging context. These data suggest that β-AR may support EL by reinforcing attention towards relevant changes in the previously learned experience, and that this process supports extinction

  3. Beta-adrenergic receptors support attention to extinction learning that occurs in the absence, but not the presence, of a context change

    Science.gov (United States)

    André, Marion Agnès Emma; Wolf, Oliver T.; Manahan-Vaughan, Denise

    2015-01-01

    The noradrenergic (NA)-system is an important regulator of cognitive function. It contributes to extinction learning (EL), and in disorders where EL is impaired NA-dysfunction has been postulated. We explored whether NA acting on beta-adrenergic-receptors (β-AR), regulates EL that depends on context, but is not fear-associated. We assessed behavior in an “AAA” or “ABA” paradigm: rats were trained for 3 days in a T-maze (context-A) to learn that a reward is consistently found in the goal arm, despite low reward probability. This was followed on day 4 by EL (unrewarded), whereby in the ABA-paradigm, EL was reinforced by a context change (B), and in the AAA-paradigm, no context change occurred. On day 5, re-exposure to the A-context (unrewarded) occurred. Typically, in control “AAA” animals EL occurred on day 4 that progressed further on day 5. In control “ABA” animals, EL also occurred on day 4, followed by renewal of the previously learned (A) behavior on day 5, that was succeeded (on day 5) by extinction of this behavior, as the animals realised that no food reward would be given. Treatment with the β-AR-antagonist, propranolol, prior to EL on day 4, impaired EL in the AAA-paradigm. In the “ABA” paradigm, antagonist treatment on day 4, had no effect on extinction that was reinforced by a context change (B). Furthermore, β-AR-antagonism prior to renewal testing (on day 5) in the ABA-paradigm, resulted in normal renewal behavior, although subsequent extinction of responses during day 5 was prevented by the antagonist. Thus, under both treatment conditions, β-AR-antagonism prevented extinction of the behavior learned in the “A” context. β-AR-blockade during an overt context change did not prevent EL, whereas β-AR were required for EL in an unchanging context. These data suggest that β-AR may support EL by reinforcing attention towards relevant changes in the previously learned experience, and that this process supports extinction

  4. Alpha and beta adrenergic effects on metabolism in contracting, perfused muscle

    DEFF Research Database (Denmark)

    Richter, Erik; Ruderman, N B; Galbo, H

    1982-01-01

    The role of alpha- and beta-adrenergic receptor stimulation for the effect of epinephrine on muscle glycogenolysis, glucose- and oxygen uptake and muscle performance was studied in the perfused rat hindquarter at rest and during electrical stimulation (60 contractions/min). Adrenergic stimulation...... was obtained by epinephrine in a physiological concentration (2.4 X 10(-8) M) and alpha- and beta-adrenergic blockade by 10(-5) M phentolamine and propranolol, respectively. Epinephrine enhanced net glycogenolysis during contractions most markedly in slow-twitch red fibers. In these fibers the effect...... was mediated by alpha- as well as by beta-adrenergic stimulation, the latter involving production of cAMP, phosphorylase activation and synthase inactivation. In contrast, in fast-twitch fibers only beta-adrenergic mechanisms were involved in the glycogenolytic effect of epinephrine. Moreover, inactivation...

  5. [Beta]-Adrenergic Receptor Activation Rescues Theta Frequency Stimulation-Induced LTP Deficits in Mice Expressing C-Terminally Truncated NMDA Receptor GluN2A Subunits

    Science.gov (United States)

    Moody, Teena D.; Watabe, Ayako M.; Indersmitten, Tim; Komiyama, Noboru H.; Grant, Seth G. N.; O'Dell, Thomas J.

    2011-01-01

    Through protein interactions mediated by their cytoplasmic C termini the GluN2A and GluN2B subunits of NMDA receptors (NMDARs) have a key role in the formation of NMDAR signaling complexes at excitatory synapses. Although these signaling complexes are thought to have a crucial role in NMDAR-dependent forms of synaptic plasticity such as long-term…

  6. Beta-Adrenergic signaling in rat heart is similarly affected by continuous and intermittent normobaric hypoxia

    Czech Academy of Sciences Publication Activity Database

    Hahnová, K.; Kašparová, D.; Žurmanová, J.; Neckář, Jan; Kolář, František; Novotný, J.

    2016-01-01

    Roč. 35, č. 2 (2016), s. 165-173 ISSN 0231-5882 R&D Projects: GA ČR(CZ) GAP303/12/1162 Institutional support: RVO:67985823 Keywords : rat myocardium * chronic hypoxia * beta-adrenergic receptors * adenylyl cyclase Subject RIV: FA - Cardiovascular Diseases incl. Cardiotharic Surgery Impact factor: 1.170, year: 2016

  7. Dopaminergic and beta-adrenergic effects on gastric antral motility

    DEFF Research Database (Denmark)

    Bech, K; Hovendal, C P; Gottrup, F

    1984-01-01

    of bethanechol or pentagastrin inducing motor activity patterns as in the phase III of the MMC and the digestive state respectively. The stimulated antral motility was dose-dependently inhibited by dopamine. The effect was significantly blocked by specifically acting dopaminergic blockers, while alpha- and beta......-adrenergic blockers were without any significant effects. Dose-response experiments with bethanechol and dopamine showed inhibition of a non-competitive type. Isoprenaline was used alone and in conjunction with selective blockade of beta 1- and beta 2-receptors during infusion of bethanechol which induces a pattern...... similar to phase III in the migrating myoelectric complex. The stimulated antral motility was dose-dependently inhibited by isoprenaline. The effect could be significantly blocked by propranolol (beta 1 + beta 2-adrenoceptor blocker) and by using in conjunction the beta 1-adrenoceptor blocker practolol...

  8. Synthesis and biodistribution of R- and S-isomers of [{sup 18}F]-fluoropropranolol, a lipophilic ligand for the {beta}-adrenergic receptor

    Energy Technology Data Exchange (ETDEWEB)

    Tewson, Timothy J. E-mail: ttewson@u.washington.edu; Stekhova, Svetlana; Kinsey, Berma; Chen, Lay; Wiens, Linda; Barber, Roger

    1999-11-01

    The S and R isomers of [{sup 18}F]-fluoropropranolol (1-[1-fluoro-2-isopropylamino]-3-naphthalen-1-yloxy-propan-2-ol) have been prepared by reductive alkylation of the appropriate aminoalcohols. The radiosynthesis provides a reasonable yield ({approx}25%) to give products of 99% enantiomeric excess and specific activities of 1-3 Ci/{mu}mol. The dissociation constants for the {beta}{sub 2} adrenergic receptor are 0.5 and 2.5 nM for the S and the R isomers, respectively. The biodistribution data in rats show that uptake and egress of the tracer is rapid but that the result of blocking studies and the difference between the R and the S isomers suggest receptor-mediated uptake in receptor-rich tissue.

  9. Absence of age-related changes in the binding of the beta adrenergic antagonist 125I-iodohydroxybenzylpindolol in rat heart

    International Nuclear Information System (INIS)

    Tumer, N.; Bender, J.; Roberts, J.

    1987-01-01

    The effect of age on the density and the affinity of beta adrenergic receptors was determined in the hearts of Fischer 344 rats at three ages, 6, 12, and 24 months old. The binding of the beta adrenergic antagonist 125 I-iodohydroxybenzylpindolol (IHYP), was used to quantitate and characterize cardiac beta adrenergic receptors. The maximal number of binding sites (B/sub max/ = F moles/mg of protein) were 26.3 +/- 2.5, 25.4 +/- 0.99, and 24.5 +/- 2.4 and the dissociation constants (K/sub d/ = nM) were 0.166 +/- 0.014, 0.126 +/- 0.006, and 0.135 +/- 0.015 for 6, 12, and 24 months old animals, respectively. There were no significant differences among the three ages. These results support the contention that neither beta adrenergic receptor density of affinity changes with age in the ventricles of the rat heart

  10. Cooperative regulation of non-small cell lung carcinoma by nicotinic and beta-adrenergic receptors: a novel target for intervention.

    Directory of Open Access Journals (Sweden)

    Hussein A N Al-Wadei

    Full Text Available Lung cancer is the leading cause of cancer death; 80-85% of lung cancer cases are non-small cell lung cancer (NSCLC. Smoking is a documented risk factor for the development of this cancer. Although nicotine does not have the ability to initiate carcinogenic events, recent studies have implicated nicotine in growth stimulation of NSCLC. Using three NSCLC cell lines (NCI-H322, NCI-H441 and NCI-H1299, we identified the cooperation of nicotinic acetylcholine receptors (nAChRs and β-adrenergic receptors (β-ARs as principal regulators of these effects. Proliferation was measured by thymidine incorporation and MTT assays, and Western blots were used to monitor the upregulation of the nAChRs and activation of signaling molecules. Noradrenaline and GABA were measured by immunoassays. Nicotine-treated NSCLC cells showed significant induction of the α7nAChR and α4nAChR, along with significant inductions of p-CREB and p-ERK1/2 accompanied by increases in the stress neurotransmitter noradrenaline, which in turn led to the observed increase in DNA synthesis and cell proliferation. Effects on cell proliferation and signaling proteins were reversed by the α7nAChR antagonist α-BTX or the β-blocker propranolol. Nicotine treatment also down-regulated expression of the GABA synthesizing enzyme GAD 65 and the level of endogenous GABA, while treatment of NSCLC cells with GABA inhibited cell proliferation. Interestingly, GABA acts by reducing β-adrenergic activated cAMP signaling. Our findings suggest that nicotine-induced activation of this autocrine noradrenaline-initiated signaling cascade and concomitant deficiency in inhibitory GABA, similar to modulation of these neurotransmitters in the nicotine-addicted brain, may contribute to the development of NSCLC in smokers. Our data suggest that exposure to nicotine either by tobacco smoke or nicotine supplements facilitates growth and progression of NSCLC and that pharmacological intervention by β blocker may

  11. The Relationship between Birthweight and Longitudinal Changes of Blood Pressure Is Modulated by Beta-Adrenergic Receptor Genes: The Bogalusa Heart Study

    Directory of Open Access Journals (Sweden)

    Wei Chen

    2010-01-01

    Full Text Available This study examines the genetic influence of β-adrenergic receptor gene polymorphisms (β2-AR Arg16Gly and β3-AR Trp64Arg on the relationship of birthweight to longitudinal changes of blood pressure (BP from childhood to adulthood in 224 black and 515 white adults, aged 21–47 years, enrolled in the Bogalusa Heart Study. Blacks showed significantly lower birthweight and frequencies of β2-AR Gly16 and β3-AR Trp64 alleles and higher BP levels and age-related trends than whites. In multivariable regression analyses using race-adjusted BP and birthweight, low birthweight was associated with greater increase in age-related trend of systolic BP (standardized regression coefficient β=−0.09, P=.002 and diastolic BP (β=−0.07, P=.037 in the combined sample of blacks and whites, adjusting for the first BP measurement in childhood, sex, age, and gestational age. Adjustment for the current body mass index strengthened the birthweight-BP association. Importantly, the strength of the association, measured as regression coefficients, was modulated by the combination of β2-AR and β3-AR genotypes for systolic (P=.042 for interaction and diastolic BP age-related trend (P=.039 for interaction, with blacks and whites showing a similar trend in the interaction. These findings indicate that the intrauterine programming of BP regulation later in life depends on β-AR genotypes.

  12. Beta Adrenergic Regulation of Intrapulmonary Arteriovenous Anastomoses in Intact Rat and Isolated Rat Lungs

    Directory of Open Access Journals (Sweden)

    Melissa L. Bates

    2017-04-01

    Full Text Available Intrapulmonary arteriovenous anastomoses (IPAVA allow large diameter particles of venous origin to bypass the pulmonary capillary bed and embolize the systemic arterial circulation. IPAVA have been routinely observed in healthy humans with exercise, hypoxia, and catecholamine infusion, but the mechanism by which they are recruited is not well-defined. We hypothesized that beta-adrenergic receptor stimulation recruits IPAVA and that receptor blockade would limit hypoxia-induced IPAVA recruitment. To test our hypothesis, we evaluated the transpulmonary passage of microspheres in intact rats and isolated rats lung infused with the beta-adrenergic receptor agonist isoproterenol. We also evaluated IPAVA recruitment in intact rats with hypoxia and the beta-adrenergic receptor blocker propranolol. We found that IPAVA are recruited in the intact rat by isoproterenol and their recruitment by hypoxia can be minimized by propranolol, suggesting a role for the adrenergic system in the recruitment of IPAVA by hypoxia. IPAVA recruitment is completely abolished by ventilation with 100% oxygen. Isoproterenol also recruits IPAVA in isolated rat lungs. The fact that isoproterenol can recruit IPAVA in isolated lungs, without increased pulmonary flow, suggests that elevated cardiac output is not required for IPAVA recruitment.

  13. Central beta-adrenergic modulation of cognitive flexibility.

    Science.gov (United States)

    Beversdorf, David Q; White, Dawn M; Chever, Daquesha C; Hughes, John D; Bornstein, Robert A

    2002-12-20

    Situational stressors and anxiety impede performance on creativity tests requiring cognitive flexibility. Preliminary research revealed better performance on a task requiring cognitive flexibility, the anagram task, after propranolol (beta-adrenergic antagonist) than after ephedrine (beta-adrenergic agonist). However, propranolol and ephedrine have both peripheral and central beta-adrenergic effects. In order to determine whether noradrenergic modulation of cognitive flexibility is a centrally or peripherally mediated phenomenon, we compared the effects of propranolol (peripheral and central beta-blocker), nadolol (peripheral beta-blocker), and placebo on anagram task performance. Solution latency scores for each subject were compared across the drug conditions. Anagram solution latency scores after propranolol were significantly lower than after nadolol. This suggests a centrally mediated modulatory influence of the noradrenergic system on cognitive flexibility.

  14. Ghrelin potentiates cardiac reactivity to stress by modulating sympathetic control and beta-adrenergic response.

    Science.gov (United States)

    Camargo-Silva, Gabriel; Turones, Larissa Córdova; da Cruz, Kellen Rosa; Gomes, Karina Pereira; Mendonça, Michelle Mendanha; Nunes, Allancer; de Jesus, Itamar Guedes; Colugnati, Diego Basile; Pansani, Aline Priscila; Pobbe, Roger Luis Henschel; Santos, Robson; Fontes, Marco Antônio Peliky; Guatimosim, Silvia; de Castro, Carlos Henrique; Ianzer, Danielle; Ferreira, Reginaldo Nassar; Xavier, Carlos Henrique

    2018-03-01

    Prior evidence indicates that ghrelin is involved in the integration of cardiovascular functions and behavioral responses. Ghrelin actions are mediated by the growth hormone secretagogue receptor subtype 1a (GHS-R1a), which is expressed in peripheral tissues and central areas involved in the control of cardiovascular responses to stress. In the present study, we assessed the role of ghrelin - GHS-R1a axis in the cardiovascular reactivity to acute emotional stress in rats. Ghrelin potentiated the tachycardia evoked by restraint and air jet stresses, which was reverted by GHS-R1a blockade. Evaluation of the autonomic balance revealed that the sympathetic branch modulates the ghrelin-evoked positive chronotropy. In isolated hearts, the perfusion with ghrelin potentiated the contractile responses caused by stimulation of the beta-adrenergic receptor, without altering the amplitude of the responses evoked by acetylcholine. Experiments in isolated cardiomyocytes revealed that ghrelin amplified the increases in calcium transient changes evoked by isoproterenol. Taken together, our results indicate that the Ghrelin-GHS-R1a axis potentiates the magnitude of stress-evoked tachycardia by modulating the autonomic nervous system and peripheral mechanisms, strongly relying on the activation of cardiac calcium transient and beta-adrenergic receptors. Copyright © 2018 Elsevier Inc. All rights reserved.

  15. Expression of inwardly rectifying potassium channels (GIRKs) and beta-adrenergic regulation of breast cancer cell lines

    International Nuclear Information System (INIS)

    Plummer, Howard K III; Yu, Qiang; Cakir, Yavuz; Schuller, Hildegard M

    2004-01-01

    Previous research has indicated that at various organ sites there is a subset of adenocarcinomas that is regulated by beta-adrenergic and arachidonic acid-mediated signal transduction pathways. We wished to determine if this regulation exists in breast adenocarcinomas. Expression of mRNA that encodes a G-protein coupled inwardly rectifying potassium channel (GIRK1) has been shown in tissue samples from approximately 40% of primary human breast cancers. Previously, GIRK channels have been associated with beta-adrenergic signaling. Breast cancer cell lines were screened for GIRK channels by RT-PCR. Cell cultures of breast cancer cells were treated with beta-adrenergic agonists and antagonists, and changes in gene expression were determined by both relative competitive and real time PCR. Potassium flux was determined by flow cytometry and cell signaling was determined by western blotting. Breast cancer cell lines MCF-7, MDA-MB-361 MDA-MB 453, and ZR-75-1 expressed mRNA for the GIRK1 channel, while MDA-MB-468 and MDA-MB-435S did not. GIRK4 was expressed in all six breast cancer cell lines, and GIRK2 was expressed in all but ZR-75-1 and MDA-MB-435. Exposure of MDA-MB-453 cells for 6 days to the beta-blocker propranolol (1 μM) increased the GIRK1 mRNA levels and decreased beta 2 -adrenergic mRNA levels, while treatment for 30 minutes daily for 7 days had no effect. Exposure to a beta-adrenergic agonist and antagonist for 24 hours had no effect on gene expression. The beta adrenergic agonist, formoterol hemifumarate, led to increases in K + flux into MDA-MB-453 cells, and this increase was inhibited by the GIRK channel inhibitor clozapine. The tobacco carcinogen 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK), a high affinity agonist for beta-adrenergic receptors stimulated activation of Erk 1/2 in MDA-MB-453 cells. Our data suggests β-adrenergic receptors and GIRK channels may play a role in breast cancer

  16. Treatment of resting tremor by beta-adrenergic blockade.

    Science.gov (United States)

    Foster, N L; Newman, R P; LeWitt, P A; Gillespie, M M; Chase, T N

    1984-10-01

    The effect of nadolol, a peripherally acting beta-adrenergic blocker, on resting tremor was examined in eight patients with idiopathic Parkinson's disease. With the use of a double-blind, placebo-controlled study of crossover design, patients received 80 to 320 mg of nadolol for 6 weeks while continuing their previous treatment regimen. Accelerometer readings showed a progressive reduction in tremor amplitude, but no change in tremor frequency, with increasing nadolol dosage. Maximum benefit was achieved at 240 mg, when resting tremor improved 50% (p less than 0.01). Physician ratings confirmed these findings. The results suggest that response to beta-adrenergic blockade may not be limited to postural or intention tremor and that such agents may not reliably differentiate between the tremor of Parkinson's disease and essential tremor.

  17. Association between Selective Beta-adrenergic Drugs and Blood Pressure Elevation: Data Mining of the Japanese Adverse Drug Event Report (JADER) Database.

    Science.gov (United States)

    Ohyama, Katsuhiro; Inoue, Michiko

    2016-01-01

    Selective beta-adrenergic drugs are used clinically to treat various diseases. Because of imperfect receptor selectivity, beta-adrenergic drugs cause some adverse drug events by stimulating other adrenergic receptors. To examine the association between selective beta-adrenergic drugs and blood pressure elevation, we reviewed the Japanese Adverse Drug Event Reports (JADERs) submitted to the Japan Pharmaceuticals and Medical Devices Agency. We used the Medical Dictionary for Regulatory Activities (MedDRA) Preferred Terms extracted from Standardized MedDRA queries for hypertension to identify events related to blood pressure elevation. Spontaneous adverse event reports from April 2004 through May 2015 in JADERs, a data mining algorithm, and the reporting odds ratio (ROR) were used for quantitative signal detection, and assessed by the case/non-case method. Safety signals are considered significant if the ROR estimates and lower bound of the 95% confidence interval (CI) exceed 1. A total of 2021 reports were included in this study. Among the nine drugs examined, significant signals were found, based on the 95%CI for salbutamol (ROR: 9.94, 95%CI: 3.09-31.93) and mirabegron (ROR: 7.52, 95%CI: 4.89-11.55). The results of this study indicate that some selective beta-adrenergic drugs are associated with blood pressure elevation. Considering the frequency of their indications, attention should be paid to their use in elderly patients to avoid adverse events.

  18. PET measures of pre- and post-synaptic cardiac beta adrenergic function

    Energy Technology Data Exchange (ETDEWEB)

    Link, Jeanne M.; Stratton, John R.; Levy, Wayne; Poole, Jeanne E.; Shoner, Steven C.; Stuetzle, Werner; Caldwell, James H. E-mail: jcald@u.washington.edu

    2003-11-01

    Positron Emission Tomography was used to measure global and regional cardiac {beta}-adrenergic function in 19 normal subjects and 9 congestive heart failure patients. [{sup 11}C]-meta-hydroxyephedrine was used to image norepinephrine transporter function as an indicator of pre-synaptic function and [{sup 11}C]-CGP12177 was used to measure cell surface {beta}-receptor density as an indicator of post-synaptic function. Pre-synaptic, but not post-synaptic, function was significantly different between normals and CHF patients. Pre-synaptic function was well matched to post-synaptic function in the normal hearts but significantly different and poorly matched in the CHF patients studied. This imaging technique can help us understand regional sympathetic function in cardiac disease.

  19. Peripheral beta-adrenergic blockade treatment of parkinsonian tremor.

    Science.gov (United States)

    Foster, N L; Newman, R P; LeWitt, P A; Gillespie, M M; Larsen, T A; Chase, T N

    1984-10-01

    The effect of nadolol, a peripherally acting beta-adrenergic blocker, on resting, postural, and intention tremor was examined in 8 patients with idiopathic Parkinson's disease whose motor symptoms, other than tremor, were well controlled with conventional medications. In a double-blind, placebo-controlled, crossover design, patients received 80 to 320 mg of nadolol for six weeks while continuing their previous therapeutic regimen. Accelerometer readings showed a 34% reduction (p less than 0.025) in tremor distance, but no change in tremor frequency, during nadolol therapy. Maximum benefit was achieved with a dose of 240 mg, when resting tremor improved 54%, postural tremor 32%, and intention tremor 54%. Physician ratings and patient reports supported the accelerometer results. Nadolol appears to be a safe, effective adjunct to current dopaminergic and anticholinergic therapy for severe tremor in Parkinson's disease.

  20. Effect of interleukin 13 on bronchial hyperresponsiveness and the bronchoprotective effect of beta-adrenergic bronchodilators and corticosteroids.

    Science.gov (United States)

    Townley, Robert G; Gendapodi, Pradeep R; Qutna, Nidal; Evans, Joseph; Romero, Francisco A; Abel, Peter

    2009-03-01

    Fluticasone affects airway bronchial hyperresponsiveness (BHR) and enhances bronchodilation and bronchoprotection induced by beta-adrenergic agonists. Interleukin 13 (IL-13), however, induces BHR. To test the hypotheses that fluticasone inhibits BHR after either allergen sensitization or IL-13 administration and that fluticasone restores the bronchodilation and bronchoprotective effects of beta-agonists. The BHR to methacholine induced by IL-13 or ovalbumin was determined in BALB/c mice, and the provocation concentration of methacholine that caused an increase in enhanced pause in expiration of 200% (PC200) was calculated. We compared this response to methacholine in control mice with the response after treatment with IL-13 receptor alpha 2-IgGFc fusion protein (IL-13R alpha 2) (an IL-13 blocker), fluticasone, albuterol, salmeterol, fluticasone-albuterol, and fluticasone-salmeterol. IL-13R alpha 2 (PC200, 17.59) completely blocks the BHR-induced effects of IL-13 (PC200, 7.28; P < .005). After IL-13 therapy (PC200, 5.90; P < .005), 1 mg/mL of albuterol (PC200, 3.38; P = .33), fluticasone (PC200, 4.59; P = .40), or fluticasone plus 50 microg/mL of salmeterol (PC200, 5.59; P = .11) showed no significant bronchoprotection. In nonsensitized mice, fluticasone plus 0.25 microg/mL of salmeterol (PC200, 25.90; P < .005) showed significantly greater bronchoprotection than did salmeterol alone (PC200, 11.08; P = .26). Fluticasone plus 0.3 mg/mL of albuterol and fluticasone plus 1 mg/mL of albuterol were significantly more protective than was fluticasone or albuterol alone in ovalbumin-sensitized mice. The protective effects of fluticasone, beta-agonists, and fluticasone plus beta-agonists are significantly less in IL-13-treated mice than in nonsensitized or ovalbumin-sensitized mice.

  1. Non-selective beta-adrenergic blockade prevents reduction of the cerebral metabolic ratio during exhaustive exercise in humans

    DEFF Research Database (Denmark)

    Larsen, T.S.; Rasmussen, P.; Overgaard, M.

    2008-01-01

    Intense exercise decreases the cerebral metabolic ratio of oxygen to carbohydrates [O(2)/(glucose + (1/2)lactate)], but whether this ratio is influenced by adrenergic stimulation is not known. In eight males, incremental cycle ergometry increased arterial lactate to 15.3 +/- 4.2 mm (mean +/- s.......d.) and the arterial-jugular venous (a-v) difference from -0.02 +/- 0.03 mm at rest to 1.0 +/- 0.5 mm (P cerebral metabolic ratio decreased from 5.5 +/- 1.4 to 3.0 +/- 0.3 (P ... of a non-selective beta-adrenergic (beta(1) + beta(2)) receptor antagonist (propranolol) reduced heart rate (69 +/- 8 to 58 +/- 6 beats min(-1)) and exercise capacity (239 +/- 42 to 209 +/- 31 W; P

  2. Substrate utilization and thermogenic responses to beta-adrenergic stimulation in obese subjects with NIDDM.

    NARCIS (Netherlands)

    Blaak, E.E.; Saris, W.H.M.; Wolffenbuttel, B.H.R.

    1999-01-01

    OBJECTIVE: This study intended to investigate disturbances in beta-adrenergically-mediated substrate utilization and thermogenesis in obese subjects with mild non insulin-dependent diabetes mellitus (NIDDM). DESIGN: Following a baseline period of 30 min, the beta-agonist isoproterenol (ISO) was

  3. Substrate utilization and thermogenic responses to beta-adrenergic stimulation in obese subjects with NIDDM

    NARCIS (Netherlands)

    Blaak, E E; Saris, W H; Wolffenbuttel, B H

    OBJECTIVE: This study intended to investigate disturbances in beta-adrenergically-mediated substrate utilization and thermogenesis in obese subjects with mild non insulin-dependent diabetes mellitus (NIDDM). DESIGN: Following a baseline period of 30 min, the beta-agonist isoproterenol (ISO) was

  4. Orange juice substantially reduces the bioavailability of the beta-adrenergic-blocking agent celiprolol.

    Science.gov (United States)

    Lilja, Jari J; Juntti-Patinen, Laura; Neuvonen, Pertti J

    2004-03-01

    Grapefruit juice was recently found to decrease plasma concentrations of the beta-adrenergic receptor-blocking agent celiprolol. Our objective was to investigate the effect of orange juice on the pharmacokinetics of celiprolol in healthy subjects. In a randomized crossover study with 2 phases and a washout of 2 weeks, 10 healthy volunteers ingested either 200 mL normal-strength orange juice or water 3 times a day for 2 days. On the morning of day 3, 1 hour after ingestion of 200 mL orange juice or water, each subject ingested 100 mg celiprolol with either 200 mL orange juice or water. In addition, 200 mL orange juice or water was ingested at 4, 10, 22, and 27 hours after celiprolol intake. The concentrations of celiprolol in plasma and its excretion into urine were measured up to 33 hours after its dosing. Systolic and diastolic blood pressures and heart rate were recorded up to 10 hours. Orange juice reduced the mean peak plasma concentration of celiprolol by 89% (P orange juice. Orange juice reduced the urinary excretion of celiprolol by 77% (P Orange juice substantially reduces the bioavailability of celiprolol, but the mechanism of this interaction remains to be resolved. For example, modulation of intestinal pH and of function of transporters implicated in the absorption of celiprolol may be involved. Because of the great extent of the orange juice-celiprolol interaction and a wide use of orange juice, this interaction is likely to have clinical importance in some patients, although hemodynamic consequences were not seen in young healthy subjects.

  5. Antihypertensive effect of alpha- and beta-adrenergic blockade in obese and lean hypertensive subjects.

    Science.gov (United States)

    Wofford, M R; Anderson, D C; Brown, C A; Jones, D W; Miller, M E; Hall, J E

    2001-07-01

    The purpose of this study was to determine the contribution of the adrenergic system in mediating hypertension in obese and lean patients. Thirteen obese, hypertensive patients with a body mass index (BMI) > or =28 kg/m2 (obese) and nine lean patients with a BMI lean) were recruited. After a 1-week washout period, participants underwent daytime ambulatory blood pressure monitoring (ABPM). Participants were then treated with the alpha-adrenergic antagonist doxazosin, titrating to 4 mg QHS in 1 week. In the next week, the beta-adrenergic antagonist atenolol was added at an initial dose of 25 mg/day and titrated to 50 mg/day within 1 week. One month after the addition of atenolol, all patients underwent a second ABPM session. There were no differences between the obese and lean subjects in baseline systolic (SBP), diastolic (DBP), or mean arterial pressures (MAP) measured by office recording or ABPM. However, obese subjects had higher heart rates than lean subjects (87.5+/-2.4 v 76.8+/-4.9 beats/min). After 1 month of treatment with the adrenergic blockers, obese patients had a significantly lower SBP (130.0+/-2.5 v 138.9+/-2.1 mm Hg, P = .02) and MAP (99.6+/-2.3 v 107.0+/-1.5 mm Hg, P = .02) than lean patients. Obese patients also tended to have a lower DBP than lean patients (84.3+/-2.5 v 90.9+/-1.6 mm Hg, P = .057), but there was no significant difference in heart rate after 1 month of adrenergic blockade. These results indicate that blood pressure is more sensitive to adrenergic blockade in obese than in lean hypertensive patients and suggest that increased sympathetic activity may be an important factor in the maintenance of hypertension in obesity.

  6. Selectivity of beta-adrenergic stimulating and blocking agents.

    Science.gov (United States)

    Löfdahl, C G; Svedmyr, N

    1984-01-01

    Studies have been performed to answer two questions: whether there are subgroups of beta 2-receptors separating effects in bronchial and skeletal muscle and whether beta 1-receptors in asthmatic airways mediate bronchoconstriction. Asthmatic patients have been studied in randomised cross-over trials. Effects on FEV1, heart rate and skeletal muscle tremor have been monitored. In some experimental studies, two new compounds, D2343 and QH-25, have shown a selectivity for beta 2-receptors in bronchial muscle compared to skeletal muscle. Studies in asthmatics did not confirm this. Thus, the beta 2-receptors in the two organs appear to be identical. The clinical effect of beta 1-receptors in the the airways was studied by giving selective beta 1-receptor blocking agents. It was shown that pafenolol , a beta-blocker more beta 1-selective than metoprolol, had less effect on FEV1 than metoprolol given in equipotent beta 1-blocking doses. Beta 1-receptor stimulation with a new selective beta 1-stimulating agent, prenalterol, did not give bronchodilation in doses which gave a significant increase of heart rate. Thus, beta 1-receptors do not contribute to bronchodilation in asthmatic patients.

  7. Effects of the angiotensin-converting enzyme inhibitor enalapril on sympathetic neuronal function and {beta}-adrenergic desensitization in heart failure after myocardial infarction in rats

    Energy Technology Data Exchange (ETDEWEB)

    Igawa, Akihiko; Nozawa, Takashi; Yoshida, Naohiro [Toyama Medical and Pharmaceutical Univ. (Japan)] [and others

    2002-11-01

    One of the beneficial effects of angiotensin-converting enzyme (ACE) inhibitors in the treatment of heart failure may derive from sympathoinhibition and the prevention of {beta}-adrenergic desensitization. However, the roles of these properties in the overall effects of ACE inhibitor are not clear. We studied the effects of chronic enalapril treatment (20 mg/L in drinking water for 12 weeks) on left ventricular (LV) function, cardiac norepinephrine (NE), sympathetic neuronal function assessed by {sup 131}I-metaiodobenzylguanidine (MIBG), {beta}-receptors, and isometric contraction of papillary muscle in rats with myocardial infarction (MI) induced by coronary artery ligation. Decreased LV function in the MI rats was associated with reduced cardiac NE content and MIBG uptake, and severely blunted responses of non-infarcted papillary muscle to isoproterenol, forskolin, and calcium. Enalapril attenuated LV remodeling in association with a reduction of the ventricular loading condition and restored baseline developed tension of non-infarcted papillary muscle to the level of sham-operated rats. However, enalapril did not improve cardiac NE content, MIBG uptake, or inotropic responsiveness to {beta}-agonists. These results suggest that the major effect of the ACE inhibitor enalapril in the treatment of heart failure is not due to sympathoinhibition or restoration of {beta}-adrenergic pathway in this model of heart failure. (author)

  8. Beta-Adrenergic gene therapy for cardiovascular disease

    Directory of Open Access Journals (Sweden)

    Koch Walter J

    2000-10-01

    Full Text Available Abstract Gene therapy using in vivo recombinant adenovirus-mediated gene transfer is an effective technique that offers great potential to improve existing drug treatments for the complex cardiovascular diseases of heart failure and vascular smooth muscle intimal hyperplasia. Cardiac-specific adenovirus-mediated transfer of the carboxyl-terminus of the β-adrenergic receptor kinase (βARKct, acting as a Gβγ-β-adrenergic receptor kinase (βARK1 inhibitor, improves basal and agonist-induced cardiac performance in both normal and failing rabbit hearts. In addition, βARKct adenovirus infection of vascular smooth muscle is capable of significantly diminishing neointimal proliferation after angioplasty. Therefore, further investigation is warranted to determine whether inhibition of βARK1 activity and sequestration of Gβγ via an adenovirus that encodes the βARKct transgene might be a useful clinical tool for the treatment of cardiovascular pathologies.

  9. Beta-Adrenergic Blockade Does not Prevent Polycythemia or Decrease in Plasma Volume in Men at 4300 m Altitude

    Science.gov (United States)

    Grover, R. F.; Selland, M. A.; McCullough, R. G.; Dahms, T. E.; Wolfel, E. E.; Butterfield, G. E.; Reeves, J. T.; Greenleaf, J. E.

    1998-01-01

    When humans ascend to high altitude (ALT) their plasma volume (PV) and total blood volume (BV) decrease during the first few days. With continued residence over several weeks, the hypoxia-induced stimulation of erythropoietin increases red cell production which tends to restore BV. Because hypoxia also activates the beta-adrenergic system, which stimulates red blood cell production, we investigated the effect of adrenergic beta-receptor inhibition with propranolol on fluid volumes and the polycythemic response in 11 healthy unacclimatized men (21-33 years old exposed to an ALT of 4300 m (barometric pressure 460 Torr) for 3 weeks on Pikes Peak, Colorado. PV was determined by the Evans blue dye method (PV(sub EB)), BV by the carbon monoxide method (BV(sub CO)), red cell volume (RCV)was calculated from hematocrit (Hct) and BV(sub CO), and serum erythropoietin concentration ([EPO]) and reticulocyte count, were also determined. All determinations were made at sea level and after 9-11 (ALT-10) and 9-20 (ALT-20) days at ALT. At sea level and ALT, six men received propranolol (pro, 240 mg/day), and five received a placebo (pla). Effective beta-blockade did not modify the mean (SE) maximal values of [EPO] [pla: 24.9 (3.5) vs pro: 24.5 (1.5) mU/ml] or reticulocyte count [pla: 2.7 (0.7) vs pro: 2.2 (0.5)%]; nor changes in PV(sub EB)[pla: -15.8 (3.8) vs pro: -19.9 (2.8)%], RCV(sub CO) [pla: +7.0 (6.7) vs pro: +10.1 (6.1)%], or BV(sub CO) [pla: -7.3 (2.3) vs pro: -7.1 (3.9)%]. In the absence of weight loss, a redistribution of body water with no net loss is implied. Hence, activation of the beta-adrenergic system did not appear to affect the hypovolemic or polycythemic responses that occurred during 3 weeks at 4300 m ALT in these subjects.

  10. Effect of nipradilol, a beta-adrenergic blocker with vasodilating activity, on oxotremorine-induced tremor in mice.

    Science.gov (United States)

    Iwata, S; Nomoto, M; Fukuda, T

    1996-10-01

    The effect of nipradilol, a nonselective beta-adrenergic receptor blocker with nitroglycerin-like vasodilating activity, on oxotremorine-induced tremor was studied in mice. General tremor in mice was elicited by 0.5 mg/kg oxotremorine. The tremor was quantified using a capacitance transducer, then analyzed by a signal processor. The strength of the tremor was expressed in "points". The point values of the tremor (mean +/- SE) in control mice for 5 mg/kg (+/-)-propranolol, 2.5 mg/kg arotinolol, 0.5 mg/kg nipradilol, 1.0 mg/kg nipradilol and 2.5 mg/kg nipradilol were 87 +/- 16, 42 +/- 6, 38 +/- 6, 99 +/- 28, 28 +/- 6 and 31 +/- 7, respectively. The strength of the tremor was reduced by all beta-blockers. Although 1.0 mg/kg nipradilol significantly reduced the tremor, further inhibition of the tremor was not obtained with dosages up to 2.5 mg/kg of the drug. In conclusion, nipradilol was effective for suppressing oxotremorine-induced tremor, as were other beta-blockers.

  11. beta-adrenergic effects on carbohydrate metabolism in the unweighted rat soleus muscle

    Science.gov (United States)

    Kirby, Christopher R.; Tischler, Marc E.

    1990-01-01

    The effect of unweighting on the response of the soleus-muscle carbohydrate metabolism to a beta-adrenergic agonist (isoproterenol) was investigated in rats that were subjected to three days of tail-cast suspension. It was found that isoproterenol promoted glycogen degradation in soleus from suspended rats to a higher degree than in weighted soleus from control rats, and had no effect in unweighted digitorum longus. However, isoproterenol did not have a greater inhibitory effect on the net uptake of tritium-labeled 2-deoxy-glucose by the unweighted soleus and that isoproterenol inhibited hexose phosphorylation less in the unweighted than in the control muscle.

  12. Potential of beta-adrenergic agonists for increasing protein deposition in ruminants in developing countries

    International Nuclear Information System (INIS)

    Berschauer, F.

    1989-01-01

    Various substituted phenylethanolamines, acting on the sympathetic nervous system, have been shown to increase protein retention (via decreased proteolysis) and reduce fat deposition (via increased lipolysis and reduced lipogenesis) in ruminants and monogastrics. Research with finishing lambs in developed countries show various beta-adrenergic agonists to improve growth rate (by 18%), feed conversion (by 12%) and carcass quality (28% increase in area of longissimus dorsi and 33% reduction in subcutaneous fat). Similar effects of beta-agonists on carcass composition of well fed cattle have been reported. The effects of beta-agonists on livestock in developing countries of the tropics have not yet been investigated, but their effects in increasing metabolic rate suggest that treated ruminants would be more vulnerable to hot environments. Beta-agonists appear to improve nitrogen retention to a greater extent in breeds with a lower potential for muscle growth. In view of this, they might be particularly effective in improving nitrogen retention in tropical breeds which have a low growth potential. This aspect, together with the response of undernourished animals in the developing countries, needs investigation. Beta-adrenergic agonists are not yet registered for use in animal production, but product licenses for some of them are expected to be granted soon. (author). 31 refs, 1 fig., 12 tabs

  13. Association between Depression, Pressure Pain Sensitivity, Stress and Autonomous Nervous System Function in Stable Ischemic Heart Disease

    DEFF Research Database (Denmark)

    Ballegaard, Søren; Bergmann, Natasha; Karpatschof, Benny

    2016-01-01

    Background: Depression and ischemic heart disease (IHD) are associated with persistent stress and autonomic nervous system (ANS) dysfunction. The former can be measured by pressure pain sensitivity (PPS) of the sternum, and the latter by the PPS and systolic blood pressure (SBP) response to a til...... in depression, reduction in persistent stress, and restoration of ANS dysfunction was only seen in non-users, suggesting a central role of beta-adrenergic receptors in the association between these factors....

  14. Beta adrenergic overstimulation impaired vascular contractility via actin-cytoskeleton disorganization in rabbit cerebral artery.

    Directory of Open Access Journals (Sweden)

    Hyoung Kyu Kim

    Full Text Available BACKGROUND AND PURPOSE: Beta adrenergic overstimulation may increase the vascular damage and stroke. However, the underlying mechanisms of beta adrenergic overstimulation in cerebrovascular dysfunctions are not well known. We investigated the possible cerebrovascular dysfunction response to isoproterenol induced beta-adrenergic overstimulation (ISO in rabbit cerebral arteries (CAs. METHODS: ISO was induced in six weeks aged male New Zealand white rabbit (0.8-1.0 kg by 7-days isoproterenol injection (300 μg/kg/day. We investigated the alteration of protein expression in ISO treated CAs using 2DE proteomics and western blot analysis. Systemic properties of 2DE proteomics result were analyzed using bioinformatics software. ROS generation and following DNA damage were assessed to evaluate deteriorative effect of ISO on CAs. Intracellular Ca(2+ level change and vascular contractile response to vasoactive drug, angiotensin II (Ang II, were assessed to evaluate functional alteration of ISO treated CAs. Ang II-induced ROS generation was assessed to evaluated involvement of ROS generation in CA contractility. RESULTS: Proteomic analysis revealed remarkably decreased expression of cytoskeleton organizing proteins (e.g. actin related protein 1A and 2, α-actin, capping protein Z beta, and vimentin and anti-oxidative stress proteins (e.g. heat shock protein 9A and stress-induced-phosphoprotein 1 in ISO-CAs. As a cause of dysregulation of actin-cytoskeleton organization, we found decreased level of RhoA and ROCK1, which are major regulators of actin-cytoskeleton organization. As functional consequences of proteomic alteration, we found the decreased transient Ca(2+ efflux and constriction response to angiotensin II and high K(+ in ISO-CAs. ISO also increased basal ROS generation and induced oxidative damage in CA; however, it decreased the Ang II-induced ROS generation rate. These results indicate that ISO disrupted actin cytoskeleton proteome network

  15. The role of stress and beta-adrenergic system in melanoma: current knowledge and possible therapeutic options.

    Science.gov (United States)

    Colucci, Roberta; Moretti, Silvia

    2016-05-01

    The aim of the present review was to discuss recent findings on the role of beta-adrenergic system in melanoma, in order to provide information on the biological responses elicited by its activation and its potential application for melanoma treatment. A literature search was performed, and evidences regarding the involvement of stress and beta-adrenergic system in cancer and melanoma were found and discussed. Our search pointed out that beta-adrenergic system is a key regulator of important biological processes involved in the onset and progression of some solid tumors. In the last decade, functional beta-adrenoceptors have been also identified on melanoma cells, as well as on their microenvironment cells. Similarly to other common cancers too, the activation of such adrenoceptors by catecholamines, usually released under stress conditions, has been found to trigger pro-tumorigenic pathways contributing to cell proliferation and motility, immune system regulation, apoptosis, epithelial-mesenchymal transition, invasion and neoangiogenesis. The biological evidences we found clarify and sustain the clinical evidences reporting the involvement of chronic stress in melanoma onset and progression. In such scenario, it is conceivable that a therapeutic approach targeting beta-adrenergic system could constitute a novel and promising strategy for melanoma treatment.

  16. Glucose-induced thermogenesis in patients with small cell lung carcinoma. The effect of acute beta-adrenergic inhibition

    DEFF Research Database (Denmark)

    Simonsen, L; Bülow, J; Tuxen, C

    1994-01-01

    Seven patients with histologically verified small cell lung carcinoma were given an oral glucose load of 75 g on two occasions to examine the effect of glucose on whole body and forearm thermogenesis with and without acute beta-adrenergic inhibition with propranolol. Whole body energy expenditure...

  17. Hemodynamic and tissue oxygenation responses to exercise and beta-adrenergic blockade in patients with hyperthyroidism.

    Science.gov (United States)

    Monachini, Maristela C; Lage, Silvia G; Ran, Miguel A N; Cardoso, Rita H A; Medeiros, Caio; Caramelli, Bruno; Sposito, Andrei C; Ramires, José A F

    2004-07-01

    Exercise-induced dyspnea is a frequent feature in patients with hyperthyroidism. Data from clinical studies to elucidate the origin of this symptom are lacking. In the current study, we examined the hemodynamic and oxygenation responses to exercise and beta-adrenergic blockade in patients with hyperthyroidism and their relationship with dyspnea. Hemodynamic studies were performed under resting conditions and after isotonic exercise in 15 patients with hyperthyroidism and 11 control subjects. Exercise was applied using a bicycle ergometer, with progressive loads. In the hyperthyroid group, measurements were repeated at rest and during supine exercise after administering 15 mg of intravenous metoprolol. End-diastolic pulmonary artery pressure and cardiac index were higher in the hyperthyroid group than in controls (18.6 +/- 5.3 vs. 11.2 +/- 4.9 mmHg; p = 0.02, and 6.0 +/- 1.7 vs. 2.8 +/- 0.5 l/min/m2; p = 0.0001, respectively). After exercise, there was an increase in end-diastolic pulmonary artery pressure in the hyperthyroid group (18.6 +/- 5.3 to 25.5 +/- 9.9 mmHg; p = 0.02), revealing impaired cardiocirculatory reserve. Pulmonary arteriolar resistance increased significantly in parallel with end-diastolic pulmonary artery pressure after drug administration, suggesting an inadequate cardiovascular response after beta blockade in patients with hyperthyroidism. We observed that functional left ventricular reserve is impaired in patients with hyperthyroidism, suggesting an explanation for the frequent symptom of dyspnea and impaired exercise tolerance. Moreover, we also suggest that beta-adrenergic blockade may adversely affect cardiovascular function in patients with hyperthyroidism.

  18. Development of serotonergic and adrenergic receptors in the rat spinal cord: effects of neonatal chemical lesions and hyperthyroidism.

    Science.gov (United States)

    Lau, C; Pylypiw, A; Ross, L L

    1985-03-01

    The sympathetic preganglionic neurons in the spinal cord receive dense serotonergic (5-HT) and catecholaminergic (CA) afferent inputs from the descending supraspinal pathways. In the rat spinal cord, the levels of these biogenic amines and their receptors are low at birth, but undergo rapid ontogenetic increases in the ensuing 2-3 postnatal weeks until the adult levels are reached. In many systems it has been shown that denervation of presynaptic neurons leads to an up-regulation of the number of postsynaptic receptors. To determine whether the 5-HT and CA receptors in the developing spinal cord are also subject to such transsynaptic regulation, we examined the ontogeny of serotonergic receptors and alpha- and beta-adrenergic receptors in thoracolumbar spinal cord of rats given neurotoxins which destroy serotonergic (5,7-dihydroxytryptamine (5,7-DHT)) or noradrenergic (6-hydroxydopamine (6-OHDA)) nerve terminals. Intracisternal administration of 5,7-DHT or 6-OHDA at 1 and 6 days of age prevented, respectively, the development of 5-HT and CA levels in the spinal cord. Rats lesioned with 5,7-DHT displayed a marked elevation of 5-HT receptors with a binding of 50% greater than controls at 1 week and a continuing increase to twice normal by 4 weeks. A similar pattern of up-regulation was also detected with the alpha-adrenergic receptor, as rats lesioned with 6-OHDA exhibited persistent increases in receptor concentration. However, in these same animals ontogeny of the beta-adrenergic receptor in the spinal cord remained virtually unaffected by the chemical lesion. In several other parts of the nervous system, it has been demonstrated that the beta-adrenergic sensitivity can be modulated by hormonal signals, particularly that of the thyroid hormones. This phenomenon was examined in the spinal cord and in confirmation with previous studies neonatal treatment of triiodothyronine (0.1 mg/kg, s.c. daily) was capable of evoking persistent increases in beta-adrenergic

  19. [Alpha but not beta-adrenergic stimulation has a positive inotropic effect associated with alkalinization of intracellular pH].

    Science.gov (United States)

    Gambassi, G; Lakatta, E G; Capogrossi, M C

    1991-01-01

    There is increasing evidence that alpha-adrenoceptors also exist in the myocardium and that an increase in force of contraction may be produced by stimulation of these sites. This positive inotropism seems to be dependent either on an increased amount of Ca++ released into the cytosol with each action potential or on increased myofilament responsiveness. In contrast, beta-adrenergic stimulation reduces the sensitivity of the contractile proteins and the positive inotropic effect is due to the activation of L-type calcium channels on the sarcolemma. We used single, isolated, enzymatically dissociated, adult rat ventricular myocytes. Cells were loaded either with the ester derivative of the Ca++ probe Indo-1 or with the intracellular pH probe Snarf-1 and at the same time we measured the contractile parameters and monitored the fluorescence as an index of intracellular calcium concentration or pH value. The single cells (bicarbonate buffer continuously gassed with O2 95%, CO2 5%, Ca++ 1.5 mM, field stimulation 0.5 Hz) were exposed to phenylephrine (50 microM) and nadolol (1 microM). Alpha-adrenergic stimulation increased twitch amplitude (delta ES = 1.93 +/- 0.77, n = 8; p less than 0.05) and showed only a slight increase in Ca++ transient. On the other end, the positive inotropic effect (delta ES = 2.84 +/- 0.86, n = 4; p less than 0.02) obtained with beta-adrenergic stimulation (isoproterenol 50 nM, bicarbonate buffer, Ca++ 0.5 mM, field stimulation 0.2 Hz) was always associated with a large increase in intracellular Ca++ concentration. Isoproterenol did not change intracellular pH (delta pH = 0.006 +/- 0.006, n = 4; NS) while phenylephrine increased it significantly (delta pH = 0.055 +/- 0.011, n = 8; p less than 0.002). Moreover, there was a statistically significant correlation between delta ES and delta pH (R2 = 0.532; p less than 0.05) when phenylephrine was present. This alkalinization as well as the increased contractility was antagonized by treatment with

  20. Human bone marrow mesenchymal stem cells secrete endocannabinoids that stimulate in vitro hematopoietic stem cell migration effectively comparable to beta-adrenergic stimulation.

    Science.gov (United States)

    Köse, Sevil; Aerts-Kaya, Fatima; Köprü, Çağla Zübeyde; Nemutlu, Emirhan; Kuşkonmaz, Barış; Karaosmanoğlu, Beren; Taşkıran, Ekim Zihni; Altun, Belgin; Uçkan Çetinkaya, Duygu; Korkusuz, Petek

    2018-01-01

    Granulocyte colony-stimulating factor (G-CSF) is a well-known hematopoietic stem cell (HSC)-mobilizing agent used in both allogeneic and autologous transplantation. However, a proportion of patients or healthy donors fail to mobilize a sufficient number of cells. New mobilization agents are therefore needed. Endocannabinoids (eCBs) are endogenous lipid mediators generated in the brain and peripheral tissues and activate the cannabinoid receptors CB1 and CB2. We suggest that eCBs may act as mobilizers of HSCs from the bone marrow (BM) under stress conditions as beta-adrenergic receptors (Adrβ). This study demonstrates that BM mesenchymal stem cells (MSCs) secrete anandamide (AEA) and 2-arachidonylglycerol (2-AG) and the peripheral blood (PB) and BM microenvironment contain AEA and 2-AG. 2-AG levels are significantly higher in PB of the G-CSF-treated group compared with BM plasma. BM mononuclear cells (MNCs) and CD34 + HSCs express CB1, CB2, and Adrβ subtypes. CD34 + HSCs had higher CB1 and CB2 receptor expression in G-CSF-untreated and G-CSF-treated groups compared with MSCs. MNCs but not MSCs expressed CB1 and CB2 receptors based on qRT-PCR and flow cytometry. AEA- and 2-AG-stimulated HSC migration was blocked by eCB receptor antagonists in an in vitro migration assay. In conclusion, components of the eCB system and their interaction with Adrβ subtypes were demonstrated on HSCs and MSCs of G-CSF-treated and G-CSF-untreated healthy donors in vitro, revealing that eCBs might be potential candidates to enhance or facilitate G-CSF-mediated HSC migration under stress conditions in a clinical setting. Copyright © 2018 ISEH – Society for Hematology and Stem Cells. Published by Elsevier Inc. All rights reserved.

  1. Metabolic consequences of beta-adrenergic receptor blockade for the acutely ischemic dog myocardium

    Energy Technology Data Exchange (ETDEWEB)

    Westera, G.; Hollander, W. den; Wall, E.E. van der; Eenige, M.J. van; Scholtalbers, S.; Visser, F.C.; Roos, J.P.

    1984-02-01

    In an experimental study in 50 dogs the myocardial uptake of free fatty acids (FFAs) after beta-blockade was determined using radioiodinated heptadecanoic acid as a metabolic tracer. All 4 beta-blockers used (metoprolol, timolol, propranolol and pindolol) lowered the uptake of FFAs in the normal canine heart. Uptake of FFAs was also diminished after coronary artery occlusion per se, but administration of beta-blockers exerted little additional influence on the uptake of FFAs. This observation was qualitatively parallelled by the uptake of /sup 201/Tl in concomitant experiments. Plasma FFA levels were increased by pindolol (non-selective with intrinsic sympathomimetic activity), not changed by metoprolol (a cardioselective betablocking agent) and lowered by timolol and propranolol (both non-selective compounds). The extent of ischemic tissue, as reflected by uptake of iodoheptadecanoic acid and /sup 201/Tl, was diminished by metoprolol but not by other beta-blockers. Regional distribution of both tracers, as shown in the endo-epicardial uptake ratios, was hardly influenced by beta-blockade, except for a small increase of /sup 201/Tl uptake in non-occluded endocardium. Uptake of /sup 201/Tl as well as of iodoheptadecanoic acid in the ischemic area was increased by metoprolol, timolol and propranolol and decreased by pindolol. We conclude that beta-blocking agents confer different effects on myocardial uptake and metabolism of FFAs which might possibly be related to their different inherent properties.

  2. Metabolic consequences of beta-adrenergic receptor blockade for the acutely ischemic dog myocardium

    International Nuclear Information System (INIS)

    Westera, G.; Hollander, W. den; Wall, E.E. van der; Eenige, M.J. van; Scholtalbers, S.; Visser, F.C.; Roos, J.P.

    1984-01-01

    In an experimental study in 50 dogs the myocardial uptake of free fatty acids (FFAs) after beta-blockade was determined using radioiodinated heptadecanoic acid as a metabolic tracer. All 4 beta-blockers used (metoprolol, timolol, propranolol and pindolol) lowered the uptake of FFAs in the normal canine heart. Uptake of FFAs was also diminished after coronary artery occlusion per se, but administration of beta-blockers exerted little additional influence on the uptake of FFAs. This observation was qualitatively parallelled by the uptake of 201 Tl in concomitant experiments. Plasma FFA levels were increased by pindolol (non-selective with intrinsic sympathomimetic activity), not changed by metoprolol (a cardioselective betablocking agent) and lowered by timolol and propranolol (both non-selective compounds). The extent of ischemic tissue, as reflected by uptake of iodoheptadecanoic acid and 201 Tl, was diminished by metoprolol but not by other beta-blockers. Regional distribution of both tracers, as shown in the endo-epicardial uptake ratios, was hardly influenced by beta-blockade, except for a small increase of 201 Tl uptake in non-occluded endocardium. Uptake of 201 Tl as well as of iodoheptadecanoic acid in the ischemic area was increased by metoprolol, timolol and propranolol and decreased by pindolol. We conclude that beta-blocking agents confer different effects on myocardial uptake and metabolism of FFAs which might possibly be related to their different inherent properties. (orig.) [de

  3. The role of alpha and beta adrenergic receptors in cortisol - induced ...

    African Journals Online (AJOL)

    OLUGBEMI OLANIYAN

    2013-09-04

    Sep 4, 2013 ... 1979; Renaud and Moon, 1980; Khani and Tayek, 2001). The hyperglycaemic response to cortisol involves metabolic actions such as glucose release from the liver as a product of glycogenolysis, increase in gluconeo- genesis and decrease in peripheral glucose utilisation. The relative contribution of each ...

  4. EMMPRIN mediates beta-adrenergic receptor-stimulated matrix metalloproteinase activity in cardiac myocytes.

    OpenAIRE

    Siwik Deborah A; Kuster Gabriela M; Brahmbhatt Jamin V; Zaidi Zaheer; Malik Julia; Ooi Henry; Ghorayeb Ghassan

    2008-01-01

    Extracellular matrix metalloproteinase inducer (EMMPRIN) expression is increased in myocardium from patients with dilated cardiomyopathy and animal models of heart failure. However little is known about the regulated expression or functional role of EMMPRIN in the myocardium. In rat cardiac cells EMMPRIN is expressed on myocytes but not endothelial cells or fibroblasts. Therefore we tested the hypothesis that EMMPRIN expression regulates matrix metalloproteinase (MMP) activity in rat ventricu...

  5. The effects of beta-adrenergic blockade on body composition in free-fed and diet-restricted rats.

    Science.gov (United States)

    Ji, L L; Doan, T D; Lennon, D L; Nagle, F J; Lardy, H A

    1987-04-01

    The effects of the non-selective beta-adrenergic blocking agent propranolol (known for its anti-lipolytic activity) on body composition were investigated in growing male rats on normal unrestricted diet (N = 7) and on diet restriction (N = 7, 95% of controls). Three animals in each group were injected i.p. with 30 mg propranolol per kg body weight (bw) dissolved in saline, 5 days/week. This dose attenuates exercising heart rate by 25% and exercise training-induced enzyme activity. The remaining animals received saline. Fat, glycogen, moisture and non-ether extractable residue were determined in the homogenized residue of the whole animal. After 9 weeks on the experimental regimen, bw gain was significantly lower in the diet restricted rats, whereas propranolol had no effect on the bw gain. The percentage of fat, moisture and non-ether extractable residue were unchanged by either propranolol or diet restriction. However, glycogen content was significantly lower in the beta-blocked rats either with or without diet restriction. These data indicated that neither beta-adrenergic blockade nor minimal diet restriction influences the percentage body fat, whereas body glycogen content is decreased under both conditions.

  6. Endogenous PKI gamma limits the duration of the anti-apoptotic effects of PTH and beta-adrenergic agonists in osteoblasts.

    Science.gov (United States)

    Chen, Xin; Song, In-Hwan; Dennis, James E; Greenfield, Edward M

    2007-05-01

    PKI gamma knockdown substantially extended the anti-apoptotic effects of PTH and beta-adrenergic agonists, whereas PKI gamma overexpression decreased these effects. Therefore, inhibition of PKI gamma activity may provide a useful co-therapy in combination with intermittent PTH or beta-adrenergic agonists for bone loss in conditions such as osteoporosis. PTH has both catabolic and anabolic effects on bone, which are primarily caused by cAMP/protein kinase A (PKA) signaling and regulation of gene expression. We previously showed that protein kinase inhibitor-gamma (PKI gamma) is required for efficient termination of cAMP/PKA signaling and gene expression after stimulation with PTH or beta-adrenergic agonists. Inhibition of osteoblast apoptosis is thought to be an important, but transient, mechanism partly responsible for the anabolic effects of intermittent PTH. Therefore, we hypothesized that endogenous PKI gamma also terminates the anti-apoptotic effect of PTH. PKI gamma knockdown by antisense transfection or siRNA was used to examine the ability of endogenous PKI gamma to modulate the anti-apoptotic effects of PTH and beta-adrenergic agonists in ROS 17/2.8 cells. Knockdown of PKI gamma substantially extended the anti-apoptotic effects of PTH, whether apoptosis was induced by etoposide or dexamethasone. In contrast, overexpression of PKI gamma decreased the anti-apoptotic effect of PTH pretreatment. This study is also the first demonstration that beta-adrenergic agonists mimic the anti-apoptotic effects of PTH in osteoblasts. Moreover, PKI gamma knockdown also substantially extended this anti-apoptotic effect of beta-adrenergic agonists. Taken together, these results show that endogenous PKI gamma limits the duration of the anti-apoptotic effects of cAMP/PKA signaling in osteoblasts. Because significant individual variability exists in the anabolic responses to PTH therapy in current clinical treatment of osteoporosis, inhibition of PKI gamma activity may provide a

  7. Effect of beta-adrenergic blockade on elevated arterial compliance and low systemic vascular resistance in cirrhosis

    DEFF Research Database (Denmark)

    Møller, Søren; Bendtsen, Flemming; Henriksen, Jens Henrik

    2001-01-01

    with beta-blockers, but the effect of this treatment on arterial compliance has not been investigated. The aim of the present study was therefore to assess the effects of propranolol on the arterial compliance of patients with cirrhosis. METHODS: Twenty patients with cirrhosis underwent a haemodynamic......) of 17.8 mmHg, and responded to beta-blocker treatment with a significant reduction in the HVPG (-16%; P beta-adrenergic blockade (1.27 versus 1.29 ml/mmHg, +2%, ns), whereas...... with beta-blockers increases small vessel (arteriolar) vascular tone towards the normal level, but does not affect the elevated compliance of the larger arteries in patients with cirrhosis....

  8. Ferulic acid with ascorbic acid synergistically extenuates the mitochondrial dysfunction during beta-adrenergic catecholamine induced cardiotoxicity in rats.

    Science.gov (United States)

    Yogeeta, Surinder Kumar; Raghavendran, Hanumantha Rao Balaji; Gnanapragasam, Arunachalam; Subhashini, Rajakannu; Devaki, Thiruvengadam

    2006-10-27

    Disruption of mitochondria and free radical mediated tissue injury have been reported during cardiotoxicity induced by isoproterenol (ISO), a beta-adrenergic catecholamine. The present study was designed to investigate the effect of the combination of ferulic acid (FA) and ascorbic acid (AA) on the mitochondrial damage in ISO induced cardiotoxicity. Induction of rats with ISO (150 mg/kg b.wt., i.p.) for 2 days resulted in a significant decrease in the activities of respiratory chain enzymes (NADH dehydrogenase and cytochrome c-oxidase), tricarboxylic acid cycle enzymes (isocitrate dehydrogenase, succinate dehydrogenase, malate dehydrogenase, alpha-ketoglutarate dehydrogenase), mitochondrial antioxidants (GPx, GST, SOD, CAT, GSH), cytochromes (b, c, c1, aa3) and in the level of mitochondrial phospholipids. A marked elevation in mitochondrial lipid peroxidation, mitochondrial levels of cholesterol, triglycerides and free fatty acids were also observed in ISO intoxicated rats. Pre-co-treatment with the combination of FA (20 mg/kg b.wt.) and AA (80 mg/kg b.wt.) orally for 6 days significantly enhanced the attenuation of these functional abnormalities and restored normal mitochondrial function when compared to individual drug treated groups. Mitigation of ISO induced biochemical and morphological changes in mitochondria were more pronounced with a combination of FA and AA rather than the individual drug treated groups. Transmission electron microscopic observations also correlated with these biochemical parameters. Hence, these findings demonstrate the synergistic ameliorative potential of FA and AA on mitochondrial function during beta-adrenergic catecholamine induced cardiotoxicity and associated oxidative stress in rats.

  9. Rapid stress-induced transcriptomic changes in the brain depend on beta-adrenergic signaling.

    Science.gov (United States)

    Roszkowski, Martin; Manuella, Francesca; von Ziegler, Lukas; Durán-Pacheco, Gonzalo; Moreau, Jean-Luc; Mansuy, Isabelle M; Bohacek, Johannes

    2016-08-01

    Acute exposure to stressful experiences can rapidly increase anxiety and cause neuropsychiatric disorders. The effects of stress result in part from the release of neurotransmitters and hormones, which regulate gene expression in different brain regions. The fast neuroendocrine response to stress is largely mediated by norepinephrine (NE) and corticotropin releasing hormone (CRH), followed by a slower and more sustained release of corticosterone. While corticosterone is an important regulator of gene expression, it is not clear which stress-signals contribute to the rapid regulation of gene expression observed immediately after stress exposure. Here, we demonstrate in mice that 45 min after an acute swim stress challenge, large changes in gene expression occur across the transcriptome in the hippocampus, a region sensitive to the effects of stress. We identify multiple candidate genes that are rapidly and transiently altered in both males and females. Using a pharmacological approach, we show that most of these rapidly induced genes are regulated by NE through β-adrenergic receptor signaling. We find that CRH and corticosterone can also contribute to rapid changes in gene expression, although these effects appear to be restricted to fewer genes. These results newly reveal a widespread impact of NE on the transcriptome and identify novel genes associated with stress and adrenergic signaling. Copyright © 2016 Elsevier Ltd. All rights reserved.

  10. Enhanced basal contractility but reduced excitation-contraction coupling efficiency and beta-adrenergic reserve of hearts with increased Cav1.2 activity.

    Science.gov (United States)

    Tang, Mingxin; Zhang, Xiaoying; Li, Yingxin; Guan, Yinzheng; Ai, Xiaojie; Szeto, Christopher; Nakayama, Hiroyuki; Zhang, Hongyu; Ge, Shuping; Molkentin, Jeffery D; Houser, Steven R; Chen, Xiongwen

    2010-08-01

    Cardiac remodeling during heart failure development induces a significant increase in the activity of the L-type Ca(2+) channel (Cav1.2). However, the effects of enhanced Cav1.2 activity on myocyte excitation-contraction (E-C) coupling, cardiac contractility, and its regulation by the beta-adrenergic system are not clear. To recapitulate the increased Cav1.2 activity, a double transgenic (DTG) mouse model overexpressing the Cavbeta2a subunit in a cardiac-specific and inducible manner was established. We studied cardiac (in vivo) and myocyte (in vitro) contractility at baseline and upon beta-adrenergic stimulation. E-C coupling efficiency was evaluated in isolated myocytes as well. The following results were found: 1) in DTG myocytes, L-type Ca(2+) current (I(Ca,L)) density, myocyte fractional shortening (FS), peak Ca(2+) transients, and sarcoplasmic reticulum (SR) Ca(2+) content (caffeine-induced Ca(2+) transient peak) were significantly increased (by 100.8%, 48.8%, 49.8%, and 46.8%, respectively); and 2) cardiac contractility evaluated with echocardiography [ejection fraction (EF) and (FS)] and invasive intra-left ventricular pressure (maximum dP/dt and -dP/dt) measurements were significantly greater in DTG mice than in control mice. However, 1) the cardiac contractility (EF, FS, dP/dt, and -dP/dt)-enhancing effect of the beta-adrenergic agonist isoproterenol (2 microg/g body wt ip) was significantly reduced in DTG mice, which could be attributed to the loss of beta-adrenergic stimulation on contraction, Ca(2+) transients, I(Ca,L), and SR Ca(2+) content in DTG myocytes; and 2) E-C couplng efficiency was significantly lower in DTG myocytes. In conclusion, increasing Cav1.2 activity by promoting its high-activity mode enhances cardiac contractility but decreases E-C coupling efficiency and the adrenergic reserve of the heart.

  11. Therapeutic effects of arotinolol, a beta-adrenergic blocker, on tremor in MPTP-induced parkinsonian monkeys.

    Science.gov (United States)

    Kuno, S; Mizuta, E; Nishida, J; Takechi, M

    1992-10-01

    The effect of arotinolol, a peripherally acting beta-adrenergic-blocking agent, on postural or kinetic tremor was studied in monkeys with 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-induced parkinsonism. Male cynomolgus monkeys (Macaca fascicularis) were treated with three injections of MPTP hydrochloride (0.3 mg/kg, i.v.) at an interval of 3-4 days, followed by several injections of the same dose every 7 days. Four monkeys with persistent parkinsonian symptoms manifested for greater than 1 year were used. The animals developed mild to moderate degrees of postural or kinetic tremor, and their motor activity was reduced. Arotinolol (20-30 mg/kg, s.c.) significantly suppressed postural tremor in a dose-dependent manner. Propranolol (20-30 mg/kg) was also effective in suppressing the tremor. However, the application of propranolol induced emesis, whereas arotinolol had no adverse effects. These results suggest that arotinolol is a useful adjunct to dopaminergic therapy for tremor in Parkinson's disease.

  12. Human adipose tissue blood flow during prolonged exercise, III. Effect of beta-adrenergic blockade, nicotinic acid and glucose infusion

    DEFF Research Database (Denmark)

    Bülow, J

    1981-01-01

    acid, during acute i.v. beta-adrenergic blockade by propranolol, and during continuous i.v. infusion of glucose. The most pronounced lipid mobilization and utilization during work was seen in the control experiments where ATBF rose 3-fold on average from the initial rest period to the third hour...... of work. No increase in lipolysis and no increase in ATBF were found when lipolysis was blocked by nicotinic acid (0.3 g/h). Propranolol treatment (0.15 mg/kg) reduced lipolysis and nearly abolished the increase in ATBF during exercise. Intravenous administration of glucose (about 0.25 g/min) did......Subcutaneous adipose tissue blood flow (ATBF) was measured in six male subjects by the 133Xe-washout technique during 3-4 h of exercise at a work load corresponding to an oxygen uptake of about 1.71/min. The measurements were done during control conditions, during blockade of lipolysis by nicotinic...

  13. Effect of age on upregulation of the cardiac adrenergic beta receptors

    International Nuclear Information System (INIS)

    Tumer, N.; Houck, W.T.; Roberts, J.

    1990-01-01

    Radioligand binding studies were performed to determine whether upregulation of postjunctional beta receptors occurs in sympathectomized hearts of aged animals. Fischer 344 rats 6, 12, and 24 months of age (n = 10) were used in these experiments. To produce sympathectomy, rats were injected with 6-hydroxydopamine hydrobromide (6-OHDA; 2 x 50 mg/kg iv) on days 1 and 8; the animals were decapitated on day 15. The depletion of norepinephrine in the heart was about 86% in each age group. 125I-Iodopindolol (IPIN), a beta adrenergic receptor antagonist, was employed to determine the affinity and total number of beta adrenergic receptors in the ventricles of the rat heart. The maximal number of binding sites (Bmax) was significantly elevated by 37%, 48%, and 50% in hearts from sympathectomized 6-, 12-, and 24-month-old rats, respectively. These results indicate that beta receptor mechanisms in older hearts can respond to procedures that cause upregulation of the beta adrenergic receptors

  14. Involvement of beta 3-adrenoceptor in altered beta-adrenergic response in senescent heart: role of nitric oxide synthase 1-derived nitric oxide.

    Science.gov (United States)

    Birenbaum, Aurélie; Tesse, Angela; Loyer, Xavier; Michelet, Pierre; Andriantsitohaina, Ramaroson; Heymes, Christophe; Riou, Bruno; Amour, Julien

    2008-12-01

    In senescent heart, beta-adrenergic response is altered in parallel with beta1- and beta2-adrenoceptor down-regulation. A negative inotropic effect of beta3-adrenoceptor could be involved. In this study, the authors tested the hypothesis that beta3-adrenoceptor plays a role in beta-adrenergic dysfunction in senescent heart. beta-Adrenergic responses were investigated in vivo (echocardiography-dobutamine, electron paramagnetic resonance) and in vitro (isolated left ventricular papillary muscle, electron paramagnetic resonance) in young adult (3-month-old) and senescent (24-month-old) rats. Nitric oxide synthase (NOS) immunolabeling (confocal microscopy), nitric oxide production (electron paramagnetic resonance) and beta-adrenoceptor Western blots were performed in vitro. Data are mean percentages of baseline +/- SD. An impaired positive inotropic effect (isoproterenol) was confirmed in senescent hearts in vivo (117 +/- 23 vs. 162 +/- 16%; P < 0.05) and in vitro (127 +/- 10 vs. 179 +/- 15%; P < 0.05). In the young adult group, the positive inotropic effect was not significantly modified by the nonselective NOS inhibitor N-nitro-L-arginine methylester (L-NAME; 183 +/- 19%), the selective NOS1 inhibitor vinyl-L-N-5(1-imino-3-butenyl)-L-ornithine (L-VNIO; 172 +/- 13%), or the selective NOS2 inhibitor 1400W (183 +/- 19%). In the senescent group, in parallel with beta3-adrenoceptor up-regulation and increased nitric oxide production, the positive inotropic effect was partially restored by L-NAME (151 +/- 8%; P < 0.05) and L-VNIO (149 +/- 7%; P < 0.05) but not by 1400W (132 +/- 11%; not significant). The positive inotropic effect induced by dibutyryl-cyclic adenosine monophosphate was decreased in the senescent group with the specific beta3-adrenoceptor agonist BRL 37344 (167 +/- 10 vs. 142 +/- 10%; P < 0.05). NOS1 and NOS2 were significantly up-regulated in the senescent rat. In senescent cardiomyopathy, beta3-adrenoceptor overexpression plays an important role in the

  15. Beta adrenergic blockade decreases the immunomodulatory effects of social disruption stress.

    Science.gov (United States)

    Hanke, M L; Powell, N D; Stiner, L M; Bailey, M T; Sheridan, J F

    2012-10-01

    During physiological or psychological stress, catecholamines produced by the sympathetic nervous system (SNS) regulate the immune system. Previous studies report that the activation of β-adrenergic receptors (βARs) mediates the actions of catecholamines and increases pro-inflammatory cytokine production in a number of different cell types. The impact of the SNS on the immune modulation of social defeat has not been examined. The following studies were designed to determine whether SNS activation during social disruption stress (SDR) influences anxiety-like behavior as well as the activation, priming, and glucocorticoid resistance of splenocytes after social stress. CD-1 mice were exposed to one, three, or six cycles of SDR and HPLC analysis of the plasma and spleen revealed an increase in catecholamines. After six cycles of SDR the open field test was used to measure behaviors characteristic of anxiety and indicated that the social defeat induced increase in anxiety-like behavior was blocked by pre-treatment with the β-adrenergic antagonist propranolol. Pre-treatment with the β-adrenergic antagonist propranolol did not significantly alter corticosterone levels indicating no difference in activation of the hypothalamic-pituitary-adrenal axis. In addition to anxiety-like behavior the SDR induced splenomegaly and increase in plasma IL-6, TNFα, and MCP-1 were each reversed by pre-treatment with propranolol. Furthermore, flow cytometric analysis of cells from propranolol pretreated mice reduced the SDR-induced increase in the percentage of CD11b(+) splenic macrophages and significantly decreased the expression of TLR2, TLR4, and CD86 on the surface of these cells. In addition, supernatants from 18h LPS-stimulated ex vivo cultures of splenocytes from propranolol-treated SDR mice contained less IL-6. Likewise propranolol pre-treatment abrogated the glucocorticoid insensitivity of CD11b(+) cells ex vivo when compared to splenocytes from SDR vehicle-treated mice

  16. Beta adrenergic blockade decreases the immunomodulatory effects of social disruption stress☆

    Science.gov (United States)

    Hanke, M.L.; Powell, N.D.; Stiner, L.M.; Bailey, M.T.; Sheridan, J.F.

    2012-01-01

    During physiological or psychological stress, catecholamines produced by the sympathetic nervous system (SNS) regulate the immune system. Previous studies report that the activation of β-adrenergic receptors (βARs) mediates the actions of catecholamines and increases pro-inflammatory cytokine production in a number of different cell types. The impact of the SNS on the immune modulation of social defeat has not been examined. The following studies were designed to determine whether SNS activation during social disruption stress (SDR) influences anxiety-like behavior as well as the activation, priming, and glucocorticoid resistance of splenocytes after social stress. CD-1 mice were exposed to one, three, or six cycles of SDR and HPLC analysis of the plasma and spleen revealed an increase in catecholamines. After six cycles of SDR the open field test was used to measure behaviors characteristic of anxiety and indicated that the social defeat induced increase in anxiety-like behavior was blocked by pre-treatment with the β-adrenergic antagonist propranolol. Pre-treatment with the β-adrenergic antagonist propranolol did not significantly alter corticosterone levels indicating no difference in activation of the hypothalamic–pituitary–adrenal axis. In addition to anxiety-like behavior the SDR induced splenomegaly and increase in plasma IL-6, TNFα, and MCP-1 were each reversed by pre-treatment with propranolol. Furthermore, flow cytometric analysis of cells from propranolol pretreated mice reduced the SDR-induced increase in the percentage of CD11b+ splenic macrophages and significantly decreased the expression of TLR2, TLR4, and CD86 on the surface of these cells. In addition, supernatants from 18 h LPS-stimulated ex vivo cultures of splenocytes from propranolol-treated SDR mice contained less IL-6. Likewise propranolol pre-treatment abrogated the glucocorticoid insensitivity of CD11b+ cells ex vivo when compared to splenocytes from SDR vehicle-treated mice

  17. The role of adrenergic receptors in nicotine-induced hyperglycemia ...

    African Journals Online (AJOL)

    The role of adrenergic receptors in nicotine-induced hyperglycaemia has not been well studied in amphibians. Thus, this study investigates the effects of alpha and beta adrenergic receptor blockers in nicotine-induced hyperglycaemia in the common African toad Bufo regularis. Toads fasted for 24 h were anaesthetized with ...

  18. Enhanced Noradrenergic Activity Potentiates Fear Memory Consolidation and Reconsolidation by Differentially Recruiting alpha1- and beta-Adrenergic Receptors

    Science.gov (United States)

    Gazarini, Lucas; Stern, Cristina A. Jark; Carobrez, Antonio P.; Bertoglio, Leandro J.

    2013-01-01

    Consolidation and reconsolidation are phases of memory stabilization that diverge slightly. Noradrenaline is known to influence both processes, but the relative contribution of alpha1- and beta-adrenoceptors is unclear. The present study sought to investigate this matter by comparing their recruitment to consolidate and/or reconsolidate a…

  19. Association of beta-adrenergic receptor polymorphisms and mortality in carvedilol-treated chronic heart-failure patients

    DEFF Research Database (Denmark)

    Petersen, Morten; Andersen, Jon T; Hjelvang, Brian R

    2011-01-01

    WHAT IS ALREADY KNOWN ABOUT THIS SUBJECT • Chronic heart failure (HF) is a syndrome with increasing prevalence. Though mortality is still high, the introduction of ß-adrenoceptor blockers for its treatment has improved survival considerably. • As is the case for all medical treatment, not all...... patients benefit from ß-adrenoceptor blocker treatment, and stratifying patients to different ß-adrenoceptor blockers by the use of pharmacogenomics might be of great value in improving HF therapy. • Previous studies have shown that the two single nucleotide polymorphisms (SNPs) ADRB1 Arg389Gly and ADRB2...... Gln27Glu interact with the ß-adrenoceptor blockers metoprolol and carvedilol, respectively. These interactions have led to stratified responses with regard to surrogate parameters, e.g. left ventricular ejection fraction (LVEF), pulse and blood pressure. • Several studies have failed to show...

  20. Enhancement of striatum-dependent memory by conditioned fear is mediated by beta-adrenergic receptors in the basolateral amygdala

    Directory of Open Access Journals (Sweden)

    Travis D. Goode

    2016-06-01

    Full Text Available Emotional arousal can have a profound impact on various learning and memory processes. For example, unconditioned emotional stimuli (e.g., predator odor or anxiogenic drugs enhance dorsolateral striatum (DLS-dependent habit memory. These effects critically depend on a modulatory role of the basolateral complex of the amygdala (BLA. Recent work indicates that, like unconditioned emotional stimuli, exposure to an aversive conditioned stimulus (CS (i.e., a tone previously paired with shock can also enhance consolidation of DLS-dependent habit memory. The present experiments examined whether noradrenergic activity, particularly within the BLA, is required for a fear CS to enhance habit memory consolidation. First, rats underwent a fear conditioning procedure in which a tone CS was paired with an aversive unconditioned stimulus. Over the course of the next five days, rats received training in a DLS-dependent water plus-maze task, in which rats were reinforced to make a consistent body-turn response to reach a hidden escape platform. Immediately after training on days 1–3, rats received post-training systemic (Experiment 1 or intra-BLA (Experiment 2 administration of the β-adrenoreceptor antagonist, propranolol. Immediately after drug administration, half of the rats were re-exposed to the tone CS in the conditioning context (without shock. Post-training CS exposure enhanced consolidation of habit memory in vehicle-treated rats, and this effect was blocked by peripheral (Experiment 1 or intra-BLA (Experiment 2 propranolol administration. The present findings reveal that noradrenergic activity within the BLA is critical for the enhancement of DLS-dependent habit memory as a result of exposure to conditioned emotional stimuli.

  1. Post-Retrieval [beta]-Adrenergic Receptor Blockade: Effects on Extinction and Reconsolidation of Cocaine-Cue Memories

    Science.gov (United States)

    Fricks-Gleason, Ashley N.; Marshall, John F.

    2008-01-01

    Contexts and discrete cues associated with drug-taking are often responsible for relapse among addicts. Animal models have shown that interference with the reconsolidation of drug-cue memories can reduce seeking of drugs or drug-paired stimuli. One such model is conditioned place preference (CPP) in which an animal is trained to associate a…

  2. Beta-adrenergic control of phosphatidylcholine synthesis by transmethylation in hepatocytes from juvenile, adult and adrenalectomized rats.

    Science.gov (United States)

    Marin-Cao, D; Alvarez Chiva, V; Mato, J M

    1983-01-01

    Changes in isoprenaline-sensitive phospholipid methyltransferase were studied in hepatocytes isolated from juvenile, mature and adrenalectomized rats. Isoprenaline produced greater stimulation of cyclic AMP accumulation in juvenile and mature adrenalectomized rats than in mature animals. Similarly, isoprenaline stimulated phospholipid methyltransferase in juvenile and mature adrenalectomized rats but had no effect in mature animals. Isoprenaline-mediated activation of phospholipid methyltransferase in adrenalectomized rats was time- and dose-dependent. In hepatocytes isolated from adrenalectomized rats incubated with [Me-3H]methionine or [3H]-ethanolamine the addition of isoprenaline increased the amount of radioactivity incorporated into phosphatidylcholine. The activation by isoprenaline of phospholipid methyltransferase was abolished by the beta-blocker propranolol and by insulin. These results indicate that rat liver the occupation of functional beta-receptors causes a stimulation of phospholipid methylation. It is suggested that, as reported previously, cyclic AMP activates phospholipid methyltransferase. PMID:6320796

  3. Characterisation of the Redox Sensitive NMDA Receptor

    KAUST Repository

    Alzahrani, Ohood

    2016-05-01

    Glucose entry into the brain and its subsequent metabolism to L-lactate, regulated by astrocytes, plays a major role in synaptic plasticity and memory formation. A recent study has shown that L-lactate produced by the brain upon stimulation of glycolysis, and glycogen-derived L-lactate from astrocytes and its transport into neurons, is crucial for memory formation. A recent study revealed the molecular mechanisms that underlie the role of L-lactate in neuronal plasticity and long-term memory formation. L-lactate was shown to induce a cascade of molecular events via modulation of redox-sensitive N-Methyl-D-aspartate (NMDA) receptor activity that was mimicked by nicotinamide adenine dinucleotide hydride (NADH) co-enzyme. This indicated that changes in cellular redox state, following L-lactate transport inside the cells and its subsequent metabolism, production of NADH, and favouring a reduced state are the key effects of L-lactate. Therefore, we are investigating the role of L-lactate in modulating NMDA receptor function via redox modulatory sites. Accordingly, crucial redox-sensitive cysteine residues, Cys320 and Cys87, of the NR2A NMDA receptor subunit are mutated using site-directed mutation, transfected, and expressed in HEK293 cells. This cellular system will then be used to characterise and monitor its activity upon Llactate stimulation, compared to the wild type. This will be achieved by calcium imaging, using fluorescent microscopy. Our data shows that L-lactate potentiated NMDA receptor activity and increased intracellular calcium influx in NR1/NR2A wild type compared to the control condition (WT NR1/NR2A perfused with (1μM) glutamate and (1μM) glycine agonist only), showing faster response initiation and slower decay rate of the calcium signal to the baseline. Additionally, stimulating with L-lactate associated with greater numbers of cells having high fluorescent intensity (peak amplitude) compared to the control. Furthermore, L-lactate rescued the

  4. Role of adrenergic receptors in the caffeine-induced increase in ...

    African Journals Online (AJOL)

    The present study was designed to investigate the effects of alpha and beta adrenergic receptor blockers on caffeine-induced increase in canine hindlimb glucose uptake. The study was carried out on fasted male anaesthetized dogs divided into five groups (5dogs per group). Each dog was given a bolus injection of normal ...

  5. Effects of acute beta-adrenergic antagonism on verbal problem solving in autism spectrum disorder and exploration of treatment response markers.

    Science.gov (United States)

    Zamzow, Rachel M; Ferguson, Bradley J; Ragsdale, Alexandra S; Lewis, Morgan L; Beversdorf, David Q

    2017-08-01

    Autism spectrum disorder (ASD) is characterized by impairments in social communication as well as restricted, repetitive behaviors. Evidence suggests that some individuals with ASD have cognitive impairments related to weak central coherence and hyperrestricted processing. Reducing noradrenergic activity may improve aspects of network processing and thus improve cognitive abilities, such as verbal problem solving, in individuals with ASD. The present pilot study explores the effects of acute administration of the beta-adrenergic antagonist propranolol on verbal problem solving in adults and adolescents with ASD. In a within-subject crossover-design, 20 participants with ASD received a single dose of propranolol or placebo on one of two sessions in a double-blinded, counterbalanced manner. Verbal problem solving was assessed via an anagram task. Baseline measurements of autonomic nervous system functioning were obtained, and anxiety was assessed at baseline and following drug administration. Participants solved the anagrams more quickly in the propranolol condition, as compared to the placebo condition, suggesting a potential cognitive benefit of this agent. Additionally, we observed a negative linear relationship between response to propranolol on the anagram task and two measures of baseline autonomic activity, as well as a positive linear relationship between drug response and baseline anxiety. These relationships propose potential markers for treatment response, as propranolol influences both autonomic functioning and anxiety. Further investigation is needed to expand on the present single-dose psychopharmacological challenge and explore the observed effects of propranolol in a serial-dose setting.

  6. Time dependent changes in myocardial norepinephrine concentration and adrenergic receptor density following X-irradiation of the rat heart

    NARCIS (Netherlands)

    Franken, N. A.; van der Laarse, A.; Bosker, F. J.; Reynart, I. W.; van Ravels, F. J.; Strootman, E.; Wondergem, J.

    1992-01-01

    The hearts of 9 to 12-weeks-old Sprague-Dawley rats were locally irradiated with a single dose of 20 Gy. The effects on myocardial norepinephrine concentrations and on alpha-adrenergic and beta-adrenergic receptor densities was examined up to 16 months post-treatment. Myocardial norepinephrine

  7. Beta 2-adrenergic receptors are colocalized and coregulated with whisker barrels in rat somatosensory cortex

    International Nuclear Information System (INIS)

    Vos, P.; Kaufmann, D.; Hand, P.J.; Wolfe, B.B.

    1990-01-01

    Autoradiography has been used to visualize independently the subtypes of beta-adrenergic receptors in rat somatosensory cortex. Beta 2-adrenergic receptors, but not beta 1-adrenergic receptors colocalize with whisker barrels in this tissue. Thus, each whisker sends a specific multisynaptic pathway to the somatosensory cortex that can be histochemically visualized and only one subtype of beta-adrenergic receptor is specifically associated with this cortical representation. Additionally, neonatal lesion of any or all of the whisker follicles results in loss of the corresponding barrel(s) as shown by histochemical markers. This loss is paralleled by a similar loss in the organization of beta 2-adrenergic receptors in the somatosensory cortex. Other results indicate that these beta 2-adrenergic receptors are not involved in moment-to-moment signal transmission in this pathway and, additionally, are not involved in a gross way in the development of whisker-barrel array

  8. Overexpression Myocardial Inducible Nitric Oxide Synthase Exacerbates Cardiac Dysfunction and Beta-Adrenergic Desensitization in Experimental Hypothyroidism☆,☆☆

    Science.gov (United States)

    Shao, Qun; Cheng, Heng-Jie; Callahan, Michael F.; Kitzman, Dalane W; Li, Wei-Min; Cheng, Che Ping

    2015-01-01

    Background Altered nitric oxide synthase (NOS) has been implicated in the pathophysiology of heart failure (HF). Recent evidence links hypothyroidism to the pathology of HF. However, the precise mechanisms are incompletely understood. The alterations and functional effects of cardiac NOS in hypothyroidism are unknown. We tested the hypothesis that hypothyroidism increases cadiomyocyte inducible NOS (iNOS) expression, which plays an important role in hypothyroidism-induced depression of cardiomyocyte contractile properties, [Ca2+]i transient ([Ca2+]iT), and β-adrenergic hyporesponsiveness. Methods and Results We simultaneously evaluated LV functional performance and compared myocyte three NOS, β-adrenergic receptors (AR) and SERCA2a expressions and assessed cardiomyocyte contractile and [Ca2+]iT responses to β-AR stimulation with and without pretreatment of iNOS inhibitor (1400W, 10−5 mol/L) in 26 controls and 26 rats with hypothyroidism induced by methimazole (~30 mg/kg/day for 8 weeks in the drinking water). Compared with controls, in hypothyroidism, total serum T3 and T4 were significantly reduced followed by significantly decreased LV contractility (EES) with increased LV time constant of relaxation. These LV abnormalities were accompanied by concomitant significant decreases in myocyte contraction (dL/dtmax), relaxation (dR/dtmax), and [Ca2+]iT. In hypothyroidism, isoproterenol (10−8 M) produced significantly smaller increases in dL/dtmax, dR/dtmax and [Ca2+]iT. These changes were associated with decreased β1-AR and SERCA2a, but significantly increased iNOS. Moreover, only in hypothyroidism, pretreatment with iNOS inhibitor significantly improved basal and isoproterenol-stimulated myocyte contraction, relaxation and [Ca2+]iT. Conclusions Hypothyroidism produces intrinsic defects of LV myocyte force-generating capacity and relaxation with β-AR desensitization. Up-regulation of cadiomyocyte iNOS may promote progressive cardiac dysfunction in

  9. Calmodulin affects sensitization of Drosophila melanogaster odorant receptors

    Directory of Open Access Journals (Sweden)

    Latha eMukunda

    2016-02-01

    Full Text Available Flying insects have developed a remarkably sensitive olfactory system to detect faint and turbulent odor traces. This ability is linked to the olfactory receptors class of odorant receptors (ORs, occurring exclusively in winged insects. ORs form heteromeric complexes of an odorant specific receptor protein (OrX and a highly conserved co-receptor protein (Orco. The ORs form ligand gated ion channels that are tuned by intracellular signaling systems. Repetitive subthreshold odor stimulation of olfactory sensory neurons sensitizes insect ORs. This OR sensitization process requires Orco activity. In the present study we first asked whether OR sensitization can be monitored with heterologously expressed OR proteins. Using electrophysiological and calcium imaging methods we demonstrate that D. melanogaster OR proteins expressed in CHO cells show sensitization upon repeated weak stimulation. This was found for OR channels formed by Orco as well as by Or22a or Or56a and Orco. Moreover, we show that inhibition of calmodulin (CaM action on OR proteins, expressed in CHO cells, abolishes any sensitization. Finally, we investigated the sensitization phenomenon using an ex vivo preparation of olfactory sensory neurons (OSNs expressing Or22a inside the fly’s antenna. Using calcium imaging, we observed sensitization in the dendrites as well as in the soma. Inhibition of calmodulin with W7 disrupted the sensitization within the outer dendritic shaft, whereas the sensitization remained in the other OSN compartments. Taken together, our results suggest that CaM action is involved in sensitizing the OR complex and that this mechanisms accounts for the sensitization in the outer dendrites, whereas further mechanisms contribute to the sensitization observed in the other OSN compartments. The use of heterologously expressed OR proteins appears to be suitable for further investigations on the mechanistic basis of OR sensitization, while investigations on native

  10. Conversion of Short-Term Potentiation to Long-Term Potentiation in Mouse CA1 by Coactivation of [beta]-Adrenergic and Muscarinic Receptors

    Science.gov (United States)

    Connor, Steven A.; Maity, Sabyasachi; Roy, Birbickram; Ali, Declan W.; Nguyen, Peter V.

    2012-01-01

    Encoding new information requires dynamic changes in synaptic strength. The brain can boost synaptic plasticity through the secretion of neuromodulatory substances, including acetylcholine and noradrenaline. Considerable effort has focused on elucidating how neuromodulatory substances alter synaptic properties. However, determination of the…

  11. Functional response of white rats isolated heart to the stimulation of adrenergic receptors after gamma-irradiation in low doses

    International Nuclear Information System (INIS)

    Antonenko, A.N.; Lobanok, L.M.

    1999-01-01

    It was investigated the effects of acute gamma-irradiation on bio mechanical activity of rats heart isolated by Langendorf's method in early and delayed terms after exposure to gamma-rays. Intra ventricle pressure and the rate of its growth, volumetric rate of coronal flow, frequency of heart contraction were registered. Stimulation of alpha-adrenergic receptors was conducted by means of specific agonist mesatone and stimulation of beta-adrenergic receptors was made by means of isoprenaline. The study has shown that acute irradiation of rats caused the decrease of both contractile ability and relaxation of myocardium in a 10 days after exposure. In delayed period bio mechanical activity of isolated heart was restored. Functional response of heart to the stimulation of alpha- and beta-adrenergic receptors was decreased in all terms of investigation

  12. Autonomic receptors in urinary tract: Sex and age differences

    International Nuclear Information System (INIS)

    Latifpour, J.; Kondo, S.; O'Hollaren, B.; Morita, T.; Weiss, R.M.

    1990-01-01

    As age and sex affect the function of the lower urinary tract, we studied the characteristics of adrenergic and cholinergic receptors in various parts of lower urinary tract smooth muscle of young (6 months) and old (4 1/2-5 years) male and female rabbits. Saturation experiments performed with [3H]prazosin, [3H]yohimbine, [3H]dihydroalprenolol and [3H]quinuclidinyl benzylate in rabbit bladder base, bladder dome and urethra indicate the presence of regional, sex- and age-related differences in the density of alpha-1, alpha-2, and beta adrenergic and muscarinic cholinergic receptors. Alpha-2 adrenergic receptor density is considerably higher in the female than in the male urethra of both age groups, whereas the higher density of beta adrenergic receptors in the female than in the male bladder base is observed only in the younger animals. The density of muscarinic receptors is higher in bladder dome than in bladder base or urethra in young rabbits of both sexes. In the old animals, the density of muscarinic receptors in bladder base increases to the level observed in bladder dome. Inhibition experiments with selective adrenergic agonists and antagonists indicate that the pharmacological profiles of alpha-2 adrenergic receptors in the urethra and beta adrenergic receptors in the bladder dome and bladder base are similar in both sexes and at both ages. Beta-2 adrenergic receptors are shown to be predominant in bladder base and bladder dome of rabbits. Parallel studies in rabbit urethra, adult rat cortex and neonatal rat lung show that the urethral alpha-2 adrenergic receptors are of the alpha-2A subtype

  13. The octopamine receptor Octβ2R regulates ovulation in Drosophila melanogaster.

    Directory of Open Access Journals (Sweden)

    Junghwa Lim

    Full Text Available Oviposition is induced upon mating in most insects. Ovulation is a primary step in oviposition, representing an important target to control insect pests and vectors, but limited information is available on the underlying mechanism. Here we report that the beta adrenergic-like octopamine receptor Octβ2R serves as a key signaling molecule for ovulation and recruits protein kinase A and Ca(2+/calmodulin-sensitive kinase II as downstream effectors for this activity. We found that the octβ2r homozygous mutant females are sterile. They displayed normal courtship, copulation, sperm storage and post-mating rejection behavior but were unable to lay eggs. We have previously shown that octopamine neurons in the abdominal ganglion innervate the oviduct epithelium. Consistently, restored expression of Octβ2R in oviduct epithelial cells was sufficient to reinstate ovulation and full fecundity in the octβ2r mutant females, demonstrating that the oviduct epithelium is a major site of Octβ2R's function in oviposition. We also found that overexpression of the protein kinase A catalytic subunit or Ca(2+/calmodulin-sensitive protein kinase II led to partial rescue of octβ2r's sterility. This suggests that Octβ2R activates cAMP as well as additional effectors including Ca(2+/calmodulin-sensitive protein kinase II for oviposition. All three known beta adrenergic-like octopamine receptors stimulate cAMP production in vitro. Octβ1R, when ectopically expressed in the octβ2r's oviduct epithelium, fully reinstated ovulation and fecundity. Ectopically expressed Octβ3R, on the other hand, partly restored ovulation and fecundity while OAMB-K3 and OAMB-AS that increase Ca(2+ levels yielded partial rescue of ovulation but not fecundity deficit. These observations suggest that Octβ2R have distinct signaling capacities in vivo and activate multiple signaling pathways to induce egg laying. The findings reported here narrow the knowledge gap and offer insight into novel

  14. Hair receptor sensitivity to changes in laminar boundary layer shape

    International Nuclear Information System (INIS)

    Dickinson, B T

    2010-01-01

    Biologists have shown that bat wings contain distributed arrays of flow-sensitive hair receptors. The hair receptors are hypothesized to feedback information on airflows over the bat wing for enhanced stability or maneuverability during flight. Here, we study the geometric specialization of hair-like structures for the detection of changes in boundary layer velocity profiles (shapes). A quasi-steady model that relates the flow velocity profile incident on the longitudinal axis of a hair to the resultant moment and shear force at the hair base is developed. The hair length relative to the boundary layer momentum thickness that maximizes the resultant moment and shear-force sensitivity to changes in boundary layer shape is determined. The sensitivity of the resultant moment and shear force is shown to be highly dependent on hair length. Hairs that linearly taper to a point are shown to provide greater output sensitivity than hairs of uniform cross-section. On an order of magnitude basis, the computed optimal hair lengths are in agreement with the range of hair receptor lengths measured on individual bat species. These results support the hypothesis that bats use hair receptors for detecting changes in boundary layer shape and provide geometric guidelines for artificial hair sensor design and application.

  15. The allosteric site regulates the voltage sensitivity of muscarinic receptors.

    Science.gov (United States)

    Hoppe, Anika; Marti-Solano, Maria; Drabek, Matthäus; Bünemann, Moritz; Kolb, Peter; Rinne, Andreas

    2018-01-01

    Muscarinic receptors (M-Rs) for acetylcholine (ACh) belong to the class A of G protein-coupled receptors. M-Rs are activated by orthosteric agonists that bind to a specific site buried in the M-R transmembrane helix bundle. In the active conformation, receptor function can be modulated either by allosteric modulators, which bind to the extracellular receptor surface or by the membrane potential via an unknown mechanism. Here, we compared the modulation of M 1 -Rs and M 3 -Rs induced by changes in voltage to their allosteric modulation by chemical compounds. We quantified changes in receptor signaling in single HEK 293 cells with a FRET biosensor for the G q protein cycle. In the presence of ACh, M 1 -R signaling was potentiated by voltage, similarly to positive allosteric modulation by benzyl quinolone carboxylic acid. Conversely, signaling of M 3 -R was attenuated by voltage or the negative allosteric modulator gallamine. Because the orthosteric site is highly conserved among M-Rs, but allosteric sites vary, we constructed "allosteric site" M 3 /M 1 -R chimeras and analyzed their voltage dependencies. Exchanging the entire allosteric sites eliminated the voltage sensitivity of ACh responses for both receptors, but did not affect their modulation by allosteric compounds. Furthermore, a point mutation in M 3 -Rs caused functional uncoupling of the allosteric and orthosteric sites and abolished voltage dependence. Molecular dynamics simulations of the receptor variants indicated a subtype-specific crosstalk between both sites, involving the conserved tyrosine lid structure of the orthosteric site. This molecular crosstalk leads to receptor subtype-specific voltage effects. Copyright © 2017 Elsevier Inc. All rights reserved.

  16. P2X4: A fast and sensitive purinergic receptor

    Directory of Open Access Journals (Sweden)

    Jaanus Suurväli

    2017-10-01

    Full Text Available Extracellular nucleotides have been recognized as important mediators of activation, triggering multiple responses via plasma membrane receptors known as P2 receptors. P2 receptors comprise P2X ionotropic receptors and G protein-coupled P2Y receptors. P2X receptors are expressed in many tissues, where they are involved in a number of functions including synaptic transmission, muscle contraction, platelet aggregation, inflammation, macrophage activation, differentiation and proliferation, neuropathic and inflammatory pain. P2X4 is one of the most sensitive purinergic receptors (at nanomolar ATP concentrations, about one thousand times more than the archetypal P2X7. P2X4 is widely expressed in central and peripheral neurons, in microglia, and also found in various epithelial tissues and endothelial cells. It localizes on the plasma membrane, but also in intracellular compartments. P2X4 is preferentially localized in lysosomes, where it is protected from proteolysis by its glycosylation. High ATP concentration in the lysosomes does not activate P2X4 at low pH; P2X4 gets activated by intra-lysosomal ATP only in its fully dissociated tetra-anionic form, when the pH increases to 7.4. Thus, P2X4 is functioning as a Ca2+-channel after the fusion of late endosomes and lysosomes. P2X4 modulates major neurotransmitter systems and regulates alcohol-induced responses in microglia. P2X4 is one of the key receptors mediating neuropathic pain. However, injury-induced upregulation of P2X4 expression is gender dependent and plays a key role in pain difference between males and females. P2X4 is also involved in inflammation. Extracellular ATP being a pro-inflammatory molecule, P2X4 can trigger inflammation in response to high ATP release. It is therefore involved in multiple pathologies, like post-ischemic inflammation, rheumatoid arthritis, airways inflammation in asthma, neurodegenerative diseases and even metabolic syndrome. Although P2X4 remains poorly

  17. Beta-adrenergic control of plasma glucose and free fatty acid levels in the air-breathing African catfish Clarias gariepinus Burchell 1822

    NARCIS (Netherlands)

    van Heeswijk, JCF; Vianen, GJ; van den Thillart, GEEJM; Zaagsma, J

    In several water-breathing fish species, P-adrenergic receptor stimulation by noradrenaline leads to a decrease in plasma free fatty acid (FFA) levels, as opposed to an increase in air-breathing mammals. We hypothesised that this change in adrenergic control is related to the mode of breathing.

  18. Hypoxia increases pulmonary arterial thromboxane receptor internalization independent of receptor sensitization.

    Science.gov (United States)

    Fediuk, J; Sikarwar, A S; Lizotte, P P; Hinton, M; Nolette, N; Dakshinamurti, S

    2015-02-01

    Persistent Pulmonary Hypertension of the Newborn (PPHN) is characterized by sustained vasospasm and an increased thromboxane:prostacyclin ratio. Thromboxane (TP) receptors signal via Gαq to mobilize IP3 and Ca(2+), causing pulmonary arterial constriction. We have previously reported increased TP internalization in hypoxic pulmonary arterial (PA) myocytes. Serum-deprived PA myocytes were grown in normoxia (NM) or hypoxia (HM) for 72 h. TP localization was visualized in agonist-naïve and -challenged NM and HM by immunocytochemistry. Pathways for agonist-induced TP receptor internalization were determined by inhibiting caveolin- or clathrin-mediated endocytosis, and caveolar fractionation. Roles of actin and tubulin in TP receptor internalization were assessed using inhibitors of tubulin, actin-stabilizing or -destabilizing agents. PKA, PKC or GRK activation and inhibition were used to determine the kinase responsible for post-agonist receptor internalization. Agonist-naïve HM had decreased cell surface TP, and greater TP internalization after agonist challenge. TP protein did not sort with caveolin-rich fractions. Inhibition of clathrin prevented TP internalization. Both actin-stabilizing and -destabilizing agents prevented TP endocytosis in NM, while normalizing TP internalization in HM. Velocity of TP internalization was unaffected by PKA activity, but PKC activation normalized TP receptor internalization in HM. GRK inhibition had no effect. We conclude that in hypoxic myocytes, TP is internalized faster and to a greater extent than in normoxic controls. Internalization of the agonist-challenged TP requires clathrin, dynamic actin and is sensitive to PKC activity. TP receptor trafficking and signaling in hypoxia are pivotal to understanding increased vasoconstrictor sensitivity. Copyright © 2014 Elsevier Ltd. All rights reserved.

  19. Hormone-sensitive lipase serine phosphorylation and glycerol exchange across skeletal muscle in lean and obese subjects

    DEFF Research Database (Denmark)

    Jocken, Johan We; Roepstorff, Carsten; Goossens, Gijs H.

    2008-01-01

    from the vastus lateralis muscle before and during ISO to investigate hormone-sensitive lipase (HSL) protein expression and serine phosphorylation. Results: Baseline total glycerol release across the forearm was significantly blunted in obese compared with lean subjects (P=0.045). This was accompanied......Objective: Increased intramuscular triacylglycerol (IMTG) storage is a characteristic of the obese insulin resistant state. We aimed to investigate whether a blunted fasting or beta-adrenergically mediated lipolysis contributes to this increased IMTG storage in obesity. Research design and Methods......: Forearm skeletal muscle (SM) lipolysis was investigated in thirteen lean and ten obese men using [(2)H(5)]-glycerol combined with the measurement of arterio-venous differences before and during beta-adrenergic stimulation using the non-selective beta-agonist isoprenaline (ISO). Muscle biopsies were taken...

  20. Skeletal muscle beta-receptors and isoproterenol-stimulated vasodilation in canine heart failure

    International Nuclear Information System (INIS)

    Frey, M.J.; Lanoce, V.; Molinoff, P.B.; Wilson, J.R.

    1989-01-01

    To investigate whether heart failure alters beta-adrenergic receptors on skeletal muscle and its associated vasculature, the density of beta-adrenergic receptors, isoproterenol-stimulated adenylate cyclase activity, and coupling of the guanine nucleotide-binding regulatory protein were compared in 18 control dogs and 16 dogs with heart failure induced by 5-8 wk of ventricular pacing at 260 beats/min. Hindlimb vascular responses to isoproterenol were compared in eight controls and eight of the dogs with heart failure. In dogs with heart failure, the density of beta-receptors on skeletal muscle was reduced in both gastrocnemius (control: 50 +/- 5; heart failure: 33 +/- 8 fmol/mg of protein) and semitendinosus muscle (control: 43 +/- 9; heart failure: 27 +/- 9 fmol/mg of protein, both P less than 0.05). Receptor coupling to the ternary complex, as determined by isoproterenol competition curves with and without guanosine 5'-triphosphate (GTP), was unchanged. Isoproterenol-stimulated adenylate cyclase activity was significantly decreased in semitendinosus muscle (control: 52.4 +/- 4.6; heart failure: 36.5 +/- 9.5 pmol.mg-1.min-1; P less than 0.05) and tended to be decreased in gastrocnemius muscle (control: 40.1 +/- 8.5; heart failure: 33.5 +/- 4.5 pmol.mg-1.min-1; P = NS). Isoproterenol-induced hindlimb vasodilation was not significantly different in controls and in dogs with heart failure. These findings suggest that heart failure causes downregulation of skeletal muscle beta-adrenergic receptors, probably due to receptor exposure to elevated catecholamine levels, but does not reduce beta-receptor-mediated vasodilation in muscle

  1. Intrapulmonary receptors in the Tegu lizard: I. Sensitivity to CO2.

    Science.gov (United States)

    Feede, M R; Kuhlmann, W D; Scheid, P

    1977-02-01

    Single unit vagal recordings from intrapulmonary receptors were obtained in decerebrate, paralyzed lizards both during pump ventilation and during unidirectional ventilation on the cannulated, sack-shaped lung. Two types of receptors were identified: (1) CO2-receptors, which increased their discharge frequency as intrapulmonary CO2 concentration decreased but were not sensitive to stretch of the lung. (2) Mechanoreceptors, which rapidly increased discharge frequency when the lung was stretched. These receptors' CO2 sensitivity varied. Lungs of lizards thus appeared to possess both CO2 receptors, which have functional characteristics similar to those in birds, and mechanoreceptors with properties similar to stretch receptors in mammals.

  2. GABA(A)-benzodiazepine receptor complex sensitivity in 5-HT(1A) receptor knockout mice on a 129/Sv background.

    NARCIS (Netherlands)

    Pattij, T.; Groenink, L.; Oosting, R.S.; Gugten, J. van der; Maes, R.A.A.; Olivier, B.

    2002-01-01

    Previous studies in 5-HT(1A) receptor knockout (1AKO) mice on a mixed Swiss Websterx129/Sv (SWx129/Sv) and a pure 129/Sv genetic background suggest a differential gamma-aminobutyric acid (GABA(A))-benzodiazepine receptor complex sensitivity in both strains, independent from the anxious phenotype. To

  3. Neurohumoral activation in heart failure: the role of adrenergic receptors

    Directory of Open Access Journals (Sweden)

    Patricia C. Brum

    2006-09-01

    Full Text Available Heart failure (HF is a common endpoint for many forms of cardiovascular disease and a significant cause of morbidity and mortality. The development of end-stage HF often involves an initial insult to the myocardium that reduces cardiac output and leads to a compensatory increase in sympathetic nervous system activity. Acutely, the sympathetic hyperactivity through the activation of beta-adrenergic receptors increases heart rate and cardiac contractility, which compensate for decreased cardiac output. However, chronic exposure of the heart to elevated levels of catecholamines released from sympathetic nerve terminals and the adrenal gland may lead to further pathologic changes in the heart, resulting in continued elevation of sympathetic tone and a progressive deterioration in cardiac function. On a molecular level, altered beta-adrenergic receptor signaling plays a pivotal role in the genesis and progression of HF. beta-adrenergic receptor number and function are decreased, and downstream mechanisms are altered. In this review we will present an overview of the normal beta-adrenergic receptor pathway in the heart and the consequences of sustained adrenergic activation in HF. The myopathic potential of individual components of the adrenergic signaling will be discussed through the results of research performed in genetic modified animals. Finally, we will discuss the potential clinical impact of beta-adrenergic receptor gene polymorphisms for better understanding the progression of HF.A insuficiência cardíaca (IC é a via final comum da maioria das doenças cardiovasculares e uma das maiores causas de morbi-mortalidade. O desenvolvimento do estágio final da IC freqüentemente envolve um insulto inicial do miocárdio, reduzindo o débito cardíaco e levando ao aumento compensatório da atividade do sistema nervoso simpático (SNS. Existem evidências de que apesar da exposição aguda ser benéfica, exposições crônicas a elevadas concentra

  4. Phospholipid environment alters hormone-sensitivity of the purified insulin receptor kinase.

    OpenAIRE

    Lewis, R E; Czech, M P

    1987-01-01

    Insulin receptor kinase, affinity-purified by adsorption and elution from immobilized insulin, is stimulated 2-3-fold by insulin in detergent solution. Reconstitution of the receptor kinase into leaky vesicles containing phosphatidylcholine and phosphatidylethanolamine (1:1, w/w) by detergent removal on Sephadex G-50 results in the complete loss of receptor kinase sensitivity to activation by insulin. Insulin receptors in these vesicles also exhibit an increase in their apparent affinity for ...

  5. Beta adrenergic blockade reduces utilitarian judgement

    Science.gov (United States)

    Sylvia, Terbeck; Guy, Kahane; Sarah, McTavish; Julian, Savulescu; Neil, Levy; Miles, Hewstone; Cowen, Philip J.

    2013-01-01

    Noradrenergic pathways are involved in mediating the central and peripheral effects of physiological arousal. The aim of the present study was to investigate the role of noradrenergic transmission in moral decision-making. We studied the effects in healthy volunteers of propranolol (a noradrenergic beta-adrenoceptor antagonist) on moral judgement in a set of moral dilemmas pitting utilitarian outcomes (e.g., saving five lives) against highly aversive harmful actions (e.g., killing an innocent person) in a double-blind, placebo-controlled, parallel group design. Propranolol (40 mg orally) significantly reduced heart rate, but had no effect on self-reported mood. Importantly, propranolol made participants more likely to judge harmful actions as morally unacceptable, but only in dilemmas where harms were ‘up close and personal’. In addition, longer response times for such personal dilemmas were only found for the placebo group. Finally, judgments in personal dilemmas by the propranolol group were more decisive. These findings indicate that noradrenergic pathways play a role in responses to moral dilemmas, in line with recent work implicating emotion in moral decision-making. However, contrary to current theorising, these findings also suggest that aversion to harming is not driven by emotional arousal. Our findings are also of significant practical interest given that propranolol is a widely used drug in different settings, and is currently being considered as a potential treatment for post-traumatic stress disorder in military and rescue service personnel. PMID:23085134

  6. Laminar pattern of cholinergic and adrenergic receptors in rat visual cortex using quantitative receptor autoradiography

    International Nuclear Information System (INIS)

    Schliebs, R.; Walch, C.

    1989-01-01

    The laminar distribution of muscarinic acetylcholine receptors, including the M1-receptor subtype, of beta-adrenergic receptors, and noradrenaline uptake sites, was studied in the adult rat visual, frontal, somatosensory and motor cortex, using quantitative receptor autoradiography. In the visual cortex, the highest density of muscarinic acetylcholine receptors was found in layer I. From layer II/III to layer V binding decreases continueously reaching a constant binding level in layers V and VI. This laminar pattern of muscarinic receptor density differs somewhat from that observed in the non-visual cortical regions examined: layer II/III contained the highest receptor density followed by layer I and IV: lowest density was found in layer V and VI. The binding profile of the muscarinic cholinergic M1-subtype through the visual cortex shows a peak in cortical layer II and in the upper part of layer VI, whereas in the non-visual cortical regions cited the binding level was high in layer II/III, moderate in layer I and IV, and low in layer VI. Layers I to IV of the visual cortex contained the highest beta-adrenergic receptor densities, whereas only low binding levels were observed in the deeper layers. A similar laminar distribution was found also in the frontal, somatosensory and motor cortex. The density of noradrenaline uptake sites was high in all layers of the cortical regions studied, but with noradrenaline uptake sites somewhat more concentrated in the superficial layers than in deeper ones. The distinct laminar pattern of cholinergic and noradrenergic receptor sites indicates a different role for acetylcholine and noradrenaline in the functional anatomy of the cerebral cortex, and in particular, the visual cortex. (author)

  7. Laminar pattern of cholinergic and adrenergic receptors in rat visual cortex using quantitative receptor autoradiography

    Energy Technology Data Exchange (ETDEWEB)

    Schliebs, R; Walch, C [Leipzig Univ. (German Democratic Republic). Bereich Medizin; Stewart, M G [Open Univ., Milton Keynes (UK)

    1989-01-01

    The laminar distribution of muscarinic acetylcholine receptors, including the M1-receptor subtype, of beta-adrenergic receptors, and noradrenaline uptake sites, was studied in the adult rat visual, frontal, somatosensory and motor cortex, using quantitative receptor autoradiography. In the visual cortex, the highest density of muscarinic acetylcholine receptors was found in layer I. From layer II/III to layer V binding decreases continueously reaching a constant binding level in layers V and VI. This laminar pattern of muscarinic receptor density differs somewhat from that observed in the non-visual cortical regions examined: layer II/III contained the highest receptor density followed by layer I and IV: lowest density was found in layer V and VI. The binding profile of the muscarinic cholinergic M1-subtype through the visual cortex shows a peak in cortical layer II and in the upper part of layer VI, whereas in the non-visual cortical regions cited the binding level was high in layer II/III, moderate in layer I and IV, and low in layer VI. Layers I to IV of the visual cortex contained the highest beta-adrenergic receptor densities, whereas only low binding levels were observed in the deeper layers. A similar laminar distribution was found also in the frontal, somatosensory and motor cortex. The density of noradrenaline uptake sites was high in all layers of the cortical regions studied, but with noradrenaline uptake sites somewhat more concentrated in the superficial layers than in deeper ones. The distinct laminar pattern of cholinergic and noradrenergic receptor sites indicates a different role for acetylcholine and noradrenaline in the functional anatomy of the cerebral cortex, and in particular, the visual cortex. (author).

  8. Engineering of Olfactory Receptor OlfCc1 for Directed Ligand Sensitivity

    OpenAIRE

    Berke, Allison Paige

    2013-01-01

    Abstract Engineering of Olfactory Receptor OlfCc1 for Directed Ligand Sensitivityby Allison Paige Berke Joint Doctor of Philosophywith the University of California San FranciscoUniversity of California, Berkeley Professor Song Li, ChairDue to structural similarity, OlfCc1and its mammalian analogue V2R2 are hypothesized to respond to amino acid ligands in a calcium-mediated fashion. By analyzing receptor structure and making targeted mutations, the specificity and sensitivity of the receptor s...

  9. A glycine residue essential for high ivermectin sensitivity in Cys-loop ion channel receptors

    DEFF Research Database (Denmark)

    Lynagh, Timothy; Lynch, Joseph W.

    2010-01-01

    Ivermectin exerts its anthelmintic effect by activating nematode Cys-loop glutamate-gated receptors. Here we show that a glycine residue at a specific transmembrane domain location is essential for high ivermectin sensitivity in both glycine- and glutamate-gated Cys-loop receptors. We also show...

  10. Increased amphetamine-induced locomotor activity, sensitization, and accumbal dopamine release in M5 muscarinic receptor knockout mice

    DEFF Research Database (Denmark)

    Schmidt, Lene S; Miller, Anthony D; Lester, Deranda B

    2010-01-01

    showed that M(5) receptor knockout (M (5) (-/-) ) mice are less sensitive to the reinforcing properties of addictive drugs. MATERIALS AND METHODS: Here, we investigate the role of M(5) receptors in the effects of amphetamine and cocaine on locomotor activity, locomotor sensitization, and dopamine release......-induced hyperactivity and dopamine release as well as amphetamine sensitization are enhanced in mice lacking the M(5) receptor. These results support the concept that the M(5) receptor modulates effects of addictive drugs....

  11. Combined sodium ion sensitivity in agonist binding and internalization of vasopressin V1b receptors.

    Science.gov (United States)

    Koshimizu, Taka-Aki; Kashiwazaki, Aki; Taniguchi, Junichi

    2016-05-03

    Reducing Na(+) in the extracellular environment may lead to two beneficial effects for increasing agonist binding to cell surface G-protein coupled receptors (GPCRs): reduction of Na(+)-mediated binding block and reduce of receptor internalization. However, such combined effects have not been explored. We used Chinese Hamster Ovary cells expressing vasopressin V1b receptors as a model to explore Na(+) sensitivity in agonist binding and receptor internalization. Under basal conditions, a large fraction of V1b receptors is located intracellularly, and a small fraction is in the plasma membrane. Decreases in external Na(+) increased cell surface [(3)H]AVP binding and decreased receptor internalization. Substitution of Na(+) by Cs(+) or NH4(+) inhibited agonist binding. To suppress receptor internalization, the concentration of NaCl, but not of CsCl, had to be less than 50 mM, due to the high sensitivity of the internalization machinery to Na(+) over Cs(+). Iso-osmotic supplementation of glucose or NH4Cl maintained internalization of the V1b receptor, even in a low-NaCl environment. Moreover, iodide ions, which acted as a counter anion, inhibited V1b agonist binding. In summary, we found external ionic conditions that could increase the presence of high-affinity state receptors at the cell surface with minimum internalization during agonist stimulations.

  12. A Cholesterol-Sensitive Regulator of the Androgen Receptor

    Science.gov (United States)

    2010-07-01

    Oncogene (2010) 29, 3745–3747; doi:10.1038/onc.2010.132; published online 3 May 2010 Cholesterol is a sterol that serves as a metabolic precursor to other...bioactive sterols , such as nuclear receptor ligands, and also has a major role in plasma membrane structure. Cholesterol and long- chain...cholesterol synthesis (these drugs are generically termed ‘statins’), have been reported to inhibit cancer incidence or progres- sion in some studies. Although

  13. A dose–response study of the effects of pre-test administration of beta-adrenergic receptor antagonist propranolol on the learning of active place avoidance, a spatial cognition task, in rats

    Czech Academy of Sciences Publication Activity Database

    Stuchlík, Aleš; Petrásek, Tomáš; Valeš, Karel

    2009-01-01

    Roč. 200, č. 1 (2009), s. 144-149 ISSN 0166-4328 R&D Projects: GA ČR(CZ) GA309/07/0341; GA ČR(CZ) GA309/09/0286 Institutional research plan: CEZ:AV0Z50110509 Keywords : propranolol * learning * spatial memory Subject RIV: FH - Neuro logy Impact factor: 3.220, year: 2009

  14. The role of the anterodorsal thalami nuclei in the regulation of adrenal medullary function, beta-adrenergic cardiac receptors and anxiety responses in maternally deprived rats under stressful conditions.

    Science.gov (United States)

    Suárez, M M; Rivarola, M A; Molina, S M; Levin, G M; Enders, J; Paglini, P

    2004-09-01

    Maternal separation can interfere with growth and development of the brain and represents a significant risk factor for adult psychopathology. In rodents, prolonged separation from the mother affects the behavioral and endocrine responses to stress for the lifetime of the animal. Limbic structures such as the anterodorsal thalamic nuclei (ADTN) play an important role in the control of neuroendocrine and sympathetic-adrenal function. In view of these findings we hypothesized that the function of the ADTN may be affected in an animal model of maternal deprivation. To test this hypothesis female rats were isolated 4.5 h daily, during the first 3 weeks of life and tested as adults. We evaluated plasma epinephrine (E) and norepinephrine (NE), cardiac adrenoreceptors and anxiety responses after maternal deprivation and variable chronic stress (VCS) in ADTN-lesioned rats. Thirty days after ADTN lesion, in non-maternally deprived rats basal plasma NE concentration was greater and cardiac beta-adrenoreceptor density was lower than that in the sham-lesioned group. Maternal deprivation induced a significant increase in basal plasma NE concentration, which was greater in lesioned rats, and cardiac beta-adrenoreceptor density was decreased in lesioned rats. After VCS plasma catecholamine concentration was much greater in non-maternally deprived rats than in maternally-deprived rats; cardiac beta-adrenoreceptor density was decreased by VCS in both maternally-deprived and non-deprived rats, but more so in non-deprived rats, and further decreased by the ADTN lesion. In the plus maze test, the number of open arm entries was greater in the maternally deprived and in the stressed rats. Thus, sympathetic-adrenal medullary activation produced by VCS was much greater in non-deprived rats, and was linked to a down regulation of myocardial beta-adrenoceptors. The ADTN are not responsible for the reduced catecholamine responses to stress in maternally-deprived rats. Maternal deprivation or chronic stress also induced a long term anxiolytic effect, which was also not affected by ADTN lesion.

  15. GABA-A Receptors Mediate Tonic Inhibition and Neurosteroid Sensitivity in the Brain.

    Science.gov (United States)

    Reddy, Doodipala Samba

    2018-01-01

    Neurosteroids like allopregnanolone (AP) are positive allosteric modulators of synaptic and extrasynaptic GABA-A receptors. AP and related neurosteroids exhibit a greater potency for δ-containing extrasynaptic receptors. The δGABA-A receptors, which are expressed extrasynaptically in the dentate gyrus and other regions, contribute to tonic inhibition, promoting network shunting as well as reducing seizure susceptibility. Levels of endogenous neurosteroids fluctuate with ovarian cycle. Natural and synthetic neurosteroids maximally potentiate tonic inhibition in the hippocampus and provide robust protection against a variety of limbic seizures and status epilepticus. Recently, a consensus neurosteroid pharmacophore model has been proposed at extrasynaptic δGABA-A receptors based on structure-activity relationship for functional activation of tonic currents and seizure protection. Aside from anticonvulsant actions, neurosteroids have been found to be powerful anxiolytic and anesthetic agents. Neurosteroids and Zn 2+ have preferential affinity for δ-containing receptors. Thus, Zn 2+ can prevent neurosteroid activation of extrasynaptic δGABA-A receptor-mediated tonic inhibition. Recently, we demonstrated that Zn 2+ selectively inhibits extrasynaptic δGABA-A receptors and thereby fully prevents AP activation of tonic inhibition and seizure protection. We confirmed that neurosteroids exhibit greater sensitivity at extrasynaptic δGABA-A receptors. Overall, extrasynaptic GABA-A receptors are primary mediators of tonic inhibition in the brain and play a key role in the pathophysiology of epilepsy and other neurological disorders. © 2018 Elsevier Inc. All rights reserved.

  16. Sensitivity of C6 Glioma Cells Carrying the Human Poliovirus Receptor to Oncolytic Polioviruses.

    Science.gov (United States)

    Sosnovtseva, A O; Lipatova, A V; Grinenko, N F; Baklaushev, V P; Chumakov, P M; Chekhonin, V P

    2016-10-01

    A humanized line of rat C6 glioma cells expressing human poliovirus receptor was obtained and tested for the sensitivity to oncolytic effects of vaccine strains of type 1, 2, and 3 polioviruses. Presentation of the poliovirus receptor on the surface of C6 glioma cells was shown to be a necessary condition for the interaction of cells with polioviruses, but insufficient for complete poliovirus oncolysis.

  17. Diagnostic sensitivity of two radio receptor assays (TRAK Assay and TRAK Dyno human) for the detection of TSH receptor antibodies

    International Nuclear Information System (INIS)

    Paunkovic, N.; Paunkovic, J.

    2003-01-01

    Radio receptor assays for the detection of TSH receptor antibodies in serum are typically based on binding the competition of TSH-R antibodies and 125I -labelled-TSH for membrane preparation of thyrocytes (TBII tests). The sensitivity of the available tests utilizing porcine cell membranes was found to be around 80%. A new test (TRAK Dyno human, BRAHMS) utilizes human recombinant TSH receptor and human standard material that is supposed to improve the performance of the test. We have compared the results of these two assays. The sensitivity of the TRAK Assay tested in 356 patients with untreated Grave's disease was found to be 85%, and 97.5% for TRAK Dyno human in 111 newly diagnosed patients. Both tests were performed from the same serum specimen for 60 of the investigated patients. The TRAK Assay was positive in 50 patients (83.2%) and TRAK Dyno human in 59 patients (98.3%). The specificity of the new radio receptor assay was also improved. (author)

  18. Functional Characterization of a Novel Class of Morantel-Sensitive Acetylcholine Receptors in Nematodes.

    Directory of Open Access Journals (Sweden)

    Elise Courtot

    2015-12-01

    Full Text Available Acetylcholine receptors are pentameric ligand-gated channels involved in excitatory neuro-transmission in both vertebrates and invertebrates. In nematodes, they represent major targets for cholinergic agonist or antagonist anthelmintic drugs. Despite the large diversity of acetylcholine-receptor subunit genes present in nematodes, only a few receptor subtypes have been characterized so far. Interestingly, parasitic nematodes affecting human or animal health possess two closely related members of this gene family, acr-26 and acr-27 that are essentially absent in free-living or plant parasitic species. Using the pathogenic parasitic nematode of ruminants, Haemonchus contortus, as a model, we found that Hco-ACR-26 and Hco-ACR-27 are co-expressed in body muscle cells. We demonstrated that co-expression of Hco-ACR-26 and Hco-ACR-27 in Xenopus laevis oocytes led to the functional expression of an acetylcholine-receptor highly sensitive to the anthelmintics morantel and pyrantel. Importantly we also reported that ACR-26 and ACR-27, from the distantly related parasitic nematode of horses, Parascaris equorum, also formed a functional acetylcholine-receptor highly sensitive to these two drugs. In Caenorhabditis elegans, a free-living model nematode, we demonstrated that heterologous expression of the H. contortus and P. equorum receptors drastically increased its sensitivity to morantel and pyrantel, mirroring the pharmacological properties observed in Xenopus oocytes. Our results are the first to describe significant molecular determinants of a novel class of nematode body wall muscle AChR.

  19. Functional Characterization of a Novel Class of Morantel-Sensitive Acetylcholine Receptors in Nematodes

    Science.gov (United States)

    Courtot, Elise; Charvet, Claude L.; Beech, Robin N.; Harmache, Abdallah; Wolstenholme, Adrian J.; Holden-Dye, Lindy; O’Connor, Vincent; Peineau, Nicolas; Woods, Debra J.; Neveu, Cedric

    2015-01-01

    Acetylcholine receptors are pentameric ligand–gated channels involved in excitatory neuro-transmission in both vertebrates and invertebrates. In nematodes, they represent major targets for cholinergic agonist or antagonist anthelmintic drugs. Despite the large diversity of acetylcholine-receptor subunit genes present in nematodes, only a few receptor subtypes have been characterized so far. Interestingly, parasitic nematodes affecting human or animal health possess two closely related members of this gene family, acr-26 and acr-27 that are essentially absent in free-living or plant parasitic species. Using the pathogenic parasitic nematode of ruminants, Haemonchus contortus, as a model, we found that Hco-ACR-26 and Hco-ACR-27 are co-expressed in body muscle cells. We demonstrated that co-expression of Hco-ACR-26 and Hco-ACR-27 in Xenopus laevis oocytes led to the functional expression of an acetylcholine-receptor highly sensitive to the anthelmintics morantel and pyrantel. Importantly we also reported that ACR-26 and ACR-27, from the distantly related parasitic nematode of horses, Parascaris equorum, also formed a functional acetylcholine-receptor highly sensitive to these two drugs. In Caenorhabditis elegans, a free-living model nematode, we demonstrated that heterologous expression of the H. contortus and P. equorum receptors drastically increased its sensitivity to morantel and pyrantel, mirroring the pharmacological properties observed in Xenopus oocytes. Our results are the first to describe significant molecular determinants of a novel class of nematode body wall muscle AChR. PMID:26625142

  20. Artificial sensory hairs based on the flow sensitive receptor hairs of crickets

    NARCIS (Netherlands)

    Dijkstra, Marcel; van Baar, J.J.J.; Wiegerink, Remco J.; Lammerink, Theodorus S.J.; de Boer, J.H.; Krijnen, Gijsbertus J.M.

    2005-01-01

    This paper presents the modelling, design, fabrication and characterization of flow sensors based on the wind-receptor hairs of crickets. Cricket sensory hairs are highly sensitive to drag-forces exerted on the hair shaft. Artificial sensory hairs have been realized in SU-8 on suspended SixNy

  1. A highly sensitive quantitative cytosensor technique for the identification of receptor ligands in tissue extracts.

    Science.gov (United States)

    Lenkei, Z; Beaudet, A; Chartrel, N; De Mota, N; Irinopoulou, T; Braun, B; Vaudry, H; Llorens-Cortes, C

    2000-11-01

    Because G-protein-coupled receptors (GPCRs) constitute excellent putative therapeutic targets, functional characterization of orphan GPCRs through identification of their endogenous ligands has great potential for drug discovery. We propose here a novel single cell-based assay for identification of these ligands. This assay involves (a) fluorescent tagging of the GPCR, (b) expression of the tagged receptor in a heterologous expression system, (c) incubation of the transfected cells with fractions purified from tissue extracts, and (d) imaging of ligand-induced receptor internalization by confocal microscopy coupled to digital image quantification. We tested this approach in CHO cells stably expressing the NT1 neurotensin receptor fused to EGFP (enhanced green fluorescent protein), in which neurotensin promoted internalization of the NT1-EGFP receptor in a dose-dependent fashion (EC(50) = 0.98 nM). Similarly, four of 120 consecutive reversed-phase HPLC fractions of frog brain extracts promoted internalization of the NT1-EGFP receptor. The same four fractions selectively contained neurotensin, an endogenous ligand of the NT1 receptor, as detected by radioimmunoassay and inositol phosphate production. The present internalization assay provides a highly specific quantitative cytosensor technique with sensitivity in the nanomolar range that should prove useful for the identification of putative natural and synthetic ligands for GPCRs.

  2. Behavioral Sensitization to the Disinhibition Effect of Ethanol Requires the Dopamine/Ecdysone Receptor in Drosophila

    Directory of Open Access Journals (Sweden)

    Gissel P. Aranda

    2017-08-01

    Full Text Available Male flies under the influence of ethanol display disinhibited courtship, which is augmented with repeated ethanol exposures. We have previously shown that dopamine is important for this type of ethanol-induced behavioral sensitization but the underlying mechanism is unknown. Here we report that DopEcR, an insect G-protein coupled receptor that binds to dopamine and steroid hormone ecdysone, is a major receptor mediating courtship sensitization. Upon daily ethanol administration, dumb and damb mutant males defective in D1 (dDA1/DopR1 and D5 (DAMB/DopR2 dopamine receptors, respectively, showed normal courtship sensitization; however, the DopEcR-deficient der males exhibited greatly diminished sensitization. der mutant males nevertheless developed normal tolerance to the sedative effect of ethanol, indicating a selective function of DopEcR in chronic ethanol-associated behavioral plasticity. DopEcR plays a physiological role in behavioral sensitization since courtship sensitization in der males was reinstated when DopEcR expression was induced during adulthood but not during development. When examined for the DopEcR’s functional site, the der mutant’s sensitization phenotype was fully rescued by restored DopEcR expression in the mushroom body (MB αβ and γ neurons. Consistently, we observed DopEcR immunoreactivity in the MB calyx and lobes in the wild-type Canton-S brain, which was barely detectable in the der brain. Behavioral sensitization to the locomotor-stimulant effect has been serving as a model for ethanol abuse and addiction. This is the first report elucidating the mechanism underlying behavioral sensitization to another stimulant effect of ethanol.

  3. Immunoautoradiographic analysis of epidermal growth factor receptors: a sensitive method for the in situ identification of receptor proteins and for studying receptor specificity

    International Nuclear Information System (INIS)

    Fernandez-Pol, J.A.

    1982-01-01

    The use of an immunoautoradiographic system for the detection and analysis of epidermal growth factor (EGF) receptors in human epidermoid carcinoma A-431 cells is reported. By utilizing this technique, the interaction between EGF and its membrane receptor in A-431 cells can be rapidly visualized. The procedure is simple, rapid, and very sensitive, and it provides conclusive evidence that the 150K dalton protein is the receptor fo EGF in A-431 cells. In summary, the immunoautoradiographic procedure brings to the analysis of hormone rceptor proteins the power that the radioimmunoassay technique has brought to the analysis of hormones. Thus, this assay system is potentially applicable in a wide spectrum in many fields of nuclear medicine and biology

  4. Recent Duplication and Functional Divergence in Parasitic Nematode Levamisole-Sensitive Acetylcholine Receptors.

    Directory of Open Access Journals (Sweden)

    Thomas B Duguet

    2016-07-01

    Full Text Available Helminth parasites rely on fast-synaptic transmission in their neuromusculature to experience the outside world and respond to it. Acetylcholine plays a pivotal role in this and its receptors are targeted by a wide variety of both natural and synthetic compounds used in human health and for the control of parasitic disease. The model, Caenorhabditis elegans is characterized by a large number of acetylcholine receptor subunit genes, a feature shared across the nematodes. This dynamic family is characterized by both gene duplication and loss between species. The pentameric levamisole-sensitive acetylcholine receptor has been characterized from C. elegans, comprised of five different subunits. More recently, cognate receptors have been reconstituted from multiple parasitic nematodes that are found to vary in subunit composition. In order to understand the implications of receptor composition change and the origins of potentially novel drug targets, we investigated a specific example of subunit duplication based on analysis of genome data for 25 species from the 50 helminth genome initiative. We found multiple independent duplications of the unc-29, acetylcholine receptor subunit, where codon substitution rate analysis identified positive, directional selection acting on amino acid positions associated with subunit assembly. Characterization of four gene copies from a model parasitic nematode, Haemonchus contortus, demonstrated that each copy has acquired unique functional characteristics based on phenotype rescue of transgenic C. elegans and electrophysiology of receptors reconstituted in Xenopus oocytes. We found evidence that a specific incompatibility has evolved for two subunits co-expressed in muscle. We demonstrated that functional divergence of acetylcholine receptors, driven by directional selection, can occur more rapidly than previously thought and may be mediated by alteration of receptor assembly. This phenomenon is common among the

  5. Upper airway CO2 receptors in tegu lizards: localization and ventilatory sensitivity.

    Science.gov (United States)

    Coates, E L; Ballam, G O

    1987-01-01

    1. Tidal volume, end-tidal CO2, and ventilatory frequency in Tupinambis nigropunctatus were measured in response to CO2 (1-4%) delivered to either the mouth or nares. Additionally, the sensitivity of the ventilatory response to nasal CO2 was evaluated at CO2 concentrations less than 1%. The ventilatory parameters were also measured in response to CO2 (1-4%) delivered to the nares after the olfactory peduncle was transected. 2. It was found that (0.4-4%) nasal CO2 depressed ventilatory frequency by 9% to 83% respectively, while tidal volume was not significantly altered. CO2 (1-4%) delivered to the mouth produced no apparent changes in any of the ventilatory parameters. Following transection of the olfactory peduncle, nasal CO2 was ineffective in producing any change in ventilatory frequency or depth. 3. These findings indicate that CO2-sensitive receptors are located in either the nasal or vomeronasal membranes of tegu lizards and that the olfactory peduncle must be intact for these receptors to affect ventilatory changes in response to elevated CO2 concentrations. The receptors are capable of mediating a ventilatory response to CO2 concentrations lower than those found in either expired air or in confined spaces such as occupied burrows. 4. The discrepancies in the ventilatory responses of lizards and snakes to inspired CO2 reported in past experiments may be partially explained by the presence of nasal or vomeronasal CO2-sensitive receptors.

  6. The effect of hyperthyroidism on opiate receptor binding and pain sensitivity

    International Nuclear Information System (INIS)

    Edmondson, E.A.; Bonnet, K.A.; Friedhoff, A.J.

    1990-01-01

    This study was conducted to determine the effect of thyroid hormone on opiate receptor ligand-binding and pain sensitivity. Specific opiate receptor-binding was performed on brain homogenates of Swiss-Webster mice. There was a significant increase in 3 H-naloxone-binding in thyroxine-fed subjects (hyperthyroid). Scatchard analysis revealed that the number of opiate receptors was increased in hyperthyroid mice (Bmax = 0.238 nM for hyperthyroid samples vs. 0.174 nM for controls). Binding affinity was unaffected (Kd = 1.54 nM for hyperthyroid and 1.58 nM for control samples). When mice were subjected to hotplate stimulation, the hyperthyroid mice were noted to be more sensitive as judged by pain aversion response latencies which were half that of control animals. After morphine administration, the hyperthyroid animals demonstrated a shorter duration of analgesia. These findings demonstrate that thyroxine increases opiate receptor number and native pain sensitivity but decreases the duration of analgesia from morphine

  7. The effect of hyperthyroidism on opiate receptor binding and pain sensitivity

    Energy Technology Data Exchange (ETDEWEB)

    Edmondson, E.A. (Baylor College of Medicine, Houston, TX (USA)); Bonnet, K.A.; Friedhoff, A.J. (New York Univ. School of Medicine, NY (USA))

    1990-01-01

    This study was conducted to determine the effect of thyroid hormone on opiate receptor ligand-binding and pain sensitivity. Specific opiate receptor-binding was performed on brain homogenates of Swiss-Webster mice. There was a significant increase in {sup 3}H-naloxone-binding in thyroxine-fed subjects (hyperthyroid). Scatchard analysis revealed that the number of opiate receptors was increased in hyperthyroid mice (Bmax = 0.238 nM for hyperthyroid samples vs. 0.174 nM for controls). Binding affinity was unaffected (Kd = 1.54 nM for hyperthyroid and 1.58 nM for control samples). When mice were subjected to hotplate stimulation, the hyperthyroid mice were noted to be more sensitive as judged by pain aversion response latencies which were half that of control animals. After morphine administration, the hyperthyroid animals demonstrated a shorter duration of analgesia. These findings demonstrate that thyroxine increases opiate receptor number and native pain sensitivity but decreases the duration of analgesia from morphine.

  8. Related-to-receptor tyrosine kinase receptor regulates hematopoietic stem and progenitor sensitivity to myelosuppressive injury in mice.

    Science.gov (United States)

    Povinelli, Benjamin J; Srivastava, Pragya; Nemeth, Michael J

    2015-03-01

    Maintaining a careful balance between quiescence and proliferation of hematopoietic stem and progenitor cells (HSPCs) is necessary for lifelong blood formation. Previously, we demonstrated that the Wnt5a ligand inhibits HSPC proliferation through a functional interaction with a noncanonical Wnt ligand receptor termed 'related-to-receptor tyrosine kinase' (Ryk). Expression of Ryk on HSPCs in vivo is associated with a lower rate of proliferation, and, following treatment with fluorouracil (5-FU), the percentage of Ryk(+/high) HSPCs increased and the percentage of Ryk(-/low) HSPCs decreased. Based on these data, we hypothesized that one function of the Ryk receptor is to protect HSPCs from the effects of myeloablative agents. We found that Ryk expression on HSPCs is associated with lower rates of apoptosis following 5-FU and radiation. Transient inhibition of Ryk signaling in vivo resulted in increased hematopoietic-stem-cell proliferation and decreased hematopoietic-stem-cell function in bone marrow transplant assays. Furthermore, inhibition of Ryk signaling sensitized HSPCs to 5-FU treatment in association with increased levels of reactive oxygen species. Together, these results demonstrated an association between Ryk expression and survival of HSPCs following suppressive injury. Copyright © 2015 ISEH - International Society for Experimental Hematology. Published by Elsevier Inc. All rights reserved.

  9. Activation of temperature-sensitive TRPV1-like receptors in ARC POMC neurons reduces food intake.

    Directory of Open Access Journals (Sweden)

    Jae Hoon Jeong

    2018-04-01

    Full Text Available Proopiomelanocortin (POMC neurons in the arcuate nucleus of the hypothalamus (ARC respond to numerous hormonal and neural signals, resulting in changes in food intake. Here, we demonstrate that ARC POMC neurons express capsaicin-sensitive transient receptor potential vanilloid 1 receptor (TRPV1-like receptors. To show expression of TRPV1-like receptors in ARC POMC neurons, we use single-cell reverse transcription-polymerase chain reaction (RT-PCR, immunohistochemistry, electrophysiology, TRPV1 knock-out (KO, and TRPV1-Cre knock-in mice. A small elevation of temperature in the physiological range is enough to depolarize ARC POMC neurons. This depolarization is blocked by the TRPV1 receptor antagonist and by Trpv1 gene knockdown. Capsaicin-induced activation reduces food intake that is abolished by a melanocortin receptor antagonist. To selectively stimulate TRPV1-like receptor-expressing ARC POMC neurons in the ARC, we generate an adeno-associated virus serotype 5 (AAV5 carrying a Cre-dependent channelrhodopsin-2 (ChR2-enhanced yellow fluorescent protein (eYFP expression cassette under the control of the two neuronal POMC enhancers (nPEs. Optogenetic stimulation of TRPV1-like receptor-expressing POMC neurons decreases food intake. Hypothalamic temperature is rapidly elevated and reaches to approximately 39 °C during treadmill running. This elevation is associated with a reduction in food intake. Knockdown of the Trpv1 gene exclusively in ARC POMC neurons blocks the feeding inhibition produced by increased hypothalamic temperature. Taken together, our findings identify a melanocortinergic circuit that links acute elevations in hypothalamic temperature with acute reductions in food intake.

  10. Signaling-sensitive amino acids surround the allosteric ligand binding site of the thyrotropin receptor.

    Science.gov (United States)

    Kleinau, Gunnar; Haas, Ann-Karin; Neumann, Susanne; Worth, Catherine L; Hoyer, Inna; Furkert, Jens; Rutz, Claudia; Gershengorn, Marvin C; Schülein, Ralf; Krause, Gerd

    2010-07-01

    The thyrotropin receptor [thyroid-stimulating hormone receptor (TSHR)], a G-protein-coupled receptor (GPCR), is endogenously activated by thyrotropin, which binds to the extracellular region of the receptor. We previously identified a low-molecular-weight (LMW) agonist of the TSHR and predicted its allosteric binding pocket within the receptor's transmembrane domain. Because binding of the LMW agonist probably disrupts interactions or leads to formation of new interactions among amino acid residues surrounding the pocket, we tested whether mutation of residues at these positions would lead to constitutive signaling activity. Guided by molecular modeling, we performed site-directed mutagenesis of 24 amino acids in this spatial region, followed by functional characterization of the mutant receptors in terms of expression and signaling, measured as cAMP accumulation. We found that mutations V421I, Y466A, T501A, L587V, M637C, M637W, S641A, Y643F, L645V, and Y667A located in several helices exhibit constitutive activity. Of note is mutation M637W at position 6.48 in transmembrane helix 6, which has a significant effect on the interaction of the receptor with the LMW agonist. In summary, we found that a high proportion of residues in several helices surrounding the allosteric binding site of LMW ligands in the TSHR when mutated lead to constitutively active receptors. Our findings of signaling-sensitive residues in this region of the transmembrane bundle may be of general importance as this domain appears to be evolutionarily retained among GPCRs.

  11. A sensitive electrochemiluminescence cytosensor for quantitative evaluation of epidermal growth factor receptor expressed on cell surfaces

    Energy Technology Data Exchange (ETDEWEB)

    Tang, Yanjuan; Zhang, Shaolian; Wen, Qingqing; Huang, Hongxing; Yang, Peihui, E-mail: typh@jnu.edu.cn

    2015-06-30

    Highlights: • EGF-cytosensor was used for evaluating EGFR expression level on cell surfaces. • CdSQDs and EGF were coated on magnetic beads (MBs) for ECL-probe. • Good sensitivity was achieved due to the signal amplification of ECL-probe. - Abstract: A sensitive electrochemiluminescence (ECL) strategy for evaluating the epidermal growth factor receptor (EGFR) expression level on cell surfaces was designed by integrating the specific recognition of EGFR expressed on MCF-7 cell surfaces with an epidermal growth factor (EGF)-funtionalized CdS quantum dots (CdSQDs)-capped magnetic bead (MB) probe. The high sensitivity of ECL probe of EGF-funtionalized CdSQD-capped-MB was used for competitive recognition with EGFR expressed on cell surfaces with recombinant EGFR protein. The changes of ECL intensity depended on both the cell number and the expression level of EGFR receptor on cell surfaces. A wide linear response to cells ranging from 80 to 4 × 10{sup 6} cells mL{sup −1} with a detection limit of 40 cells mL{sup −1} was obtained. The EGF-cytosensor was used to evaluate EGFR expression levels on MCF-7 cells, and the average number of EGFR receptor on single MCF-7 cells was 1.35 × 10{sup 5} with the relative standard deviation of 4.3%. This strategy was further used for in-situ and real-time evaluating EGFR receptor expressed on cell surfaces in response to drugs stimulation at different concentration and incubation time. The proposed method provided potential applications in the detection of receptors on cancer cells and anticancer drugs screening.

  12. Different serotonin receptor types participate in 5-hydroxytryptophan-induced gonadotropins and prolactin release in the female infantile rat.

    Science.gov (United States)

    Lacau-Mengido, I M; Libertun, C; Becú-Villalobos, D

    1996-05-01

    Serotonin (5-HT) receptors can be classified into at least three, possibly up to seven, classes of receptors. They comprise the 5-HT1, 5-HT2, and 5-HT3 classes, the "uncloned' 5-HT4 receptor and the recombinant receptors 5-ht5, 5-ht6 and 5-ht7. We investigated the role of different serotonin receptor types in a neuroendocrine response to the activation of the serotonergic system. Female immature rats were chosen as an experimental model as it has been shown that during the 3rd week of life, and not at later developmental stages, 5-hydroxytryptophan (5-HTP, a serotonin precursor) induces gonadotropin release in females and not in males. Besides, at this age, serotonin releases prolactin in both sexes. 5-HTP (50 mg/kg) released prolactin, luteinizing hormone (LH) and follicle-stimulating hormone (FSH) as expected. Ketanserin (5-HT2A antagonist) and methysergide (5-HT2C antagonist) blocked 5-HTP-induced prolactin release, but did not block the LH or FSH responses. Ondansetron (5-HT3 receptor antagonist) did not modify prolactin response to 5-HTP, whereas it blocked 5-HTP-induced LH and FSH release. Propranolol (5-HT1 and beta-adrenergic antagonist) blocked prolactin, LH and FSH release induced by 5-HTP. The 5-HT2C agonist 1-(3-chlorophenyl)piperazine dihydrochloride released prolactin, without modifying LH or FSH release. Methyl-quipazine and phenylbiguanide (5-HT3 agonists) increased both LH and FSH levels, without altering prolactin secretion. The present experiments indicate that serotonin acting at the 5-HT3 receptor mediates LH and FSH release in infantile female rats, whereas 5-HT2C or 2A receptor types participate in the release of prolactin at this age. 5-HT1 receptor type may be involved in the release of the three hormones, though a beta-adrenergic component of the response cannot be discarded.

  13. Presynaptic muscarinic receptors: Change of sensitivity during long-term drug treatment

    International Nuclear Information System (INIS)

    Marchi, M.; Raiteri, M.

    1986-01-01

    The authors investigate some of the characteristics of auto- and heteroreceptors from different brain areas in male rats; their alteration in sensitivity following chronic drug treatment is monitored. The synaptosomes were prelabeled with tritium-choline or tritium-dopamine and the release of tritium-acetylcholine and tritium-DA was studied in superfusion. It is shown that the difference in susceptibility between auto- and heteroreceptors with respect to changes of sensitivity may represent a further criterion to discriminate between muscarinic receptor subtypes

  14. Hippocampal GluA1-containing AMPA receptors mediate context-dependent sensitization to morphine

    OpenAIRE

    Xia, Yan; Portugal, George S.; Fakira, Amanda K.; Melyan, Zara; Neve, Rachael; Lee, H. Thomas; Russo, Scott J.; Liu, Jie; Morón, Jose A.

    2011-01-01

    Glutamatergic systems, including α-amino-3-hydroxy-5-methyl-4-isoxazole propionic acid receptors (AMPARs) are involved in opiate-induced neuronal and behavioral plasticity, although the mechanisms underlying these effects are not fully understood. In the present study, we investigated the effects of repeated morphine administration on AMPAR expression, synaptic plasticity, and context-dependent behavioral sensitization to morphine. We found that morphine treatment produced changes of synaptic...

  15. Extrasynaptic glycine receptors of rodent dorsal raphe serotonergic neurons:a sensitive target for ethanol

    OpenAIRE

    Maguire, Edward P.; Mitchell, Elizabeth A.; Greig, Scott J.; Corteen, Nicole; Balfour, David J. K.; Swinny, Jerome; Lambert, Jeremy J.; Belelli, Delia

    2014-01-01

    Alcohol abuse is a significant medical and social problem. Several neurotransmitter systems are implicated in ethanol's actions, with certain receptors and ion channels emerging as putative targets. The dorsal raphe (DR) nucleus is associated with the behavioral actions of alcohol, but ethanol actions on these neurons are not well understood. Here, using immunohistochemistry and electrophysiology we characterize DR inhibitory transmission and its sensitivity to ethanol. DR neurons exhibit inh...

  16. Micromolar-Affinity Benzodiazepine Receptors Regulate Voltage-Sensitive Calcium Channels in Nerve Terminal Preparations

    Science.gov (United States)

    Taft, William C.; Delorenzo, Robert J.

    1984-05-01

    Benzodiazepines in micromolar concentrations significantly inhibit depolarization-sensitive Ca2+ uptake in intact nerve-terminal preparations. Benzodiazepine inhibition of Ca2+ uptake is concentration dependent and stereospecific. Micromolar-affinity benzodiazepine receptors have been identified and characterized in brain membrane and shown to be distinct from nanomolar-affinity benzodiazepine receptors. Evidence is presented that micromolar, and not nanomolar, benzodiazepine binding sites mediate benzodiazepine inhibition of Ca2+ uptake. Irreversible binding to micromolar benzodiazepine binding sites also irreversibly blocked depolarization-dependent Ca2+ uptake in synaptosomes, indicating that these compounds may represent a useful marker for identifying the molecular components of Ca2+ channels in brain. Characterization of benzodiazepine inhibition of Ca2+ uptake demonstrates that these drugs function as Ca2+ channel antagonists, because benzodiazepines effectively blocked voltage-sensitive Ca2+ uptake inhibited by Mn2+, Co2+, verapamil, nitrendipine, and nimodipine. These results indicate that micromolar benzodiazepine binding sites regulate voltage-sensitive Ca2+ channels in brain membrane and suggest that some of the neuronal stabilizing effects of micromolar benzodiazepine receptors may be mediated by the regulation of Ca2+ conductance.

  17. Differentiated human midbrain-derived neural progenitor cells express excitatory strychnine-sensitive glycine receptors containing α2β subunits.

    Directory of Open Access Journals (Sweden)

    Florian Wegner

    Full Text Available BACKGROUND: Human fetal midbrain-derived neural progenitor cells (NPCs may deliver a tissue source for drug screening and regenerative cell therapy to treat Parkinson's disease. While glutamate and GABA(A receptors play an important role in neurogenesis, the involvement of glycine receptors during human neurogenesis and dopaminergic differentiation as well as their molecular and functional characteristics in NPCs are largely unknown. METHODOLOGY/PRINCIPAL FINDINGS: Here we investigated NPCs in respect to their glycine receptor function and subunit expression using electrophysiology, calcium imaging, immunocytochemistry, and quantitative real-time PCR. Whole-cell recordings demonstrate the ability of NPCs to express functional strychnine-sensitive glycine receptors after differentiation for 3 weeks in vitro. Pharmacological and molecular analyses indicate a predominance of glycine receptor heteromers containing α2β subunits. Intracellular calcium measurements of differentiated NPCs suggest that glycine evokes depolarisations mediated by strychnine-sensitive glycine receptors and not by D-serine-sensitive excitatory glycine receptors. Culturing NPCs with additional glycine, the glycine-receptor antagonist strychnine, or the Na(+-K(+-Cl(- co-transporter 1 (NKCC1-inhibitor bumetanide did not significantly influence cell proliferation and differentiation in vitro. CONCLUSIONS/SIGNIFICANCE: These data indicate that NPCs derived from human fetal midbrain tissue acquire essential glycine receptor properties during neuronal maturation. However, glycine receptors seem to have a limited functional impact on neurogenesis and dopaminergic differentiation of NPCs in vitro.

  18. In vitro function of the aryl hydrocarbon receptor predicts in vivo sensitivity of oviparous vertebrates to dioxin-like compounds

    Science.gov (United States)

    Differences in sensitivity to dioxin-like compounds (DLCs) among species and taxa presents a major challenge to ecological risk assessments. Activation of the aryl hydrocarbon receptor (AHR) regulates adverse effects associated with exposure to DLCs in vertebrates. Prior investig...

  19. GQ-16, a Novel Peroxisome Proliferator-activated Receptor gamma (PPAR gamma) Ligand, Promotes Insulin Sensitization without Weight Gain

    NARCIS (Netherlands)

    Amato, Angelica A.; Rajagopalan, Senapathy; Lin, Jean Z.; Carvalho, Bruno M.; Figueira, Ana C. M.; Lu, Jenny; Ayers, Stephen D.; Mottin, Melina; Silveira, Rodrigo L.; Telles de Souza, Paulo; Mourao, Rosa H. V.; Saad, Mario J. A.; Togashi, Marie; Simeoni, Luiz A.; Abdalla, Dulcineia S. P.; Skaf, Munir S.; Polikparpov, Igor; Lima, Maria C. A.; Galdino, Suely L.; Brennan, Richard G.; Baxter, John D.; Pitta, Ivan R.; Webb, Paul; Phillips, Kevin J.; Neves, Francisco A. R.

    2012-01-01

    The recent discovery that peroxisome proliferator-activated receptor gamma (PPAR gamma) targeted anti-diabetic drugs function by inhibiting Cdk5-mediated phosphorylation of the receptor has provided a new viewpoint to evaluate and perhaps develop improved insulin-sensitizing agents. Herein we report

  20. Ghrelin receptor antagonism of hyperlocomotion in cocaine-sensitized mice requires βarrestin-2.

    Science.gov (United States)

    Toth, Krisztian; Slosky, Lauren M; Pack, Thomas F; Urs, Nikhil M; Boone, Peter; Mao, Lan; Abraham, Dennis; Caron, Marc G; Barak, Lawrence S

    2018-01-01

    The "brain-gut" peptide ghrelin, which mediates food-seeking behaviors, is recognized as a very strong endogenous modulator of dopamine (DA) signaling. Ghrelin binds the G protein-coupled receptor GHSR1a, and administration of ghrelin increases the rewarding properties of psychostimulants while ghrelin receptor antagonists decrease them. In addition, the GHSR1a signals through βarrestin-2 to regulate actin/stress fiber rearrangement, suggesting βarrestin-2 participation in the regulation of actin-mediated synaptic plasticity for addictive substances like cocaine. The effects of ghrelin receptor ligands on reward strongly suggest that modulation of ghrelin signaling could provide an effective strategy to ameliorate undesirable behaviors arising from addiction. To investigate this possibility, we tested the effects of ghrelin receptor antagonism in a cocaine behavioral sensitization paradigm using DA neuron-specific βarrestin-2 KO mice. Our results show that these mice sensitize to cocaine as well as wild-type littermates. The βarrestin-2 KO mice, however, no longer respond to the locomotor attenuating effects of the GHSR1a antagonist YIL781. The data presented here suggest that the separate stages of addictive behavior differ in their requirements for βarrestin-2 and show that pharmacological inhibition of βarrestin-2 function through GHSR1a antagonism is not equivalent to the loss of βarrestin-2 function achieved by genetic ablation. These data support targeting GHSR1a signaling in addiction therapy but indicate that using signaling biased compounds that modulate βarrestin-2 activity differentially from G protein activity may be required. © 2017 Wiley Periodicals, Inc.

  1. Dynamical modeling of the moth pheromone-sensitive olfactory receptor neuron within its sensillar environment.

    Directory of Open Access Journals (Sweden)

    Yuqiao Gu

    Full Text Available In insects, olfactory receptor neurons (ORNs, surrounded with auxiliary cells and protected by a cuticular wall, form small discrete sensory organs--the sensilla. The moth pheromone-sensitive sensillum is a well studied example of hair-like sensillum that is favorable to both experimental and modeling investigations. The model presented takes into account both the molecular processes of ORNs, i.e. the biochemical reactions and ionic currents giving rise to the receptor potential, and the cellular organization and compartmentalization of the organ represented by an electrical circuit. The number of isopotential compartments needed to describe the long dendrite bearing pheromone receptors was determined. The transduction parameters that must be modified when the number of compartments is increased were identified. This model reproduces the amplitude and time course of the experimentally recorded receptor potential. A first complete version of the model was analyzed in response to pheromone pulses of various strengths. It provided a quantitative description of the spatial and temporal evolution of the pheromone-dependent conductances, currents and potentials along the outer dendrite and served to determine the contribution of the various steps in the cascade to its global sensitivity. A second simplified version of the model, utilizing a single depolarizing conductance and leak conductances for repolarizing the ORN, was derived from the first version. It served to analyze the effects on the sensory properties of varying the electrical parameters and the size of the main sensillum parts. The consequences of the results obtained on the still uncertain mechanisms of olfactory transduction in moth ORNs--involvement or not of G-proteins, role of chloride and potassium currents--are discussed as well as the optimality of the sensillum organization, the dependence of biochemical parameters on the neuron spatial extension and the respective contributions

  2. A common haplotype in the G-protein-coupled receptor gene GPR74 is associated with leanness and increased lipolysis

    DEFF Research Database (Denmark)

    Dahlman, Ingrid; Dicker, Andrea; Jiao, Hong

    2007-01-01

    0.36; P=.036) among those selected for obese or lean phenotypes. The ATAG haplotype was associated with increased adipocyte lipid mobilization (lipolysis) in vivo and in vitro. In human fat cells, GPR74 receptor stimulation and inhibition caused a significant and marked decrease and increase......, respectively, of lipolysis, which could be linked to catecholamine stimulation of adipocytes through beta -adrenergic receptors. These findings suggest that a common haplotype in the GPR74 gene protects against obesity, which, at least in part, is caused by a relief of inhibition of lipid mobilization from......The G-protein-coupled receptor GPR74 is a novel candidate gene for body weight regulation. In humans, it is predominantly expressed in brain, heart, and adipose tissue. We report a haplotype in the GPR74 gene, ATAG, with allele frequency ~4% in Scandinavian cohorts, which was associated...

  3. Nature and regulation of the insulin receptor: structure and function

    International Nuclear Information System (INIS)

    Czech, M.P.

    1985-01-01

    Native, cell-surface insulin receptor consists of two glycoprotein subunit types with apparent masses of about 125,000 daltons (alpha subunit) and 90,000 daltons (beta subunit). The alpha and beta insulin-receptor subunits seem to have distinct functions such that alpha appears to bind hormone whereas beta appears to possess intrinsic tyrosine kinase activity. In detergent extracts, insulin activates receptor autophosphorylation of tyrosine residues on its beta subunit, whereas in the presence of reductant, the alpha subunit is also phosphorylated. In intact cells, insulin activates serine/threonine phosphorylation of insulin receptor beta subunit as well as tyrosine phosphorylation. The biological role of the receptor-associated tyrosine kinase is not known. The insulin receptor kinase is regulated by beta-adrenergic agonists and other agents that elevate cAMP in adipocytes, presumably via the cAMP-dependent protein kinase. Such agents decrease receptor affinity for insulin and partially uncouple receptor tyrosine kinase activity from activation by insulin. These effects appear to contribute to the biological antagonism between insulin and beta-agonists. These data suggest the hypothesis that a complex network of tyrosine and serine/threonine phosphorylations on the insulin receptor modulate its binding and kinase activities in an antagonistic manner

  4. Interactions between lysergic acid diethylamide and dopamine-sensitive adenylate cyclase systems in rat brain.

    Science.gov (United States)

    Hungen, K V; Roberts, S; Hill, D F

    1975-08-22

    Investigations were carried out on the interactions of the hallucinogenic drug, D-lysergic acid diethylamide (D-LSD), and other serotonin antagonists with catecholamine-sensitive adenylate cyclase systems in cell-free preparations from different regions of rat brain. In equimolar concentration, D-LSD, 2-brono-D-lysergic acid diethylamide (BOL), or methysergide (UML) strongly blocked maximal stimulation of adenylate cyclase activity by either norepinephrine or dopamine in particulate preparations from cerebral cortices of young adult rats. D-LSD also eliminated the stimulation of adenylate cyclase activity of equimolar concentrations of norepinephrine or dopamine in particulate preparations from rat hippocampus. The effects of this hallucinogenic agent on adenylate cyclase activity were most striking in particulate preparations from corpus striatum. Thus, in 10 muM concentration, D-LSD not only completely eradicated the response to 10 muM dopamine in these preparations but also consistently stimulated adenylate cyclase activity. L-LSD (80 muM) was without effect. Significant activation of striatal adenylate cyclase was produced by 0.1 muM D-LSD. Activation of striatal adenylate cyclase of either D-LSD or dopamine was strongly blocked by the dopamine-blocking agents trifluoperazine, thioridazine, chlorpromazine, and haloperidol. The stimulatory effects of D-LSD and dopamine were also inhibited by the serotonin-blocking agents, BOL, 1-methyl-D-lysergic acid diethylamide (MLD), and cyproheptadine, but not by the beta-adrenergic-blocking agent, propranolol. However, these serotonin antagonists by themselves were incapable of stimulating adenylate cyclase activity in the striatal preparations. Several other hallucinogens, which were structurally related to serotonin, were also inactive in this regard, e.g., mescaline, N,N-dimethyltryptamine, psilocin and bufotenine. Serotonin itself produced a small stimulation of adenylate cyclase activity in striatal preparations and

  5. Opiate receptor binding in the brain of the seizure sensitive Mongolian gerbil (Meriones unguiculatus).

    Science.gov (United States)

    Lee, R J; Olsen, R W; Lomax, P; McCabe, R T; Wamsley, J K

    1984-12-01

    Opiate receptor binding was studied in seizure sensitive (SS) and seizure resistant (SR) strains of the Mongolian gerbil. Cryostat sections of the brain were labeled with [3H]-dihydromorphine, subjected to autoradiography and analysed by microdensitometry. SS gerbils, prior to seizure induction, demonstrated overall greater brain opiate binding when compared to SR animals. Immediately following a seizure, binding in the interpeduncular nucleus fell to levels found in SR animals. The increased opiate binding in the SS (pre-seizure) compared to SR gerbils could reflect a deficit of endogenous ligand which could underlie the seizure diathesis in the gerbil.

  6. Differentiation-associated decrease in muscarinic receptor sensitivity in human neuroblastoma cells

    International Nuclear Information System (INIS)

    Heikkilae, J.E.; Scott, J.G.; Suominen, L.A.; Akerman, K.E.O.

    1987-01-01

    Muscarinic receptor-linked increases in intracellular free Ca 2+ as measured with quin-2 and Ca 2+ release from monolayers of cells have been measured in the human neuroblastoma cell line SH-SY5Y. Induction of differentiation with the phorbol ester 12-O-tetradecanoylphorbol-13-acetate (TPA) leads to a decrease in the sensitivity of the cells to low concentrations of agonists with respect to the induced increase in cytosolic free Ca 2+ and stimulation of Ca 2+ efflux. No decrease in agonist binding affinity was observed when the displacement of a labelled antagonist, 3 H-NMS, by a non-labelled agonist was studied

  7. (125I)Iodoazidococaine, a photoaffinity label for the haloperidol-sensitive sigma receptor

    International Nuclear Information System (INIS)

    Kahoun, J.R.; Ruoho, A.E.

    1992-01-01

    A carrier-free radioiodinated cocaine photoaffinity label, (-)-3-( 125 I)iodo-4-azidococaine [( 125 I)IACoc], has been synthesized and used as a probe for cocaine-binding proteins. Photoaffinity labeling with 0.5 nM ( 125 I)IACoc resulted in selective derivatization of a 26-kDa polypeptide with the pharmacology of a sigma receptor in membranes derived from whole rat brain, rat liver, and human placenta. ( 125 I)IACoc labeling of the 26-kDa polypeptide was also inhibited by 10 μM imipramine, amitriptyline, fluoxetine, benztropine, and tetrabenazine. The size of the ( 125 I)I-ACoc-labeled proteins is consistent with the size of proteins photolabeled in guinea pig brain and liver membranes by using the sigma photolabel azido-[ 3 H]DTG. Kinetic analysis of ( 125 I)IACoc binding to rat liver microsomes revealed two sites with K d values of 19 and 126 pM, respectively. The presence or absence of proteolytic inhibitors during membrane preparation did not alter the size of the photolabeled sigma receptor, indicating that the 26-kDa polypeptide was not derived from a larger protein. In summary, ( 125 I)IACoc is a potent and highly specific photoaffinity label for the haloperidol-sensitive sigma receptor and will be useful for its biochemical and molecular characterization

  8. Are basophil histamine release and high affinity IgE receptor expression involved in asymptomatic skin sensitization?

    DEFF Research Database (Denmark)

    Jensen, Bettina Margrethe; Assing, K; Jensen, Lone Hummelshøj

    2006-01-01

    Immunoglobulin (Ig)E-sensitized persons with positive skin prick test, but no allergy symptoms, are classified as being asymptomatic skin sensitized (AS). The allergic type 1 disease is dependant on IgE binding to the high affinity IgE-receptor (FcepsilonRI) expressed on basophils and mast cells....

  9. Inhibition of the CSF-1 receptor sensitizes ovarian cancer cells to cisplatin.

    Science.gov (United States)

    Yu, Rong; Jin, Hao; Jin, Congcong; Huang, Xuefeng; Lin, Jinju; Teng, Yili

    2018-03-01

    Ovarian cancer is one of the most common female malignancies, and cisplatin-based chemotherapy is routinely used in locally advanced ovarian cancer patients. Acquired or de novo cisplatin resistance remains the barrier to patient survival, and the mechanisms of cisplatin resistance are still not well understood. In the current study, we found that colony-stimulating-factor-1 receptor (CSF-1R) was upregulated in cisplatin-resistant SK-OV-3 and CaoV-3 cells. Colony-stimulating-factor-1 receptor knockdown suppressed proliferation and enhanced apoptosis in cisplatin-resistant SK-OV-3 and CaoV-3 cells. However, CSF-1R overexpression had inverse effects. While parental SK-OV-3 and CaoV-3 cells were more resistant to cisplatin after CSF-1R overexpression, CSF-1R knockdown in SK-OV-3 and CaoV-3 cells promoted cisplatin sensitivity. Overexpression and knockdown studies also showed that CSF-1R significantly promoted active AKT and ERK1/2 signalling pathways in cisplatin-resistant cells. Furthermore, a combination of cisplatin and CSF-1R inhibitor effectively inhibited tumour growth in xenografts. Taken together, our results provide the first evidence that CSF-1R inhibition can sensitize cisplatin-refractory ovarian cancer cells. This study may help to increase understanding of the molecular mechanisms underlying cisplatin resistance in tumours. Copyright © 2018 John Wiley & Sons, Ltd.

  10. Oxaliplatin Alters Expression of T1R2 Receptor and Sensitivity to Sweet Taste in Rats.

    Science.gov (United States)

    Ohishi, Akihiro; Nishida, Kentaro; Yamanaka, Yuri; Miyata, Ai; Ikukawa, Akiko; Yabu, Miharu; Miyamoto, Karin; Bansho, Saho; Nagasawa, Kazuki

    2016-01-01

    As one of the adverse effects of oxaliplatin, a key agent in colon cancer chemotherapy, a taste disorder is a severe issue in a clinical situation because it decreases the quality of life of patients. However, there is little information on the mechanism underlying the oxaliplatin-induced taste disorder. Here, we examined the molecular and behavioral characteristics of the oxaliplatin-induced taste disorder in rats. Oxaliplatin (4-16 mg/kg) was administered to Sprague-Dawley (SD) rats intraperitoneally for 2 d. Expression levels of mRNA and protein of taste receptors in circumvallate papillae (CP) were measured by real-time quantitative polymerase chain reaction (PCR) and immunohistochemistry, respectively. Taste sensitivity was assessed by their behavioral change using a brief-access test. Morphological change of the taste buds in CP was evaluated by hematoxyline-eosin (HE) staining, and the number of taste cells in taste buds was counted by immunohistochemical analysis. Among taste receptors, the expression levels of mRNA and protein of T1R2, a sweet taste receptor subunit, were increased transiently in CP of oxaliplatin-administered rats on day 7. In a brief-access test, the lick ratio was decreased in oxaliplatin-administered rats on day 7 and the alteration was recovered to the control level on day 14. There was no detectable alteration in the morphology of taste buds, number of taste cells or plasma zinc level in oxaliplatin-administered rats. These results suggest that decreased sensitivity to sweet taste in oxaliplatin-administered rats is due, at least in part, to increased expression of T1R2, while these alterations are reversible.

  11. R+-methanandamide inhibits tracheal response to endogenously released acetylcholine via capsazepine-sensitive receptors.

    Science.gov (United States)

    Nieri, Paola; Martinotti, Enrica; Testai, Lara; Adinolfi, Barbara; Calderone, Vincenzo; Breschi, Maria Cristina

    2003-01-10

    The effects of cannabinoid drugs on the cholinergic response evoked by electrical field stimulation (0.2 ms pulse width, 20 V amplitude, 10 Hz, 7.5 s train duration) in guinea-pig tracheal preparations were investigated. The stable analogue of the endocannabinoid anandamide, R(+)-methanandamide (10(-7)-10(-4) M), produced a dose-dependent inhibition (up to 27+/-5% of control) of electrical field stimulation-mediated atropine-sensitive response. This effect was not blocked by the selective cannabinoid CB(1) receptor antagonist N-(piperidin-1-yl)-5-(4-chlorophenyl)-1-(2,4-dichlorophenyl)-4-methyl-1H-pyrazole-3 carboxamide hydrochloride (SR 141716A; 10(-6) M), and was not reproduced with the cannabinoid CB(1)/CB(2) receptor agonist R(+)-[2,3-dihydro-5-methyl-[(morpholinyl)methyl]pyrrolo [1,2,3-de]-1,4-benzoxazin-6-yl]-(1-naphthalenyl)methanone mesylate) (WIN 55,212-2; 10(-8)-10(-5) M) or the cannabinoid CB(2) receptor selective agonist 1-propyl-2-methyl-3-(1-naphthoyl)indole (JWH-015; 10(-8)-10(-5) M); it was, on the contrary, antagonized by the vanilloid antagonist 2-[2-(4-chlorophenyl)ethyl-amino-thiocarbonyl]-7,8-dihydroxy-2,3,4,5-tetrahydro-1H-2 benzazepine (capsazepine; 10(-6) M). At the postjunctional level, neither R(+)-methanandamide nor WIN 55,212-2 nor JWH-015 did affect tracheal contractions induced by exogenous acetylcholine (10(-6) M). An inhibitory vanilloid receptor-mediated effect on the cholinergic response evoked by electrical stimulation was confirmed with the vanilloid agonist capsaicin, at doses (3-6 x 10(-8) M) which poorly influenced the basal smooth muscle tone of trachea. In conclusion, our data indicate that in guinea-pig trachea (a) neither CB(1) nor CB(2) cannabinoid receptor-mediated modulation of acetylcholine release occurs; (b) vanilloid VR1-like receptors appear involved in R(+)-methanandamide inhibitory activity on the cholinergic response to electrical field stimulation.

  12. Human umbilical vein: involvement of cyclooxygenase-2 pathway in bradykinin B1 receptor-sensitized responses.

    Science.gov (United States)

    Errasti, A E; Rey-Ares, V; Daray, F M; Rogines-Velo, M P; Sardi, S P; Paz, C; Podestá, E J; Rothlin, R P

    2001-08-01

    In isolated human umbilical vein (HUV), the contractile response to des-Arg9-bradykinin (des-Arg9-BK), selective BK B1 receptor agonist, increases as a function of the incubation time. Here, we evaluated whether cyclooxygenase (COX) pathway is involved in BK B1-sensitized response obtained in 5-h incubated HUV rings. The effect of different concentrations of indomethacin, sodium salicylate, ibuprofen, meloxicam, lysine clonixinate or NS-398 administrated 30 min before concentration-response curves (CRC) was studied. All treatments produced a significant rightward shift of the CRC to des-Arg9-BK in a concentration-dependent manner, which provides pharmacological evidence that COX pathway is involved in the BK B1 responses. Moreover, in this tissue, the NS-398 pKb (5.2) observed suggests that COX-2 pathway is the most relevant. The strong correlation between published pIC50 for COX-2 and the NSAIDs' pKbs estimated further supports the hypothesis that COX-2 metabolites are involved in BK B1 receptor-mediated responses. In other rings, indomethacin (30, 100 micromol/l) or NS-398 (10, 30 micromol/l) produced a significant rightward shift of the CRC to BK, selective BK B2 agonist, and its pKbs were similar to the values to inhibit BK B1 receptor responses, suggesting that COX-2 pathway also is involved in BK B2 receptor responses. Western blot analysis shows that COX-1 and COX-2 isoenzymes are present before and after 5-h in vitro incubation and apparently COX-2 does not suffer additional induction.

  13. The macrophage A2B adenosine receptor regulates tissue insulin sensitivity.

    Directory of Open Access Journals (Sweden)

    Hillary Johnston-Cox

    Full Text Available High fat diet (HFD-induced type 2 diabetes continues to be an epidemic with significant risk for various pathologies. Previously, we identified the A2b adenosine receptor (A2bAR, an established regulator of inflammation, as a regulator of HFD-induced insulin resistance. In particular, HFD was associated with vast upregulation of liver A2bAR in control mice, and while mice lacking this receptor showed augmented liver inflammation and tissue insulin resistance. As the A2bAR is expressed in different tissues, here, we provide the first lead to cellular mechanism by demonstrating that the receptor's influence on tissue insulin sensitivity is mediated via its expression in macrophages. This was shown using a newly generated transgenic mouse model expressing the A2bAR gene in the macrophage lineage on an otherwise A2bAR null background. Reinstatement of macrophage A2bAR expression in A2bAR null mice fed HFD restored insulin tolerance and tissue insulin signaling to the level of control mice. The molecular mechanism for this effect involves A2bAR-mediated changes in cyclic adenosine monophosphate in macrophages, reducing the expression and release of inflammatory cytokines, which downregulate insulin receptor-2. Thus, our results illustrate that macrophage A2bAR signaling is needed and sufficient for relaying the protective effect of the A2bAR against HFD-induced tissue inflammation and insulin resistance in mice.

  14. Internalized insulin-receptor complexes are unidirectionally translocated to chloroquine-sensitive degradative sites. Dependence on metabolic energy

    International Nuclear Information System (INIS)

    Berhanu, P.

    1988-01-01

    Insulin receptors on the surface of isolated rat adipocytes were photoaffinity labeled at 12 degrees C with the iodinated photoreactive insulin analogue, 125I-B2 (2-nitro-4-azidophenylacetyl)-des-PheB1-insulin, and the pathways in the intracellular processing of the labeled receptors were studied at 37 degrees C. During 37 degrees C incubations, the labeled 440-kDa insulin receptors were continuously internalized (as assessed by trypsin inaccessibility) and degraded such that up to 50% of the initially labeled receptors were lost by 120 min. Metabolic poisons (0.125-0.75 mM 2,4-dinitrophenol (DNP) and 1-10 mM NaF), which led to dose-dependent depletion of adipocyte ATP pools, inhibited receptor loss, and caused up to 3-fold increase in intracellular receptor accumulation. This effect was due to inhibition of intracellular receptor degradation, and there was no apparent effect of the metabolic poisons on initial internalization of the receptors. Following maximal intracellular accumulation of labeled insulin receptors in the presence of NaF or DNP, removal of these agents resulted in a subsequent, time-dependent degradation of the accumulated receptors. However, when the lysosomotropic agent, chloroquine (0.2 mM), was added immediately following removal of the metabolic poisons, further degradation of the intracellularly accumulated receptors was prevented, suggesting that the chloroquine-sensitive degradation of insulin receptors occurs distal to the site of inhibition by NaF or DNP. To confirm this, maximal intracellular accumulation of labeled receptors was first allowed to occur in the presence of chloroquine and the cells were then washed and reincubated in chloroquine-free media in the absence or presence of NaF or DNP. Under these conditions, degradation of the intracellularly accumulated receptors continued to occur, and NaF or DNP failed to block the degradation

  15. Distinct functional characteristics of levocabastine sensitive rat neurotensin NT2 receptor expressed in Chinese hamster ovary cells.

    Science.gov (United States)

    Yamada, M; Yamada, M; Lombet, A; Forgez, P; Rostène, W

    1998-01-01

    Neurotensin has been shown to produce pharmacological effects both in brain and periphery. Several of these effects are mediated by a high-affinity neurotensin NT1 receptor. On the other hand, a low-affinity levocabastine-sensitive neurotensin NT2 receptor was molecularly cloned from rodent brain recently. In this study, in contrast to NT1 receptor, levocabastine (a histamine H1 receptor antagonist) and SR48692 (an antagonist for NT1 receptor) strongly stimulated intracellular Ca2+ mobilization in transfected Chinese hamster ovary cells expressing rat NT2 receptor, thus acting as potent NT2 receptor. Furthermore, despite of their affinities for NT2 receptor, the Ca2+ responses to potent NT1 agonists, neurotensin or JMV449 ([Lys8-(CH2NH)-Lys9]Pro-Tyr-Ile-Leu, a peptidase resistant analogue of neurotensin) were much smaller than that observed with SR48692. These findings suggest that NT1 and NT2 receptors present distinct functional characteristics and that SR48692 may act as a potent agonist for NT2 receptor.

  16. Inflammatory sensitization of nociceptors depends on activation of NMDA receptors in DRG satellite cells.

    Science.gov (United States)

    Ferrari, Luiz Fernando; Lotufo, Celina Monteiro; Araldi, Dionéia; Rodrigues, Marcos A; Macedo, Larissa P; Ferreira, Sérgio H; Parada, Carlos Amilcar

    2014-12-23

    The present study evaluated the role of N-methyl-D-aspartate receptors (NMDARs) expressed in the dorsal root ganglia (DRG) in the inflammatory sensitization of peripheral nociceptor terminals to mechanical stimulation. Injection of NMDA into the fifth lumbar (L5)-DRG induced hyperalgesia in the rat hind paw with a profile similar to that of intraplantar injection of prostaglandin E2 (PGE2), which was significantly attenuated by injection of the NMDAR antagonist D(-)-2-amino-5-phosphonopentanoic acid (D-AP-5) in the L5-DRG. Moreover, blockade of DRG AMPA receptors by the antagonist 6,7-dinitroquinoxaline-2,3-dione had no effect in the PGE2-induced hyperalgesia in the paw, showing specific involvement of NMDARs in this modulatory effect and suggesting that activation of NMDAR in the DRG plays an important role in the peripheral inflammatory hyperalgesia. In following experiments we observed attenuation of PGE2-induced hyperalgesia in the paw by the knockdown of NMDAR subunits NR1, NR2B, NR2D, and NR3A with antisense-oligodeoxynucleotide treatment in the DRG. Also, in vitro experiments showed that the NMDA-induced sensitization of cultured DRG neurons depends on satellite cell activation and on those same NMDAR subunits, suggesting their importance for the PGE2-induced hyperalgesia. In addition, fluorescent calcium imaging experiments in cultures of DRG cells showed induction of calcium transients by glutamate or NMDA only in satellite cells, but not in neurons. Together, the present results suggest that the mechanical inflammatory nociceptor sensitization is dependent on glutamate release at the DRG and subsequent NMDAR activation in satellite glial cells, supporting the idea that the peripheral hyperalgesia is an event modulated by a glutamatergic system in the DRG.

  17. Hippocampal GluA1-containing AMPA receptors mediate context-dependent sensitization to morphine.

    Science.gov (United States)

    Xia, Yan; Portugal, George S; Fakira, Amanda K; Melyan, Zara; Neve, Rachael; Lee, H Thomas; Russo, Scott J; Liu, Jie; Morón, Jose A

    2011-11-09

    Glutamatergic systems, including AMPA receptors (AMPARs), are involved in opiate-induced neuronal and behavioral plasticity, although the mechanisms underlying these effects are not fully understood. In the present study, we investigated the effects of repeated morphine administration on AMPAR expression, synaptic plasticity, and context-dependent behavioral sensitization to morphine. We found that morphine treatment produced changes of synaptic AMPAR expression in the hippocampus, a brain area that is critically involved in learning and memory. These changes could be observed 1 week after the treatment, but only when mice developed context-dependent behavioral sensitization to morphine in which morphine treatment was associated with drug administration environment. Context-dependent behavioral sensitization to morphine was also associated with increased basal synaptic transmission and disrupted hippocampal long-term potentiation (LTP), whereas these effects were less robust when morphine administration was not paired with the drug administration environment. Interestingly, some effects may be related to the prior history of morphine exposure in the drug-associated environment, since alterations of AMPAR expression, basal synaptic transmission, and LTP were observed in mice that received a saline challenge 1 week after discontinuation of morphine treatment. Furthermore, we demonstrated that phosphorylation of GluA1 AMPAR subunit plays a critical role in the acquisition and expression of context-dependent behavioral sensitization, as this behavior is blocked by a viral vector that disrupts GluA1 phosphorylation. These data provide evidence that glutamatergic signaling in the hippocampus plays an important role in context-dependent sensitization to morphine and supports further investigation of glutamate-based strategies for treating opiate addiction.

  18. The Proton-Activated Receptor GPR4 Modulates Glucose Homeostasis by Increasing Insulin Sensitivity

    Directory of Open Access Journals (Sweden)

    Luca Giudici

    2013-11-01

    Full Text Available Background: The proton-activated G protein-coupled receptor GPR4 is expressed in many tissues including white adipose tissue. GPR4 is activated by extracellular protons in the physiological pH range (i.e. pH 7.7 - 6.8 and is coupled to the production of cAMP. Methods: We examined mice lacking GPR4 and examined glucose tolerance and insulin sensitivity in young and aged mice as well as in mice fed with a high fat diet. Expression profiles of pro- and anti-inflammatory cytokines in white adipose tissue, liver and skeletal muscle was assessed. Results: Here we show that mice lacking GPR4 have an improved intraperitoneal glucose tolerance test and increased insulin sensitivity. Insulin levels were comparable but leptin levels were increased in GPR4 KO mice. Gpr4-/- showed altered expression of PPARα, IL-6, IL-10, TNFα, and TGF-1β in skeletal muscle, white adipose tissue, and liver. High fat diet abolished the differences in glucose tolerance and insulin sensitivity between Gpr4+/+ and Gpr4-/- mice. In contrast, in aged mice (12 months old, the positive effect of GPR4 deficiency on glucose tolerance and insulin sensitivity was maintained. Liver and adipose tissue showed no major differences in the mRNA expression of pro- and anti-inflammatory factors between aged mice of both genotypes. Conclusion: Thus, GPR4 deficiency improves glucose tolerance and insulin sensitivity. The effect may involve an altered balance between pro- and anti-inflammatory factors in insulin target tissues.

  19. Mechanical stress regulates insulin sensitivity through integrin-dependent control of insulin receptor localization.

    Science.gov (United States)

    Kim, Jung; Bilder, David; Neufeld, Thomas P

    2018-01-15

    Insulin resistance, the failure to activate insulin signaling in the presence of ligand, leads to metabolic diseases, including type 2 diabetes. Physical activity and mechanical stress have been shown to protect against insulin resistance, but the molecular mechanisms remain unclear. Here, we address this relationship in the Drosophila larval fat body, an insulin-sensitive organ analogous to vertebrate adipose tissue and livers. We found that insulin signaling in Drosophila fat body cells is abolished in the absence of physical activity and mechanical stress even when excess insulin is present. Physical movement is required for insulin sensitivity in both intact larvae and fat bodies cultured ex vivo. Interestingly, the insulin receptor and other downstream components are recruited to the plasma membrane in response to mechanical stress, and this membrane localization is rapidly lost upon disruption of larval or tissue movement. Sensing of mechanical stimuli is mediated in part by integrins, whose activation is necessary and sufficient for mechanical stress-dependent insulin signaling. Insulin resistance develops naturally during the transition from the active larval stage to the immotile pupal stage, suggesting that regulation of insulin sensitivity by mechanical stress may help coordinate developmental programming with metabolism. © 2018 Kim et al.; Published by Cold Spring Harbor Laboratory Press.

  20. An ATP sensitive light addressable biosensor for extracellular monitoring of single taste receptor cell.

    Science.gov (United States)

    Wu, Chunsheng; Du, Liping; Zou, Ling; Zhao, Luhang; Wang, Ping

    2012-12-01

    Adenosine triphosphate (ATP) is considered as the key neurotransmitter in taste buds for taste signal transmission and processing. Measurements of ATP secreted from single taste receptor cell (TRC) with high sensitivity and specificity are essential for investigating mechanisms underlying taste cell-to-cell communications. In this study, we presented an aptamer-based biosensor for the detection of ATP locally secreted from single TRC. ATP sensitive DNA aptamer was used as recognition element and its DNA competitor was served as signal transduction element that was covalently immobilized on the surface of light addressable potentiometric sensor (LAPS). Due to the light addressable capability of LAPS, local ATP secretion from single TRC can be detected by monitoring the working potential shifts of LAPS. The results show this biosensor can detect ATP with high sensitivity and specificity. It is demonstrated this biosensor can effectively detect the local ATP secretion from single TRC responding to tastant mixture. This biosensor could provide a promising new tool for the research of taste cell-to-cell communications as well as for the detection of local ATP secretion from other types of ATP secreting individual cells.

  1. Distress of ostracism: oxytocin receptor gene polymorphism confers sensitivity to social exclusion.

    Science.gov (United States)

    McQuaid, Robyn J; McInnis, Opal A; Matheson, Kimberly; Anisman, Hymie

    2015-08-01

    A single-nucleotide polymorphism on the oxytocin receptor gene (OXTR), rs53576, involving a guanine (G) to adenine (A) substitution has been associated with altered prosocial features. Specifically, individuals with the GG genotype (i.e. the absence of the polymorphism) display beneficial traits including enhanced trust, empathy and self-esteem. However, because G carriers might also be more socially sensitive, this may render them more vulnerable to the adverse effects of a negative social stressor. The current investigation, conducted among 128 white female undergraduate students, demonstrated that relative to individuals with AA genotype, G carriers were more emotionally sensitive (lower self-esteem) in response to social ostracism promoted through an on-line ball tossing game (Cyberball). Furthermore, GG individuals also exhibited altered blood pressure and cortisol levels following rejection, effects not apparent among A carriers. The data support the view that the presence of the G allele not only promotes prosocial behaviors but also favors sensitivity to a negative social stressor. © The Author (2015). Published by Oxford University Press. For Permissions, please email: journals.permissions@oup.com.

  2. Androgen receptor signaling is required for androgen-sensitive human prostate cancer cell proliferation and survival

    Directory of Open Access Journals (Sweden)

    Day Wanda V

    2005-04-01

    Full Text Available Abstract Background Androgens and androgen receptors (AR regulate normal prostate development and growth. They also are involved in pathological development of prostatic diseases, including benign prostatic hyperplasia (BPH and prostate cancer (PCa. Antiandrogen therapy for PCa, in conjunction with chemical or surgical castration, offers initial positive responses and leads to massive prostate cell death. However, cancer cells later appear as androgen-independent PCa. To investigate the role of AR in prostate cell proliferation and survival, we introduced a vector-based small interfering RNA (siRNA. This siRNA targeted 5'-untranslated region of AR mRNA for extended suppression of AR expression in androgen-sensitive human prostate LNCaP cells. Results The siRNA design successfully suppressed endogenous AR expression, as revealed by western blotting and immunofluorescence staining in LNCaP cells. LNCaP cells did not proliferate in the absence of AR and underwent apoptosis, based on elevated phospho-Histone H2B expression and higher number of apoptotic body as compared to control cells. Conclusion We demonstrated that AR is vital for prostate cell proliferation and survival in this androgen-sensitive prostate cell line. These results further strengthen the hypothesis that AR can be a therapeutic target for treating androgen-sensitive stages of PCa. Unlike antiandorgens, however, siRNA targeting AR provides a direct inactivation of AR function through the suppression of AR protein expression.

  3. Highly selective and sensitive detection of neurotransmitters using receptor-modified single-walled carbon nanotube sensors

    Science.gov (United States)

    Kim, Byeongju; Song, Hyun Seok; Jin, Hye Jun; Park, Eun Jin; Lee, Sang Hun; Lee, Byung Yang; Park, Tai Hyun; Hong, Seunghun

    2013-07-01

    We present receptor-modified carbon nanotube sensors for the highly selective and sensitive detection of acetylcholine (ACh), one kind of neurotransmitter. Here, we successfully expressed the M1 muscarinic acetylcholine receptor (M1 mAChR), a family of G protein-coupled receptors (GPCRs), in E. coli and coated single-walled carbon nanotube (swCNT)-field effect transistors (FETs) with lipid membrane including the receptor, enabling highly selective and sensitive ACh detection. Using this sensor, we could detect ACh at 100 pM concentration. Moreover, we showed that this sensor could selectively detect ACh among other neurotransmitters. This is the first demonstration of the real-time detection of ACh using specific binding between ACh and M1 mAChR, and it may lead to breakthroughs for various applications such as disease diagnosis and drug screening.

  4. Highly selective and sensitive detection of neurotransmitters using receptor-modified single-walled carbon nanotube sensors

    International Nuclear Information System (INIS)

    Kim, Byeongju; Jin, Hye Jun; Park, Eun Jin; Hong, Seunghun; Song, Hyun Seok; Lee, Sang Hun; Park, Tai Hyun; Lee, Byung Yang

    2013-01-01

    We present receptor-modified carbon nanotube sensors for the highly selective and sensitive detection of acetylcholine (ACh), one kind of neurotransmitter. Here, we successfully expressed the M1 muscarinic acetylcholine receptor (M1 mAChR), a family of G protein-coupled receptors (GPCRs), in E. coli and coated single-walled carbon nanotube (swCNT)-field effect transistors (FETs) with lipid membrane including the receptor, enabling highly selective and sensitive ACh detection. Using this sensor, we could detect ACh at 100 pM concentration. Moreover, we showed that this sensor could selectively detect ACh among other neurotransmitters. This is the first demonstration of the real-time detection of ACh using specific binding between ACh and M1 mAChR, and it may lead to breakthroughs for various applications such as disease diagnosis and drug screening. (paper)

  5. [BETA-ADRENERGIC REGULATION OF THE ADENYLYL CYCLASE SIGNALING SYSTEM IN MYOCARDIUM AND BRAIN OF RATS WITH OBESITY AND TYPES 2 DIABETES MELLITUS AND THE EFFECT OF LONG-TERM INTRANASAL INSULIN TREATMENT].

    Science.gov (United States)

    Kuznetsova, L A; Sharova, T S; Pertseva, M N; Shpakov, A O

    2015-01-01

    The stimulating effect of norepinephrine, isoproterenol and selective β-adrenoceptor (β3-AR) agonists BRL 37344 and CL 316.243 on the adenylyl cyclase signaling system (ACSS) in the brain and myocardium of young and mature rats (disease induction at 2 and 4 months, respectively) with experimental obesity and type 2 diabetes mellitus (DM2), and the influence of long-term treatment of animals with intranasal insulin (I-I) were studied. The AC stimulatory effects of β-agonist isoproterenol in animals with obesity and DM2 was shown to be practically unchanged. The respective effects of norepinephrine on the AC activity were attenuated in the brain of young and mature rats and in the myocardium if mature rats, and the I-I treatment led to their partial recovery. In the brain and myocardium of mature rats with obesity and DM2, the enhancement of the AC stimulatory effects of β3-AR agonists was observed, white in young rats the influence of the same pathological conditions was lacking. The I-I treatment decreased the AC stimulatory effects of β3-agonists to their levels in the control. Since functional disruption of the adrenergic agonist-sensitive ACSS can lead to metabolic syndrome and DM2, the recovery of this system by the I-I treatment offers one of the ways to correct these diseases and their complications in the nervous and cardiovascular systems.

  6. Parkinson’s Disease: Low-Dose Haloperidol Increases Dopamine Receptor Sensitivity and Clinical Response

    Directory of Open Access Journals (Sweden)

    Craig J. Hudson

    2014-01-01

    Full Text Available Background. It is known that ultra-low doses of haloperidol can cause dopamine supersensitivity of dopamine D2 receptors and related behaviour in animals. Objective. The objective was to determine whether a daily ultra-low dose of 40 micrograms of haloperidol could enhance the clinical action of levodopa in Parkinson’s disease patients. Method. While continuing their daily treatment with levodopa, 16 patients with Parkinson’s disease were followed weekly for six weeks. They received an add-on daily dose of 40 micrograms of haloperidol for the first two weeks only. The SPES/SCOPA scale (short scale for assessment of motor impairments and disabilities in Parkinson’s disease was administered before treatment and weekly throughout the trial. Results. The results showed a mean decrease in SPES/SCOPA scores after one week of the add-on treatment. Conclusion. SCOPA scores decreased after the addition of low-dose haloperidol to the standard daily levodopa dose. This finding is consistent with an increase in sensitivity of dopamine D2 receptors induced by haloperidol. Such treatment for Parkinson’s disease may possibly permit the levodopa dose to be reduced and, thus, delay the onset of levodopa side effects.

  7. Ryk receptor regulates hematopoietic stem and progenitor sensitivity to myelosuppressive injury in mice

    Science.gov (United States)

    Povinelli, Benjamin J.; Srivastava, Pragya; Nemeth, Michael J.

    2017-01-01

    Maintaining a careful balance between quiescence and proliferation of hematopoietic stem and progenitor cells (HSPCs) is necessary for lifelong blood formation. Previously, we demonstrated that the Wnt5a ligand inhibits HSPC proliferation through a functional interaction with a non-canonical Wnt ligand receptor termed Ryk. Expression of Ryk on HSPCs in vivo is associated with a lower rate of proliferation and following treatment with fluorouracil (5-FU), the percentage of Ryk+/high HSPCs increased while the percent of Ryk−/low HSPCs decreased. Based on these data, we hypothesized that one function of the Ryk receptor is to protect HSPCs from the effects of myeloablative agents. We found that Ryk expression on HSPCs is associated with lower rates of apoptosis following 5-FU and radiation. Transient inhibition of Ryk signaling in vivo resulted in increased HSC proliferation and decreased HSC function in bone marrow transplant assays. Furthermore, inhibition of Ryk signaling sensitized HSPCs to 5-FU treatment in association with increased levels of reactive oxygen species. Together, these results demonstrated an association between Ryk expression and survival of HSPCs following suppressive injury. PMID:25461251

  8. Characterization of the insulin sensitivity of ghrelin receptor KO mice using glycemic clamps

    Directory of Open Access Journals (Sweden)

    Morgan Kristen

    2011-01-01

    Full Text Available Abstract Background We and others have demonstrated previously that ghrelin receptor (GhrR knock out (KO mice fed a high fat diet (HFD have increased insulin sensitivity and metabolic flexibility relative to WT littermates. A striking feature of the HFD-fed GhrR KO mouse is the dramatic decrease in hepatic steatosis. To characterize further the underlying mechanisms of glucose homeostasis in GhrR KO mice, we conducted both hyperglycemic (HG and hyperinsulinemic-euglycemic (HI-E clamps. Additionally, we investigated tissue glucose uptake and specifically examined liver insulin sensitivity. Results Consistent with glucose tolerance-test data, in HG clamp experiments, GhrR KO mice showed a reduction in glucose-stimulated insulin release relative to WT littermates. Nevertheless, a robust 1st phase insulin secretion was still achieved, indicating that a healthy β-cell response is maintained. Additionally, GhrR KO mice demonstrated both a significantly increased glucose infusion rate and significantly reduced insulin requirement for maintenance of the HG clamp, consistent with their relative insulin sensitivity. In HI-E clamps, both LFD-fed and HFD-fed GhrR KO mice showed higher peripheral insulin sensitivity relative to WT littermates as indicated by a significant increase in insulin-stimulated glucose disposal (Rd, and decreased hepatic glucose production (HGP. HFD-fed GhrR KO mice showed a marked increase in peripheral tissue glucose uptake in a variety of tissues, including skeletal muscle, brown adipose tissue and white adipose tissue. GhrR KO mice fed a HFD also showed a modest, but significant decrease in conversion of pyruvate to glucose, as would be anticipated if these mice displayed increased liver insulin sensitivity. Additionally, the levels of UCP2 and UCP1 were reduced in the liver and BAT, respectively, in GhrR KO mice relative to WT mice. Conclusions These results indicate that improved glucose homeostasis of GhrR KO mice is

  9. Differential ontogenetic patterns of levocabastine-sensitive neurotensin NT2 receptors and of NT1 receptors in the rat brain revealed by in situ hybridization.

    Science.gov (United States)

    Lépée-Lorgeoux, I; Betancur, C; Rostène, W; Pélaprat, D

    1999-03-12

    The postnatal ontogeny of the levocabastine-sensitive neurotensin receptor (NT2) mRNA was studied by in situ hybridization in the rat brain and compared with the distribution of the levocabastine-insensitive NT1 receptor. NT2 receptor mRNA was absent at birth from all brain structures except the ependymal cell layer lining the ventricles. The development of NT2 receptor mRNA followed three ontogenetic patterns. The first pattern, involving the majority of the cerebral gray matter, was characterized by a continuous increase from postnatal day 5 (P5) to P30. The second one, involving regions rich in myelinated fibers such as the corpus callosum and lacunosum moleculare layer of the hippocampus, exhibited a pronounced increase between P5 and P10, peaked at P15 and was followed by a plateau or a slight decrease. The third pattern was observed in the ependymal cell layer lining the olfactory and lateral ventricles, where the high labeling already present at birth continued to increase during development. These different developmental patterns could reflect the variety of cells expressing NT2 receptor mRNA, including neurons, protoplasmic astrocytes in gray matter, fibrous astrocytes present in myelinated fibers tracts, and ependymal cells. In contrast, NT1 receptor mRNA, which seems to be associated only with neurons, was highly and transiently expressed during the perinatal period in the cerebral cortex, hippocampus and striatal neuroepithelium. Other regions, notably the ventral tegmental area and substantia nigra compacta, exhibited a gradual increase in NT1 receptor signal, reaching adult levels by P21. Both the differential localization and ontogenetic profiles of NT1 and NT2 receptor mRNAs suggest different involvement of these two receptors in brain functions and development. Copyright 1999 Elsevier Science B.V.

  10. Effect of paraoxon on muscarinic, dopamine and γ-aminobutyric acid receptors of brain and sensitivity to muscarinic antagonists

    International Nuclear Information System (INIS)

    Fernando, J.C.R.; Hoskins, B.; Ho, I.K.

    1986-01-01

    Several acetylcholinesterase (AChE) inhibitors decrease muscarinic cholinergic (mACh) receptors in the brain, alteration of dopamine (DA) and γ-aminobutyric acid (GABA) receptors after AChE inhibition was also reported. In view of the important interactions among DA, GABA and ACh systems, whether this is a common effect of AChE inhibitors should be established. They report the effect of the AChE inhibitor, paraoxon, on DA, GABA and mACh receptors in the rat. The binding of 3 H-QNB (for mACh), 3 H-spiperone (for DA) and 3 H-muscimol (for GABA) to striatal and hippocampal membranes was analyzed. Also, behavioral sensitivity to atropine was studied. Twenty-four hr after a single dose (0.75 mg/kg, s.c.) of paraoxon, the density of mACh receptors in the striatum was decreased but, at 3 days, no change was seen. In the hippocampus, the mACh receptors were not affected. Repeated treatment with paraoxon (0.3 mg/kg, 48 hourly) for 2 weeks reduced the mACh receptor density in both regions. Neither single nor repeated paraoxon treatment had an effect on DA or GABA receptors. After single or repeated dosing with paraoxon, myoclonus induced by atropine (10 mg/kg, i.p.) was enhanced. The results show rapid downregulation of mACh receptors by paraoxon. DA or GABA, however, appear not to be affected under these treatment regimens

  11. Deletion of Type 2 Metabotropic Glutamate Receptor Decreases Sensitivity to Cocaine Reward in Rats.

    Science.gov (United States)

    Yang, Hong-Ju; Zhang, Hai-Ying; Bi, Guo-Hua; He, Yi; Gao, Jun-Tao; Xi, Zheng-Xiong

    2017-07-11

    Cocaine users show reduced expression of the metabotropic glutamate receptor (mGluR2), but it is not clear whether this is a predisposing trait for addiction or a consequence of drug exposure. In this study, we found that a nonsense mutation at the mGluR2 gene decreased mGluR2 expression and altered the seeking and taking of cocaine. mGluR2 mutant rats show reduced sensitivity to cocaine reward, requiring more cocaine to reach satiation when it was freely available and ceasing their drug-seeking behavior sooner than controls when the response requirement was increased. mGluR2 mutant rats also show a lower propensity to relapse after a period of cocaine abstinence, an effect associated with reduced cocaine-induced dopamine and glutamate overflow in the nucleus accumbens. These findings suggest that mGluR2 polymorphisms or reduced availability of mGluR2 might be risk factors for the initial development of cocaine use but could actually protect against addiction by reducing sensitivity to cocaine reward. Published by Elsevier Inc.

  12. PCA3 Silencing Sensitizes Prostate Cancer Cells to Enzalutamide-mediated Androgen Receptor Blockade.

    Science.gov (United States)

    Özgür, Emre; Celik, Ayca Iribas; Darendeliler, Emin; Gezer, Ugur

    2017-07-01

    Prostate cancer (PCa) is an androgen-dependent disease. Novel anti-androgens (i.e. enzalutamide) have recently been developed for the treatment of patients with metastatic castration-resistant prostate cancer (CRPC). Evidence is accumulating that prostate cancer antigen 3 (PCA3) is involved in androgen receptor (AR) signaling. Here, in combination with enzalutamide-mediated AR blockade, we investigated the effect of PCA3 targeting on the viability of PCa cells. In hormone-sensitive LNCaP cells, AR-overexpressing LNCaP-AR + cells and VCaP cells (representing CRPC), PCA3 was silenced using siRNA oligonucleotides. Gene expression and cell viability was assessed in PCA3-silenced and/or AR-blocked cells. PCA3 targeting reduced the expression of AR-related genes (i.e. prostate-specific antigen (PSA) and prostate-specific transcript 1 (non-protein coding) (PCGEM1)) and potentiated the effect of enzalutamide. Proliferation of PCa cells was suppressed upon PCA3 silencing with a greater effect in LNCaP-AR + cells. Furthermore, PCA3 silencing sensitized PCa cells to enzalutamide-induced loss of cell growth. PCA3, as a therapeutic target in PCa, might be used to potentiate AR antagonists. Copyright© 2017, International Institute of Anticancer Research (Dr. George J. Delinasios), All rights reserved.

  13. Oxytocin receptor gene polymorphisms (rs53576) and early paternal care sensitize males to distressing female vocalizations.

    Science.gov (United States)

    Truzzi, Anna; Poquérusse, Jessie; Setoh, Peipei; Shinohara, Kazuyuki; Bornstein, Marc H; Esposito, Gianluca

    2018-04-01

    The oxytocinergic system is highly involved in social bonding and early caregiver-infant interactions. Here, we hypothesize that oxytocin receptor (OXTR) gene genotype and parental bonding history interact in influencing social development. To address this question, we assessed adult males' arousal (heart rate changes) in response to different distress vocalizations (human female, human infant and bonobo). Region rs53576 of the OXTR gene was genotyped from buccal mucosa cell samples, and a self-report Parental Bonding Instrument was used (which provide information about parental care or parental overprotection). A significant gene-environment interaction between OXTR genotype and parenting style was found to influence participants' social responsivity to female cry vocalizations. Specifically, a history of appropriate paternal care in participants accentuated the heightened social sensitivity determined by G/G homozygosity, while higher versus lower paternal overprotection lead to distinct levels of physiological arousal particularly in A carriers individuals. These results add to our understanding of the dynamic interplay between genetic susceptibility and early environmental experience in shaping the development of appropriate social sensitivity in males. © 2018 Wiley Periodicals, Inc.

  14. Trace Amine-Associated Receptor 1 Modulates the Locomotor and Sensitization Effects of Nicotine

    Science.gov (United States)

    Sukhanov, Ilya; Dorofeikova, Mariia; Dolgorukova, Antonina; Dorotenko, Artem; Gainetdinov, Raul R.

    2018-01-01

    Trace amine-associated receptor 1 (TAAR1) has emerged as a promising target for addiction treatments because it affects dopamine transmission in the mesolimbic pathway. TAAR1 is involved in the effects of addictive drugs, such as amphetamines, cocaine and ethanol, but the impact of TAAR1 on the effects of nicotine, the psychoactive drug responsible for the development and maintenance of tobacco smoking, has not yet been studied. This study was performed to investigate the possible modulatory action of TAAR1 on the effects of nicotine on locomotor behaviors in rats and mice. Pretreatment with the TAAR1 agonist RO5263397 dose-dependently decreased nicotine-induced hyperlocomotion in rats habituated to locomotor boxes, prevented the development of nicotine sensitization and blocked hypermotility in nicotine-sensitized rats at the highest tested dose (10 mg/kg). The lack of TAAR1 failed to affect the effects of nicotine on the locomotion of mutant mice. Based on the results of the present study, TAAR1 activation attenuates the locomotion-stimulating effects of nicotine on rats. These results further support the previously proposed hypothesis that TAAR1 is a promising target for the prevention and treatment of drug addiction. Further studies aimed at analyzing the effects of TAAR1 agonists on animal models of nicotine addiction are warranted. PMID:29681856

  15. Trace Amine-Associated Receptor 1 Modulates the Locomotor and Sensitization Effects of Nicotine

    Directory of Open Access Journals (Sweden)

    Ilya Sukhanov

    2018-04-01

    Full Text Available Trace amine-associated receptor 1 (TAAR1 has emerged as a promising target for addiction treatments because it affects dopamine transmission in the mesolimbic pathway. TAAR1 is involved in the effects of addictive drugs, such as amphetamines, cocaine and ethanol, but the impact of TAAR1 on the effects of nicotine, the psychoactive drug responsible for the development and maintenance of tobacco smoking, has not yet been studied. This study was performed to investigate the possible modulatory action of TAAR1 on the effects of nicotine on locomotor behaviors in rats and mice. Pretreatment with the TAAR1 agonist RO5263397 dose-dependently decreased nicotine-induced hyperlocomotion in rats habituated to locomotor boxes, prevented the development of nicotine sensitization and blocked hypermotility in nicotine-sensitized rats at the highest tested dose (10 mg/kg. The lack of TAAR1 failed to affect the effects of nicotine on the locomotion of mutant mice. Based on the results of the present study, TAAR1 activation attenuates the locomotion-stimulating effects of nicotine on rats. These results further support the previously proposed hypothesis that TAAR1 is a promising target for the prevention and treatment of drug addiction. Further studies aimed at analyzing the effects of TAAR1 agonists on animal models of nicotine addiction are warranted.

  16. Pore helix domain is critical to camphor sensitivity of transient receptor potential vanilloid 1 channel.

    Science.gov (United States)

    Marsakova, Lenka; Touska, Filip; Krusek, Jan; Vlachova, Viktorie

    2012-04-01

    The recent discovery that camphor activates and strongly desensitizes the capsaicin-sensitive and noxious heat-sensitive channel transient receptor potential vanilloid subfamily member 1 (TRPV1) has provided new insights and opened up new research paths toward understanding why this naturally occurring monoterpene is widely used in human medicine for its local counter-irritant, antipruritic, and anesthetic properties. However, the molecular basis for camphor sensitivity remains mostly unknown. The authors attempt to explore the nature of the activation pathways evoked by camphor and narrow down a putative interaction site at TRPV1. The authors transiently expressed wild-type or specifically mutated recombinant TRPV1 channels in human embryonic kidney cells HEK293T and recorded cation currents with the whole cell, patch clamp technique. To monitor changes in the spatial distribution of phosphatidylinositol 4,5-bisphosphate, they used fluorescence resonance energy transfer measurements from cells transfected with the fluorescent protein-tagged pleckstrin homology domains of phospholipase C. The results revealed that camphor modulates TRPV1 channel through the outer pore helix domain by affecting its overall gating equilibrium. In addition, camphor, which generally is known to decrease the fluidity of cell plasma membranes, may also regulate the activity of TRPV1 by inducing changes in the spatial distribution of phosphatidylinositol-4,5-bisphosphate on the inner leaflet of the plasma membrane. The findings of this study provide novel insights into the structural basis for the modulation of TRPV1 channel by camphor and may provide an explanation for the mechanism by which camphor modulates thermal sensation in vivo.

  17. The role of G-protein-coupled receptors in mediating the effect of fatty acids on inflammation and insulin sensitivity.

    Science.gov (United States)

    Oh, Da Young; Lagakos, William S

    2011-07-01

    Chronic activation of inflammatory pathways mediates the pathogenesis of insulin resistance, and the macrophage/adipocyte nexus provides a key mechanism underlying decreased insulin sensitivity. Free fatty acids are important in the pathogenesis of insulin resistance, although their precise mechanisms of action have yet to be fully elucidated. Recently, a family of G-protein-coupled receptors has been identified that exhibits high affinity for fatty acids. This review summarizes recent findings on six of these receptors, their ligands, and their potential physiological functions in vivo. Upon activation, the free fatty acid receptors affect inflammation, glucose metabolism, and insulin sensitivity. Genetic deletion of GPR40 and GPR41, receptors for long-chain and short-chain fatty acids, respectively, results in resistance to diet-induced obesity. Deletion of GPR43 and GPR84 exacerbates inflammation, and deletion of the long-chain fatty acid receptors GPR119 and GPR120 reduces or is predicted to reduce glucose tolerance. These studies provide a new understanding of the general biology of gastric motility and also shed valuable insight into some potentially beneficial therapeutic targets. Furthermore, highly selective agonists or antagonists for the free fatty acid receptors have been developed and look promising for treating various metabolic diseases.

  18. In vivo evolution of HIV-1 co-receptor usage and sensitivity to chemokine-mediated suppression.

    Science.gov (United States)

    Scarlatti, G; Tresoldi, E; Björndal, A; Fredriksson, R; Colognesi, C; Deng, H K; Malnati, M S; Plebani, A; Siccardi, A G; Littman, D R; Fenyö, E M; Lusso, P

    1997-11-01

    Following the identification of the C-C chemokines RANTES, MIP-1alpha and MIP-1beta as major human immunodeficiency virus (HIV)-suppressive factors produced by CD8+ T cells, several chemokine receptors were found to serve as membrane co-receptors for primate immunodeficiency lentiretroviruses. The two most widely used co-receptors thus far recognized, CCR5 and CXCR4, are expressed by both activated T lymphocytes and mononuclear phagocytes. CCR5, a specific RANTES, MIP-1alpha and MIP-1 receptor, is used preferentially by non-MT2-tropic HIV-1 and HIV-2 strains and by simian immunodeficiency virus (SIV), whereas CXCR4, a receptor for the C-X-C chemokine SDF-1, is used by MT2-tropic HIV-1 and HIV-2, but not by SIV. Other receptors with a more restricted cellular distribution, such as CCR2b, CCR3 and STRL33, can also function as co-receptors for selected viral isolates. The third variable region (V3) of the gp120 envelope glycoprotein of HIV-1 has been fingered as a critical determinant of the co-receptor choice. Here, we document a consistent pattern of evolution of viral co-receptor usage and sensitivity to chemokine-mediated suppression in a longitudinal follow-up of children with progressive HIV-1 infection. Viral isolates obtained during the asymptomatic stages generally used only CCR5 as a co-receptor and were inhibited by RANTES, MIP-1alpha and MIP-1beta, but not by SDF-1. By contrast, the majority of the isolates derived after the progression of the disease were resistant to C-C chemokines, having acquired the ability to use CXCR4 and, in some cases, CCR3, while gradually losing CCR5 usage. Surprisingly, most of these isolates were also insensitive to SDF-1, even when used in combination with RANTES. An early acquisition of CXCR4 usage predicted a poor prognosis. In children who progressed to AIDS without a shift to CXCR4 usage, all the sequential isolates were CCR5-dependent but showed a reduced sensitivity to C-C chemokines. Discrete changes in the V3 domain

  19. Drosophila Insulin receptor regulates the persistence of injury-induced nociceptive sensitization

    Science.gov (United States)

    Patel, Atit A.

    2018-01-01

    ABSTRACT Diabetes-associated nociceptive hypersensitivity affects diabetic patients with hard-to-treat chronic pain. Because multiple tissues are affected by systemic alterations in insulin signaling, the functional locus of insulin signaling in diabetes-associated hypersensitivity remains obscure. Here, we used Drosophila nociception/nociceptive sensitization assays to investigate the role of Insulin receptor (Insulin-like receptor, InR) in nociceptive hypersensitivity. InR mutant larvae exhibited mostly normal baseline thermal nociception (absence of injury) and normal acute thermal hypersensitivity following UV-induced injury. However, their acute thermal hypersensitivity persists and fails to return to baseline, unlike in controls. Remarkably, injury-induced persistent hypersensitivity is also observed in larvae that exhibit either type 1 or type 2 diabetes. Cell type-specific genetic analysis indicates that InR function is required in multidendritic sensory neurons including nociceptive class IV neurons. In these same nociceptive sensory neurons, only modest changes in dendritic morphology were observed in the InRRNAi-expressing and diabetic larvae. At the cellular level, InR-deficient nociceptive sensory neurons show elevated calcium responses after injury. Sensory neuron-specific expression of InR rescues the persistent thermal hypersensitivity of InR mutants and constitutive activation of InR in sensory neurons ameliorates the hypersensitivity observed with a type 2-like diabetic state. Our results suggest that a sensory neuron-specific function of InR regulates the persistence of injury-associated hypersensitivity. It is likely that this new system will be an informative genetically tractable model of diabetes-associated hypersensitivity. PMID:29752280

  20. Intractable diarrhea in hyperthyroidism: management with beta-adrenergic blockade.

    Science.gov (United States)

    Bricker, L A; Such, F; Loehrke, M E; Kavanaugh, K

    2001-01-01

    To describe a patient with intractable diarrhea and thyrotoxic Graves' disease, for whom b-adrenergic blockade ultimately proved to be effective therapy for the diarrhea, and to review the types of hyperthyroidism-associated diarrhea. We present the clinical course of a young man with a prolonged siege of diarrhea that proved elusive to diagnostic inquiries and resistant to all means of management until its endocrine basis was discovered. Control of such cases with b-adrenergic blockade is discussed, as are the pathophysiologic bases of intestinal hypermotility in hyperthyroidism. A 26-year-old man with Down syndrome, and no prior gastrointestinal disorder, had insidious, chronic, constant diarrhea, which was associated with loss of 14 kg during a 5-month period. Numerous laboratory and imaging studies and endoscopic examinations failed to disclose the cause of the diarrhea. Furthermore, a broad range of antibiotics and other empiric remedies failed to control the problem. No other symptoms of hyperthyroidism were reported, but when the endocrinopathy was suspected and identified, the diarrhea was promptly controlled by treatment with propranolol. In patients with hyperthyroidism, two types of diarrheal disorders have been described-secretory diarrhea and steatorrhea; bile acid malabsorption may have a role in either of these settings. In addition to its capacity for blocking the peripheral effects of thyroid hormone on the heart and central nervous system, b-adrenergic blockade is effective in slowing intestinal transit time and ameliorating the uncommon diarrhea associated with hyperthyroidism. Thyroid hormone in excess, among its other possible effects on the gastrointestinal tract, may exert a stimulatory effect by means of intermediary sympathetic activation, as it does with the heart. Thus, sympathetic blockade can mimic the salutary effects on the gastrointestinal tract conventionally brought about by direct antithyroid therapy, and well before the hyperthyroid state per se is eliminated. The current patient illustrates the value of considering hyperthyroidism in the differential diagnosis of diarrhea of unknown cause.

  1. Negative allosteric modulation of the mGlu7 receptor reduces visceral hypersensitivity in a stress-sensitive rat strain

    Directory of Open Access Journals (Sweden)

    Rachel D. Moloney

    2015-01-01

    Full Text Available Glutamate, the main excitatory neurotransmitter in the central nervous system, exerts its effect through ionotropic and metabotropic receptors. Of these, group III mGlu receptors (mGlu 4, 6, 7, 8 are among the least studied due to a lack of pharmacological tools. mGlu7 receptors, the most highly conserved isoform, are abundantly distributed in the brain, especially in regions, such as the amygdala, known to be crucial for the emotional processing of painful stimuli. Visceral hypersensitivity is a poorly understood phenomenon manifesting as an increased sensitivity to visceral stimuli. Glutamate has long been associated with somatic pain processing leading us to postulate that crossover may exist between these two modalities. Moreover, stress has been shown to exacerbate visceral pain. ADX71743 is a novel, centrally penetrant, negative allosteric modulator of mGlu7 receptors. Thus, we used this tool to explore the possible involvement of this receptor in the mediation of visceral pain in a stress-sensitive model of visceral hypersensitivity, namely the Wistar Kyoto (WKY rat. ADX71743 reduced visceral hypersensitivity in the WKY rat as exhibited by increased visceral sensitivity threshold with concomitant reductions in total number of pain behaviours. Moreover, AD71743 increased total distance and distance travelled in the inner zone of the open field. These findings show, for what is to our knowledge, the first time, that mGlu7 receptor signalling plays a role in visceral pain processing. Thus, negative modulation of the mGlu7 receptor may be a plausible target for the amelioration of stress-induced visceral pain where there is a large unmet medical need.

  2. Super-Penetrant Androgen Receptor: Overcoming Enzalutamide Sensitivity in Castration-Resistant Prostate Cancer

    Science.gov (United States)

    2016-07-01

    Prostate Cancer Research Symposium- Prostate Cancer Epigenetic Reprogramming of the Androgen Receptor in Castration Resistant Prostate Cancer , May19... cancer cells rely critically on the androgen receptor (AR) for initiation, growth and progression to castration resistant prostate cancer (CRPC...Androgen receptor, castration resistant prostate cancer , Enzalutamide , kinases. 16. SECURITY CLASSIFICATION OF: 17. LIMITATION OF ABSTRACT 18. NUMBER

  3. Molecular determinants of ivermectin sensitivity at the glycine receptor chloride channel

    DEFF Research Database (Denmark)

    Lynagh, Timothy; Webb, Timothy I.; Dixon, Christine L.

    2011-01-01

    Ivermectin is an anthelmintic drug that works by activating glutamate-gated chloride channel receptors (GluClRs) in nematode parasites. GluClRs belong to the Cys-loop receptor family that also includes glycine receptor (GlyR) chloride channels. GluClRs and A288G mutant GlyRs are both activated...

  4. Soluble N-ethylmaleimide-sensitive factor attachment protein receptors required during Trypanosoma cruzi parasitophorous vacuole development.

    Science.gov (United States)

    Cueto, Juan Agustín; Vanrell, María Cristina; Salassa, Betiana Nebaí; Nola, Sébastien; Galli, Thierry; Colombo, María Isabel; Romano, Patricia Silvia

    2017-06-01

    Trypanosoma cruzi, the etiologic agent of Chagas disease, is an obligate intracellular parasite that exploits different host vesicular pathways to invade the target cells. Vesicular and target soluble N-ethylmaleimide-sensitive factor attachment protein receptors (SNAREs) are key proteins of the intracellular membrane fusion machinery. During the early times of T. cruzi infection, several vesicles are attracted to the parasite contact sites in the plasma membrane. Fusion of these vesicles promotes the formation of the parasitic vacuole and parasite entry. In this work, we study the requirement and the nature of SNAREs involved in the fusion events that take place during T. cruzi infection. Our results show that inhibition of N-ethylmaleimide-sensitive factor protein, a protein required for SNARE complex disassembly, impairs T. cruzi infection. Both TI-VAMP/VAMP7 and cellubrevin/VAMP3, two v-SNAREs of the endocytic and exocytic pathways, are specifically recruited to the parasitophorous vacuole membrane in a synchronized manner but, although VAMP3 is acquired earlier than VAMP7, impairment of VAMP3 by tetanus neurotoxin fails to reduce T. cruzi infection. In contrast, reduction of VAMP7 activity by expression of VAMP7's longin domain, depletion by small interfering RNA or knockout, significantly decreases T. cruzi infection susceptibility as a result of a minor acquisition of lysosomal components to the parasitic vacuole. In addition, overexpression of the VAMP7 partner Vti1b increases the infection, whereas expression of a KIF5 kinesin mutant reduces VAMP7 recruitment to vacuole and, concomitantly, T. cruzi infection. Altogether, these data support a key role of TI-VAMP/VAMP7 in the fusion events that culminate in the T. cruzi parasitophorous vacuole development. © 2016 John Wiley & Sons Ltd.

  5. Hormone-sensitive lipase (HSL) expression and regulation in skeletal muscle

    DEFF Research Database (Denmark)

    Langfort, J; Ploug, T; Ihlemann, J

    1998-01-01

    Because the enzymatic regulation of muscle triglyceride metabolism is poorly understood we explored the character and activation of neutral lipase in muscle. Western blotting of isolated rat muscle fibers demonstrated expression of hormone-sensitive lipase (HSL). In incubated soleus muscle...... epinephrine increased neutral lipase activity by beta-adrenergic mechanisms involving cyclic AMP-dependent protein kinase (PKA). The increase was paralleled by an increase in glycogen phosphorylase activity and could be abolished by antiserum against HSL. Electrical stimulation caused a transient increase...... in activity of both neutral lipase and glycogen phosphorylase. The increase in lipase activity during contractions was not influenced by sympathectomy or propranolol. Training diminished the epinephrine induced lipase activation in muscle but enhanced the activation as well as the overall concentration...

  6. Acoustic emission monitoring of medieval towers considered as sensitive earthquake receptors

    Directory of Open Access Journals (Sweden)

    A. Carpinteri

    2007-01-01

    Full Text Available Many ancient masonry towers are present in Italian territory. In some cases these structures are at risk on account of the intensity of the stresses they are subjected to due to the high level of regional seismicity. In order to preserve this inestimable cultural heritage, a sound safety assessment should take into account the evolution of damage phenomena. In this connection, acoustic emission (AE monitoring can be highly effective. This study concerns the structural stability of three medieval towers rising in the centre of Alba, a characteristic town in Piedmont (Italy. During the monitoring period a correlation between peaks of AE activity in the masonry of these towers and regional seismicity was found. Earthquakes always affect structural stability. Besides that, the towers behaved as sensitive earthquake receptors. Here a method to correlate bursts of AE activity in a masonry building and regional seismicity is proposed. In particular, this method permits to identify the premonitory signals that precede a catastrophic event on a structure, since, in most cases, these warning signs can be captured well in advance.

  7. Pheromone binding proteins enhance the sensitivity of olfactory receptors to sex pheromones in Chilo suppressalis.

    Science.gov (United States)

    Chang, Hetan; Liu, Yang; Yang, Ting; Pelosi, Paolo; Dong, Shuanglin; Wang, Guirong

    2015-08-27

    Sexual communication in moths offers a simplified scenario to model and investigate insect sensory perception. Both PBPs (pheromone-binding proteins) and PRs (pheromone receptors) are involved in the detection of sex pheromones, but the interplay between them still remains largely unknown. In this study, we have measured the binding affinities of the four recombinant PBPs of Chilo suppressalis (CsupPBPs) to pheromone components and analogs and characterized the six PRs using the Xenopus oocytes expression system. Interestingly, when the responses of PRs were recorded in the presence of PBPs, we measured in several combinations a dramatic increase in signals as well as in sensitivity of such combined systems. Furthermore, the discrimination ability of appropriate combinations of PRs and PBPs was improved compared with the performance of PBPs or PRs alone. Besides further supporting a role of PBPs in the pheromone detection and discrimination, our data shows for the first time that appropriate combinations of PRs and PBPs improved the discrimination ability of PBPs or PRs alone. The variety of responses measured with different pairing of PBPs and PRs indicates the complexity of the olfaction system, which, even for the relatively simple task of detecting sex pheromones, utilises a highly sophisticated combinatorial approach.

  8. Effects of β-estradiol on cold-sensitive receptor channel TRPM8 in ovariectomized rats.

    Science.gov (United States)

    Kubo, Takuro; Tsuji, Shunichiro; Amano, Tsukuru; Yoshino, Fumi; Niwa, Yoko; Kasahara, Kyoko; Yoshida, Saori; Mukaisho, Ken-Ichi; Sugihara, Hiroyuki; Tanaka, Sachiko; Kimura, Fuminori; Takahashi, Kentaro; Murakami, Takashi

    2017-10-30

    Transient receptor potential cation channel subfamily M member 8 (TRPM8) is associated with sensitivity to cold sensation in mammals. A previous study demonstrated that TRPM8 was overexpressed in the skin of ovariectomized (OVX) rats due to the loss of estrogen. In the present study, we investigated whether estrogen replacement restricts overexpression of the TRPM8 channel in the skin of OVX rats. We divided 15 Sprague Dawley rats into three groups: a non-operated group (NON-OPE), an ovariectomy group (OVX), and a group subjected to estrogen replacement during 4 weeks beginning 7 days after ovariectomy (OVX + E2). Five weeks later, TRPM8 channel mRNA and protein in lumbar skin were quantified by real-time RT-PCR, protein ELISA, and immunohistochemistry. The OVX + E2 group exhibited a trend for decreased expression of the TRPM8 channel in the lumbar skin in comparison with the OVX group, whereas ELISA data and immunohistochemistry data and immunohistochemistry graphs relating to TRPM8 protein did not show any obvious differences between the OVX group and the OVX + E2 group. Estrogen replacement may restrict the overexpression of TRPM8 in the dermis of OVX rats.

  9. Naloxone-sensitive, haloperidol-sensitive, [3H](+)SKF-10047-binding protein partially purified from rat liver and rat brain membranes: an opioid/sigma receptor?

    Science.gov (United States)

    Tsao, L I; Su, T P

    1997-02-01

    A naloxone-sensitive, haloperidol-sensitive, [3H](+)SKF-10047-binding protein was partially purified from rat liver and rat brain membranes in an affinity chromatography originally designed to purify sigma receptors. Detergent-solubilized extracts from membranes were adsorbed to Sephadex G-25 resin containing an affinity ligand for sigma receptors: N-(2- 3,4-dichlorophenyl]ethyl)-N-(6-aminohexyl)-(2-[1-pyrrolidinyl]) ethylamine (DAPE). After eluting the resin with haloperidol, a protein that bound [3H](+)SKF-10047 was detected in the eluates. However, the protein was not the sigma receptor. [3H](+)SKF-10047 binding to the protein was inhibited by the following compounds in the order of decreasing potency: (+)pentazocine > (-) pentazocine > (+/-)cyclazocine > (-)morphine > (-)naloxone > haloperidol > (+)SKF-10047 > DADLE > (-)SKF-10047. Further, the prototypic sigma receptor ligands, such as 1,3-di-o-tolylguanidine (DTG), (+)3-PPP, and progesterone, bound poorly to the protein. Tryptic digestion and heat treatment of the affinity-purified protein abolished radioligand binding. Sodium dodecyl sulfate/polyacrylamide gel electrophoresis (SDS/PAGE) of the partially-purified protein from the liver revealed a major diffuse band with a molecular mass of 31 kDa, a polypeptide of 65 kDa, and another polypeptide of > 97 kDa. This study demonstrates the existence of a novel protein in the rat liver and rat brain which binds opioids, benzomorphans, and haloperidol with namomolar affinity. The protein resembles the opioid/sigma receptor originally proposed by Martin et al. [(1976): J. Pharmacol. Exp. Ther., 197:517-532.]. A high degree of purification of this protein has been achieved in the present study.

  10. Tumor necrosis factor α sensitizes spinal cord TRPV1 receptors to the endogenous agonist N-oleoyldopamine

    Directory of Open Access Journals (Sweden)

    Spicarova Diana

    2010-08-01

    Full Text Available Abstract Modulation of synaptic transmission in the spinal cord dorsal horn is thought to be involved in the development and maintenance of different pathological pain states. The proinflamatory cytokine, tumor necrosis factor α (TNFα, is an established pain modulator in both the peripheral and the central nervous system. Up-regulation of TNFα and its receptors (TNFR in dorsal root ganglion (DRG cells and in the spinal cord has been shown to play an important role in neuropathic and inflammatory pain conditions. Transient receptor potential vanilloid 1 (TRPV1 receptors are known as molecular integrators of nociceptive stimuli in the periphery, but their role on the spinal endings of nociceptive DRG neurons is unclear. The endogenous TRPV1 receptor agonist N-oleoyldopamine (OLDA was shown previously to activate spinal TRPV1 receptors. In our experiments the possible influence of TNFα on presynaptic spinal cord TRPV1 receptor function was investigated. Using the patch-clamp technique, miniature excitatory postsynaptic currents (mEPSCs were recorded in superficial dorsal horn neurons in acute slices after incubation with 60 nM TNFα. A population of dorsal horn neurons with capsaicin sensitive primary afferent input recorded after the TNFα pretreatment had a basal mEPSC frequency of 1.35 ± 0.20 Hz (n = 13, which was significantly higher when compared to a similar population of neurons in control slices (0.76 ± 0.08 Hz; n = 53; P

  11. Purification and reconstitution of the calcium antagonist receptor of the voltage-sensitive calcium channel

    International Nuclear Information System (INIS)

    Curtis, B.M.

    1986-01-01

    Treatment with digitonin solubilized the calcium antagonist receptor as a stable complex with [ 3 H]nitrendipine from rat brain membranes. The solubilized complex retains allosteric coupling to binding sites for diltiazem, verapamil, and inorganic calcium antagonist sites. The calcium antagonist receptor from cardiac sarcolemma and the transverse-tubule membrane of skeletal muscle is also efficiently solubilized with digitonin and the receptor in all three tissues is a large glycoprotein with a sedimentation coefficient of 20 S. The T-tubule calcium antagonist receptor complex was extensively purified by a combination of chromatography on WGA-Sepharose, ion exchange chromatography, and sedimentation on sucrose gradients to yield preparations estimated to be 41% homogeneous by specific activity and 63% homogeneous by SDS gel electrophoresis. Analysis of SDS gels detect three polypeptides termed α(Mr 135,000), β(Mr 50,000), and γ(Mr 32,000) as noncovalently associated subunits of the calcium antagonist receptor. The α and γ subunits are glycosylated polypeptides, and the molecular weight of the core polypeptides are 108,000 and 24,000 respectively. The calcium antagonist receptor was reconstituted into a phospholipid bilayer by adding CHAPS and exogeneous lipid to the purified receptor followed by rapid detergent removal. This procedure resulted in the incorporation of 45% of the calcium antagonist receptor into closed phospholipid vesicles. Data suggests that the α, β, and γ subunits of the T-tubule calcium antagonist receptor are sufficient to form a functional calcium channel

  12. The brain 5-HT4 receptor binding is down-regulated in the Flinders Sensitive Line depression model and in response to paroxetine administration

    DEFF Research Database (Denmark)

    Licht, Cecilie Löe; Marcussen, Anders Bue; Wegener, Gregers

    2009-01-01

    The 5-hydroxytryptamine (5-HT(4)) receptor may be implicated in depression and is a new potential target for antidepressant treatment. We have investigated the brain 5-HT(4) receptor [(3)H]SB207145 binding in the Flinders Sensitive Line rat depression model by quantitative receptor autoradiography....... In the Flinders Sensitive Line, the 5-HT(4) receptor and 5-HT transporter binding were decreased in the dorsal and ventral hippocampus, and the changes in binding were directly correlated within the dorsal hippocampus. Chronic but not acute paroxetine administration caused a 16-47% down-regulation of 5-HT(4......) receptor binding in all regions evaluated including the basal ganglia and hippocampus, while 5-HT depletion increased the 5-HT(4) receptor binding in the dorsal hippocampus, hypothalamus, and lateral globus pallidus. In comparison, the 5-HT(2A) receptor binding was decreased in the frontal and cingulate...

  13. Unraveling the high- and low-sensitivity agonist responses of nicotinic acetylcholine receptors

    DEFF Research Database (Denmark)

    Harpsøe, Kasper; Ahring, Philip K; Christensen, Jeppe K

    2011-01-01

    The neuronal a4ß2 nicotinic acetylcholine receptors exist as two distinct subtypes, (a4)(2)(ß2)(3) and (a4)(3)(ß2)(2), and biphasic responses to acetylcholine and other agonists have been ascribed previously to coexistence of these two receptor subtypes. We offer a novel and radical explanation...

  14. The farnesoid X receptor modulates adiposity and peripheral insulin sensitivity in mice

    NARCIS (Netherlands)

    Cariou, B; van Harmelen, K; Duran-Sandoval, D; van Dijk, TH; Grefhorst, A; Abdelkarim, M; Caron, S; Torpier, G; Fruchart, JC; Gonzalez, FJ; Kuipers, F; Staels, B

    2006-01-01

    The farnesoid X receptor (FXR) is a bile acid (BA)-activated nuclear receptor that plays a major role in the regulation of BA and lipid metabolism. Recently, several studies have suggested a potential role of FXR in the control of hepatic carbohydrate metabolism, but its contribution to the

  15. Endocrine sensitivity of the receptor-positive T61 human breast carcinoma serially grown in nude mice

    DEFF Research Database (Denmark)

    Brünner, N; Spang-Thomsen, M; Skovgaard Poulsen, H

    1985-01-01

    A study was made on the effect of ovariectomy, 17 beta-oestradiol, and tamoxifen on the oestrogen and progesterone receptor-positive T61 human breast carcinoma grown in nude mice. The effect of the treatment was evaluated by the specific growth delay calculated on the basis of Gompertz growth cur...... but is not a sufficiently clear marker to allow prediction of the endocrine sensitivity of individual breast tumours....

  16. S36. DIFFERENTIAL ENCODING OF SENSITIZATION AND CROSS SENSITIZATION TO PSYCHOSTIMULANTS AND ANTIPSYCHOTICS IN NUCLEUS ACCUMBENS D1- AND D2- RECEPTOR EXPRESSING MEDIUM SPINY NEURONS

    Science.gov (United States)

    Amato, Davide; Heinsbroek, Jasper; Kalivas, Peter W

    2018-01-01

    Abstract Background Nearly half of all individuals diagnosed with schizophrenia abuse addictive substances such as cocaine. Currently, the neurobiological mechanisms in patients with schizophrenia that lead to cocaine abuse are unknown. A possible explanation for the co-morbidity between schizophrenia and addiction is that the rewarding properties of cocaine reverse the diminished motivational drive caused by chronic antipsychotic regimen. Moreover, chronic antipsychotic treatment can sensitize and amplify cocaine rewarding effects and exacerbate psychoses. Methods The rewarding properties of cocaine are attributed to the differential effects of dopamine on D1 and D2 receptor-expressing medium spiny neurons (MSNs) in the nucleus accumbens (NAc). Using in vivo Ca2+ miniature microscopic imaging, we characterize the role of D1 and D2 MSN in mono- and a cross- sensitization paradigms. D1- and D2-Cre mice were injected with a Cre dependent calcium indicator (gCaMP6f) and implanted with a gradient index (GRIN) lens above the nucleus accumbens and calcium activity was recorded using a head mounted miniature microscope. Cocaine sensitization was measured after a classic repeated cocaine regiment and antipsychotic and psychostimulant cross-sensitization was measured by a single cocaine injection after chronic pre-treatment with haloperidol. Results We found that both D1-MSN and D2-MSN populations are modulated by initial cocaine experience and further modulated during the expression of cocaine sensitization. A subpopulation of D1-MSN displayed initial activation, but reduced activity during the expression of sensitization. By contrast, the majority of D2-MSNs were suppressed by initial cocaine experience, but became active during the expression of sensitization. Furthermore, activity of D1- and D2-MSNs bidirectionally related with the observed behavioral responses to cocaine. Cross-sensitization following haloperidol treatment led to increased behavioral responses to

  17. Transmembrane potential polarization, calcium influx, and receptor conformational state modulate the sensitivity of the imidacloprid-insensitive neuronal insect nicotinic acetylcholine receptor to neonicotinoid insecticides.

    Science.gov (United States)

    Bodereau-Dubois, Béatrice; List, Olivier; Calas-List, Delphine; Marques, Olivier; Communal, Pierre-Yves; Thany, Steeve H; Lapied, Bruno

    2012-05-01

    Neonicotinoid insecticides act selectively on insect nicotinic acetylcholine receptors (nAChRs). Recent studies revealed that their efficiency was altered by the phosphorylation/dephosphorylation process and the intracellular signaling pathway involved in the regulation of nAChRs. Using whole-cell patch-clamp electrophysiology adapted for dissociated cockroach dorsal unpaired median (DUM) neurons, we demonstrated that intracellular factors involved in the regulation of nAChR function modulated neonicotinoid sensitivity. DUM neurons were known to express two α-bungarotoxin-insensitive nAChR subtypes: nAChR1 and nAChR2. Whereas nAChR1 was sensitive to imidacloprid, nAChR2 was insensitive to this insecticide. Here, we demonstrated that, like nicotine, acetamiprid and clothianidin, other types of neonicotinoid insecticides, acted as agonists on the nAChR2 subtype. Using acetamiprid, we revealed that both steady-state depolarization and hyperpolarization affected nAChR2 sensitivity. The measurement of the input membrane resistance indicated that change in the acetamiprid-induced agonist activity was related to the receptor conformational state. Using cadmium chloride, ω-conotoxin GVIA, and (R,S)-(3,4-dihydro-6,7-dimethoxy-isoquinoline-1-yl)-2-phenyl-N,N-di-acetamide (LOE 908), we found that inhibition of calcium influx through high voltage-activated calcium channels and transient receptor potential γ (TRPγ) activated by both depolarization and hyperpolarization increased nAChR2 sensitivity to acetamiprid. Finally, using N-(6-aminohexyl)-5-chloro-1-naphthalenesulfonamide hydrochloride (W7), forskolin, and cAMP, we demonstrated that adenylyl cyclase sensitive to the calcium/calmodulin complex regulated internal cAMP concentration, which in turn modulated TRPγ function and nAChR2 sensitivity to acetamiprid. Similar TRPγ-induced modulatory effects were also obtained when clothianidin was tested. These findings bring insights into the signaling pathway modulating

  18. Association between depression, pressure pain sensitivity, stress and autonomous nervous system function in stable ischemic heart disease

    DEFF Research Database (Denmark)

    Ballegaard, Søren; Bergmann, Natasha; Karpatschof, Benny

    2016-01-01

    Background: Depression and ischemic heart disease (IHD) are associated with persistent stress and autonomic nervous system (ANS) dysfunction. The former can be measured by pressure pain sensitivity (PPS) of the sternum, and the latter by the PPS and systolic blood pressure (SBP) response to a tilt...... table test (TTT). Beta-blocker treatment reduces the efferent beta-adrenergic ANS function, and thus, the physiological stress response. Objective: To test the effect of beta-blockers on changes in depression score in patients with IHD, as well as the influence on persistent stress and ANS dysfunction...... PPS score correlated in non-users, only (r = 0.69, p = 0.007). Reduction in resting PPS correlated with an increase in PPS and SBP response to TTT. Conclusions: Stress intervention in patients with IHD was anti-depres- sive in non-users, only. Similarly, the association between the reduction...

  19. Importance of D1 and D2 receptor stimulation for the induction and expression of cocaine-induced behavioral sensitization in preweanling rats.

    Science.gov (United States)

    McDougall, Sanders A; Rudberg, Krista N; Veliz, Ana; Dhargalkar, Janhavi M; Garcia, Aleesha S; Romero, Loveth C; Gonzalez, Ashley E; Mohd-Yusof, Alena; Crawford, Cynthia A

    2017-05-30

    The behavioral manifestations of psychostimulant-induced sensitization vary markedly between young and adult rats, suggesting that the neural mechanisms mediating this phenomenon differ across ontogeny. In this project we examined the importance of D1 and D2 receptors for the induction and expression of cocaine-induced behavioral sensitization during the preweanling period. In the behavioral experiments, rats were injected with reversible D1 and/or D2 antagonists (SCH23390 and/or raclopride) or an irreversible receptor antagonist (EEDQ) either before cocaine administration on the pretreatment day (induction) or before cocaine challenge on the test day (expression). In the EEDQ experiments, receptor specificity was assessed by using selective dopamine antagonists to protect D1 and/or D2 receptors from inactivation. Receptor binding assays showed that EEDQ caused substantial reductions in dorsal striatal D1 and D2 binding sites, while SCH23390 and raclopride fully protected D1 and D2 receptors from EEDQ-induced alkylation. Behavioral results showed that neither D1 nor D2 receptor stimulation was necessary for the induction of cocaine sensitization in preweanling rats. EEDQ disrupted the sensitization process, suggesting that another receptor type sensitive to EEDQ alkylation was necessary for the induction process. Expression of the sensitized response was prevented by an acute injection of a D1 receptor antagonist. The pattern of DA antagonist-induced effects described for preweanling rats is, with few exceptions, similar to what is observed when the same drugs are administered to adult rats. Thus, it appears that maturational changes in D1 and D2 receptor systems are not responsible for ontogenetic differences in the behavioral manifestation of cocaine sensitization. Copyright © 2017 Elsevier B.V. All rights reserved.

  20. The α7-nicotinic acetylcholine receptor mediates the sensitivity of gastric cancer cells to taxanes.

    Science.gov (United States)

    Tu, Chao-Chiang; Huang, Chien-Yu; Cheng, Wan-Li; Hung, Chin-Sheng; Uyanga, Batzorig; Wei, Po-Li; Chang, Yu-Jia

    2016-04-01

    Gastric cancer is difficult to cure because most patients are diagnosed at an advanced disease stage. Systemic chemotherapy remains an important therapy for gastric cancer, but both progression-free survival and disease-free survival associated with various combination regimens are limited because of refractoriness and chemoresistance. Accumulating evidence has revealed that the homomeric α7-nicotinic acetylcholine receptor (A7-nAChR) promotes human gastric cancer by driving cancer cell proliferation, migration, and metastasis. Therefore, A7-nAChR may serve as a potential therapeutic target for gastric cancer. However, the role of A7-nAChR in taxane therapy for gastric cancer was unclear. Cells were subjected to A7-nAChR knockdown (A7-nAChR KD) using short interfering RNA (siRNA). The anti-proliferative effects of taxane were assessed via 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide (MTT), terminal deoxynucleotidyl transferase-mediated nick-end labeling (TUNEL), and cell cycle distribution assays. A7-nAChR-KD cells exhibited low resistance to docetaxel and paclitaxel treatment, as measured by the MTT assay. Following paclitaxel treatment, the proportion of apoptotic cells was higher among A7-nAChR-KD cells than among scrambled control cells, as measured by cell cycle distribution and TUNEL assays. Further molecular analyses showed a reduction in the pAKT levels and a dramatic increase in the Bad levels in paclitaxel-treated A7-nAChR-KD cells but not in scrambled control cells. Following paclitaxel treatment, the level of Bax was slightly increased in both cell populations, whereas Poly (ADP-ribose) polymerase (PARP) cleavage was increased only in A7-nAChR-KD cells. These findings indicate that A7-nAChR-KD cells are more sensitive to paclitaxel treatment. We conclude that A7-nAChR may be a key biomarker for assessing the chemosensitivity of gastric cancer cells to taxane.

  1. Gene transfer of heterologous G protein-coupled receptors to cardiomyocytes: differential effects on contractility.

    Science.gov (United States)

    Laugwitz, K L; Weig, H J; Moretti, A; Hoffmann, E; Ueblacker, P; Pragst, I; Rosport, K; Schömig, A; Ungerer, M

    2001-04-13

    In heart failure, reduced cardiac contractility is accompanied by blunted cAMP responses to beta-adrenergic stimulation. Parathyroid hormone (PTH)-related peptide and arginine vasopressin are released from the myocardium in response to increased wall stress but do not stimulate contractility or adenylyl cyclase at physiological concentrations. To bypass the defective beta-adrenergic signaling cascade, recombinant P1 PTH/PTH-related peptide receptors (rPTH1-Rs) and V(2) vasopressin receptors (rV(2)-Rs), which are normally not expressed in the myocardium and which are both strongly coupled to adenylyl cyclase, and recombinant beta(2)-adrenergic receptors (rbeta(2)-ARs) were overexpressed in cardiomyocytes by viral gene transfer. The capacity of endogenous hormones to increase contractility via the heterologous, recombinant receptors was compared. Whereas V(2)-Rs are uniquely coupled to Gs, PTH1-Rs and beta(2)-ARs are also coupled to other G proteins. Gene transfer of rPTH1-Rs or rbeta(2)-ARs to adult cardiomyocytes resulted in maximally increased basal contractility, which could not be further stimulated by adding receptor agonists. Agonists at rPTH1-Rs induced increased cAMP formation and phospholipase C activity. In contrast, healthy or failing rV(2)-R-expressing cardiomyocytes showed unaltered basal contractility. Their contractility and cAMP formation increased only at agonist exposure, which did not activate phospholipase C. In summary, we found that gene transfer of PTH1-Rs to cardiomyocytes results in constitutive activity of the transgene, as does that of beta(2)-ARS: In the absence of receptor agonists, rPTH1-Rs and rbeta(2)-ARs increase basal contractility, coupling to 2 G proteins simultaneously. In contrast, rV(2)-Rs are uniquely coupled to Gs and are not constitutively active, retaining their property to be activated exclusively on agonist stimulation. Therefore, gene transfer of V(2)-Rs might be more suited to test the effects of c

  2. Role of membrane cholesterol in differential sensitivity of muscarinic receptor subtypes to persistently bound xanomeline

    Czech Academy of Sciences Publication Activity Database

    Randáková, Alena; Dolejší, Eva; Rudajev, Vladimír; Zimčík, Pavel; Doležal, Vladimír; El-Fakahany, E. E.; Jakubík, Jan

    2018-01-01

    Roč. 133, May 1 (2018), s. 129-144 ISSN 0028-3908 R&D Projects: GA ČR(CZ) GA14-05696S; GA ČR(CZ) GA17-16182S Institutional support: RVO:67985823 Keywords : muscarinic acetylcholine receptors * membrane cholesterol * xanomeline * receptor activation * molecular dynamics Subject RIV: ED - Physiology OBOR OECD: Physiology (including cytology) Impact factor: 5.012, year: 2016

  3. The human transient receptor potential vanilloid 3 channel is sensitized via the ERK pathway

    Czech Academy of Sciences Publication Activity Database

    Vyklická, Lenka; Boukalová, Štěpána; Mačíková, Lucie; Chvojka, Štěpán; Vlachová, Viktorie

    2017-01-01

    Roč. 292, č. 51 (2017), s. 21083-21091 ISSN 0021-9258 R&D Projects: GA ČR(CZ) GA15-15839S Institutional support: RVO:67985823 Keywords : epidermal growth factor receptor (EGFR) * extracellular-signal-regulated kinase (ERK) * keratinocyte * phosphorylation * transient receptor potential channels * TRP channels Subject RIV: FH - Neurology OBOR OECD: Neurosciences (including psychophysiology Impact factor: 4.125, year: 2016

  4. Cannabinoid 2 Receptor Agonist Improves Systemic Sensitivity to Insulin in High-Fat Diet/Streptozotocin-Induced Diabetic Mice

    Directory of Open Access Journals (Sweden)

    Xiuyuan Zhang

    2016-12-01

    Full Text Available Background/Aims: The endocannabinoid signalling (ECS system has been known to regulate glucose homeostasis. Previous studies have suggested that the cannabinoid 2 (CB2 receptor may play a regulatory role on insulin secretion, immune modulation and insulin resistance. Given that diabetes and insulin resistance are attributable to elevated inflammatory tone, we investigated the role of CB2 receptor on glucose tolerance and insulin sensitivity in high-fat diet (HFD/streptozotocin (STZ-induced mice. Methods: Diabetes was induced in male ICR mice by HFD/STZ and exposed to a CB2 receptor agonist, SER601, for 2- or 4-weeks via subcutaneous implantation of osmotic minipumps. Glucose and insulin tolerance tests were performed at the end of treatment. Islets were isolated for assessment of β-cell function. Pancreases and skeletal muscles were also obtained for histological analyses. Results: Despite a lack of impact on glucose tolerance, substantial improvement on insulin sensitivity was observed in SER601-treated mice, which could partly be attributed to improved islet β-cell function, shown as increased glucose-induced insulin secretion and insulin content. No changes on islet macrophage infiltration or skeletal muscle fat deposition were detectable from SER601-treated mice. However, a major decrease in body weight was recorded at the end of 4-week SER601 exposure, accompanied by a lack of epididymal adipose mass in SER601-treated mice. Conclusion: Our data suggest a lipolytic role of SER601 in HFD/STZ-induced diabetic mice, which results in significant improvement of systemic insulin sensitivity. Thus, the CB2 receptor may be considered a promising target for therapeutic development against insulin resistance and obesity-related diabetes.

  5. Reactivation of estrogen receptor α by vorinostat sensitizes mesenchymal-like triple-negative breast cancer to aminoflavone, a ligand of the aryl hydrocarbon receptor.

    Science.gov (United States)

    Stark, Karri; Burger, Angelika; Wu, Jianmei; Shelton, Phillip; Polin, Lisa; Li, Jing

    2013-01-01

    Aminoflavone (AF) acts as a ligand of the aryl hydrocarbon receptor (AhR). Expression of estrogen receptor α (ERα) and AhR-mediated transcriptional induction of CYP1A1 can sensitize breast cancer cells to AF. The objective of this study was to investigate the combined antitumor effect of AF and the histone deacetylase inhibitor vorinostat for treating mesenchymal-like triple-negative breast cancer (TNBC) as well as the underlying mechanisms of such treatment. In vitro antiproliferative activity of AFP464 (AF prodrug) in breast cancer cell lines was evaluated by MTS assay. In vitro, the combined effect of AFP464 and vorinostat on cell proliferation was assessed by the Chou-Talalay method. In vivo, antitumor activity of AFP464, given alone and in combination with vorinostat, was studied using TNBC xenograft models. Knockdown of ERα was performed using specific, small-interfering RNA. Western blot, quantitative RT-PCR, immunofluorescence, and immunohistochemical staining were performed to study the mechanisms underlying the combined antitumor effect. Luminal and basal A subtype breast cancer cell lines were sensitive to AFP464, whereas basal B subtype or mesenchymal-like TNBC cells were resistant. Vorinostat sensitized mesenchymal-like TNBC MDA-MB-231 and Hs578T cells to AFP464. It also potentiated the antitumor activity of AFP464 in a xenograft model using MDA-MB-231 cells. In vitro and in vivo mechanistic studies suggested that vorinostat reactivated ERα expression and restored AhR-mediated transcriptional induction of CYP1A1. The response of breast cancer cells to AF or AFP464 was associated with their gene expression profile. Vorinostat sensitized mesenchymal-like TNBC to AF, at least in part, by reactivating ERα expression and restoring the responsiveness of AhR to AF.

  6. GABAB Receptor Stimulation Accentuates the Locomotor Effects of Morphine in Mice Bred for Extreme Sensitivity to the Stimulant Effects of Ethanol

    OpenAIRE

    Holstein, Sarah E.; Phillips, Tamara J.

    2006-01-01

    Mice selectively bred for divergent sensitivity to the locomotor stimulant effects of ethanol (FAST and SLOW) also differ in their locomotor response to morphine. The GABAB receptor has been implicated in the mediation of locomotor stimulation to both ethanol and morphine, and a reduction in ethanol-induced stimulation has been found with the GABAB receptor agonist baclofen in FAST mice. We hypothesized that GABAB receptor activation would also attenuate the locomotor stimulant responses to m...

  7. Receptor protection studies comparing recombinant and native nicotinic receptors: Evidence for a subpopulation of mecamylamine-sensitive native alpha3beta4* nicotinic receptors.

    Science.gov (United States)

    Free, R Benjamin; Kaser, Daniel J; Boyd, R Thomas; McKay, Dennis B

    2006-01-09

    Studies involving receptor protection have been used to define the functional involvement of specific receptor subtypes in tissues expressing multiple receptor subtypes. Previous functional studies from our laboratory demonstrate the feasibility of this approach when applied to neuronal tissues expressing multiple nicotinic acetylcholine receptors (nAChRs). In the current studies, the ability of a variety of nAChR agonists and antagonists to protect native and recombinant alpha3beta4 nAChRs from alkylation were investigated using nAChR binding techniques. Alkylation of native alpha3beta4* nAChRs from membrane preparations of bovine adrenal chromaffin cells resulted in a complete loss of specific [(3)H]epibatidine binding. This loss of binding to native nAChRs was preventable by pretreatment with the agonists, carbachol or nicotine. The partial agonist, cytisine, produced partial protection. Several nAChR antagonists were also tested for their ability to protect. Hexamethonium and decamethonium were without protective activity while mecamylamine and tubocurarine were partially effective. Addition protection studies were performed on recombinant alpha3beta4 nAChRs. As with native alpha3beta4* nAChRs, alkylation produced a complete loss of specific [(3)H]epibatidine binding to recombinant alpha3beta4 nAChRs which was preventable by pretreatment with nicotine. However, unlike native alpha3beta4* nAChRs, cytisine and mecamylamine, provide no protection for alkylation. These results highlight the differences between native alpha3beta4* nAChRs and recombinant alpha3beta4 nAChRs and support the use of protection assays to characterize native nAChR subpopulations.

  8. Evidence for a role of NTS2 receptors in the modulation of tonic pain sensitivity

    Directory of Open Access Journals (Sweden)

    Martinez Jean

    2009-07-01

    Full Text Available Abstract Background Central neurotensin (NT administration results in a naloxone-insensitive antinociceptive response in animal models of acute and persistent pain. Both NTS1 and NTS2 receptors were shown to be required for different aspects of NT-induced analgesia. We recently demonstrated that NTS2 receptors were extensively associated with ascending nociceptive pathways, both at the level of the dorsal root ganglia and of the spinal dorsal horn. Then, we found that spinally administered NTS2-selective agonists induced dose-dependent antinociceptive responses in the acute tail-flick test. In the present study, we therefore investigated whether activation of spinal NTS2 receptors suppressed the persistent inflammatory pain symptoms observed after intraplantar injection of formalin. Results We first demonstrated that spinally administered NT and NT69L agonists, which bind to both NTS1 and NTS2 receptors, significantly reduced pain-evoked responses during the inflammatory phase of the formalin test. Accordingly, pretreatment with the NTS2-selective analogs JMV-431 and levocabastine was effective in inhibiting the aversive behaviors induced by formalin. With resolution at the single-cell level, we also found that activation of spinal NTS2 receptors reduced formalin-induced c-fos expression in dorsal horn neurons. However, our results also suggest that NTS2-selective agonists and NTS1/NTS2 mixed compounds differently modulated the early (21–39 min and late (40–60 min tonic phase 2 and recruited endogenous pain inhibitory mechanisms integrated at different levels of the central nervous system. Indeed, while non-selective drugs suppressed pain-related behaviors activity in both part of phase 2, intrathecal injection of NTS2-selective agonists was only efficient in reducing pain during the late phase 2. Furthermore, assessment of the stereotypic pain behaviors of lifting, shaking, licking and biting to formalin also revealed that unlike non

  9. Glucocorticoid receptor haplotypes conferring increased sensitivity (BclI and N363S) are associated with faster progression of multiple sclerosis

    DEFF Research Database (Denmark)

    Melief, Jeroen; Koper, Jan W; Endert, Erik

    2016-01-01

    As high cortisol levels are implicated in suppressed disease activity of multiple sclerosis (MS), glucocorticoid receptor (GR) polymorphisms that affect glucocorticoid (GC) sensitivity may impact on this by changing local immunomodulation or regulation of the hypothalamus-pituitary-adrenal (HPA...

  10. Individual differences in ethanol locomotor sensitization are associated with dopamine D1 receptor intra-cellular signaling of DARPP-32 in the nucleus accumbens.

    Directory of Open Access Journals (Sweden)

    Karina Possa Abrahao

    Full Text Available In mice there are clear individual differences in the development of behavioral sensitization to ethanol, a progressive potentiation of its psychomotor stimulant effect. Variability in the behavioral responses to ethanol has been associated with alcohol preference. Here we investigated if the functional hyperresponsiveness of D1 receptors observed in ethanol sensitized mice leads to an increased activation of DARPP-32, a central regulatory protein in medium spiny neurons, in the nucleus accumbens - a brain region known to play a role in drug reinforcement. Swiss Webster mice received ethanol (2.2 g/kg/day or saline i.p. administrations for 21 days and were weekly evaluated regarding their locomotor activity. From those treated with ethanol, the 33% with the highest levels of locomotor activity were classified as "sensitized" and the 33% with the lowest levels as "non-sensitized". The latter presented similar locomotor levels to those of saline-treated mice. Different subgroups of mice received intra-accumbens administrations of saline and, 48 h later, SKF-38393, D1 receptor agonist 0.1 or 1 µg/side. Indeed, sensitized mice presented functional hyperresponsiveness of D1 receptors in the accumbens. Two weeks following the ethanol treatment, other subgroups received systemic saline or SKF 10 mg/kg, 20 min before the euthanasia. The nucleus accumbens were dissected for the Western Blot analyses of total DARPP-32 and phospho-Thr34-DARPP-32 expression. D1 receptor activation induced higher phospho-Thr34-DARPP-32 expression in sensitized mice than in non-sensitized or saline. The functionally hyperresponsiveness of D1 receptors in the nucleus accumbens is associated with an increased phospho-Thr34-DARPP-32 expression after D1 receptor activation. These data suggest that an enduring increase in the sensitivity of the dopamine D1 receptor intracellular pathway sensitivity represents a neurobiological correlate associated with the development of

  11. The EGFR family of receptors sensitizes cancer cells towards UV light

    DEFF Research Database (Denmark)

    Petersen, Steffen B.; Neves Petersen, Teresa; Olsen, Birgitte

    2008-01-01

    A combination of bioinformatics, biophysical, advanced laser studies and cell biology lead to the realization that laser-pulsed UV light stops cancer growth and induces apoptosis. We have previously shown that laser-pulsed UV (LP-UV) illumination of two different skin-derived cancer cell lines both...... bridges. The EGF receptor is often overexpressed in cancers and other proliferative skin disorders, it might be possible to significantly reduce the proliferative potential of these cells making them good targets for laser-pulsed UV-light treatment. The discovery that UV light can be used to open...... disulphide bridges in proteins upon illumination of nearby aromatic amino acids was the first step that lead to the hypothesis that UV light could modulate the structure and therefore the function of these key receptor proteins. The observation that membrane receptors (EGFR) contained exactly the motifs...

  12. Relationship between Fc receptors and Ia alloantigens: analysis with a sensitive radioimmunoassay

    International Nuclear Information System (INIS)

    Rieber, E.P.; Wernet, P.

    1977-01-01

    This paper describes the successful use of 125 I-labeled lgG aggregate to detect la-type alloantibodies in pregnancy sera. The blockade of aggregate uptake of a variety of normal mononuclear and leukemic cell types by anti-Ia alloantibodies is analyzed. Fc receptors and la alloantigens are clearly two distinct molecular entities. The association between Fc receptors and Ia alloantigens on a quantitative level seems to depend on a ligand-binding mechanism to control their interaction rather than the presence of a topographical molecular tandem arrangement. (Auth.)

  13. Pore Helix Domain Is Critical to Camphor Sensitivity of Transient Receptor Potential Vanilloid 1 Channel

    Czech Academy of Sciences Publication Activity Database

    Maršáková, Lenka; Touška, Filip; Krůšek, Jan; Vlachová, Viktorie

    2012-01-01

    Roč. 116, č. 4 (2012), s. 903-917 ISSN 0003-3022 R&D Projects: GA ČR(CZ) GA305/09/0081; GA ČR(CZ) GA202/09/0806; GA ČR(CZ) GD305/08/H037; GA MŠk(CZ) 1M0517; GA MŠk(CZ) LC554; GA ČR(CZ) GBP304/12/G069 Grant - others:Univerzita Karlova(CZ) 25409 Institutional research plan: CEZ:AV0Z50110509 Keywords : vanilloid receptor * camphor * transient receptor potential Subject RIV: ED - Physiology Impact factor: 5.163, year: 2012

  14. Evolution of vertebrate transient receptor potential vanilloid 3 channels: opposite temperature sensitivity between mammals and western clawed frogs.

    Directory of Open Access Journals (Sweden)

    Shigeru Saito

    2011-04-01

    Full Text Available Transient Receptor Potential (TRP channels serve as temperature receptors in a wide variety of animals and must have played crucial roles in thermal adaptation. The TRP vanilloid (TRPV subfamily contains several temperature receptors with different temperature sensitivities. The TRPV3 channel is known to be highly expressed in skin, where it is activated by warm temperatures and serves as a sensor to detect ambient temperatures near the body temperature of homeothermic animals such as mammals. Here we performed comprehensive comparative analyses of the TRPV subfamily in order to understand the evolutionary process; we identified novel TRPV genes and also characterized the evolutionary flexibility of TRPV3 during vertebrate evolution. We cloned the TRPV3 channel from the western clawed frog Xenopus tropicalis to understand the functional evolution of the TRPV3 channel. The amino acid sequences of the N- and C-terminal regions of the TRPV3 channel were highly diversified from those of other terrestrial vertebrate TRPV3 channels, although central portions were well conserved. In a heterologous expression system, several mammalian TRPV3 agonists did not activate the TRPV3 channel of the western clawed frog. Moreover, the frog TRPV3 channel did not respond to heat stimuli, instead it was activated by cold temperatures. Temperature thresholds for activation were about 16 °C, slightly below the lower temperature limit for the western clawed frog. Given that the TRPV3 channel is expressed in skin, its likely role is to detect noxious cold temperatures. Thus, the western clawed frog and mammals acquired opposite temperature sensitivity of the TRPV3 channel in order to detect environmental temperatures suitable for their respective species, indicating that temperature receptors can dynamically change properties to adapt to different thermal environments during evolution.

  15. Pharmacological characterization of the dopamine-sensitive adenylate cyclase in cockroach brain: evidence for a distinct dopamine receptor

    International Nuclear Information System (INIS)

    Orr, G.L.; Gole, J.W.D.; Notman, H.J.; Downer, R.G.H.

    1987-01-01

    Dopamine increases cyclic AMP production in crude membrane preparations of cockroach brain with plateaus in cyclic AMP production occurring between 1-10 μM and 10 mM. Maximal production of cyclic AMP is 2.25 fold greater than that of control values. Octopamine also increases cyclic AMP production with a Ka of 1.4 μM and maximal production 3.5 fold greater than that of control. 5-Hydroxytryptamine does not increase cyclic AMP production. The effects of octopamine and dopamine are fully additive. The vertebrate dopamine agonists ADTN and epinine stimulate the dopamine-sensitive adenylate cyclase (AC) with Ka values of 4.5 and 0.6 μM respectively and with maximal effectiveness 1.7 fold greater than that of control. The selective D 2 -dopamine agonist LY-171555 stimulates cyclic AMP production to a similar extent with a Ka of 50 μM. Other dopamine agonists have no stimulatory effects. With the exception of mianserin, 3 H-piflutixol is displaced from brain membranes by dopamine antagonists with an order of potency similar to that observed for the inhibition of dopamine-sensitive AC. The results indicate that the octopamine- and dopamine-sensitive AC in cockroach brain can be distinguished pharmacologically and the dopamine receptors coupled to AC have pharmacological characteristics distinct from vertebrate D 1 - and D 2 -dopamine receptors. 33 references, 3 figures, 2 tables

  16. [Effect of (+/-)-pindolol on the central 5-HT1A receptor by the use of in vivo microdialysis and hippocampal slice preparations].

    Science.gov (United States)

    Tsuji, Keiichiro

    2002-06-01

    Although it is suggested that (+/-)-pindolol, a beta-adrenergic/5-HT1A receptor antagonist, may enhance the efficacy of selective serotonin reuptake inhibitors (SSRI), the results of double-blind studies are contradictory and recent animal studies suggest that (+/-)-pindolol may act as a partial agonist to the 5-HT1A receptor. In this study we have investigated the effect of (+/-)-pindolol on both pre- and postsynaptic 5-HT1A receptors using in vivo microdialysis and hippocampal slice preparations. (+/-)-pindolol and flesinoxan, a 5-HT1A receptor full agonist, significantly decreased the extracellular levels of 5-HT in the raphe and prefrontal cortex. The 5-HT and other 5-HT1A receptor agonists, flesinoxan and 8-hydroxy-2- (di-n-propylamino)tetralon (8-OH-DPAT), significantly decreased the population excitatory postsynaptic potential (EPSP) in the CA3-CA1 excitatory synapse in a dose-dependent manner. The effect of 5-HT and other 5-HT1A receptor agonists accompanied the increase in paired-pulse facilitation (ppf) induced by short-interval two stimuli and were reversed by the coadministration of the 5-HT1A receptor agonist, NAN-190, but not by (+/-)-pindolol. (+/-)-pindolol also suppressed the EPSP, but this effect was not reversed by NAN-190. These results suggest that (+/-)-pindolol acts as a partial agonist to the somatodendritic 5-HT1A receptor in the raphe, whereas it may have no action on the postsynaptic 5-HT1A receptor in the hippocampus.

  17. α-Hispanolol sensitizes hepatocellular carcinoma cells to TRAIL-induced apoptosis via death receptor up-regulation

    Energy Technology Data Exchange (ETDEWEB)

    Mota, Alba, E-mail: amota@iib.uam.es [Unidad de Terapias Farmacológicas, Área de Genética Humana, Instituto de Investigación de Enfermedades Raras (IIER), Instituto de Salud Carlos III, Madrid (Spain); Jiménez-Garcia, Lidia, E-mail: ljimenez@isciii.es [Unidad de Terapias Farmacológicas, Área de Genética Humana, Instituto de Investigación de Enfermedades Raras (IIER), Instituto de Salud Carlos III, Madrid (Spain); Herránz, Sandra, E-mail: sherranz@isciii.es [Unidad de Terapias Farmacológicas, Área de Genética Humana, Instituto de Investigación de Enfermedades Raras (IIER), Instituto de Salud Carlos III, Madrid (Spain); Heras, Beatriz de las, E-mail: lasheras@ucm.es [Departamento de Farmacología, Facultad de Farmacia, Universidad Complutense de Madrid (UCM), Madrid (Spain); Hortelano, Sonsoles, E-mail: shortelano@isciii.es [Unidad de Terapias Farmacológicas, Área de Genética Humana, Instituto de Investigación de Enfermedades Raras (IIER), Instituto de Salud Carlos III, Madrid (Spain)

    2015-08-01

    Hispanolone derivatives have been previously described as anti-inflammatory and antitumoral agents. However, their effects on overcoming Tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) resistance remain to be elucidated. In this study, we analyzed the cytotoxic effects of the synthetic hispanolone derivative α-hispanolol (α-H) in several tumor cell lines, and we evaluated the induction of apoptosis, as well as the TRAIL-sensitizing potential of α-H in the hepatocellular carcinoma cell line HepG2. Our data show that α-H decreased cell viability in a dose-dependent manner in HeLa, MDA-MB231, U87 and HepG2 cell lines, with a more prominent effect in HepG2 cells. Interestingly, α-H had no effect on non-tumoral cells. α-H induced activation of caspase-8 and caspase-9 and also increased levels of the proapoptotic protein Bax, decreasing antiapoptotic proteins (Bcl-2, X-IAP and IAP-1) in HepG2 cells. Specific inhibition of caspase-8 abrogated the cascade of caspase activation, suggesting that the extrinsic pathway has a critical role in the apoptotic events induced by α-H. Furthermore, combined treatment of α-H with TRAIL enhanced apoptosis in HepG2 cells, activating caspase-8 and caspase-9. This correlated with up-regulation of both the TRAIL death receptor DR4 and DR5. DR4 or DR5 neutralizing antibodies abolished the effect of α-H on TRAIL-induced apoptosis, suggesting that sensitization was mediated through the death receptor pathway. Our results demonstrate that α-H induced apoptosis in the human hepatocellular carcinoma cell line HepG2 through activation of caspases and induction of the death receptor pathway. In addition, we describe a novel function of α-H as a sensitizer on TRAIL-induced apoptotic cell death in HepG2 cells. - Highlights: • α-Hispanolol induced apoptosis in the human hepatocellular carcinoma cell line HepG2. • α-Hispanolol induced activation of caspases and the death receptor pathway. • α-Hispanolol enhanced

  18. α-Hispanolol sensitizes hepatocellular carcinoma cells to TRAIL-induced apoptosis via death receptor up-regulation

    International Nuclear Information System (INIS)

    Mota, Alba; Jiménez-Garcia, Lidia; Herránz, Sandra; Heras, Beatriz de las; Hortelano, Sonsoles

    2015-01-01

    Hispanolone derivatives have been previously described as anti-inflammatory and antitumoral agents. However, their effects on overcoming Tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) resistance remain to be elucidated. In this study, we analyzed the cytotoxic effects of the synthetic hispanolone derivative α-hispanolol (α-H) in several tumor cell lines, and we evaluated the induction of apoptosis, as well as the TRAIL-sensitizing potential of α-H in the hepatocellular carcinoma cell line HepG2. Our data show that α-H decreased cell viability in a dose-dependent manner in HeLa, MDA-MB231, U87 and HepG2 cell lines, with a more prominent effect in HepG2 cells. Interestingly, α-H had no effect on non-tumoral cells. α-H induced activation of caspase-8 and caspase-9 and also increased levels of the proapoptotic protein Bax, decreasing antiapoptotic proteins (Bcl-2, X-IAP and IAP-1) in HepG2 cells. Specific inhibition of caspase-8 abrogated the cascade of caspase activation, suggesting that the extrinsic pathway has a critical role in the apoptotic events induced by α-H. Furthermore, combined treatment of α-H with TRAIL enhanced apoptosis in HepG2 cells, activating caspase-8 and caspase-9. This correlated with up-regulation of both the TRAIL death receptor DR4 and DR5. DR4 or DR5 neutralizing antibodies abolished the effect of α-H on TRAIL-induced apoptosis, suggesting that sensitization was mediated through the death receptor pathway. Our results demonstrate that α-H induced apoptosis in the human hepatocellular carcinoma cell line HepG2 through activation of caspases and induction of the death receptor pathway. In addition, we describe a novel function of α-H as a sensitizer on TRAIL-induced apoptotic cell death in HepG2 cells. - Highlights: • α-Hispanolol induced apoptosis in the human hepatocellular carcinoma cell line HepG2. • α-Hispanolol induced activation of caspases and the death receptor pathway. • α-Hispanolol enhanced

  19. Analysis of hydrophobic interactions of antagonists with the beta2-adrenergic receptor.

    Science.gov (United States)

    Novoseletsky, V N; Pyrkov, T V; Efremov, R G

    2010-01-01

    The adrenergic receptors mediate a wide variety of physiological responses, including vasodilatation and vasoconstriction, heart rate modulation, and others. Beta-adrenergic antagonists ('beta-blockers') thus constitute a widely used class of drugs in cardiovascular medicine as well as in management of anxiety, migraine, and glaucoma. The importance of the hydrophobic effect has been evidenced for a wide range of beta-blocker properties. To better understand the role of the hydrophobic effect in recognition of beta-blockers by their receptor, we carried out a molecular docking study combined with an original approach to estimate receptor-ligand hydrophobic interactions. The proposed method is based on automatic detection of molecular fragments in ligands and the analysis of their interactions with receptors separately. A series of beta-blockers, based on phenylethanolamines and phenoxypropanolamines, were docked to the beta2-adrenoceptor binding site in the crystal structure. Hydrophobic complementarity between the ligand and the receptor was calculated using the PLATINUM web-server (http://model.nmr.ru/platinum). Based on the analysis of the hydrophobic match for molecular fragments of beta-blockers, we have developed a new scoring function which efficiently predicts dissociation constant (pKd) with strong correlations (r(2) approximately 0.8) with experimental data.

  20. Insulin receptor substrate 1 expression enhances the sensitivity of 32D cells to chemotherapy-induced cell death

    International Nuclear Information System (INIS)

    Porter, Holly A.; Carey, Gregory B.; Keegan, Achsah D.

    2012-01-01

    The adapters IRS1 and IRS2 link growth factor receptors to downstream signaling pathways that regulate proliferation and survival. Both suppress factor-withdrawal-induced apoptosis and have been implicated in cancer progression. However, recent studies suggest IRS1 and IRS2 mediate differential functions in cancer pathogenesis. IRS1 promoted breast cancer proliferation, while IRS2 promoted metastasis. The role of IRS1 and IRS2 in controlling cell responses to chemotherapy is unknown. To determine the role of IRS1 and IRS2 in the sensitivity of cells to chemotherapy, we treated 32D cells lacking or expressing IRS proteins with various concentrations of chemotherapeutic agents. We found that expression of IRS1, in contrast to IRS2, enhanced the sensitivity of 32D cells to chemotherapy-induced apoptosis. When IRS2 was expressed with IRS1, the cells no longer showed enhanced sensitivity. Expression of IRS1 did not alter the expression of pro- and anti-apoptotic proteins; however, 32D-IRS1 cells expressed higher levels of Annexin A2. In 32D-IRS1 cells, IRS1 and Annexin A2 were both located in cytoplasmic and membrane fractions. We also found that IRS1 coprecipitated with Annexin A2, while IRS2 did not. Decreasing Annexin A2 levels reduced 32D-IRS1 cell sensitivity to chemotherapy. These results suggest IRS1 enhances sensitivity to chemotherapy in part through Annexin A2. -- Highlights: ► IRS1 enhanced the sensitivity of 32D cells to chemotherapy-induced apoptosis. ► This sensitivity is abrogated by the expression of IRS2. ► Expressing IRS1 in 32D cells increased levels of Annexin A2. ► Both IRS1 and Annexin A2 were located in cytoplasmic and membrane fractions. ► Decreasing Annexin A2 in 32D-IRS1 cells abated their sensitivity to chemotherapy.

  1. Enhanced sensitivity of postsynaptic serotonin-1A receptors in rats and mice with high trait aggression

    NARCIS (Netherlands)

    van der Vegt, BJ; de Boer, SF; Buwalda, B; de Ruiter, AJH; de Jong, JG; Koolhaas, JM

    2001-01-01

    Individual differences in aggressive behaviour have been linked to variability in central serotonergic activity, both in humans and animals. A previous experiment in mice, selectively bred for high or low levels of aggression, showed an up-regulation of postsynaptic serotonin-1A (5-HT1A) receptors,

  2. Greater Sensitivity of Blood Pressure Than Renal Toxicity to Tyrosine Kinase Receptor Inhibition With Sunitinib

    DEFF Research Database (Denmark)

    Lankhorst, Stephanie; Baelde, Hans J; Kappers, Mariëtte H W

    2015-01-01

    Hypertension and renal injury are off-target effects of sunitinib, a tyrosine kinase receptor inhibitor used for the treatment of various tumor types. Importantly, these untoward effects are accompanied by activation of the endothelin system. Here, we set up a study to explore the dose dependency...

  3. Insulin receptor substrate 1 expression enhances the sensitivity of 32D cells to chemotherapy-induced cell death

    Science.gov (United States)

    Porter, Holly A.; Carey, Gregory B.; Keegan, Achsah D.

    2012-01-01

    The adaptors IRS1 and IRS2 link growth factor receptors to downstream signaling pathways that regulate proliferation and survival. Both suppress factor-withdrawal-induced apoptosis and have been implicated in cancer progression. However, recent studies suggest IRS1 and IRS2 mediate differential functions in cancer pathogenesis. IRS1 promoted breast cancer proliferation, while IRS2 promoted metastasis. The role of IRS1 and IRS2 in controlling cell responses to chemotherapy is unknown. To determine the role of IRS1 and IRS2 in the sensitivity of cells to chemotherapy, we treated 32D cells lacking or expressing IRS proteins with various concentrations of chemotherapeutic agents. We found that expression of IRS1, in contrast to IRS2, enhanced the sensitivity of 32D cells to chemotherapy-induced apoptosis. When IRS2 was expressed with IRS1, the cells no longer showed enhanced sensitivity. Expression of IRS1 did not alter the expression of pro- and anti-apoptotic proteins; however, 32D-IRS1 cells expressed higher levels of Annexin A2. In 32D-IRS1 cells, IRS1 and Annexin A2 were both located in cytoplasmic and membrane fractions. We also found that IRS1 coprecipitated with Annexin A2, while IRS2 did not. Decreasing Annexin A2 levels reduced 32D-IRS1 cell sensitivity to chemotherapy. These results suggest IRS1 enhances sensitivity to chemotherapy in part through Annexin A2. PMID:22652453

  4. Alpha 2-adrenergic receptor turnover in adipose tissue and kidney: irreversible blockade of alpha 2-adrenergic receptors by benextramine

    International Nuclear Information System (INIS)

    Taouis, M.; Berlan, M.; Lafontan, M.

    1987-01-01

    The recovery of post- and extrasynaptic alpha 2-adrenergic receptor-binding sites was studied in vivo in male golden hamsters after treatment with an irreversible alpha-adrenoceptor antagonist benextramine, a tetramine disulfide that possesses a high affinity for alpha 2-binding sites. The kidney alpha 2-adrenergic receptor number was measured with [ 3 H]yohimbine, whereas [ 3 H]clonidine was used for fat cell and brain membrane alpha 2-binding site identification. Benextramine treatment of fat cell, kidney, and brain membranes reduced or completely suppressed, in an irreversible manner, [ 3 H] clonidine and [ 3 H]yohimbine binding without modifying adenosine (A1-receptor) and beta-adrenergic receptor sites. This irreversible binding was also found 1 and 2 hr after intraperitoneal administration of benextramine to the hamsters. Although it bound irreversibly to peripheral and central alpha 2-adrenergic receptors on isolated membranes, benextramine was unable to cross the blood-brain barrier of the hamster at the concentrations used (10-20 mg/kg). After the irreversible blockade, alpha 2-binding sites reappeared in kidney and adipose tissue following a monoexponential time course. Recovery of binding sites was more rapid in kidney than in adipose tissue; the half-lives of the receptor were 31 and 46 hr, respectively in the tissues. The rates of receptor production were 1.5 and 1.8 fmol/mg of protein/hr in kidney and adipose tissue. Reappearance of alpha 2-binding sites was associated with a rapid recovery of function (antilipolytic potencies of alpha 2-agonists) in fat cells inasmuch as occupancy of 15% of [ 3 H]clonidine-binding sites was sufficient to promote 40% inhibition of lipolysis. Benextramine is a useful tool to estimate turnover of alpha 2-adrenergic receptors under normal and pathological situations

  5. Background odour induces adaptation and sensitization of olfactory receptors in the antennae of houseflies

    NARCIS (Netherlands)

    Kelling, F.J; Ialenti, F.; den Otter, C.J

    The presence of background odour was found to have a small but significant effect on the sensitivity of the antennal olfactory system of houseflies, Musca domestica Linnaeus (Diptera: Muscidae), to new pulses of odour. We show that cross-adaptation and cross-sensitization between a background odour

  6. Neural Signatures of Cognitive Flexibility and Reward Sensitivity Following Nicotinic Receptor Stimulation in Dependent Smokers: A Randomized Trial.

    Science.gov (United States)

    Lesage, Elise; Aronson, Sarah E; Sutherland, Matthew T; Ross, Thomas J; Salmeron, Betty Jo; Stein, Elliot A

    2017-06-01

    Withdrawal from nicotine is an important contributor to smoking relapse. Understanding how reward-based decision making is affected by abstinence and by pharmacotherapies such as nicotine replacement therapy and varenicline tartrate may aid cessation treatment. To independently assess the effects of nicotine dependence and stimulation of the nicotinic acetylcholine receptor on the ability to interpret valence information (reward sensitivity) and subsequently alter behavior as reward contingencies change (cognitive flexibility) in a probabilistic reversal learning task. Nicotine-dependent smokers and nonsmokers completed a probabilistic reversal learning task during acquisition of functional magnetic resonance imaging (fMRI) in a 2-drug, double-blind placebo-controlled crossover design conducted from January 21, 2009, to September 29, 2011. Smokers were abstinent from cigarette smoking for 12 hours for all sessions. In a fully Latin square fashion, participants in both groups underwent MRI twice while receiving varenicline and twice while receiving a placebo pill, wearing either a nicotine or a placebo patch. Imaging analysis was performed from June 15, 2015, to August 10, 2016. A well-established computational model captured effects of smoking status and administration of nicotine and varenicline on probabilistic reversal learning choice behavior. Neural effects of smoking status, nicotine, and varenicline were tested for on MRI contrasts that captured reward sensitivity and cognitive flexibility. The study included 24 nicotine-dependent smokers (12 women and 12 men; mean [SD] age, 35.8 [9.9] years) and 20 nonsmokers (10 women and 10 men; mean [SD] age, 30.4 [7.2] years). Computational modeling indicated that abstinent smokers were biased toward response shifting and that their decisions were less sensitive to the available evidence, suggesting increased impulsivity during withdrawal. These behavioral impairments were mitigated with nicotine and varenicline

  7. Altered ratio of D1 and D2 dopamine receptors in mouse striatum is associated with behavioral sensitization to cocaine.

    Directory of Open Access Journals (Sweden)

    Dawn Thompson

    Full Text Available BACKGROUND: Drugs of abuse elevate brain dopamine levels, and, in vivo, chronic drug use is accompanied by a selective decrease in dopamine D2 receptor (D2R availability in the brain. Such a decrease consequently alters the ratio of D1R:D2R signaling towards the D1R. Despite a plethora of behavioral studies dedicated to the understanding of the role of dopamine in addiction, a molecular mechanism responsible for the downregulation of the D2R, in vivo, in response to chronic drug use has yet to be identified. METHODS AND FINDINGS: ETHICS STATEMENT: All animal work was approved by the Gallo Center IACUC committee and was performed in our AAALAC approved facility. In this study, we used wild type (WT and G protein coupled receptor associated sorting protein-1 (GASP-1 knock out (KO mice to assess molecular changes that accompany cocaine sensitization. Here, we show that downregulation of D2Rs or upregulation of D1Rs is associated with a sensitized locomotor response to an acute injection of cocaine. Furthermore, we demonstrate that disruption of GASP-1, that targets D2Rs for degradation after endocytosis, prevents cocaine-induced downregulation of D2Rs. As a consequence, mice with a GASP-1 disruption show a reduction in the sensitized locomotor response to cocaine. CONCLUSIONS: Together, our data suggests that changes in the ratio of the D1:D2R could contribute to cocaine-induced behavioral plasticity and demonstrates a role of GASP-1 in regulating both the levels of the D2R and cocaine sensitization.

  8. Reducing and oxidizing agents sensitize heat-activated vanilloid receptor (TRPV1) current

    Czech Academy of Sciences Publication Activity Database

    Sušánková, Klára; Toušová, Karolina; Vyklický st., Ladislav; Teisinger, Jan; Vlachová, Viktorie

    2006-01-01

    Roč. 70, č. 1 (2006), s. 383-394 ISSN 0026-895X R&D Projects: GA MŠk(CZ) 1M0517; GA MŠk(CZ) LC554; GA ČR(CZ) GA309/04/0496; GA ČR(CZ) GA305/06/0319 Institutional research plan: CEZ:AV0Z5011922 Keywords : capsaicin * TRPV1 * receptor Subject RIV: ED - Physiology Impact factor: 4.469, year: 2006

  9. Catecholamine-induced vasoconstriction is sensitive to carbonic anhydrase I activation

    Directory of Open Access Journals (Sweden)

    Puscas I.

    2001-01-01

    Full Text Available We studied the relationship between alpha- and beta-adrenergic agonists and the activity of carbonic anhydrase I and II in erythrocyte, clinical and vessel studies. Kinetic studies were performed. Adrenergic agonists increased erythrocyte carbonic anhydrase as follows: adrenaline by 75%, noradrenaline by 68%, isoprenaline by 55%, and orciprenaline by 62%. The kinetic data indicated a non-competitive mechanism of action. In clinical studies carbonic anhydrase I from erythrocytes increased by 87% after noradrenaline administration, by 71% after orciprenaline and by 82% after isoprenaline. The increase in carbonic anhydrase I paralleled the increase in blood pressure. Similar results were obtained in vessel studies on piglet vascular smooth muscle. We believe that adrenergic agonists may have a dual mechanism of action: the first one consists of a catecholamine action on its receptor with the formation of a stimulus-receptor complex. The second mechanism proposed completes the first one. By this second component of the mechanism, the same stimulus directly acts on the carbonic anhydrase I isozyme (that might be functionally coupled with adrenergic receptors, so that its activation ensures an adequate pH for stimulus-receptor coupling for signal transduction into the cell, resulting in vasoconstriction.

  10. Decreased agonist sensitivity of human GABA(A) receptors by an amino acid variant, isoleucine to valine, in the alpha1 subunit.

    Science.gov (United States)

    Westh-Hansen, S E; Rasmussen, P B; Hastrup, S; Nabekura, J; Noguchi, K; Akaike, N; Witt, M R; Nielsen, M

    1997-06-25

    Recombinant human GABA(A) receptors were investigated in vitro by coexpression of cDNAs coding for alpha1, beta2, and gamma2 subunits in the baculovirus/Sf-9 insect cell system. We report that a single amino acid exchange (isoleucine 121 to valine 121) in the N-terminal, extracellular part of the alpha1 subunit induces a marked decrease in agonist GABA(A) receptor ligand sensitivity. The potency of muscimol and GABA to inhibit the binding of the GABA(A) receptor antagonist [3H]SR 95531 (2-(3-carboxypropyl)-3-amino-6-(4-methoxyphenyl)pyridazinium bromide) was higher in receptor complexes of alpha1(ile 121) beta2gamma2 than in those of alpha1(val 121) beta2gamma2 (IC50 values were 32-fold and 26-fold lower for muscimol and GABA, respectively). The apparent affinity of the GABA(A) receptor antagonist bicuculline methiodide to inhibit the binding of [3H]SR 95531 did not differ between the two receptor complex variants. Electrophysiological measurements of GABA induced whole-cell Cl- currents showed a ten-fold decrease in the GABA(A) receptor sensitivity of alpha1 (val 121) beta2gamma2 as compared to alpha1(ile 121) beta2gamma2 receptor complexes. Thus, a relatively small change in the primary structure of the alpha1 subunit leads to a decrease selective for GABA(A) receptor sensitivity to agonist ligands, since no changes were observed in a GABA(A) receptor antagonist affinity and benzodiazepine receptor binding.

  11. APPL1 potentiates insulin sensitivity by facilitating the binding of IRS1/2 to the insulin receptor.

    Science.gov (United States)

    Ryu, Jiyoon; Galan, Amanda K; Xin, Xiaoban; Dong, Feng; Abdul-Ghani, Muhammad A; Zhou, Lijun; Wang, Changhua; Li, Cuiling; Holmes, Bekke M; Sloane, Lauren B; Austad, Steven N; Guo, Shaodong; Musi, Nicolas; DeFronzo, Ralph A; Deng, Chuxia; White, Morris F; Liu, Feng; Dong, Lily Q

    2014-05-22

    Binding of insulin receptor substrate proteins 1 and 2 (IRS1/2) to the insulin receptor (IR) is essential for the regulation of insulin sensitivity and energy homeostasis. However, the mechanism of IRS1/2 recruitment to the IR remains elusive. Here, we identify adaptor protein APPL1 as a critical molecule that promotes IRS1/2-IR interaction. APPL1 forms a complex with IRS1/2 under basal conditions, and this complex is then recruited to the IR in response to insulin or adiponectin stimulation. The interaction between APPL1 and IR depends on insulin- or adiponectin-stimulated APPL1 phosphorylation, which is greatly reduced in insulin target tissues in obese mice. appl1 deletion in mice consistently leads to systemic insulin resistance and a significant reduction in insulin-stimulated IRS1/2, but not IR, tyrosine phosphorylation, indicating that APPL1 sensitizes insulin signaling by acting at a site downstream of the IR. Our study uncovers a mechanism regulating insulin signaling and crosstalk between the insulin and adiponectin pathways. Copyright © 2014 The Authors. Published by Elsevier Inc. All rights reserved.

  12. Dissociation of corticotropin-releasing factor receptor subtype involvement in sensitivity to locomotor effects of methamphetamine and cocaine.

    Science.gov (United States)

    Giardino, William J; Mark, Gregory P; Stenzel-Poore, Mary P; Ryabinin, Andrey E

    2012-02-01

    Enhanced sensitivity to the euphoric and locomotor-activating effects of psychostimulants may influence an individual's predisposition to drug abuse and addiction. While drug-induced behaviors are mediated by the actions of several neurotransmitter systems, past research revealed that the corticotropin-releasing factor (CRF) system is important in driving the acute locomotor response to psychostimulants. We previously reported that genetic deletion of the CRF type-2 receptor (CRF-R2), but not the CRF type-1 receptor (CRF-R1) dampened the acute locomotor stimulant response to methamphetamine (1 mg/kg). These results contrasted with previous studies implicating CRF-R1 in the locomotor effects of psychostimulants. Since the majority of previous studies focused on cocaine, rather than methamphetamine, we set out to test the hypothesis that these drugs differentially engage CRF-R1 and CRF-R2. We expanded our earlier findings by first replicating our previous experiments at a higher dose of methamphetamine (2 mg/kg), and by assessing the effects of the CRF-R1-selective antagonist CP-376,395 (10 mg/kg) on methamphetamine-induced locomotor activity. Next, we used both genetic and pharmacological tools to examine the specific components of the CRF system underlying the acute locomotor response to cocaine (5-10 mg/kg). While genetic deletion of CRF-R2 dampened the locomotor response to methamphetamine (but not cocaine), genetic deletion and pharmacological blockade of CRF-R1 dampened the locomotor response to cocaine (but not methamphetamine). These findings highlight the differential involvement of CRF receptors in acute sensitivity to two different stimulant drugs of abuse, providing an intriguing basis for the development of more targeted therapeutics for psychostimulant addiction.

  13. Beta receptor-mediated modulation of the late positive potential in humans.

    Science.gov (United States)

    de Rover, Mischa; Brown, Stephen B R E; Boot, Nathalie; Hajcak, Greg; van Noorden, Martijn S; van der Wee, Nic J A; Nieuwenhuis, Sander

    2012-02-01

    Electrophysiological studies have identified a scalp potential, the late positive potential (LPP), which is modulated by the emotional intensity of observed stimuli. Previous work has shown that the LPP reflects the modulation of activity in extrastriate visual cortical structures, but little is known about the source of that modulation. The present study investigated whether beta-adrenergic receptors are involved in the generation of the LPP. We used a genetic individual differences approach (experiment 1) and a pharmacological manipulation (experiment 2) to test the hypothesis that the LPP is modulated by the activation of β-adrenergic receptors. In experiment 1, we found that LPP amplitude depends on allelic variation in the β1-receptor gene polymorphism. In experiment 2, we found that LPP amplitude was modulated by the β-blocker propranolol in a direction dependent on subjects' level of trait anxiety: In participants with lower trait anxiety, propranolol led to a (nonsignificant) decrease in the LPP modulation; in participants with higher trait anxiety, propranolol increased the emotion-related LPP modulation. These results provide initial support for the hypothesis that the LPP reflects the downstream effects, in visual cortical areas, of β-receptor-mediated activation of the amygdala.

  14. Changes in sensitivity of brain dopamine and serotonin receptors during long-term treatment with carbidine

    International Nuclear Information System (INIS)

    Zharkovskii, A.M.; Allikmets, L.K.; Chereshka, K.S.; Zharkovskaya, T.A.

    1986-01-01

    The authors study the state of the dopamine and serotonin receptors of the brain during chronic administration of carbidine to animals. Parts of the brain from two rats were pooled and binding of tritium-spiperone and tritium-LSD was determined. Statistical analysis of the data for apomorphine sterotypy was carried out and the Student's test was used for analysis of the remaining data. It is shown that after discontinuation of carbidine binding of tritium-spiperone and tritium-LSD in the cortex was reduced

  15. Parenteral medium-chain triglyceride-induced neutrophil activation is not mediated by a Pertussis Toxin sensitive receptor.

    Science.gov (United States)

    Versleijen, Michelle W J; van Esterik, Joantine C J; Roelofs, Hennie M J; van Emst-de Vries, Sjenet E; Willems, Peter H G M; Wanten, Geert J A

    2009-02-01

    Lipid-induced immune modulation might contribute to the increased infection rate that is observed in patients using parenteral nutrition. We previously showed that emulsions containing medium-chain triglycerides (LCT/MCTs or pure MCTs), but not pure long-chain triglycerides (LCTs), impair neutrophil functions, modulate cell-signaling and induce neutrophil activation in vitro. It has recently been shown that medium-chain fatty acids are ligands for GPR84, a pertussis toxin (PT)-sensitive G-protein-coupled receptor (GPCR). This finding urged us to investigate whether MCT-induced neutrophil activation is mediated by PT-sensitive GPCRs. Neutrophils isolated from blood of healthy volunteers were pre-incubated with PT (0.5-1 microg/mL, 1.5 h) and analyzed for the effect of this pre-incubation on LCT/MCT (2.5 mmol/L)-dependent modulation of serum-treated zymosan (STZ)-induced intracellular Ca(2+) mobilization and on LCT/MCT (5 mmol/L)-induced expression of cell surface adhesion (CD11b) and degranulation (CD66b) markers and oxygen radical (ROS) production. PT did not inhibit the effects of LCT/MCT on the STZ-induced increase in cytosolic free Ca(2+) concentration. LCT/MCT increased ROS production to 146% of unstimulated cells. However, pre-incubation with PT did not inhibit the LCT/MCT-induced ROS production. Furthermore, the LCT/MCT-induced increase in CD11b and CD66b expression (196% and 235% of unstimulated cells, respectively) was not inhibited by pre-incubation with PT. LCT/MCT-induced neutrophil activation does not involve the action of a PT-sensitive G-protein-coupled receptor.

  16. High sensitivity and specificity in proposed clinical diagnostic criteria for anti-N-methyl-D-aspartate receptor encephalitis.

    Science.gov (United States)

    Ho, Alvin C C; Mohammad, Shekeeb S; Pillai, Sekhar C; Tantsis, Esther; Jones, Hannah; Ho, Reena; Lim, Ming; Hacohen, Yael; Vincent, Angela; Dale, Russell C

    2017-12-01

    To determine the validity of the proposed clinical diagnostic criteria for anti-N-methyl-d-aspartate receptor (NMDAR) encephalitis in paediatric patients. The diagnostic criteria for anti-NMDAR encephalitis proposed by Graus et al. (2016) use clinical features and conventional investigations to facilitate early immunotherapy before antibody status is available. The criteria are satisfied if patients develop four out of six symptom groups within 3 months, together with at least one abnormal investigation (electroencephalography/cerebrospinal fluid) and reasonable exclusion of other disorders. We evaluated the validity of the criteria using a retrospective cohort of paediatric patients with encephalitis. Twenty-nine patients with anti-NMDAR encephalitis and 74 comparison children with encephalitis were included. As expected, the percentage of patients with anti-NMDAR encephalitis who fulfilled the clinical criteria increased over time. During the hospital inpatient admission, most patients (26/29, 90%) with anti-NMDAR encephalitis fulfilled the criteria, significantly more than the comparison group (3/74, 4%) (panti-NMDAR encephalitis was 2 weeks from first symptom onset (range 1-6). The sensitivity of the criteria was 90% (95% confidence interval 73-98) and the specificity was 96% (95% confidence interval 89-99). The proposed diagnostic criteria for anti-NMDAR encephalitis have good sensitivity and specificity. Incomplete criteria do not exclude the diagnosis. The proposed clinical diagnostic criteria for anti-N-methyl-d-aspartate receptor (NMDAR) encephalitis by Graus et al. (2016) have high sensitivity and specificity in paediatric patients. The median time of fulfilling the criteria in patients with anti-NMDAR was 2 weeks from first symptom onset. © 2017 Mac Keith Press.

  17. Anti-Inflammatory and Insulin-Sensitizing Effects of Free Fatty Acid Receptors.

    Science.gov (United States)

    Miyamoto, Junki; Kasubuchi, Mayu; Nakajima, Akira; Kimura, Ikuo

    2017-01-01

    Chronic low-grade inflammation in macrophages and adipose tissues can promote the development of obesity and type 2 diabetes. Free fatty acids (FFAs) have important roles in various tissues, acting as both essential energy sources and signaling molecules. FFA receptors (FFARs) can modulate inflammation in various types of cells and tissues; however the underlying mechanisms mediating these effects are unclear. FFARs are activated by specific FFAs; for example, GPR40 and GPR120 are activated by medium and long chain FFAs, GPR41 and GPR43 are activated by short chain FFAs, and GPR84 is activated by medium-chain FFAs. To date, a number of studies associated with the physiological functions of G protein-coupled receptors (GPCRs) have reported that these GPCRs are expressed in various tissues and involved in inflammatory and metabolic responses. Thus, the development of selective agonists or antagonists for various GPCRs may facilitate the establishment of novel therapies for the treatment of various diseases. In this review, we summarize current literature describing the potential of GPCRs as therapeutic targets for inflammatory and metabolic disorders.

  18. Aberrant expression of glucagon receptors in adrenal glands of a patient with Cushing's syndrome and ACTH-independent macronodular adrenal hyperplasia

    Directory of Open Access Journals (Sweden)

    Valeria de Miguel

    2010-06-01

    Full Text Available Adrenocorticotropin (ACTH independent bilateral macronodular adrenal hyperplasia (AIMAH is a rare cause of Cushing´s syndrome, characterized by bilateral adrenal lesions and excess cortisol production despite ACTH suppression. Cortisol synthesis is produced in response to abnormal activation of G-protein- coupled receptors, such as gastric inhibitory peptide, vasopressin, beta adrenergic agonists, LH/hCG and serotonin receptors. The aim of this study was to analyze the expression of glucagon receptors in adrenal glands from an AIMAH patient. A patient with ACTH-independent Cushing´s syndrome and bilateral macronodular adrenal hyperplasia was screened for altered activation of adrenal receptors by physiological (mixed meal and pharmacological (gonadotrophin releasing hormone, ACTH and glucagon tests. The results showed abnormally high levels of serum cortisol after stimulation with glucagon. Hypercortisolism was successfully managed with ketoconazole treatment. Interestingly, a 4-month treatment with a somatostatin analogue (octreotide was also able to reduce cortisol secretion. Finally, Cushing's syndrome was cured after bilateral adrenalectomy. Abnormal mRNA expression for glucagon receptor in the patient´s adrenal glands was observed by Real-Time PCR procedure. These results strongly suggest that the mechanism of AIMAH causing Cushing´s syndrome in this case involves the illicit activation of adrenal glucagon receptors. This is the first case reported of AIMAH associated with ectopic glucagon receptors.

  19. The Importance of G Protein-Coupled Receptor Kinase 4 (GRK4 in Pathogenesis of Salt Sensitivity, Salt Sensitive Hypertension and Response to Antihypertensive Treatment

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    Brian Rayner

    2015-03-01

    Full Text Available Salt sensitivity is probably caused by either a hereditary or acquired defect of salt excretion by the kidney, and it is reasonable to consider that this is the basis for differences in hypertension between black and white people. Dopamine acts in an autocrine/paracrine fashion to promote natriuresis in the proximal tubule and thick ascending loop of Henle. G-protein receptor kinases (or GRKs are serine and threonine kinases that phosphorylate G protein-coupled receptors in response to agonist stimulation and uncouple the dopamine receptor from its G protein. This results in a desensitisation process that protects the cell from repeated agonist exposure. GRK4 activity is increased in spontaneously hypertensive rats, and infusion of GRK4 antisense oligonucleotides attenuates the increase in blood pressure (BP. This functional defect is replicated in the proximal tubule by expression of GRK4 variants namely p.Arg65Leu, p.Ala142Val and p.Val486Ala, in cell lines, with the p.Ala142Val showing the most activity. In humans, GRK4 polymorphisms were shown to be associated with essential hypertension in Australia, BP regulation in young adults, low renin hypertension in Japan and impaired stress-induced Na excretion in normotensive black men. In South Africa, GRK4 polymorphisms are more common in people of African descent, associated with impaired Na excretion in normotensive African people, and predict blood pressure response to Na restriction in African patients with mild to moderate essential hypertension. The therapeutic importance of the GRK4 single nucleotide polymorphisms (SNPs was emphasised in the African American Study of Kidney Disease (AASK where African-Americans with hypertensive nephrosclerosis were randomised to receive amlodipine, ramipril or metoprolol. Men with the p.Ala142Val genotype were less likely to respond to metoprolol, especially if they also had the p.Arg65Leu variant. Furthermore, in the analysis of response to treatment in

  20. Dual orexin receptor antagonist 12 inhibits expression of proteins in neurons and glia implicated in peripheral and central sensitization.

    Science.gov (United States)

    Cady, R J; Denson, J E; Sullivan, L Q; Durham, P L

    2014-06-06

    Sensitization and activation of trigeminal nociceptors is implicated in prevalent and debilitating orofacial pain conditions including temporomandibular joint (TMJ) disorders. Orexins are excitatory neuropeptides that function to regulate many physiological processes and are reported to modulate nociception. To determine the role of orexins in an inflammatory model of trigeminal activation, the effects of a dual orexin receptor antagonist (DORA-12) on levels of proteins that promote peripheral and central sensitization and changes in nocifensive responses were investigated. In adult male Sprague-Dawley rats, mRNA for orexin receptor 1 (OX₁R) and receptor 2 (OX₂R) were detected in trigeminal ganglia and spinal trigeminal nucleus (STN). OX₁R immunoreactivity was localized primarily in neuronal cell bodies in the V3 region of the ganglion and in laminas I-II of the STN. Animals injected bilaterally with complete Freund's adjuvant (CFA) in the TMJ capsule exhibited increased expression of P-p38, P-ERK, and lba1 in trigeminal ganglia and P-ERK and lba1 in the STN at 2 days post injection. However, levels of each of these proteins in rats receiving daily oral DORA-12 were inhibited to near basal levels. Similarly, administration of DORA-12 on days 3 and 4 post CFA injection in the TMJ effectively inhibited the prolonged stimulated expression of protein kinase A, NFkB, and Iba1 in the STN on day 5 post injection. While injection of CFA mediated a nocifensive response to mechanical stimulation of the orofacial region at 2h and 3 and 5 days post injection, treatment with DORA-12 suppressed the nocifensive response on day 5. Somewhat surprisingly, nocifensive responses were again observed on day 10 post CFA stimulation in the absence of daily DORA-12 administration. Our results provide evidence that DORA-12 can inhibit CFA-induced stimulation of trigeminal sensory neurons by inhibiting expression of proteins associated with sensitization of peripheral and central

  1. High concentrations of morphine sensitize and activate mouse dorsal root ganglia via TRPV1 and TRPA1 receptors

    Directory of Open Access Journals (Sweden)

    Messlinger Karl

    2009-04-01

    Full Text Available Abstract Background Morphine and its derivatives are key drugs in pain control. Despite its well-known analgesic properties morphine at high concentrations may be proalgesic. Particularly, short-lasting painful sensations have been reported upon dermal application of morphine. To study a possible involvement of TRP receptors in the pro-nociceptive effects of morphine (0.3 – 10 mM, two models of nociception were employed using C57BL/6 mice and genetically related TRPV1 and TRPA1 knockout animals, which were crossed and generated double knockouts. Hindpaw skin flaps were used to investigate the release of calcitonin gene-related peptide indicative of nociceptive activation. Results Morphine induced release of calcitonin gene-related peptide and sensitized the release evoked by heat or the TRPA1 agonist acrolein. Morphine activated HEK293t cells transfected with TRPV1 or TRPA1. Activation of C57BL/6 mouse dorsal root ganglion neurons in culture was investigated with calcium imaging. Morphine induced a dose-dependent rise in intracellular calcium in neurons from wild-type animals. In neurons from TRPV1 and TRPA1 knockout animals activation by morphine was markedly reduced, in the TRPV1/A1 double knockout animals this morphine effect was abrogated. Naloxone induced an increase in calcium levels similar to morphine. The responses to both morphine and naloxone were sensitized by bradykinin. Conclusion Nociceptor activation and sensitization by morphine is conveyed by TRPV1 and TRPA1.

  2. Descending serotonergic facilitation mediated by spinal 5-HT3 receptors engages spinal rapamycin-sensitive pathways in the rat

    Science.gov (United States)

    Asante, Curtis O.; Dickenson, Anthony H.

    2010-01-01

    We have recently reported the importance of spinal rapamycin-sensitive pathways in maintaining persistent pain-like states. A descending facilitatory drive mediated through spinal 5-HT3 receptors (5-HT3Rs) originating from superficial dorsal horn NK1-expressing neurons and that relays through the parabrachial nucleus and the rostroventral medial medulla to act on deep dorsal horn neurons is known be important in maintaining these pain-like states. To determine if spinal rapamycin-sensitive pathways are activated by a descending serotonergic drive, we investigated the effects of spinally administered rapamycin on responses of deep dorsal horn neurons that had been pre-treated with the selective 5-HT3R antagonist ondansetron. We also investigated the effects of spinally administered cell cycle inhibitor (CCI)-779 (a rapamycin ester analogue) on deep dorsal horn neurons from rats with carrageenan-induced inflammation of the hind paw. Unlike some other models of persistent pain, this model does not involve an altered 5-HT3R-mediated descending serotonergic drive. We found that the inhibitory effects of rapamycin were significantly reduced for neuronal responses to mechanical and thermal stimuli when the spinal cord was pre-treated with ondansetron. Furthermore, CCI-779 was found to be ineffective in attenuating spinal neuronal responses to peripheral stimuli in carrageenan-treated rats. Therefore, we conclude that 5-HT3R-mediated descending facilitation is one requirement for activation of rapamycin-sensitive pathways that contribute to persistent pain-like states. PMID:20709148

  3. Evidence for a high and a low sensitivity receptor site for radiation-induced vomiting in the dog

    International Nuclear Information System (INIS)

    Harding, R.K.; Hugenholtz, H.; Kucharczyk, J.

    1987-01-01

    Ablation of the area postrema (AP) has been shown to prevent radiation-induced vomiting in the dog (induced by 6-8 By /sup 60/Co γ). In other species (cat, monkey) a higher dose of radiation is necessary to elicit emesis and visceral deafferentation has been more effective than AP ablation in preventing vomiting. The AP and the dorsal motor nucleus of the vagus (DMV), an important visceral afferent terminus, are anatomically adjacent structures in the medulla oblongata. Aggressive AP ablation could affect the DMV. The author's removed the AP in 6 dogs. Previous work showed this surgery prevented vomiting following exposure to 6-8 Gy. To prove the lesion did not invade the underlying DMV, the animals were given a hypertonic saline gavage, to elicit vomiting via visceral receptors. Animals were later submitted to 15-20 Gy. Those with proved visceral afferent connections vomited. They conclude that the AP is the most sensitive site for the stimulation of radiation-induced vomiting and that a less sensitive visceral site also exists. Differences in the relative sensitivities of these 2 systems may account for published species differences

  4. Receptor trafficking via the perinuclear recycling compartment accompanied by cell division is necessary for permanent neurotensin cell sensitization and leads to chronic mitogen-activated protein kinase activation.

    Science.gov (United States)

    Toy-Miou-Leong, Mireille; Cortes, Catherine Llorens; Beaudet, Alain; Rostène, William; Forgez, Patricia

    2004-03-26

    Most G protein-coupled receptors are internalized after interaction with their respective ligand, a process that subsequently contributes to cell desensitization, receptor endocytosis, trafficking, and finally cell resensitization. Although cellular mechanisms leading to cell desensitization have been widely studied, those responsible for cell resensitization are still poorly understood. We examined here the traffic of the high affinity neurotensin receptor (NT1 receptor) following prolonged exposure to high agonist concentration. Fluorescence and confocal microscopy of Chinese hamster ovary, human neuroblastoma (CHP 212), and murine neuroblastoma (N1E-115) cells expressing green fluorescent protein-tagged NT1 receptor revealed that under prolonged treatment with saturating concentrations of neurotensin (NT) agonist, NT1 receptor and NT transiently accumulated in the perinuclear recycling compartment (PNRC). During this cellular event, cell surface receptors remained markedly depleted as detected by both confocal microscopy and (125)I-NT binding assays. In dividing cells, we observed that following prolonged NT agonist stimulation, NT1 receptors were removed from the PNRC, accumulated in dispersed vesicles inside the cytoplasm, and subsequently reappeared at the cell surface. This NT binding recovery allowed for constant cell sensitization and led to a chronic activation of mitogen-activated protein kinases p42 and p44. Under these conditions, the constant activation of NT1 receptor generates an oncogenic regulation. These observations support the potent role for neuropeptides, such as NT, in cancer progression.

  5. Overexpression of Poplar Pyrabactin Resistance-Like Abscisic Acid Receptors Promotes Abscisic Acid Sensitivity and Drought Resistance in Transgenic Arabidopsis.

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    Jingling Yu

    Full Text Available Drought stress is an important environmental factor limiting productivity of plants, especially fast growing species with high water consumption like poplar. Abscisic acid (ABA is a phytohormone that positively regulates seed dormancy and drought resistance. The PYR1 (Pyrabactin Resistance 1/ PYRL (PYR-Like/ RCAR (Regulatory Component of ABA Receptor (PYR/PYL/RCAR ABA receptor family has been identified and widely characterized in Arabidopsis thaliana. However, their functions in poplars remain unknown. Here, we report that 2 of 14 PYR/PYL/RCAR orthologues in poplar (Populus trichocarpa (PtPYRLs function as a positive regulator of the ABA signal transduction pathway. The Arabidopsis transient expression and yeast two-hybrid assays showed the interaction among PtPYRL1 and PtPYRL5, a clade A protein phosphatase 2C, and a SnRK2, suggesting that a core signalling complex for ABA signaling pathway exists in poplars. Phenotypic analysis of PtPYRL1 and PtPYRL5 transgenic Arabidopsis showed that these two genes positively regulated the ABA responses during the seed germination. More importantly, the overexpression of PtPYRL1 and PtPYRL5 substantially improved ABA sensitivity and drought stress tolerance in transgenic plants. In summary, we comprehensively uncovered the properties of PtPYRL1 and PtPYRL5, which might be good target genes to genetically engineer drought-Resistant plants.

  6. Hotspot mutations in KIT receptor differentially modulate its allosterically coupled conformational dynamics: impact on activation and drug sensitivity.

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    Isaure Chauvot de Beauchêne

    2014-07-01

    Full Text Available Receptor tyrosine kinase KIT controls many signal transduction pathways and represents a typical allosterically regulated protein. The mutation-induced deregulation of KIT activity impairs cellular physiological functions and causes serious human diseases. The impact of hotspots mutations (D816H/Y/N/V and V560G/D localized in crucial regulatory segments, the juxtamembrane region (JMR and the activation (A- loop, on KIT internal dynamics was systematically studied by molecular dynamics simulations. The mutational outcomes predicted in silico were correlated with in vitro and in vivo activation rates and drug sensitivities of KIT mutants. The allosteric regulation of KIT in the native and mutated forms is described in terms of communication between the two remote segments, JMR and A-loop. A strong correlation between the communication profile and the structural and dynamical features of KIT in the native and mutated forms was established. Our results provide new insight on the determinants of receptor KIT constitutive activation by mutations and resistance of KIT mutants to inhibitors. Depiction of an intra-molecular component of the communication network constitutes a first step towards an integrated description of vast communication pathways established by KIT in physiopathological contexts.

  7. Highly Selective and Sensitive Detection of Acetylcholine Using Receptor-Modified Single-Walled Carbon Nanotube Sensors

    Science.gov (United States)

    Xu, Shihong; Kim, Byeongju; Song, Hyun Seok; Jin, Hye Jun; Park, Eun Jin; Lee, Sang Hun; Lee, Byung Yang; Park, Tai Hyun; Hong, Seunghun

    2015-03-01

    Acetylcholine (ACh) is a neurotransmitter in a human central nervous system and is related to various neural functions such as memory, learning and muscle contractions. Dysfunctional ACh regulations in a brain can induce several neuropsychiatric diseases such as Alzheimer's disease, Parkinson's disease and myasthenia gravis. In researching such diseases, it is important to measure the concentration of ACh in the extracellular fluid of the brain. Herein, we developed a highly sensitive and selective ACh sensor based on single-walled carbon nanotube-field effect transistors (swCNT-FETs). In our work, M1 mAChR protein, an ACh receptor, was expressed in E.coli and coated on swCNT-FETs with lipid membranes. Here, the binding of ACh onto the receptors could be detected by monitoring the change of electrical currents in the underlying swCNT-FETs, allowing the real-time detection of ACh at a 100 pM concentration. Furthermore, our sensor could selectively detect ACh from other neurotransmitters. This is the first report of the real-time sensing of ACh utilizing specific binding between the ACh and M1 mAChR, and it may lead to breakthroughs in various biomedical applications such as drug screening and disease diagnosis.

  8. Nesfatin-1/NUCB2 in the amygdala influences visceral sensitivity via glucocorticoid and mineralocorticoid receptors in male maternal separation rats.

    Science.gov (United States)

    Zhou, X-P; Sha, J; Huang, L; Li, T-N; Zhang, R-R; Tang, M-D; Lin, L; Li, X-L

    2016-10-01

    Nesfatin-1, a recently identified satiety molecule derived from nucleobindin 2 (NUCB2), is associated with visceral hypersensitivity in rats and is expressed in the amygdala. We tested the hypothesis that nesfatin-1 expression in the amygdala is involved in the pathogenesis of irritable bowel syndrome (IBS) visceral hypersensitivity. An animal model of IBS-like visceral hypersensitivity was established using maternal separation (MS) during postnatal days 2-16. The role of nesfatin-1 in the amygdala on visceral sensitivity was evaluated. Rats subjected to MS showed a significantly increased mean abdominal withdrawal reflex (AWR) score and electromyographic (EMG) activity at 40, 60, and 80 mmHg colorectal distension. Plasma concentrations of nesfatin-1 and corticosterone were significantly higher than in non-handled (NH) rats. mRNA and protein expression of nesfatin-1/NUCB2 in the amygdala were increased in MS rats, but not in NH rats. In MS rats, AWR scores and EMG activity were significantly decreased after anti-nesfatin-1/NUCB2 injection. In normal rats, mean AWR score, EMG activity, and corticosterone expression were significantly increased after nesfatin-1 injection into the amygdala. Nesfatin-1-induced visceral hypersensitivity was abolished following application of glucocorticoid receptor (GR) and mineralocorticoid receptor (MR) antagonists. Elevated expression of nesfatin-1/NUCB2 in the amygdala in MS rats suggests a potential role in the pathogenesis of visceral hypersensitivity, which could potentially take place via activation of GR and MR signaling pathways. © 2016 John Wiley & Sons Ltd.

  9. Prolactin-sensitive neurons express estrogen receptor-α and depend on sex hormones for normal responsiveness to prolactin.

    Science.gov (United States)

    Furigo, Isadora C; Kim, Ki Woo; Nagaishi, Vanessa S; Ramos-Lobo, Angela M; de Alencar, Amanda; Pedroso, João A B; Metzger, Martin; Donato, Jose

    2014-05-30

    Estrogens and prolactin share important target tissues, including the gonads, brain, liver, kidneys and some types of cancer cells. Herein, we sought anatomical and functional evidence of possible crosstalk between prolactin and estrogens in the mouse brain. First, we determined the distribution of prolactin-responsive neurons that express the estrogen receptor α (ERα). A large number of prolactin-induced pSTAT5-immunoreactive neurons expressing ERα mRNA were observed in several brain areas, including the anteroventral periventricular nucleus, medial preoptic nucleus, arcuate nucleus of the hypothalamus, ventrolateral subdivision of the ventromedial nucleus of the hypothalamus (VMH), medial nucleus of the amygdala and nucleus of the solitary tract. However, although the medial preoptic area, periventricular nucleus of the hypothalamus, paraventricular nucleus of the hypothalamus, retrochiasmatic area, dorsomedial subdivision of the VMH, lateral hypothalamic area, dorsomedial nucleus of the hypothalamus and ventral premammillary nucleus contained significant numbers of prolactin-responsive neurons, these areas showed very few pSTAT5-immunoreactive cells expressing ERα mRNA. Second, we evaluated prolactin sensitivity in ovariectomized mice and observed that sex hormones are required for a normal responsiveness to prolactin as ovariectomized mice showed a lower number of prolactin-induced pSTAT5 immunoreactive neurons in all analyzed brain nuclei compared to gonad-intact females. In addition, we performed hypothalamic gene expression analyses to determine possible post-ovariectomy changes in components of prolactin signaling. We observed no significant changes in the mRNA expression of prolactin receptor, STAT5a or STAT5b. In summary, sex hormones exert a permissive role in maintaining the brain's prolactin sensitivity, most likely through post-transcriptional mechanisms. Copyright © 2014 Elsevier B.V. All rights reserved.

  10. Ghrelin receptor antagonism of morphine-induced conditioned place preference and behavioral and accumbens dopaminergic sensitization in rats.

    Science.gov (United States)

    Jerabek, Pavel; Havlickova, Tereza; Puskina, Nina; Charalambous, Chrysostomos; Lapka, Marek; Kacer, Petr; Sustkova-Fiserova, Magdalena

    2017-11-01

    An increasing number of studies over the past few years have demonstrated ghrelin's role in alcohol, cocaine and nicotine abuse. However, the role of ghrelin in opioid effects has rarely been examined. Recently we substantiated in rats that ghrelin growth hormone secretagogue receptors (GHS-R1A) appear to be involved in acute opioid-induced changes in the mesolimbic dopaminergic system associated with the reward processing. The aim of the present study was to ascertain whether a ghrelin antagonist (JMV2959) was able to inhibit morphine-induced biased conditioned place preference and challenge-morphine-induced accumbens dopaminergic sensitization and behavioral sensitization in adult male rats. In the place preference model, the rats were conditioned for 8 days with morphine (10 mg/kg s.c.). On the experimental day, JMV2959 (3 and 6 mg/kg i.p.) or saline were administered before testing. We used in vivo microdialysis to determine changes of dopamine and its metabolites in the nucleus accumbens in rats following challenge-morphine dose (5 mg/kg s.c.) with or without JMV2959 (3 and 6 mg/kg i.p.) pretreatment, administered on the 12th day of spontaneous abstinence from morphine repeated treatment (5 days, 10-40 mg/kg). Induced behavioral changes were simultaneously monitored. Pretreatment with JMV2959 significantly and dose dependently reduced the morphine-induced conditioned place preference and significantly and dose dependently reduced the challenge-morphine-induced dopaminergic sensitization and affected concentration of by-products associated with dopamine metabolism in the nucleus accumbens. JMV2959 pretreatment also significantly reduced challenge-morphine-induced behavioral sensitization. Our present data suggest that GHS-R1A antagonists deserve to be further investigated as a novel treatment strategy for opioid addiction. Copyright © 2017 Elsevier Ltd. All rights reserved.

  11. Sensitization of restraint-induced corticosterone secretion after chronic restraint in rats: Involvement of 5-HT7 receptors

    Science.gov (United States)

    García-Iglesias, Brenda B.; Mendoza-Garrido, María E.; Gutiérrez-Ospina, Gabriel; Rangel-Barajas, Claudia; Noyola-Díaz, Martha; Terrón, José A.

    2013-01-01

    Serotonin (5-HT) modulates the hypothalamic-pituitary-adrenal (HPA) axis response to stress. We examined the effect of chronic restraint stress (CRS; 20 min/day) as compared to control (CTRL) conditions for 14 days, on: 1) restraint-induced ACTH and corticosterone (CORT) secretion in rats pretreated with vehicle or SB-656104 (a 5-HT7 receptor antagonist); 2) 5-HT7 receptor-like immunoreactivity (5-HT7-LI) and protein in the hypothalamic paraventricular nucleus (PVN) and adrenal glands (AG); 3) baseline levels of 5-HT and 5-hydroxyindolacetic acid (5-HIAA), and 5-HIAA/5-HT ratio in PVN and AG; and 4) 5-HT-like immunoreactivity (5-HT-LI) in AG and tryptophan hydroxylase (TPH) protein in PVN and AG. On day 15, animals were subdivided into Treatment and No treatment groups. Treatment animals received an i.p. injection of vehicle or SB-656104; No Treatment animals received no injection. Sixty min later, Treatment animals were either decapitated with no further stress (0 min) or submitted to acute restraint (10, 30, 60 or 120 min); hormone serum levels were measured. No Treatment animals were employed for the rest of measurements. CRS decreased body weight gain and increased adrenal weight. In CTRL animals, acute restraint increased ACTH and CORT secretion in a time of restraint-dependent manner; both responses were inhibited by SB-656104. Exposure to CRS abolished ACTH but magnified CORT responses to restraint as compared to CTRL conditions; SB-656104 had no effect on ACTH levels but significantly inhibited sensitized CORT responses. In CTRL animals, 5-HT7-LI was detected in magnocellular and parvocellular subdivisions of PVN and sparsely in adrenal cortex. Exposure to CRS decreased 5-HT7-LI and protein in the PVN, but increased 5-HT7-LI in the adrenal cortex and protein in whole AG. Higher 5-HT and 5-HIAA levels were detected in PVN and AG from CRS animals but 5-HIAA/5-HT ratio increased in AG only. Finally, whereas 5-HT-LI was sparsely observed in the adrenal cortex

  12. Abnormal norepinephrine clearance and adrenergic receptor sensitivity in idiopathic orthostatic intolerance

    Science.gov (United States)

    Jacob, G.; Shannon, J. R.; Costa, F.; Furlan, R.; Biaggioni, I.; Mosqueda-Garcia, R.; Robertson, R. M.; Robertson, D.

    1999-01-01

    BACKGROUND: Chronic orthostatic intolerance (OI) is characterized by symptoms of inadequate cerebral perfusion with standing, in the absence of significant orthostatic hypotension. A heart rate increase of >/=30 bpm is typical. Possible underlying pathophysiologies include hypovolemia, partial dysautonomia, or a primary hyperadrenergic state. We tested the hypothesis that patients with OI have functional abnormalities in autonomic neurons regulating cardiovascular responses. METHODS AND RESULTS: Thirteen patients with chronic OI and 10 control subjects underwent a battery of autonomic tests. Systemic norepinephrine (NE) kinetics were determined with the patients supine and standing before and after tyramine administration. In addition, baroreflex sensitivity, hemodynamic responses to bolus injections of adrenergic agonists, and intrinsic heart rate were determined. Resting supine NE spillover and clearance were similar in both groups. With standing, patients had a greater decrease in NE clearance than control subjects (55+/-5% versus 30+/-7%, Pheart rate 25 bpm was lower in patients than in control subjects (0.5+/-0.05 versus 1.0+/-0.1 microg, Pheart rate was similar in both groups. CONCLUSIONS: The decreased NE clearance with standing, resistance to the NE-releasing effect of tyramine, and increased sensitivity to adrenergic agonists demonstrate dramatically disordered sympathetic cardiovascular regulation in patients with chronic OI.

  13. Fractalkine receptor (CX3CR1 deficiency sensitizes mice to the behavioral changes induced by lipopolysaccharide

    Directory of Open Access Journals (Sweden)

    Kelley Keith W

    2010-12-01

    Full Text Available Abstract Background Interactions between fractalkine (CX3CL1 and fractalkine receptor (CX3CR1 regulate microglial activation in the CNS. Recent findings indicate that age-associated impairments in CX3CL1 and CX3CR1 are directly associated with exaggerated microglial activation and an impaired recovery from sickness behavior after peripheral injection of lipopolysaccharide (LPS. Therefore, the purpose of this study was to determine the extent to which an acute LPS injection causes amplified and prolonged microglial activation and behavioral deficits in CX3CR1-deficient mice (CX3CR1-/-. Methods CX3CR1-/- mice or control heterozygote mice (CX3CR1+/- were injected with LPS (0.5 mg/kg i.p. or saline and behavior (i.e., sickness and depression-like behavior, microglial activation, and markers of tryptophan metabolism were determined. All data were analyzed using Statistical Analysis Systems General Linear Model procedures and were subjected to one-, two-, or three-way ANOVA to determine significant main effects and interactions. Results LPS injection caused a prolonged duration of social withdrawal in CX3CR1-/- mice compared to control mice. This extended social withdrawal was associated with enhanced mRNA expression of IL-1β, indolamine 2,3-dioxygenase (IDO and kynurenine monooxygenase (KMO in microglia 4 h after LPS. Moreover, elevated expression of IL-1β and CD14 was still detected in microglia of CX3CR1-/- mice 24 h after LPS. There was also increased turnover of tryptophan, serotonin, and dopamine in the brain 24 h after LPS, but these increases were independent of CX3CR1 expression. When submitted to the tail suspension test 48 and 72 h after LPS, an increased duration of immobility was evident only in CX3CR1-/- mice. This depression-like behavior in CX3CR1-/- mice was associated with a persistent activated microglial phenotype in the hippocampus and prefrontal cortex. Conclusions Taken together, these data indicate that a deficiency of CX3CR1

  14. Fractalkine receptor (CX3CR1) deficiency sensitizes mice to the behavioral changes induced by lipopolysaccharide

    Science.gov (United States)

    2010-01-01

    Background Interactions between fractalkine (CX3CL1) and fractalkine receptor (CX3CR1) regulate microglial activation in the CNS. Recent findings indicate that age-associated impairments in CX3CL1 and CX3CR1 are directly associated with exaggerated microglial activation and an impaired recovery from sickness behavior after peripheral injection of lipopolysaccharide (LPS). Therefore, the purpose of this study was to determine the extent to which an acute LPS injection causes amplified and prolonged microglial activation and behavioral deficits in CX3CR1-deficient mice (CX3CR1-/-). Methods CX3CR1-/- mice or control heterozygote mice (CX3CR1+/-) were injected with LPS (0.5 mg/kg i.p.) or saline and behavior (i.e., sickness and depression-like behavior), microglial activation, and markers of tryptophan metabolism were determined. All data were analyzed using Statistical Analysis Systems General Linear Model procedures and were subjected to one-, two-, or three-way ANOVA to determine significant main effects and interactions. Results LPS injection caused a prolonged duration of social withdrawal in CX3CR1-/- mice compared to control mice. This extended social withdrawal was associated with enhanced mRNA expression of IL-1β, indolamine 2,3-dioxygenase (IDO) and kynurenine monooxygenase (KMO) in microglia 4 h after LPS. Moreover, elevated expression of IL-1β and CD14 was still detected in microglia of CX3CR1-/- mice 24 h after LPS. There was also increased turnover of tryptophan, serotonin, and dopamine in the brain 24 h after LPS, but these increases were independent of CX3CR1 expression. When submitted to the tail suspension test 48 and 72 h after LPS, an increased duration of immobility was evident only in CX3CR1-/- mice. This depression-like behavior in CX3CR1-/- mice was associated with a persistent activated microglial phenotype in the hippocampus and prefrontal cortex. Conclusions Taken together, these data indicate that a deficiency of CX3CR1 is permissive to

  15. Environmental ground borne noise and vibration protection of sensitive cultural receptors along the Athens Metro Extension to Piraeus.

    Science.gov (United States)

    Vogiatzis, Konstantinos

    2012-11-15

    Attiko Metro S.A., the state company ensuring the development of the Athens Metro network, has recently initiated a new extension of 7.6 km, has planned for line 3 of Athens Metro from Haidari to Piraeus "Dimotikon Theatre" towards "University of Piraeus" (forestation), connecting the major Piraeus Port with "Eleftherios Venizelos" International Airport. The Piraeus extension consists of a Tunnel Boring Machine, 2 tracks and, tunnel sections, as well as 6 stations and a forestation (New Austrian Tunnelling Method) at the end of the alignment. In order to avoid the degradation of the urban acoustic environment from ground borne noise and vibration during metro operation, the assessment of the required track types and possible noise mitigation measures was executed, and for each section and each sensitive building, the ground borne noise and vibration levels will be numerically predicted. The calculated levels were then compared with ground borne noise and vibration level criteria. The necessary mitigation measures were defined in order to guarantee, in each location along the extension, the allowable ground borne Noise and Vibration max. levels inside nearby sensitive buildings taking into account alternative Transfer Functions for ground borne noise diffusion inside the buildings. Ground borne noise levels were proven to be higher than the criterion where special track work is present and also in the case of the sensitive receptor: "Dimotikon Theatre". In order to reduce the ground borne noise levels to allowable values in these sections, the installation of tracks and special track work on a floating slab was assessed and recommended. Copyright © 2012 Elsevier B.V. All rights reserved.

  16. receptores

    Directory of Open Access Journals (Sweden)

    Salete Regina Daronco Benetti

    2006-01-01

    Full Text Available Se trata de un estudio etnográfico, que tuvo lo objetivo de interpretar el sistema de conocimiento y del significado atribuidos a la sangre referente a la transfusión sanguínea por los donadores y receptores de un banco de sangre. Para la colecta de las informaciones se observaron los participantes y la entrevista etnográfica se realizó el análisis de dominio, taxonómicos y temáticos. Los dominios culturales fueron: la sangre es vida: fuente de vida y alimento valioso; creencias religiosas: fuentes simbólicas de apoyos; donación sanguínea: un gesto colaborador que exige cuidarse, gratifica y trae felicidad; donación sanguínea: fuente simbólica de inseguridad; estar enfermo es una condición para realizar transfusión sanguínea; transfusión sanguínea: esperanza de vida; Creencias populares: transfusión sanguínea como riesgo para la salud; donadores de sangre: personas benditas; donar y recibir sangre: como significado de felicidad. Temática: “líquido precioso que origina, sostiene, modifica la vida, provoca miedo e inseguridad”.

  17. One week treatment with the IL-1 receptor antagonist anakinra leads to a sustained improvement in insulin sensitivity in insulin resistant patients with type 1 diabetes mellitus

    NARCIS (Netherlands)

    Asseldonk, van E.J.P.; Poppel, van P.C.M.; Ballak, D.B.; Stienstra, Rinke; Netea, M.G.; Tack, C.J.

    2015-01-01

    Inflammation associated with obesity is involved in the development of insulin resistance. We hypothesized that anti-inflammatory treatment with the Interleukin-1 receptor antagonist anakinra would improve insulin sensitivity.In an open label proof-of-concept study, we included overweight

  18. Biological variation and reference intervals for circulating osteopontin, osteoprotegerin, total soluble receptor activator of nuclear factor kappa B ligand and high-sensitivity C-reactive protein

    DEFF Research Database (Denmark)

    Sennels, H P; Jacobsen, Søren; Jensen, T

    2007-01-01

    Objective. Monitoring inflammatory diseases and osteoclastogenesis with osteopontin (OPN), osteoprotegerin (OPG), total soluble receptor activator of nuclear factor kappa B ligand (total sRANKL) and high-sensitivity C-reactive protein (hsCRP) has recently attracted increased interest. The purpose...

  19. Modelling a historic oil-tank fire allows an estimation of the sensitivity of the infrared receptors in pyrophilous Melanophila beetles.

    Directory of Open Access Journals (Sweden)

    Helmut Schmitz

    Full Text Available Pyrophilous jewel beetles of the genus Melanophila approach forest fires and there is considerable evidence that these beetles can detect fires from great distances of more than 60 km. Because Melanophila beetles are equipped with infrared receptors and are also attracted by hot surfaces it can be concluded that these infrared receptors are used for fire detection.The sensitivity of the IR receptors is still unknown. The lowest threshold published so far is 0.6 W/m(2 which, however, cannot explain the detection of forest fires by IR radiation from distances larger than approximately 10 km. To investigate the possible sensitivity of the IR receptors we assumed that beetles use IR radiation for remote fire detection and we made use of a historic report about a big oil-tank fire in Coalinga, California, in 1924. IR emission of an oil-tank fire can be calculated by "pool fire" simulations which now are used for fire safety and risk analysis. Assuming that beetles were lured to the fire from the nearest forests 25 and 130 km away, our results show that detection from a distance of 25 km requires a threshold of the IR receptors of at least 3×10(-2 W/m(2. According to our investigations most beetles became aware of the fire from a distance of 130 km. In this case the threshold has to be 1.3×10(-4 W/m(2. Because such low IR intensities are buried in thermal noise we suggest that the infrared sensory system of Melanophila beetles utilizes stochastic resonance for the detection of weak IR radiation. Our simulations also suggest that the biological IR receptors might be even more sensitive than uncooled technical IR sensors. Thus a closer look into the mode of operation of the Melanophila IR receptors seems promising for the development of novel IR sensors.

  20. Calcium pathways such as cAMP modulate clothianidin action through activation of α-bungarotoxin-sensitive and -insensitive nicotinic acetylcholine receptors.

    Science.gov (United States)

    Calas-List, Delphine; List, Olivier; Quinchard, Sophie; Thany, Steeve H

    2013-07-01

    Clothianidin is a neonicotinoid insecticide developed in the early 2000s. We have recently demonstrated that it was a full agonist of α-bungarotoxin-sensitive and -insensitive nicotinic acetylcholine receptors expressed in the cockroach dorsal unpaired median neurons. Clothianidin was able to act as an agonist of imidacloprid-insensitive nAChR2 receptor and internal regulation of cAMP concentration modulated nAChR2 sensitivity to clothianidin. In the present study, we demonstrated that cAMP modulated the agonist action of clothianidin via α-bungarotoxin-sensitive and insensitive receptors. Clothianidin-induced current-voltage curves were dependent to clothianidin concentrations. At 10 μM clothianidin, increasing cAMP concentration induced a linear current-voltage curve. Clothianidin effects were blocked by 0.5 μM α-bungarotoxin suggesting that cAMP modulation occurred through α-bungarotoxin-sensitive receptors. At 1 mM clothianidin, cAMP effects were associated to α-bungarotoxin-insensitive receptors because clothianidin-induced currents were blocked by 5 μM mecamylamine and 20 μM d-tubocurarine. In addition, we found that application of 1mM clothianidin induced a strong increase of intracellular calcium concentration. These data reinforced the finding that calcium pathways including cAMP modulated clothianidin action on insect nicotinic acetylcholine receptors. We proposed that intracellular calcium pathways such as cAMP could be a target to modulate the mode of action of neonicotinoid insecticides. Copyright © 2013 Elsevier Inc. All rights reserved.

  1. Acute stress-induced sensitization of the pituitary-adrenal response to heterotypic stressors: independence of glucocorticoid release and activation of CRH1 receptors.

    Science.gov (United States)

    Belda, Xavier; Daviu, Núria; Nadal, Roser; Armario, Antonio

    2012-09-01

    A single exposure to some severe stressors causes sensitization of the hypothalamic-pituitary-adrenal (HPA) response to novel stressors. However, the putative factors involved in stress-induced sensitization are not known. In the present work we studied in adult male rats the possible role of glucocorticoids and CRH type 1 receptor (CRH-R1), using an inhibitor of glucocorticoid synthesis (metyrapone, MET), the glucocorticoid receptor (GR) antagonist RU38486 (mifepristone) and the non-peptide CRH-R1 antagonist R121919. In a first experiment we demonstrated with different doses of MET (40-150 mg/kg) that the highest dose acted as a pharmacological stressor greatly increasing ACTH release and altering the normal circadian pattern of HPA hormones, but no dose affected ACTH responsiveness to a novel environment as assessed 3 days after drug administration. In a second experiment, we found that MET, at a dose (75 mg/kg) that blocked the corticosterone response to immobilization (IMO), did not alter IMO-induced ACTH sensitization. Finally, neither the GR nor the CRH-R1 antagonists blocked IMO-induced ACTH sensitization on the day after IMO. Thus, a high dose of MET, in contrast to IMO, was unable to sensitize the HPA response to a novel environment despite the huge activation of the HPA axis caused by the drug. Neither a moderate dose of MET that markedly reduced corticosterone response to IMO, nor the blockade of GR or CRH-R1 receptors was able to alter stress-induced HPA sensitization. Therefore, stress-induced sensitization is not the mere consequence of a marked HPA activation and does not involve activation of glucocorticoid or CRH-R1 receptors. Copyright © 2012 Elsevier Inc. All rights reserved.

  2. Myofilament calcium sensitivity: Role in regulation of in vivo cardiac contraction and relaxation

    Directory of Open Access Journals (Sweden)

    Jae-Hoon Chung

    2016-12-01

    Full Text Available Myofilament calcium sensitivity is an often-used indicator of cardiac muscle function, often assessed in disease states such as hypertrophic cardiomyopathy (HCM and dilated cardiomyopathy (DCM. While calcium sensitivity measurement provides important insights into the mechanical force-generating capability of a muscle at steady-state, the dynamic behavior of the muscle cannot be sufficiently assessed with a force-pCa curve alone. The dissociation constant (Kd of the force-pCa curve depends on the ratio of the apparent on-rate (kon and apparent off-rate (koff of calcium on TnC and as a stand-alone parameter cannot provide an accurate depiction of the dynamic contraction and relaxation behavior without the additional quantification of kon or koff, or actually measuring dynamic twitch kinetics in an intact muscle. In this review, we examine the effect of length, frequency, and beta-adrenergic stimulation on myofilament calcium sensitivity and dynamic contraction, the effect of membrane permeabilization on calcium sensitivity, and the dynamic consequences of various myofilament protein mutations with potential implications in contractile and relaxation behavior.

  3. Effect of chronic metoprolol and coronary occlusion (CO) on cardiac beta receptor density in cats

    Energy Technology Data Exchange (ETDEWEB)

    Lathers, C.M.; Spivey, W.H.; Levin, R.M.

    1986-03-05

    The effect of metoprolol (M) on beta receptor density (BRD) was examined. M (5 mg/kg, p.o., b.i.d.) was given for 2 and 8 wks prior to CO of the left anterior descending artery (LAD) at its origin. BRD, determined by binding of /sup 3/H-dihydroalprenol, was examined in the myocardium (LA = left atrium, RA = right atrium, LV1 = proximal LAD distribution, LV = 2 distal LAD distribution, LV3 = posterior left ventricle, RV = right ventricle, and S = septum. A 2 factor ANOVA followed by simple effect and Newman-Keuls post hoc tests revealed that M produced no effect in BRD in LA, RA, LV2, or S. M increased BRD in LV1, LV3, and RV after 2 wk when compared to no M. In addition, BRD in LV3 and RV were also greater at 2 wk than after 8 wk M. The data indicate that there are regional differences in the beta adrenergic receptor densities among the areas of the heart and within the left ventricle. Chronic dosing with M produced increased BRD in only some of the areas of the heart. These differences may be related to functional differences in the various areas of the heart after CO.

  4. Inactivation of the maternal fragile X gene results in sensitization of GABAB receptor function in the offspring.

    Science.gov (United States)

    Zupan, Bojana; Toth, Miklos

    2008-12-01

    Fragile X syndrome is an X-linked disorder caused by the inactivation of the FMR1 gene, with symptoms ranging from impaired cognitive functions to seizures, anxiety, sensory abnormalities, and hyperactivity. Although fragile X syndrome is considered a typical Mendelian disorder, we have recently reported that the environment, specifically the fmr1(+/-) or fmr1(-/-) [H or knockout (KO)] maternal environment, elicits on its own a partial fragile X-like phenotype and can contribute to the overall phenotype of fmr1(-/0) (KO) male offspring. Genetically fmr1(+/0) (WT) males born to H females (H(maternal) > WT(offspring)), similar to KO male offspring born to H and KO mothers (H > KO and KO > KO), exhibit locomotor hyperactivity. These mice also showed reduced D(2) autoreceptor function, indicating a possible diminished feedback inhibition of dopamine (DA) release in the nigrostriatal and mesolimbic systems. The GABAergic system also regulates DA release, in part via presynaptic GABA(B) receptors (Rs) located on midbrain dopaminergic neurons. Here, we show that the locomotor inhibitory effect of the GABA(B)R agonist baclofen [4-amino-3-(4-chlorophenyl)-butanoic acid] is enhanced in all progeny of mutant mothers (H > WT, H > KO, and KO > KO) compared with WT > WT mice, irrespective of their own genotype. However, increased sensitivity to baclofen was selective and limited to the locomotor response because the muscle-relaxant and sedative effects of the drug were not altered by the maternal environment. These data show that GABA(B)R sensitization, traditionally induced pharmacologically, can also be elicited by the fmr1-deficient maternal environment.

  5. Strategy to Identify and Test Putative Light-Sensitive Non-Opsin G-Protein-Coupled Receptors: A Case Study.

    Science.gov (United States)

    Faggionato, Davide; Serb, Jeanne M

    2017-08-01

    The rise of high-throughput RNA sequencing (RNA-seq) and de novo transcriptome assembly has had a transformative impact on how we identify and study genes in the phototransduction cascade of non-model organisms. But the advantage provided by the nearly automated annotation of RNA-seq transcriptomes may at the same time hinder the possibility for gene discovery and the discovery of new gene functions. For example, standard functional annotation based on domain homology to known protein families can only confirm group membership, not identify the emergence of new biochemical function. In this study, we show the importance of developing a strategy that circumvents the limitations of semiautomated annotation and apply this workflow to photosensitivity as a means to discover non-opsin photoreceptors. We hypothesize that non-opsin G-protein-coupled receptor (GPCR) proteins may have chromophore-binding lysines in locations that differ from opsin. Here, we provide the first case study describing non-opsin light-sensitive GPCRs based on tissue-specific RNA-seq data of the common bay scallop Argopecten irradians (Lamarck, 1819). Using a combination of sequence analysis and three-dimensional protein modeling, we identified two candidate proteins. We tested their photochemical properties and provide evidence showing that these two proteins incorporate 11-cis and/or all-trans retinal and react to light photochemically. Based on this case study, we demonstrate that there is potential for the discovery of new light-sensitive GPCRs, and we have developed a workflow that starts from RNA-seq assemblies to the discovery of new non-opsin, GPCR-based photopigments.

  6. Disruption of growth hormone receptor gene causes diminished pancreatic islet size and increased insulin sensitivity in mice.

    Science.gov (United States)

    Liu, Jun-Li; Coschigano, Karen T; Robertson, Katie; Lipsett, Mark; Guo, Yubin; Kopchick, John J; Kumar, Ujendra; Liu, Ye Lauren

    2004-09-01

    Growth hormone, acting through its receptor (GHR), plays an important role in carbohydrate metabolism and in promoting postnatal growth. GHR gene-deficient (GHR(-/-)) mice exhibit severe growth retardation and proportionate dwarfism. To assess the physiological relevance of growth hormone actions, GHR(-/-) mice were used to investigate their phenotype in glucose metabolism and pancreatic islet function. Adult GHR(-/-) mice exhibited significant reductions in the levels of blood glucose and insulin, as well as insulin mRNA accumulation. Immunohistochemical analysis of pancreatic sections revealed normal distribution of the islets despite a significantly smaller size. The average size of the islets found in GHR(-/-) mice was only one-third of that in wild-type littermates. Total beta-cell mass was reduced 4.5-fold in GHR(-/-) mice, significantly more than their body size reduction. This reduction in pancreatic islet mass appears to be related to decreases in proliferation and cell growth. GHR(-/-) mice were different from the human Laron syndrome in serum insulin level, insulin responsiveness, and obesity. We conclude that growth hormone signaling is essential for maintaining pancreatic islet size, stimulating islet hormone production, and maintaining normal insulin sensitivity and glucose homeostasis.

  7. Soluble N-Ethylmaleimide-Sensitive Factor Attachment Protein Receptor-Derived Peptides for Regulation of Mast Cell Degranulation.

    Science.gov (United States)

    Yang, Yoosoo; Kong, Byoungjae; Jung, Younghoon; Park, Joon-Bum; Oh, Jung-Mi; Hwang, Jaesung; Cho, Jae Youl; Kweon, Dae-Hyuk

    2018-01-01

    Vesicle-associated V-soluble N -ethylmaleimide-sensitive factor attachment protein receptor (SNARE) proteins and target membrane-associated T-SNAREs (syntaxin 4 and SNAP-23) assemble into a core trans -SNARE complex that mediates membrane fusion during mast cell degranulation. This complex plays pivotal roles at various stages of exocytosis from the initial priming step to fusion pore opening and expansion, finally resulting in the release of the vesicle contents. In this study, peptides with the sequences of various SNARE motifs were investigated for their potential inhibitory effects against SNARE complex formation and mast cell degranulation. The peptides with the sequences of the N-terminal regions of vesicle-associated membrane protein 2 (VAMP2) and VAMP8 were found to reduce mast cell degranulation by inhibiting SNARE complex formation. The fusion of protein transduction domains to the N-terminal of each peptide enabled the internalization of the fusion peptides into the cells equally as efficiently as cell permeabilization by streptolysin-O without any loss of their inhibitory activities. Distinct subsets of mast cell granules could be selectively regulated by the N-terminal-mimicking peptides derived from VAMP2 and VAMP8, and they effectively decreased the symptoms of atopic dermatitis in mouse models. These results suggest that the cell membrane fusion machinery may represent a therapeutic target for atopic dermatitis.

  8. Receptor for advanced glycation end products and its ligand high-mobility group box-1 mediate allergic airway sensitization and airway inflammation.

    Science.gov (United States)

    Ullah, Md Ashik; Loh, Zhixuan; Gan, Wan Jun; Zhang, Vivian; Yang, Huan; Li, Jian Hua; Yamamoto, Yasuhiko; Schmidt, Ann Marie; Armour, Carol L; Hughes, J Margaret; Phipps, Simon; Sukkar, Maria B

    2014-08-01

    The receptor for advanced glycation end products (RAGE) shares common ligands and signaling pathways with TLR4, a key mediator of house dust mite (Dermatophagoides pteronyssinus) (HDM) sensitization. We hypothesized that RAGE and its ligand high-mobility group box-1 (HMGB1) cooperate with TLR4 to mediate HDM sensitization. To determine the requirement for HMGB1 and RAGE, and their relationship with TLR4, in airway sensitization. TLR4(-/-), RAGE(-/-), and RAGE-TLR4(-/-) mice were intranasally exposed to HDM or cockroach (Blatella germanica) extracts, and features of allergic inflammation were measured during the sensitization or challenge phase. Anti-HMGB1 antibody and the IL-1 receptor antagonist Anakinra were used to inhibit HMGB1 and the IL-1 receptor, respectively. The magnitude of allergic airway inflammation in response to either HDM or cockroach sensitization and/or challenge was significantly reduced in the absence of RAGE but not further diminished in the absence of both RAGE and TLR4. HDM sensitization induced the release of HMGB1 from the airway epithelium in a biphasic manner, which corresponded to the sequential activation of TLR4 then RAGE. Release of HMGB1 in response to cockroach sensitization also was RAGE dependent. Significantly, HMGB1 release occurred downstream of TLR4-induced IL-1α, and upstream of IL-25 and IL-33 production. Adoptive transfer of HDM-pulsed RAGE(+/+)dendritic cells to RAGE(-/-) mice recapitulated the allergic responses after HDM challenge. Immunoneutralization of HMGB1 attenuated HDM-induced allergic airway inflammation. The HMGB1-RAGE axis mediates allergic airway sensitization and airway inflammation. Activation of this axis in response to different allergens acts to amplify the allergic inflammatory response, which exposes it as an attractive target for therapeutic intervention. Copyright © 2014 American Academy of Allergy, Asthma & Immunology. Published by Mosby, Inc. All rights reserved.

  9. Effects of the NMDA receptor antagonist, D-CPPene, on sensitization to the operant decrement produced by naloxone in morphine-treated rats.

    Science.gov (United States)

    Bespalov, A Y; Medvedev, I O; Sukhotina, I A; Zvartau, E E

    2001-04-01

    Sensitization to the rate-decreasing effects of opioid antagonists induced by acute pretreatment with opioid agonists has been suggested to reflect initial changes in opioid systems that underlie physical dependence. Glutamate receptors are implicated in the development and expression of opioid dependence, and antagonists acting at the N-methyl-D-aspartate (NMDA) subtype of glutamate receptors have been shown repeatedly to attenuate the severity of opioid withdrawal. The present study evaluated the ability of a competitive NMDA receptor antagonist, D-CPPene (SDZ EAA 494; 3-(2-carboxypiperazin-4-yl)-1-propenyl-1-phosphonic acid), to affect morphine-induced sensitization to naloxone in rats trained to lever-press on a multiple-trial, fixed-ratio 10 schedule of food reinforcement. D-CPPene (0.3-3 mg/kg) was administered either 4 h or 30 min prior to the test session. Morphine (10 mg/kg) or its vehicle was administered 4 h before naloxone challenge (0.3-3 mg/kg). D-CPPene failed to prevent morphine-induced potentiation of the naloxone-produced decrement in operant performance. Thus, these results suggest that agonist-induced sensitization to behavioral effects of opioid antagonists may be insensitive to NMDA receptor blockade.

  10. Early continuous white noise exposure alters auditory spatial sensitivity and expression of GAD65 and GABAA receptor subunits in rat auditory cortex.

    Science.gov (United States)

    Xu, Jinghong; Yu, Liping; Cai, Rui; Zhang, Jiping; Sun, Xinde

    2010-04-01

    Sensory experiences have important roles in the functional development of the mammalian auditory cortex. Here, we show how early continuous noise rearing influences spatial sensitivity in the rat primary auditory cortex (A1) and its underlying mechanisms. By rearing infant rat pups under conditions of continuous, moderate level white noise, we found that noise rearing markedly attenuated the spatial sensitivity of A1 neurons. Compared with rats reared under normal conditions, spike counts of A1 neurons were more poorly modulated by changes in stimulus location, and their preferred locations were distributed over a larger area. We further show that early continuous noise rearing induced significant decreases in glutamic acid decarboxylase 65 and gamma-aminobutyric acid (GABA)(A) receptor alpha1 subunit expression, and an increase in GABA(A) receptor alpha3 expression, which indicates a returned to the juvenile form of GABA(A) receptor, with no effect on the expression of N-methyl-D-aspartate receptors. These observations indicate that noise rearing has powerful adverse effects on the maturation of cortical GABAergic inhibition, which might be responsible for the reduced spatial sensitivity.

  11. The cannabinoid receptor 2 agonist, β-caryophyllene, reduced voluntary alcohol intake and attenuated ethanol-induced place preference and sensitivity in mice.

    Science.gov (United States)

    Al Mansouri, Shamma; Ojha, Shreesh; Al Maamari, Elyazia; Al Ameri, Mouza; Nurulain, Syed M; Bahi, Amine

    2014-09-01

    Several recent studies have suggested that brain CB2 cannabinoid receptors play a major role in alcohol reward. In fact, the implication of cannabinoid neurotransmission in the reinforcing effects of ethanol (EtOH) is becoming increasingly evident. The CB2 receptor agonist, β-caryophyllene (BCP) was used to investigate the role of the CB2 receptors in mediating alcohol intake and ethanol-induced conditioned place preference (EtOH-CPP) and sensitivity in mice. The effect of BCP on alcohol intake was evaluated using the standard two-bottle choice drinking method. The mice were presented with increasing EtOH concentrations and its consumption was measured daily. Consumption of saccharin and quinine solutions was measured following the EtOH preference tests. Finally, the effect of BCP on alcohol reward and sensitivity was tested using an unbiased EtOH-CPP and loss of righting-reflex (LORR) procedures, respectively. BCP dose-dependently decreased alcohol consumption and preference. Additionally, BCP-injected mice did not show any difference from vehicle mice in total fluid intake in a 24-hour paradigm nor in their intake of graded concentrations of saccharin or quinine, suggesting that the CB2 receptor activation did not alter taste function. More importantly, BCP inhibited EtOH-CPP acquisition and exacerbated LORR duration. Interestingly, these effects were abrogated when mice were pre-injected with a selective CB2 receptor antagonist, AM630. Overall, the CB2 receptor system appears to be involved in alcohol dependence and sensitivity and may represent a potential pharmacological target for the treatment of alcoholism. Copyright © 2014 Elsevier Inc. All rights reserved.

  12. In the Blink of an Eye: Relating Positive-Feedback Sensitivity to Striatal Dopamine D2-Like Receptors through Blink Rate

    Science.gov (United States)

    Groman, Stephanie M.; James, Alex S.; Seu, Emanuele; Tran, Steven; Clark, Taylor A.; Harpster, Sandra N.; Crawford, Maverick; Burtner, Joanna Lee; Feiler, Karen; Roth, Robert H.; Elsworth, John D.; London, Edythe D.

    2014-01-01

    For >30 years, positron emission tomography (PET) has proven to be a powerful approach for measuring aspects of dopaminergic transmission in the living human brain; this technique has revealed important relationships between dopamine D2-like receptors and dimensions of normal behavior, such as human impulsivity, and psychopathology, particularly behavioral addictions. Nevertheless, PET is an indirect estimate that lacks cellular and functional resolution and, in some cases, is not entirely pharmacologically specific. To identify the relationships between PET estimates of D2-like receptor availability and direct in vitro measures of receptor number, affinity, and function, we conducted neuroimaging and behavioral and molecular pharmacological assessments in a group of adult male vervet monkeys. Data gathered from these studies indicate that variation in D2-like receptor PET measurements is related to reversal-learning performance and sensitivity to positive feedback and is associated with in vitro estimates of the density of functional dopamine D2-like receptors. Furthermore, we report that a simple behavioral measure, eyeblink rate, reveals novel and crucial links between neuroimaging assessments and in vitro measures of dopamine D2 receptors. PMID:25339755

  13. [Study on the expression of bradykinin and its receptors B1R and B2R in the kidney immune injury in trichloroethylene-sensitized mouse].

    Science.gov (United States)

    Wang, Hui; Zhang, Jiaxiang; Li, Shulong; Zha, Wansheng; Wang, Feng; Zhu, Qixing

    2015-07-01

    To study the expression of bradykinin and its receptors B1R and B2R in the kidney immune injury in trichloroethylene-sensitized mouse and discuss the pathogenesis of Dermatitis Medicamentosa-like of TCE (ODMLT). On the first days, intradermal injection by 50% TCE and the amount of FCA mixture 100 µl for initial sensitization; on 4, 7, 10 days, painted abdominal skin by 100 µl 50% TCE for three sensitization, on 17, 19 days, painted on the back skin by 100 µl 30% TCE for initial excitation and the last challenge; 24 h before each challenge, PKSI-527+TCE group received intraperitoneal injection by inhibitor PKSI-527 (50 mg/kg); solvent control group treat without TCE and sensitization and excitation reagent the same proportion of olive oil and acetone mixture, blank control group without any treatment. Before killing the mouse, renal weight and body weight were recorded. The renals and plasma were separated at 24 h, 48 h, 72 h and 7 d after the last challenge and observed pathological of the renals. Expression of B1R and B2R in renal were examined by immunofluorescence technique. Plasma were examined by ELISA for BK. The renal pathological examination revealed the apparent damage of TCE sensitized mice which compared to solvent control group showed obvious cellular infiltration, vacuolar degeneration of renal tubular epithelial cells. The renal damage of PKSI-527+TCE-sensitized groups which compared to the corresponding point of TCE-sensitized groups showed significantly reduced. The expression of BK in 24 h, 48 h and 72 h TCE-sensitized groups were significant higher than solvent control group and related TCE non-sensitized groups (P trichloroethylene-sensitized mouse and the expression change of bradykinin and its receptors B1R and B2R which may play an important role in the process.

  14. Novel estrogen receptor-related Transcripts in Marisa cornuarietis; a freshwater snail with reported sensitivity to estrogenic chemicals.

    Science.gov (United States)

    Bannister, Richard; Beresford, Nicola; May, Denise; Routledge, Edwin J; Jobling, Susan; Rand-Weaver, Mariann

    2007-04-01

    We have isolated novel molluskan steroid receptor transcripts orthologous to vertebrate estrogen receptors (ERs) and estrogen receptor-related receptors (ERRs) from the freshwater snail Marisa cornuarietis. Radiolabeled ligand binding analyses showed that neither recombinant receptor protein specifically bound 17beta-estradiol over the range applied (0.3-9.6 nM). These novel receptor transcripts have thus been designated mcER-like and mcERR respectively. Quantitative PCR revealed mcER-like to be expressed ubiquitously throughout a range of male and female structures studied, including neural and reproductive tissues. Highest absolute levels were seen in the male penis-sheath complex. The mcERR mRNA was also expressed ubiquitously throughout all male and female tissues analyzed here, with very low absolute transcript numbers in female accessory sex structures compared to other tissues.

  15. Gefitinib upregulates death receptor 5 expression to mediate rmhTRAIL-induced apoptosis in Gefitinib-sensitive NSCLC cell line

    Directory of Open Access Journals (Sweden)

    Yan D

    2015-07-01

    Full Text Available Dong Yan,1,2 Yang Ge,1 Haiteng Deng,3 Wenming Chen,4 Guangyu An1 1Department of Oncology, Beijing Chao-yang Hospital, Capital Medical University, Beijing, People’s Republic of China; 2Translational Molecular pathology, M.D Anderson Cancer Center, Houston, TX, USA; 3School of Sciences, Tsinghua University, 4Department of Hematology, Beijing Chao-yang Hospital, Capital Medical University, Beijing, People’s Republic of China Background: Tumor necrosis factor-related apoptosis-inducing ligand (TRAIL triggers apoptosis in tumor cells, but when used alone, it is not effective in the treatment of TRAIL-resistant tumors. Some studies have shown that gefitinib interacts with recombinant mutant human TRAIL (rmhTRAIL to induce high levels of apoptosis in gefitinib-responsive bladder cancer cell lines; however, the molecular mechanisms underlying the anticancer effects are not fully understood. Several reports have shown that the death receptor 5 (DR5 plays an important role in sensitizing cancer cells to apoptosis induced by TRAIL. Therefore, we investigated the effects of the combination of drugs and the expression of the DR5 to analyze the growth of a gefitinib-responsive non-small cell lung cancer cell line PC9, which was treated with rmhTRAIL and gefitinib individually or in combination.Methods: Human PC9 non-small cell lung cancer cells harboring an epidermal growth factor receptor mutation were used as a model for the identification of the therapeutic effects of gefitinib alone or in combination with rmhTRAIL, and cytotoxicity was assessed by MTT assays. Cell cycle and apoptosis were investigated using flow cytometry. Moreover, the effects of drugs on DR5, BAX, FLIP, and cleaved-caspase3 proteins expressions were analyzed using Western blot analyses. Finally, quantitative polymerase chain reaction analysis was carried out to assess whether rmhTRAIL and gefitinib modulate the expression of genes related to drug activity.Results: Gefitinib and rmh

  16. Virus-mediated swapping of zolpidem-insensitive with zolpidem-sensitive GABA(A) receptors in cortical pyramidal cells.

    Science.gov (United States)

    Sumegi, Mate; Fukazawa, Yugo; Matsui, Ko; Lorincz, Andrea; Eyre, Mark D; Nusser, Zoltan; Shigemoto, Ryuichi

    2012-04-01

    Recently developed pharmacogenetic and optogenetic approaches, with their own advantages and disadvantages, have become indispensable tools in modern neuroscience. Here, we employed a previously described knock-in mouse line (GABA(A)Rγ2(77I)lox) in which the γ2 subunit of the GABA(A) receptor (GABA(A)R) was mutated to become zolpidem insensitive (γ2(77I)) and used viral vectors to swap γ2(77I) with wild-type, zolpidem-sensitive γ2 subunits (γ2(77F)). The verification of unaltered density and subcellular distribution of the virally introduced γ2 subunits requires their selective labelling. For this we generated six N- and six C-terminal-tagged γ2 subunits, with which cortical cultures of GABA(A)Rγ2(−/−) mice were transduced using lentiviruses. We found that the N-terminal AU1 tag resulted in excellent immunodetection and unimpaired synaptic localization. Unaltered kinetic properties of the AU1-tagged γ2 ((AU1)γ2(77F)) channels were demonstrated with whole-cell patch-clamp recordings of spontaneous IPSCs from cultured cells. Next, we carried out stereotaxic injections of lenti- and adeno-associated viruses containing Cre-recombinase and the (AU1)γ2(77F) subunit (Cre-2A-(AU1)γ2(77F)) into the neocortex of GABA(A)Rγ2(77I)lox mice. Light microscopic immunofluorescence and electron microscopic freeze-fracture replica immunogold labelling demonstrated the efficient immunodetection of the AU1 tag and the normal enrichment of the (AU1)γ2(77F) subunits in perisomatic GABAergic synapses. In line with this,miniature and action potential-evoked IPSCs whole-cell recorded from transduced cells had unaltered amplitudes, kinetics and restored zolpidem sensitivity. Our results obtained with a wide range of structural and functional verification methods reveal unaltered subcellular distributions and functional properties of γ2(77I) and (AU1)γ2(77F) GABA(A)Rs in cortical pyramidal cells. This transgenic–viral pharmacogenetic approach has the advantage that it

  17. Relationship of dopamine type 2 receptor binding potential with fasting neuroendocrine hormones and insulin sensitivity in human obesity.

    Science.gov (United States)

    Dunn, Julia P; Kessler, Robert M; Feurer, Irene D; Volkow, Nora D; Patterson, Bruce W; Ansari, Mohammad S; Li, Rui; Marks-Shulman, Pamela; Abumrad, Naji N

    2012-05-01

    Midbrain dopamine (DA) neurons, which are involved with reward and motivation, are modulated by hormones that regulate food intake (insulin, leptin, and acyl ghrelin [AG]). We hypothesized that these hormones are associated with deficits in DA signaling in obesity. We assessed the relationships between fasting levels of insulin and leptin, and AG, BMI, and insulin sensitivity index (S(I)) with the availability of central DA type 2 receptor (D2R). We measured D2R availability using positron emission tomography and [(18)F]fallypride (radioligand that competes with endogenous DA) in lean (n = 8) and obese (n = 14) females. Fasting hormones were collected prior to scanning and S(I) was determined by modified oral glucose tolerance test. Parametric image analyses revealed associations between each metabolic measure and D2R. The most extensive findings were negative associations of AG with clusters involving the striatum and inferior temporal cortices. Regional regression analyses also found extensive negative relationships between AG and D2R in the caudate, putamen, ventral striatum (VS), amygdala, and temporal lobes. S(I) was negatively associated with D2R in the VS, while insulin was not. In the caudate, BMI and leptin were positively associated with D2R availability. The direction of associations of leptin and AG with D2R availability are consistent with their opposite effects on DA levels (decreasing and increasing, respectively). After adjusting for BMI, AG maintained a significant relationship in the VS. We hypothesize that the increased D2R availability in obese subjects reflects relatively reduced DA levels competing with the radioligand. Our findings provide evidence for an association between the neuroendocrine hormones and DA brain signaling in obese females.

  18. Lateral Fluid Percussion Injury Impairs Hippocampal Synaptic Soluble N-Ethylmaleimide Sensitive Factor Attachment Protein Receptor Complex Formation

    Directory of Open Access Journals (Sweden)

    Shaun W. Carlson

    2017-10-01

    Full Text Available Traumatic brain injury (TBI and the activation of secondary injury mechanisms have been linked to impaired cognitive function, which, as observed in TBI patients and animal models, can persist for months and years following the initial injury. Impairments in neurotransmission have been well documented in experimental models of TBI, but the mechanisms underlying this dysfunction are poorly understood. Formation of the soluble N-ethylmaleimide-sensitive factor attachment protein receptor (SNARE complex facilitates vesicular docking and neurotransmitter release in the synaptic cleft. Published studies highlight a direct link between reduced SNARE complex formation and impairments in neurotransmitter release. While alterations in the SNARE complex have been described following severe focal TBI, it is not known if deficits in SNARE complex formation manifest in a model with reduced severity. We hypothesized that lateral fluid percussion injury (lFPI reduces the abundance of SNARE proteins, impairs SNARE complex formation, and contributes to impaired neurobehavioral function. To this end, rats were subjected to lFPI or sham injury and tested for acute motor performance and cognitive function at 3 weeks post-injury. lFPI resulted in motor impairment between 1 and 5 days post-injury. Spatial acquisition and spatial memory, as assessed by the Morris water maze, were significantly impaired at 3 weeks after lFPI. To examine the effect of lFPI on synaptic SNARE complex formation in the injured hippocampus, a separate cohort of rats was generated and brains processed to evaluate hippocampal synaptosomal-enriched lysates at 1 week post-injury. lFPI resulted in a significant reduction in multiple monomeric SNARE proteins, including VAMP2, and α-synuclein, and SNARE complex abundance. The findings in this study are consistent with our previously published observations suggesting that impairments in hippocampal SNARE complex formation may contribute to

  19. Knockout of NMDA-receptors from parvalbumin interneurons sensitizes to schizophrenia-related deficits induced by MK-801

    Science.gov (United States)

    Bygrave, A M; Masiulis, S; Nicholson, E; Berkemann, M; Barkus, C; Sprengel, R; Harrison, P J; Kullmann, D M; Bannerman, D M; Kätzel, D

    2016-01-01

    It has been suggested that a functional deficit in NMDA-receptors (NMDARs) on parvalbumin (PV)-positive interneurons (PV-NMDARs) is central to the pathophysiology of schizophrenia. Supportive evidence come from examination of genetically modified mice where the obligatory NMDAR-subunit GluN1 (also known as NR1) has been deleted from PV interneurons by Cre-mediated knockout of the corresponding gene Grin1 (Grin1ΔPV mice). Notably, such PV-specific GluN1 ablation has been reported to blunt the induction of hyperlocomotion (a surrogate for psychosis) by pharmacological NMDAR blockade with the non-competitive antagonist MK-801. This suggests PV-NMDARs as the site of the psychosis-inducing action of MK-801. In contrast to this hypothesis, we show here that Grin1ΔPV mice are not protected against the effects of MK-801, but are in fact sensitized to many of them. Compared with control animals, Grin1ΔPVmice injected with MK-801 show increased stereotypy and pronounced catalepsy, which confound the locomotor readout. Furthermore, in Grin1ΔPVmice, MK-801 induced medial-prefrontal delta (4 Hz) oscillations, and impaired performance on tests of motor coordination, working memory and sucrose preference, even at lower doses than in wild-type controls. We also found that untreated Grin1ΔPVmice are largely normal across a wide range of cognitive functions, including attention, cognitive flexibility and various forms of short-term memory. Taken together these results argue against PV-specific NMDAR hypofunction as a key starting point of schizophrenia pathophysiology, but support a model where NMDAR hypofunction in multiple cell types contribute to the disease. PMID:27070406

  20. An extrahepatic receptor-associated protein-sensitive mechanism is involved in the metabolism of triglyceride-rich lipoproteins

    NARCIS (Netherlands)

    Vlijmen, B.J.M. van; Rohlmann, A.; Page, S.T.; Bensadoun, A.; Bos, I.S.T.; Berkel, T.J.C. van; Havekes, L.M.; Herz, J.

    1999-01-01

    We have used adenovirus-mediated gene transfer in mice to investigate low density lipoprotein receptor (LDLR) and LDLR-related protein (LRP)- independent mechanisms that control the metabolism of chylomicron and very low density lipoprotein (VLDL) remnants in vivo. Overexpression of receptor-

  1. In vivo [3H]spiperone binding: evidence for accumulation in corpus striatum by agonist-mediated receptor internalization

    International Nuclear Information System (INIS)

    Chugani, D.C.; Ackermann, R.F.; Phelps, M.E.

    1988-01-01

    The processes of receptor internalization and recycling have been well-documented for receptors for hormones, growth factors, lysosomal enzymes, and cellular substrates. Evidence also exists that these processes also occur for beta-adrenergic, muscarinic cholinergic, and delta-opiate receptors in frog erythrocytes or cultured nervous tissue. In this study, evidence is presented that agonist-mediated receptor internalization and recycling occurs at the dopamine receptor in rat corpus striatum. First, the in vivo binding of the dopamine antagonist [3H]spiperone was increased by both electrical stimulation and pharmacologically induced increases of dopamine release. Conversely, depletion of dopamine with reserpine decreased in vivo [3H]spiperone binding, but the same reserpine treatment did not alter its in vitro binding. Second, the rate of dissociation of [3H]spiperone from microsomal membranes prepared from rat striatum following in vivo binding was fivefold slower than its dissociation following in vitro equilibrium binding. Mild detergent treatment, employed to disrupt endocytic vesicle membranes, increased the rate of dissociation of in vivo bound [3H]spiperone from microsomal membranes to values not significantly different from its in vitro bound dissociation rate. Third, treatment of rats with chloroquine, a drug that prevents receptor recycling but not internalization, prior to [3H]spiperone injection resulted in a selective increase of in vivo [3H]spiperone binding in the light microsome membranes. The existence of mechanisms that rapidly alter the number of neurotransmitter receptors at synapses provides dynamic regulation of receptors in response to varied acute stimulation states

  2. A library of 7TM receptor C-terminal tails - Interactions with the proposed post-endocytic sorting proteins ERM-binding phosphoprotein 50 (EBP50), N-ethylmaleimide-sensitive factor (NSF), sorting nexin 1 (SNX1), and G protein-coupled receptor-associated sorting protein (GASP)

    DEFF Research Database (Denmark)

    Heydorn, A.; Sondergaard, B.P.; Ersbøll, Bjarne Kjær

    2004-01-01

    Adaptor and scaffolding proteins determine the cellular targeting, the spatial, and thereby the functional association of G protein-coupled seven-transmembrane receptors with co-receptors, transducers, and downstream effectors and the adaptors determine post-signaling events such as receptor...... only a single receptor tail, i.e. the beta(2)-adrenergic receptor, whereas N-ethylmaleimide-sensitive factor bound 11 of the tail-fusion proteins. Of the two proteins proposed to target receptors for lysosomal degradation, sorting nexin 1 (SNX1) bound 10 and the C-terminal domain of G protein...... the expected nanomolar affinities for interaction with SNX1. Truncations of the NK1 receptor revealed that an extended binding epitope is responsible for the interaction with both SNX1 and G protein-coupled receptor-associated sorting protein as well as with N-ethylmaleimide-sensitive factor. It is concluded...

  3. A library of 7TM receptor C-terminal tails. Interactions with the proposed post-endocytic sorting proteins ERM-binding phosphoprotein 50 (EBP50), N-ethylmaleimide-sensitive factor (NSF), sorting nexin 1 (SNX1), and G protein-coupled receptor-associated sorting protein (GASP)

    DEFF Research Database (Denmark)

    Heydorn, Arne; Søndergaard, Birgitte P; Ersbøll, Bjarne

    2004-01-01

    Adaptor and scaffolding proteins determine the cellular targeting, the spatial, and thereby the functional association of G protein-coupled seven-transmembrane receptors with co-receptors, transducers, and downstream effectors and the adaptors determine post-signaling events such as receptor...... only a single receptor tail, i.e. the beta(2)-adrenergic receptor, whereas N-ethylmaleimide-sensitive factor bound 11 of the tail-fusion proteins. Of the two proteins proposed to target receptors for lysosomal degradation, sorting nexin 1 (SNX1) bound 10 and the C-terminal domain of G protein...... the expected nanomolar affinities for interaction with SNX1. Truncations of the NK(1) receptor revealed that an extended binding epitope is responsible for the interaction with both SNX1 and G protein-coupled receptor-associated sorting protein as well as with N-ethylmaleimide-sensitive factor. It is concluded...

  4. The γ-aminobutyric acid type B (GABAB) receptor agonist baclofen inhibits morphine sensitization by decreasing the dopamine level in rat nucleus accumbens.

    Science.gov (United States)

    Fu, Zhenyu; Yang, Hongfa; Xiao, Yuqiang; Zhao, Gang; Huang, Haiyan

    2012-07-10

    Repeated morphine exposure can induce behavioral sensitization. There are evidences have shown that central gamma-aminobutyric acid (GABA) system is involved in morphine dependence. However, the effect of a GABAB receptor agonist baclofen on morphine-induced behavioral sensitization in rats is unclear. We used morphine-induced behavioral sensitization model in rat to investigate the effects of baclofen on behavioral sensitization. Moreover, dopamine release in the shell of the nucleus accumbens was evaluated using microdialysis assay in vivo. The present study demonstrated that morphine challenge (3 mg/kg, s.c.) obviously enhanced the locomotor activity following 4-day consecutive morphine administration and 3-day withdrawal period, which indicated the expression of morphine sensitization. In addition, chronic treatment with baclofen (2.5, 5 mg/kg) significantly inhibited the development of morphine sensitization. It was also found that morphine challenge 3 days after repeated morphine administration produced a significant increase of extracellular dopamine release in nucleus accumbens. Furthermore, chronic treatment with baclofen decreased the dopamine release induced by morphine challenge. Our results indicated that gamma-aminobutyric acid system plays an important role in the morphine sensitization in rat and suggested that behavioral sensitization is a promising model to study the mechanism underlying drug abuse.

  5. Co-targeting the HER and IGF/insulin receptor axis in breast cancer, with triple targeting with endocrine therapy for hormone-sensitive disease.

    Science.gov (United States)

    Chakraborty, Ashok; Hatzis, Christos; DiGiovanna, Michael P

    2017-05-01

    Interactions between HER2, estrogen receptor (ER), and insulin-like growth factor I receptor (IGF1R) are implicated in resistance to monotherapies targeting these receptors. We have previously shown in pre-clinical studies synergistic anti-tumor effects for co-targeting each pairwise combination of HER2, IGF1R, and ER. Strikingly, synergy for HER2/IGF1R targeting occurred not only in a HER2+ model, but also in a HER2-normal model. The purpose of the current study was therefore to determine the generalizability of synergistic anti-tumor effects of co-targeting HER2/IGF1R, the anti-tumor activity of triple-targeting HER2/IGF1R/ER in hormone-dependent cell lines, and the effect of using the multi-targeting drugs neratinib (pan-HER) and BMS-754807 (dual IGF1R/insulin receptor). Proliferation and apoptosis assays were performed in a large panel of cell lines representing varying receptor expression levels. Mechanistic effects were studied using phospho-protein immunoblotting. Analyses of drug interaction effects were performed using linear mixed-effects regression models. Enhanced anti-proliferative effects of HER/IGF-insulin co-targeting were seen in most, though not all, cell lines, including HER2-normal lines. For ER+ lines, triple targeting with inclusion of anti-estrogen generally resulted in the greatest anti-tumor effects. Double or triple targeting generally resulted in marked increases in apoptosis in the sensitive lines. Mechanistic studies demonstrated that the synergy between drugs was correlated with maximal inhibition of Akt and ERK pathway signaling. Dual HER/IGF-insulin targeting, and triple targeting with inclusion of anti-estrogen drugs, shows striking anti-tumor activity across breast cancer types, and drugs with broader receptor specificity may be more effective than single receptor selective drugs, particularly for ER- cells.

  6. Life in the fat lane: seasonal regulation of insulin sensitivity, food intake, and adipose biology in brown bears.

    Science.gov (United States)

    Rigano, K S; Gehring, J L; Evans Hutzenbiler, B D; Chen, A V; Nelson, O L; Vella, C A; Robbins, C T; Jansen, H T

    2017-05-01

    Grizzly bears (Ursus arctos horribilis) have evolved remarkable metabolic adaptations including enormous fat accumulation during the active season followed by fasting during hibernation. However, these fluctuations in body mass do not cause the same harmful effects associated with obesity in humans. To better understand these seasonal transitions, we performed insulin and glucose tolerance tests in captive grizzly bears, characterized the annual profiles of circulating adipokines, and tested the anorectic effects of centrally administered leptin at different times of the year. We also used bear gluteal adipocyte cultures to test insulin and beta-adrenergic sensitivity in vitro. Bears were insulin resistant during hibernation but were sensitive during the spring and fall active periods. Hibernating bears remained euglycemic, possibly due to hyperinsulinemia and hyperglucagonemia. Adipokine concentrations were relatively low throughout the active season but peaked in mid-October prior to hibernation when fat content was greatest. Serum glycerol was highest during hibernation, indicating ongoing lipolysis. Centrally administered leptin reduced food intake in October, but not in August, revealing seasonal variation in the brain's sensitivity to its anorectic effects. This was supported by strong phosphorylated signal transducer and activator of transcription 3 labeling within the hypothalamus of hibernating bears; labeling virtually disappeared in active bears. Adipocytes collected during hibernation were insulin resistant when cultured with hibernation serum but became sensitive when cultured with active season serum. Heat treatment of active serum blocked much of this action. Clarifying the cellular mechanisms responsible for the physiology of hibernating bears may inform new treatments for metabolic disorders.

  7. Increased abundance of insulin/insulin-like growth factor-I hybrid receptors in skeletal muscle of obese subjects is correlated with in vivo insulin sensitivity.

    Science.gov (United States)

    Federici, M; Porzio, O; Lauro, D; Borboni, P; Giovannone, B; Zucaro, L; Hribal, M L; Sesti, G

    1998-08-01

    We reported that in noninsulin-dependent diabetes melitus (NIDDM) patients expression of insulin/insulin-like growth factor I (IGF-I) hybrid receptors is increased in insulin target tissues. Whether this is a defect associated with NIDDM or represents a generalized abnormality associated with insulin resistant states is still unsettled. To address this, we applied a microwell-based immunoassay to measure abundance of insulin receptors, type 1 IGF receptors, and hybrid receptors in muscle of eight normal and eight obese subjects. Maximal insulin binding to insulin receptors was lower in obese than in control subjects (B/T = 1.8 +/- 0.20 and 2.6 +/- 0.30; P < 0.03, respectively) and was negatively correlated with insulinemia (r = -0.60; P < 0.01). Maximal IGF-I binding to type 1 IGF receptors was higher in obese than in controls (B/T = 1.9 +/- 0.20 and 0.86 +/- 0.10; P < 0.0001, respectively) and was negatively correlated with plasma IGF-I levels (r = -0.69; P < 0.003). Hybrid receptor abundance was higher in obese than in normal subjects (B/T = 1.21 +/- 0.14 and 0.44 +/- 0.06; P < 0.0003, respectively) and was negatively correlated with insulin binding (r = -0.60; P < 0.01) and positively correlated with IGF-I binding (r = 0.92; P < 0.0001). Increased abundance of hybrids was correlated with insulinemia (r = 0.70; P < 0.002) and body mass index (r = 0.71; P < 0.0019), whereas it was negatively correlated with in vivo insulin sensitivity measured by ITT (r = -0.67; P < 0.016). These results indicate that downregulation of insulin receptors or upregulation of type 1 IGF receptors because of changes in plasma insulin and IGF-I levels may result in modifications in hybrid receptor abundance.

  8. Subjective social status predicts in vivo responsiveness of β-adrenergic receptors.

    Science.gov (United States)

    Euteneuer, Frank; Mills, Paul J; Rief, Winfried; Ziegler, Michael G; Dimsdale, Joel E

    2012-07-01

    Several poor health outcomes, including cardiovascular risk, have been associated with both subjective social status (SSS) and sympathetic overactivity. Because prolonged sympathetic overactivation down regulates beta adrenergic receptor (β-AR) function, reduced β-AR responsiveness is considered an indicator of sympathetic overactivity and a cardiovascular risk factor. Though prior research has focused on objective social status and β-AR function, no studies have examined the association between SSS and β-AR function. We aimed to learn whether SSS predicts the in vivo responsiveness of β-ARs. We assessed the chronotropic 25 dose (CD25), an in vivo marker of β-AR responsiveness, in 94 healthy participants. The MacArthur scales of subjective social status were used to assess SSS in the U.S.A. (SSS-USA) and in the local community (SSS-C). Objective social status was analyzed by calculating the Hollingshead two-factor index. β-AR responsiveness was reduced (as indicated by higher CD25 values) in participants with lower SSS-USA (p = .007) and lower SSS-C (p social status. Our results indicate that β-AR function may be an important component of the link between SSS and health.

  9. [3H] glycogen hydrolysis in brain slices: responses to meurotransmitters and modulation of noradrenaline receptors

    International Nuclear Information System (INIS)

    Quach, T.T.; Rose, C.; Schwartz, J.C.

    1978-01-01

    Different agents have been investigated for their effects on [ 3 H] glycogen synthesized in mouse cortical slices. Of these noradrenaline, serotonin and histamine induced clear concentration-dependent glycogenesis. [ 3 H] glycogen hydrolysis induced by noradrenaline appears to be mediated by beta-adrenergic receptors because it is completely prevented by timolol, while phentolamine is ineffective. It seems to involve cyclic AMP because it is potentiated in the presence of isobutylmethylxanthine; in addition dibutyryl cyclic AMP (but not dibutyryl cyclic GMP) promotes glycogenolysis. Lower concentrations of noradrenaline were necessary for [ 3 H] glycogen hydrolysis (ECsub(50) 0.5μM) than for stimulation of cyclic AMP accumulation (ECsub(50) = 8μM). After subchronic reserpine treatment the concentration-response curve to noradrenaline was significantly shifted to the left (ECsub(50) = 0.09 +- 0.02 μM as compared with 0.49 +- 0.08μM in saline-pretreated mice) without modifications of either the basal [ 3 H] glycogen level, maximal glycogenolytic effect, or the dibutyryl cAMP-induced glycogenolytic response. In addition to noradrenaline, clear concentration-dependent [ 3 H] glycogen hydrolysis was observed in the presence of histamine or serotonin. In contrast to the partial [ 3 H] glycogen hydrolysis elicited by these biogenic amines, depolarization of the slices by 50 mM K + provoked a nearly total [ 3 H] glycogen hydrolysis. (author)

  10. Transient receptor potential ankyrin 1 activation enhances hapten sensitization in a T-helper type 2-driven fluorescein isothiocyanate-induced contact hypersensitivity mouse model

    International Nuclear Information System (INIS)

    Shiba, Takahiro; Tamai, Takuma; Sahara, Yurina; Kurohane, Kohta; Watanabe, Tatsuo; Imai, Yasuyuki

    2012-01-01

    Some chemicals contribute to the development of allergies by increasing the immunogenicity of other allergens. We have demonstrated that several phthalate esters, including dibutyl phthalate (DBP), enhance skin sensitization to fluorescein isothiocyanate (FITC) in a mouse contact hypersensitivity model, in which the T-helper type 2 (Th2) response is essential. On the other hand, some phthalate esters were found to activate transient receptor potential ankyrin 1 (TRPA1) cation channels on sensory neurons. We then found a positive correlation between the enhancing effects of several types of phthalate esters on skin sensitization to FITC and their ability to activate TRPA1. Here we examined the involvement of TRPA1 in sensitization to FITC by using TRPA1 agonists other than phthalate esters. During skin sensitization to FITC, the TRPA1 agonists (menthol, carvacrol, cinnamaldehyde and DBP) augmented the ear-swelling response as well as trafficking of FITC-presenting dendritic cells to draining lymph nodes. We confirmed that these TRPA1 agonists induced calcium influx into TRPA1-expressing Chinese hamster ovary (CHO) cells. We also found that TRPA1 antagonist HC-030031 inhibited DBP-induced calcium influx into TRPA1-expressing CHO cells. After pretreatment with this antagonist upon skin sensitization to FITC, the enhancing effect of DBP on sensitization was suppressed. These results suggest that TRPA1 activation will become a useful marker to find chemicals that facilitate sensitization in combination with other immunogenic haptens. -- Highlights: ► Role of TRPA1 activation was revealed in a mouse model of skin sensitization to FITC. ► TRPA1 agonists enhanced skin sensitization as well as dendritic cell trafficking. ► Dibutyl phthalate (DBP) has been shown to enhance skin sensitization to FITC. ► TRPA1 activation by DBP was inhibited by a selective antagonist, HC-030031. ► HC-030031 inhibited the enhancing effect of DBP on skin sensitization to FITC.

  11. Transient receptor potential ankyrin 1 activation enhances hapten sensitization in a T-helper type 2-driven fluorescein isothiocyanate-induced contact hypersensitivity mouse model

    Energy Technology Data Exchange (ETDEWEB)

    Shiba, Takahiro; Tamai, Takuma; Sahara, Yurina; Kurohane, Kohta [Laboratory of Microbiology and Immunology, School of Pharmaceutical Sciences, University of Shizuoka, 52‐1 Yada, Suruga-ku, Shizuoka City, Shizuoka 422‐8526 (Japan); Watanabe, Tatsuo [Laboratory of Food Chemistry, School of Food and Nutritional Sciences, University of Shizuoka, 52‐1 Yada, Suruga-ku, Shizuoka City, Shizuoka 422‐8526 (Japan); Imai, Yasuyuki, E-mail: imai@u-shizuoka-ken.ac.jp [Laboratory of Microbiology and Immunology, School of Pharmaceutical Sciences, University of Shizuoka, 52‐1 Yada, Suruga-ku, Shizuoka City, Shizuoka 422‐8526 (Japan)

    2012-11-01

    Some chemicals contribute to the development of allergies by increasing the immunogenicity of other allergens. We have demonstrated that several phthalate esters, including dibutyl phthalate (DBP), enhance skin sensitization to fluorescein isothiocyanate (FITC) in a mouse contact hypersensitivity model, in which the T-helper type 2 (Th2) response is essential. On the other hand, some phthalate esters were found to activate transient receptor potential ankyrin 1 (TRPA1) cation channels on sensory neurons. We then found a positive correlation between the enhancing effects of several types of phthalate esters on skin sensitization to FITC and their ability to activate TRPA1. Here we examined the involvement of TRPA1 in sensitization to FITC by using TRPA1 agonists other than phthalate esters. During skin sensitization to FITC, the TRPA1 agonists (menthol, carvacrol, cinnamaldehyde and DBP) augmented the ear-swelling response as well as trafficking of FITC-presenting dendritic cells to draining lymph nodes. We confirmed that these TRPA1 agonists induced calcium influx into TRPA1-expressing Chinese hamster ovary (CHO) cells. We also found that TRPA1 antagonist HC-030031 inhibited DBP-induced calcium influx into TRPA1-expressing CHO cells. After pretreatment with this antagonist upon skin sensitization to FITC, the enhancing effect of DBP on sensitization was suppressed. These results suggest that TRPA1 activation will become a useful marker to find chemicals that facilitate sensitization in combination with other immunogenic haptens. -- Highlights: ► Role of TRPA1 activation was revealed in a mouse model of skin sensitization to FITC. ► TRPA1 agonists enhanced skin sensitization as well as dendritic cell trafficking. ► Dibutyl phthalate (DBP) has been shown to enhance skin sensitization to FITC. ► TRPA1 activation by DBP was inhibited by a selective antagonist, HC-030031. ► HC-030031 inhibited the enhancing effect of DBP on skin sensitization to FITC.

  12. 3-[2,4-Dimethoxybenzylidene]anabaseine (DMXB) selectively activates rat alpha7 receptors and improves memory-related behaviors in a mecamylamine-sensitive manner.

    Science.gov (United States)

    Meyer, E M; Tay, E T; Papke, R L; Meyers, C; Huang, G L; de Fiebre, C M

    1997-09-12

    The alpha7 nicotinic receptor agonist 3-[2,4-dimethoxybenzylidene]anabaseine (DMXB; GTS-21) was investigated for its ability to: (1) activate a variety of nicotinic receptor subtypes in Xenopus oocytes; (2) improve passive avoidance and spatial Morris water task performances in mecamylamine-sensitive manners in bilaterally nucleus basalis lesioned rats; and (3) elevate high-affinity [3H]acetylcholine (ACh) and high-affinity alpha-[125I]bungarotoxin binding in rat neocortex following 2 weeks of daily injections. DMXB (100 microM) activated alpha7 homo-oligomeric receptors, without significant activity at alpha2-, alpha3- and alpha4-containing subtypes. Mecamylamine blocked rat alpha7 receptors weakly if co-administered with agonist, but much more potently when pre-applied. Bilateral ibotenic acid lesions of the nucleus basalis interfered with passive avoidance and spatial memory-related behaviors. DMXB (0.5 mg/kg, i.p.) improved passive avoidance behavior in lesioned animals in a mecamylamine-sensitive manner. DMXB (0.5 mg/kg 15 min before each session) also improved performance in the training and probe components of the Morris water task. DMXB-induced improvement in the probe component but not the training phase was mecamylamine-sensitive. [3H]ACh binding was elevated after 14 days of daily i.p. injections with 0.2 mg/kg nicotine but not after 1 mg/kg DMXB. Neither drug elevated high-affinity alpha-[125I]bungarorotoxin binding over this interval.

  13. The AhR Ligand, TCDD, Regulates Androgen Receptor Activity Differently in Androgen-Sensitive versus Castration-Resistant Human Prostate Cancer Cells

    Directory of Open Access Journals (Sweden)

    Maryam Ghotbaddini

    2015-07-01

    Full Text Available The reported biological effects of TCDD include induction of drug metabolizing enzymes, wasting syndrome and tumor promotion. TCDD elicits most of its effects through binding the aryl hydrocarbon receptor (AhR. TCDD induced degradation of AhR has been widely reported and requires ubiquitination of the protein. The rapid depletion of AhR following TCDD activation serves as a mechanism to modulate AhR mediated gene induction. In addition to inducing AhR degradation, TCDD has been reported to induce degradation of hormone receptors. The studies reported here, evaluate the effect of TCDD exposure on androgen receptor (AR expression and activity in androgen-sensitive LNCaP and castration-resistant C4-2 prostate cancer cells. Our results show that TCDD exposure does not induce AhR or AR degradation in C4-2 cells. However, both AhR and AR are degraded in LNCaP cells following TCDD exposure. In addition, TCDD enhances AR phosphorylation and induces expression of AR responsive genes in LNCaP cells. Our data reveals that TCDD effect on AR expression and activity differs in androgen-sensitive and castration-resistant prostate cancer cell models.

  14. Lysergic acid diethylamide (LSD) administration selectively downregulates serotonin2 receptors in rat brain.

    Science.gov (United States)

    Buckholtz, N S; Zhou, D F; Freedman, D X; Potter, W Z

    1990-04-01

    A dosage regimen of lysergic acid diethylamide (LSD) that reliably produces behavioral tolerance in rats was evaluated for effects on neurotransmitter receptor binding in rat brain using a variety of radioligands selective for amine receptor subtypes. Daily administration of LSD [130 micrograms/kg (0.27 mumol/kg) intraperitoneally (IP)] for 5 days produced a decrease in serotonin2 (5-hydroxytryptamine2, 5-HT2) binding in cortex (measured 24 hours after the last drug administration) but did not affect binding to other receptor systems (5-HT1A, 5-HT1B, beta-adrenergic, alpha 1- or alpha 2-adrenergic, D2-dopaminergic) or to a recognition site for 5-HT uptake. The decrease was evident within 3 days of LSD administration but was not demonstrable after the first LSD dose. Following 5 days of LSD administration the decrease was still present 48 hours, but not 96 hours, after the last administration. The indole hallucinogen psilocybin [1.0 mg/kg (3.5 mumol/kg) for 8 days] also produced a significant decrease in 5HT2 binding, but neither the nonhallucinogenic analog bromo-LSD [1.3 mg/kg (2.4 mumol/kg) for 5 days] nor mescaline [10 mg/kg (40.3 mumol/kg) for 5 or 10 days] affected 5-HT2 binding. These observations suggest that LSD and other indole hallucinogens may act as 5-HT2 agonists at postsynaptic 5-HT2 receptors. Decreased 5-HT2 binding strikingly parallels the development and loss of behavioral tolerance seen with repeated LSD administration, but the decreased binding per se cannot explain the gamut of behavioral tolerance and cross-tolerance phenomena among the indole and phenylethylamine hallucinogens.

  15. Receptor assay

    Energy Technology Data Exchange (ETDEWEB)

    Kato, K; Ibayashi, H [Kyushu Univ., Fukuoka (Japan). Faculty of Medicine

    1975-05-01

    This paper summarized present status and problems of analysis of hormone receptor and a few considerations on clinical significance of receptor abnormalities. It was pointed that in future clinical field quantitative and qualitative analysis of receptor did not remain only in the etiological discussion, but that it was an epoch-making field of investigation which contained the possiblity of artificial change of sensitivity of living body on drugs and the development connected directly with treatment of various diseases.

  16. First direct electron microscopic visualization of a tight spatial coupling between GABAA-receptors and voltage-sensitive calcium channels

    DEFF Research Database (Denmark)

    Hansen, Gert Helge; Belhage, B; Schousboe, A

    1992-01-01

    Using cerebellar granule neurons in culture it was demonstrated that exposure of the cells to the GABAA receptor agonist 4,5,6,7-tetrahydroisoxazolo[5,4-c]pyridin-3-ol (THIP) leads to an increase in the number of voltage-gated calcium channels as revealed by quantitative preembedding indirect imm...

  17. Nonconserved tryptophan 38 of the cell surface receptor for subgroup J avian leukosis virus discriminates sensitive from resistant avian species

    Czech Academy of Sciences Publication Activity Database

    Kučerová, Dana; Plachý, Jiří; Reinišová, Markéta; Šenigl, Filip; Trejbalová, Kateřina; Geryk, Josef; Hejnar, Jiří

    2013-01-01

    Roč. 87, č. 15 (2013), s. 8399-8407 ISSN 0022-538X R&D Projects: GA ČR GAP502/10/1651 Institutional support: RVO:68378050 Keywords : avian leukosis virus * ALV-J * NHE1 * host resistance * receptor Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 4.648, year: 2013

  18. High sensitivity of the in vivo detection of somatostatin receptors by 111Indium (DTPA-Octreotide)-scintigraphy in meningioma patients

    International Nuclear Information System (INIS)

    Hildebrandt, G.; Luyken, C.; Klug, N.; Scheidhauer, K.; Schicha, H.; Dahms, P.; Krisch, B.

    1994-01-01

    The recent availability of isotope-labelled somatostatin analogues has allowed one to detect somatostatin receptors in normal tissue as well as in endocrine or non-endocrine cranial tumours. The purpose of the present study was to establish the value of somatostatin receptor scintigraphy using an 111 indium-labelled somatostatin analogue, octreotide, in the diagnostic work-up of meningioma patients. Twenty-two patients (16 women, 6 men, aged from 19-70 years) with newly diagnosed, residual or recurrent cranial meningiomas were examined. 111 indium-labelled DTPA-octreotide was injected i.v.. Planar and tomographic images were obtained with a gamma camera 4-6, and 24 hours after injection. In all of the meningiomas studies a high density of somatostatin receptor was detected by scintigraphy. No false negative test result was found. Due to this, a 100% predictive value of a negative test was calculated. However, when the tumours were taken in culture differing staining intensity could be seen in the light- and electron microscopic level even on individual cells of a single culture when silver intensified somatostatin-gold was used as ligand. We conclude, that in vivo somatostatin receptor scintigraphy may aid in the pre-operative differential diagnosis of skull base tumours

  19. Sensitization of (colon) cancer cells to death receptor related therapies A report from the FP6-ONCODEATH research consortium

    Czech Academy of Sciences Publication Activity Database

    Pintzas, A.; Zhivotovsky, B.; Workman, P.; Clarke, P.A.; Linardopoulos, S.; Martinou, J.C.; Lacal, J.C.; Robine, S.; Nasioulas, G.; Anděra, Ladislav

    2012-01-01

    Roč. 13, č. 7 (2012), s. 458-466 ISSN 1538-4047 Grant - others:EK(XE) LSHC-CT-2006-037278 Institutional support: RVO:68378050 Keywords : cancer * death receptors * kinase inhibitors * mitochondria * targeted therapies Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 3.287, year: 2012

  20. Emotional eating is associated with increased brain responses to food-cues and reduced sensitivity to GLP-1 receptor activation

    NARCIS (Netherlands)

    van Bloemendaal, L.; Veltman, D.J.; ten Kulve, J.S.; Drent, M.L.; Barkhof, F.; Diamant, M.; IJzerman, R.G.

    2015-01-01

    Objective The neural correlates and pathophysiology of emotional eating are insufficiently known. Glucagon-like peptide-1 (GLP-1), a postprandial hormone, plays a role in feeding behavior by signaling satiety to the brain. GLP-1 receptor agonists, used for treatment of type 2 diabetes (T2DM),

  1. Genetic evidence for involvement of neuronally expressed S1P₁ receptor in nociceptor sensitization and inflammatory pain.

    Directory of Open Access Journals (Sweden)

    Norbert Mair

    2011-02-01

    Full Text Available Sphingosine-1-phosphate (S1P is a key regulator of immune response. Immune cells, epithelia and blood cells generate high levels of S1P in inflamed tissue. However, it is not known if S1P acts on the endings of nociceptive neurons, thereby contributing to the generation of inflammatory pain. We found that the S1P₁ receptor for S1P is expressed in subpopulations of sensory neurons including nociceptors. Both S1P and agonists at the S1P₁ receptor induced hypersensitivity to noxious thermal stimulation in vitro and in vivo. S1P-induced hypersensitivity was strongly attenuated in mice lacking TRPV1 channels. S1P and inflammation-induced hypersensitivity was significantly reduced in mice with a conditional nociceptor-specific deletion of the S1P₁ receptor. Our data show that neuronally expressed S1P₁ receptors play a significant role in regulating nociceptor function and that S1P/S1P₁ signaling may be a key player in the onset of thermal hypersensitivity and hyperalgesia associated with inflammation.

  2. Transcranial Random Noise Stimulation-induced plasticity is NMDA-receptor independent but sodium-channel blocker and benzodiazepines sensitive

    Directory of Open Access Journals (Sweden)

    Leila eChaieb

    2015-04-01

    Full Text Available Background: Application of transcranial random noise stimulation (tRNS between 0.1 and 640 Hz of the primary motor cortex (M1 for 10 minutes induces a persistent excitability increase lasting for at least 60 minutes. However, the mechanism of tRNS-induced cortical excitability alterations is not yet fully understood. Objective: The main aim of this study was to get first efficacy data with regard to the possible neuronal effect of tRNS. Methods: Single-pulse transcranial magnetic stimulation (TMS was used to measure levels of cortical excitability before and after combined application of tRNS at an intensity of 1mA for 10mins stimulation duration and a pharmacological agent (or sham on 8 healthy male participants. Results: The sodium channel blocker carbamazepine showed a tendency towards inhibiting MEPs 5-60 mins poststimulation. The GABAA agonist lorazepam suppressed tRNS-induced cortical excitability increases at 0-20 and 60 min time points. The partial NMDA receptor agonist D-cycloserine, the NMDA receptor antagonist dextromethorphan and the D2/D3 receptor agonist ropinirole had no significant effects on the excitability increases seen with tRNS.Conclusions: In contrast to transcranial direct current stimulation (tDCS, aftereffects of tRNS are seem to be not NMDA receptor dependent and can be suppressed by benzodiazepines suggesting that tDCS and tRNS depend upon different mechanisms.

  3. Targeting pro-apoptotic trail receptors sensitizes HeLa cervical cancer cells to irradiation-induced apoptosis

    NARCIS (Netherlands)

    Maduro, John H.; de Vries, Elisabeth G. E.; Meersma, Gert-Jan; Hougardy, Brigitte M. T.; van der Zee, Ate G. J.; De Jong, Steven

    2008-01-01

    Purpose: To investigate the potential of irradiation in combination with drugs targeting the tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) death receptor (DR)4 and DR5 and their mechanism of action in a cervical cancer cell line. Methods and Materials: Recombinant human TRAIL

  4. One week treatment with the IL-1 receptor antagonist anakinra leads to a sustained improvement in insulin sensitivity in insulin resistant patients with type 1 diabetes mellitus.

    Science.gov (United States)

    van Asseldonk, Edwin J P; van Poppel, Pleun C M; Ballak, Dov B; Stienstra, Rinke; Netea, Mihai G; Tack, Cees J

    2015-10-01

    Inflammation associated with obesity is involved in the development of insulin resistance. We hypothesized that anti-inflammatory treatment with the Interleukin-1 receptor antagonist anakinra would improve insulin sensitivity. In an open label proof-of-concept study, we included overweight patients diagnosed with type 1 diabetes with an HbA1c level over 7.5%. Selecting insulin resistant patients with longstanding type 1 diabetes allowed us to study the effects of anakinra on insulin sensitivity. Patients were treated with 100mg anakinra daily for one week. Insulin sensitivity, insulin need and blood glucose profiles were measured before, after one week and after four weeks of follow-up. Fourteen patients completed the study. One week of anakinra treatment led to an improvement of insulin sensitivity, an effect that was sustained for four weeks. Similarly, glucose profiles, HbA1c levels and insulin needs improved. In conclusion, one week of treatment with anakinra improves insulin sensitivity in patients with type 1 diabetes. Copyright © 2015 Elsevier Inc. All rights reserved.

  5. Stress Sensitization of Ethanol Withdrawal-Induced Reduction in Social Interaction: Inhibition by CRF-1 and Benzodiazepine Receptor Antagonists and a 5-HT1A-Receptor Agonist

    OpenAIRE

    Breese, George R; Knapp, Darin J; Overstreet, David H

    2004-01-01

    Repeated withdrawals from chronic ethanol sensitize the withdrawal-induced reduction in social interaction behaviors. This study determined whether stress might substitute for repeated withdrawals to facilitate withdrawal-induced anxiety-like behavior. When two 1-h periods of restraint stress were applied at 1-week intervals to rats fed control diet, social interaction was reduced upon withdrawal from a subsequent 5-day exposure to ethanol diet. Neither this ethanol exposure alone nor exposur...

  6. Response to Vicriviroc in Treatment-Experienced Subjects Using an Enhanced Sensitivity Co-receptor Tropism Assay: Reanalysis of AIDS Clinical Trials Group A5211

    Science.gov (United States)

    Su, Zhaohui; Gulick, Roy M.; Krambrink, Amy; Coakley, Eoin; Hughes, Michael D.; Han, Dong; Flexner, Charles; Wilkin, Timothy J.; Skolnik, Paul R.; Greaves, Wayne L.; Kuritzkes, Daniel R.; Reeves, Jacqueline D.

    2009-01-01

    The enhanced sensitivity Trofile assay was used to re-test co-receptor usage at study screening and entry for the 118 ACTG A5211 treatment-experienced subjects who had CCR5-tropic (R5) virus by the original Trofile assay at study screening. Among 90 vicriviroc recipients, a significantly (P<0.001) greater mean reduction in HIV-1 RNA was observed in 72 subjects with R5 virus versus 15 subjects reclassified with dual/mixed-tropic viruses at screening: −1.11 vs. −0.09 (day 14), −1.91 vs. −0.57 (week 24) log10 copies/mL, respectively. Results suggest that the enhanced sensitivity assay is a better screening tool for determining patient eligibility for CCR5 antagonist therapy. PMID:19874179

  7. Direct demonstration of guanine nucleotide sensitive receptors for vasoactive intestinal peptide in the anterior lobe of the rat pituitary gland

    International Nuclear Information System (INIS)

    Agui, T.; Matsumoto, K.

    1990-01-01

    The vasoactive intestinal peptide (VIP) receptors were identified on the membranes from the rat anterior pituitary gland with [ 125 I]VIP. The dissociation constant (Kd) and the maximal binding capacity (Bmax) values were estimated from the competitive inhibition data. The Kd and Bmax values were 1.05 +/- 0.75 nM and 103 +/- 11 fmol/mg protein, respectively. The order of molar potency of related peptides to inhibit [ 125 I]VIP binding was VIP greater than peptide histidine isoleucine (PHI) greater than secretin greater than glucagon. Glucagon was not effective to inhibit the binding. [ 125 I]VIP binding was effectively inhibited by the addition of guanine nucleotides. The order of molar potency to inhibit the binding was Gpp(NH)p greater than GTP greater than GDP greater than GMP greater than ATP. These results directly suggest the coupling of VIP receptors with guanine nucleotide binding proteins in the anterior pituitary gland

  8. Influence of body weight and type of chow on the sensitivity of rats to the behavioral effects of the direct-acting dopamine receptor agonist quinpirole

    Science.gov (United States)

    Baladi, Michelle G; Newman, Amy H; France, Charles P

    2013-01-01

    Rationale Amount and type of food can alter dopamine systems and sensitivity to drugs acting on those systems. Objectives This study examined whether changes in body weight, food type, or both body weight and food type contribute to these effects. Methods Rats had free or restricted access (increasing, decreasing, or maintaining body weight) to standard (5.7% fat) or high fat (34.3%) chow. Results In rats gaining weight with restricted or free access to high fat chow, both limbs of the quinpirole yawning dose-response curve (0.0032–0.32 mg/kg) shifted leftward compared with rats eating standard chow. Restricting access to standard or high fat chow (maintaining or decreasing body weight) decreased or eliminated quinpirole-induced yawning; within one week of resuming free feeding, sensitivity to quinpirole was restored, although the descending limb of the dose-response curve was shifted leftward in rats eating high fat chow. These are not likely pharmacokinetic differences because quinpirole-induced hypothermia was not different among groups. PG01037 and L-741,626 antagonized the ascending and descending limbs of the quinpirole dose-response curve in rats eating high fat chow, indicating D3 and D2 receptor mediation, respectively. Rats eating high fat chow also developed insulin resistance. Conclusions These results show that amount and type of chow alter sensitivity to a direct-acting dopamine receptor agonist with the impact of each factor depending on whether body weight increases, decreases, or is maintained. These data demonstrate that feeding conditions, perhaps related to insulin and insulin sensitivity, profoundly impact the actions of drugs acting on dopamine systems. PMID:21544521

  9. Influence of body weight and type of chow on the sensitivity of rats to the behavioral effects of the direct-acting dopamine-receptor agonist quinpirole.

    Science.gov (United States)

    Baladi, Michelle G; Newman, Amy H; France, Charles P

    2011-10-01

    Amount and type of food can alter dopamine systems and sensitivity to drugs acting on those systems. This study examined whether changes in body weight, food type, or both body weight and food type contribute to these effects. Rats had free or restricted access (increasing, decreasing, or maintaining body weight) to standard (5.7% fat) or high-fat (34.3%) chow. In rats gaining weight with restricted or free access to high-fat chow, both limbs of the quinpirole yawning dose-response curve (0.0032-0.32 mg/kg) shifted leftward compared with rats eating standard chow. Restricting access to standard or high-fat chow (maintaining or decreasing body weight) decreased or eliminated quinpirole-induced yawning; within 1 week of resuming free feeding, sensitivity to quinpirole was restored, although the descending limb of the dose-response curve was shifted leftward in rats eating high-fat chow. These are not likely pharmacokinetic differences because quinpirole-induced hypothermia was not different among groups. PG01037 and L-741,626 antagonized the ascending and descending limbs of the quinpirole dose-response curve in rats eating high-fat chow, indicating D3 and D2 receptor mediation, respectively. Rats eating high-fat chow also developed insulin resistance. These results show that amount and type of chow alter sensitivity to a direct-acting dopamine-receptor agonist with the impact of each factor depending on whether body weight increases, decreases, or is maintained. These data demonstrate that feeding conditions, perhaps related to insulin and insulin sensitivity, profoundly impact the actions of drugs acting on dopamine systems.

  10. Complement C3a binding to its receptor as a negative modulator of Th2 response in liver injury in trichloroethylene-sensitized mice.

    Science.gov (United States)

    Wang, Feng; Zha, Wan-sheng; Zhang, Jia-xiang; Li, Shu-long; Wang, Hui; Ye, Liang-ping; Shen, Tong; Wu, Chang-hao; Zhu, Qi-xing

    2014-08-17

    Trichloroethylene (TCE) is a major occupational health hazard and causes occupational medicamentosa-like dermatitis (OMLDT) and liver damage. Recent evidence suggests immune response as a distinct mode of action for TCE-induced liver damage. This study aimed to explore the role of the key complement activation product C3a and its receptor C3aR in TCE-induced immune liver injury. A mouse model of skin sensitization was induced by TCE in the presence and absence of the C3aR antagonist SB 290157. Liver function was evaluated by alanine aminotransferase (ALT) and aspartate aminotransferase (AST) in conjunction with histopathological characterizations. C3a and C3aR were detected by immunohistochemistry and C5b-9 was assessed by immunofluorescence. IFN-γ and IL4 expressions were determined by flow cytometry and ELISA. The total sensitization rate was 44.1%. TCE sensitization caused liver cell necrosis and inflammatory infiltration, elevated serum ALT and AST, expression of C3a and C3aR, and deposition of C5b-9 in the liver. IFN-γ and IL-4 expressions were up-regulated in spleen mononuclear cells and their serum levels were also increased. Pretreatment with SB 290157 resulted in more inflammatory infiltration in the liver, higher levels of AST, reduced C3aR expression on Kupffer cells, and decreased IL-4 levels while IFN-γ remained unchanged. These data demonstrate that blocking of C3a binding to C3aR reduces IL4, shifts IFN-γ and IL-4 balance, and aggravates TCE-sensitization induced liver damage. These findings reveal a novel mechanism whereby modulation of Th2 response by C3a binding to C3a receptor contributes to immune-mediated liver damage by TCE exposure. Copyright © 2014. Published by Elsevier Ireland Ltd.

  11. Development of EMab-51, a Sensitive and Specific Anti-Epidermal Growth Factor Receptor Monoclonal Antibody in Flow Cytometry, Western Blot, and Immunohistochemistry.

    Science.gov (United States)

    Itai, Shunsuke; Kaneko, Mika K; Fujii, Yuki; Yamada, Shinji; Nakamura, Takuro; Yanaka, Miyuki; Saidoh, Noriko; Handa, Saori; Chang, Yao-Wen; Suzuki, Hiroyoshi; Harada, Hiroyuki; Kato, Yukinari

    2017-10-01

    The epidermal growth factor receptor (EGFR) is a member of the human epidermal growth factor receptor (HER) family of receptor tyrosine kinases and is involved in cell growth and differentiation. EGFR homodimers or heterodimers with other HER members, such as HER2 and HER3, activate downstream signaling cascades in many cancers. In this study, we developed novel anti-EGFR monoclonal antibodies (mAbs) and characterized their efficacy in flow cytometry, Western blot, and immunohistochemical analyses. First, we expressed the full-length or ectodomain of EGFR in LN229 glioblastoma cells and then immunized mice with LN229/EGFR or ectodomain of EGFR, and performed the first screening using enzyme-linked immunosorbent assays. Subsequently, we selected mAbs according to their efficacy in flow cytometry (second screening), Western blot (third screening), and immunohistochemical (fourth screening) analyses. Among 100 mAbs, only one clone EMab-51 (IgG 1 , kappa) reacted with EGFR in Western blot analysis. Finally, immunohistochemical analyses with EMab-51 showed sensitive and specific reactions against oral cancer cells, warranting the use of EMab-51 to detect EGFR in pathological analyses of EGFR-expressing cancers.

  12. Highly Sensitive Electrochemical Sensor for the Detection of Anions in Water Based on a Redox-Active Monolayer Incorporating an Anion Receptor.

    Science.gov (United States)

    Kaur, Balwinder; Erdmann, Cristiane Andreia; Daniëls, Mathias; Dehaen, Wim; Rafiński, Zbigniew; Radecka, Hanna; Radecki, Jerzy

    2017-12-05

    In the present work, gold electrodes were modified using a redox-active layer based on dipyrromethene complexes with Cu(II) or Co(II) and a dipodal anion receptor functionalized with dipyrromethene. These modified gold electrodes were then applied for the electrochemical detection of anions (Cl - , SO 4 2- , and Br - ) in a highly diluted water solution (in the picomolar range). The results showed that both systems, incorporating Cu(II) as well as Co(II) redox centers, exhibited highest sensitivity toward Cl - . The selectivity sequence found for both systems was Cl - > SO 4 2- > Br - . The high selectivity of Cl - anions can be attributed to the higher binding constant of Cl - with the anion receptor and the stronger electronic effect between the central metal and anion in the complex. The detection limit for the determination of Cl - was found at the 1.0 pM level for both sensing systems. The electrodes based on Co(II) redox centers displayed better selectivity toward Cl - anion detection than those based on Cu(II) centers which can be attributed to the stronger electronic interaction between the receptor-target anion complex and the Co(II)/Co(III) redox centers in comparison to the Cu(II)/Cu(I) system. Applicability of gold electrodes modified with DPM-Co(II)-DPM-AR for the electrochemical determination of Cl - anions was demonstrated using the artificial matrix mimicking human serum.

  13. Development and utilization of a fluorescence-based receptor-binding assay for the site 5 voltage-sensitive sodium channel ligands brevetoxin and ciguatoxin.

    Science.gov (United States)

    McCall, Jennifer R; Jacocks, Henry M; Niven, Susan C; Poli, Mark A; Baden, Daniel G; Bourdelais, Andrea J

    2014-01-01

    Brevetoxins are a family of ladder-frame polyether toxins produced during blooms of the marine dinoflagellate Karenia brevis. Consumption of fish exposed to K. brevis blooms can lead to the development of neurotoxic shellfish poisoning. The toxic effects of brevetoxins are due to activation of voltage-sensitive sodium channels (VSSCs) in cell membranes. Binding of toxins has historically been measured using a radioligand competition assay that is fraught with difficulty. In this study, we developed a novel fluorescence-based binding assay for the brevetoxin receptor. Several fluorophores were conjugated to polyether brevetoxin-2 and used as the labeled ligand. Brevetoxin analogs were able to compete for binding with the fluorescent ligands. This assay was qualified against the standard radioligand receptor assay for the brevetoxin receptor. Furthermore, the fluorescence-based assay was used to determine relative concentrations of toxins in raw extracts of K. brevis culture, and to determine ciguatoxin affinity to site 5 of VSSCs. The fluorescence-based assay was quicker, safer, and far less expensive. As such, this assay can be used to replace the current radioligand assay and will be a vital tool for future experiments examining the binding affinity of various ligands for site 5 on sodium channels.

  14. Sustained Brown Fat Stimulation and Insulin Sensitization by a Humanized Bispecific Antibody Agonist for Fibroblast Growth Factor Receptor 1/βKlotho Complex

    Directory of Open Access Journals (Sweden)

    Ganesh Kolumam

    2015-07-01

    Full Text Available Dissipating excess calories as heat through therapeutic stimulation of brown adipose tissues (BAT has been proposed as a potential treatment for obesity-linked disorders. Here, we describe the generation of a humanized effector-less bispecific antibody that activates fibroblast growth factor receptor (FGFR 1/βKlotho complex, a common receptor for FGF21 and FGF19. Using this molecule, we show that antibody-mediated activation of FGFR1/βKlotho complex in mice induces sustained energy expenditure in BAT, browning of white adipose tissue, weight loss, and improvements in obesity-associated metabolic derangements including insulin resistance, hyperglycemia, dyslipidemia and hepatosteatosis. In mice and cynomolgus monkeys, FGFR1/βKlotho activation increased serum high-molecular-weight adiponectin, which appears to contribute over time by enhancing the amplitude of the metabolic benefits. At the same time, insulin sensitization by FGFR1/βKlotho activation occurs even before the onset of weight loss in a manner that is independent of adiponectin. Together, selective activation of FGFR1/βKlotho complex with a long acting therapeutic antibody represents an attractive approach for the treatment of type 2 diabetes and other obesity-linked disorders through enhanced energy expenditure, insulin sensitization and induction of high-molecular-weight adiponectin.

  15. Reversal of propranolol blockade of adrenergic receptors and related toxicity with drugs that increase cyclic AMP.

    Science.gov (United States)

    Whitehurst, V E; Vick, J A; Alleva, F R; Zhang, J; Joseph, X; Balazs, T

    1999-09-01

    An overdose of propranolol, a widely used nonselective beta-adrenergic receptor blocking agent, can result in hypotension and bradycardia leading to irreversible shock and death. In addition, the blockade of adrenergic receptors can lead to alterations in neurotransmitter receptors resulting in the interruption of the activity of other second messengers and the ultimate cellular responses. In the present experiment, three agents, aminophylline, amrinone, and forskolin were tested in an attempt to reverse the potential lethal effects of a propranolol overdose in dogs. Twenty-two anesthetized beagle dogs were given a 10-min infusion of propranolol at a dose of 1 mg/kg/min. Six of the dogs, treated only with intravenous saline, served as controls. Within 15-30 min all six control dogs exhibited profound hypotension and severe bradycardia that led to cardiogenic shock and death. Seven dogs were treated with intravenous aminophylline 20 mg/kg 5 min after the end of the propranolol infusion. Within 10-15 min heart rate and systemic arterial blood pressure returned to near control levels, and all seven dogs survived. Intravenous amrinone (2-3 mg/kg) given to five dogs, and forskolin (1-2 mg/kg) given to four dogs, also increased heart rate and systemic arterial blood pressure but the recovery of these parameters was appreciably slower than that seen with aminophylline. All of these animals also survived with no apparent adverse effects. Histopathologic evaluation of the hearts of the dogs treated with aminophylline showed less damage (vacuolization, inflammation, hemorrhage) than the hearts from animals given propranolol alone. Results of this study showed that these three drugs, all of which increase cyclic AMP, are capable of reversing the otherwise lethal effects of a propranolol overdose in dogs.

  16. Computational Analysis of Epidermal Growth Factor Receptor Mutations Predicts Differential Drug Sensitivity Profiles toward Kinase Inhibitors.

    Science.gov (United States)

    Akula, Sravani; Kamasani, Swapna; Sivan, Sree Kanth; Manga, Vijjulatha; Vudem, Dashavantha Reddy; Kancha, Rama Krishna

    2018-05-01

    A significant proportion of patients with lung cancer carry mutations in the EGFR kinase domain. The presence of a deletion mutation in exon 19 or L858R point mutation in the EGFR kinase domain has been shown to cause enhanced efficacy of inhibitor treatment in patients with NSCLC. Several less frequent (uncommon) mutations in the EGFR kinase domain with potential implications in treatment response have also been reported. The role of a limited number of uncommon mutations in drug sensitivity was experimentally verified. However, a huge number of these mutations remain uncharacterized for inhibitor sensitivity or resistance. A large-scale computational analysis of clinically reported 298 point mutants of EGFR kinase domain has been performed, and drug sensitivity profiles for each mutant toward seven kinase inhibitors has been determined by molecular docking. In addition, the relative inhibitor binding affinity toward each drug as compared with that of adenosine triphosphate was calculated for each mutant. The inhibitor sensitivity profiles predicted in this study for a set of previously characterized mutants correlated well with the published clinical, experimental, and computational data. Both the single and compound mutations displayed differential inhibitor sensitivity toward first- and next-generation kinase inhibitors. The present study provides predicted drug sensitivity profiles for a large panel of uncommon EGFR mutations toward multiple inhibitors, which may help clinicians in deciding mutant-specific treatment strategies. Copyright © 2018 International Association for the Study of Lung Cancer. Published by Elsevier Inc. All rights reserved.

  17. Deletion of interleukin 1 receptor-associated kinase 1 (Irak1) improves glucose tolerance primarily by increasing insulin sensitivity in skeletal muscle.

    Science.gov (United States)

    Sun, Xiao-Jian; Kim, Soohyun Park; Zhang, Dongming; Sun, Helen; Cao, Qi; Lu, Xin; Ying, Zhekang; Li, Liwu; Henry, Robert R; Ciaraldi, Theodore P; Taylor, Simeon I; Quon, Michael J

    2017-07-21

    Chronic inflammation may contribute to insulin resistance via molecular cross-talk between pathways for pro-inflammatory and insulin signaling. Interleukin 1 receptor-associated kinase 1 (IRAK-1) mediates pro-inflammatory signaling via IL-1 receptor/Toll-like receptors, which may contribute to insulin resistance, but this hypothesis is untested. Here, we used male Irak1 null (k/o) mice to investigate the metabolic role of IRAK-1. C57BL/6 wild-type (WT) and k/o mice had comparable body weights on low-fat and high-fat diets (LFD and HFD, respectively). After 12 weeks on LFD (but not HFD), k/o mice ( versus WT) had substantially improved glucose tolerance (assessed by the intraperitoneal glucose tolerance test (IPGTT)). As assessed with the hyperinsulinemic euglycemic glucose clamp technique, insulin sensitivity was 30% higher in the Irak1 k/o mice on chow diet, but the Irak1 deletion did not affect IPGTT outcomes in mice on HFD, suggesting that the deletion did not overcome the impact of obesity on glucose tolerance. Moreover, insulin-stimulated glucose-disposal rates were higher in the k/o mice, but we detected no significant difference in hepatic glucose production rates (± insulin infusion). Positron emission/computed tomography scans indicated higher insulin-stimulated glucose uptake in muscle, but not liver, in Irak1 k/o mice in vivo Moreover, insulin-stimulated phosphorylation of Akt was higher in muscle, but not in liver, from Irak1 k/o mice ex vivo In conclusion, Irak1 deletion improved muscle insulin sensitivity, with the effect being most apparent in LFD mice. © 2017 by The American Society for Biochemistry and Molecular Biology, Inc.

  18. Establishment of EMab-134, a Sensitive and Specific Anti-Epidermal Growth Factor Receptor Monoclonal Antibody for Detecting Squamous Cell Carcinoma Cells of the Oral Cavity.

    Science.gov (United States)

    Itai, Shunsuke; Yamada, Shinji; Kaneko, Mika K; Chang, Yao-Wen; Harada, Hiroyuki; Kato, Yukinari

    2017-12-01

    Epidermal growth factor receptor (EGFR), a receptor tyrosine kinase, activates downstream signaling cascades in many tumors. In this study, we established novel anti-EGFR monoclonal antibodies (mAbs) and characterized their efficacy in flow cytometry, Western blot, and immunohistochemical analyses. We immunized mice with a combination of the extracellular domain of EGFR and EGFR-overexpressing LN229 glioblastoma cells (LN229/EGFR) and performed the first screening using enzyme-linked immunosorbent assay. Next, we selected mAbs using flow cytometry. Among 156 established clones, two mAbs, EMab-51 (IgG 1 , kappa) and EMab-134 (IgG 1 , kappa), reacted with EGFR in Western blot analysis; EMab-134 showed a much higher sensitivity compared with EMab-51. We compared the binding affinities of EMab-51 and EMab-134 using flow cytometry; the calculated K D values for EMab-51 and EMab-134 against SAS cells/HSC-2 cells were 9.2 × 10 -9 M/9.9 × 10 -9 M and 2.6 × 10 -9 M/8.3 × 10 -9 M, respectively, indicating that EMab-134 has a higher affinity to EGFR-expressing cells. Immunohistochemical analysis of EMab-51 and EMab-134 showed sensitive and specific reactions against oral cancer cells; EMab-134 demonstrated a much higher sensitivity (36/38 cases; 94.7%) to oral squamous cell carcinomas compared with EMab-51 (6/38 cases; 15.8%). This novel anti-EGFR mAb, EMab-134, could be advantageous for detecting EGFR in the pathological analysis of EGFR-expressing cancers.

  19. Rapid Estrogen Receptor-Mediated Mechanisms Determine the Sexually Dimorphic Sensitivity of Ventricular Myocytes to 17β-Estradiol and the Environmental Endocrine Disruptor Bisphenol A

    Science.gov (United States)

    Belcher, Scott M.; Chen, Yamei; Yan, Sujuan

    2012-01-01

    Previously we showed that 17β-estradiol (E2) and/or the xenoestrogen bisphenol A (BPA) alter ventricular myocyte Ca2+ handing, resulting in increased cardiac arrhythmias in a female-specific manner. In the present study, the roles of estrogen receptors (ER) in mediating the rapid contractile and arrhythmogenic effects of estrogens were examined. Contractility was used as an index to assess the impact of E2 or BPA on Ca2+ handling in rodent ventricular myocytes. The concentration-response curve for the stimulatory effects of BPA and E2 on female myocyte was inverted-U shaped. Detectable effects for each compound were observed at 10−12 m, and the most efficacious concentrations for each were at 10−9 m. Sensitivity to E2 and BPA was not observed in male myocytes and was abolished in myocytes from ovariectomized females. Analysis using protein-conjugated E2 suggests that these rapid actions are induced by membrane-associated receptors. Analysis using selective ER agonists and antagonists and a genetic ERβ knockout mouse model showed that ERα and ERβ have opposing actions in myocytes and that the balance between ERβ and ERα signaling is the prime regulator of the sex-specific sensitivity toward estrogens. The response of female myocytes to E2 and BPA is dominated by the stimulatory ERβ-mediated signaling, and the absence of BPA and E2 responsiveness in males is due to a counterbalancing-suppressive action of ERα. We conclude that the sex-specific sensitivity of myocytes to estrogens and the rapid arrhythmogenic effects of BPA and estradiol in the female heart are regulated by the balance between ERα and ERβ signaling. PMID:22166976

  20. Identification of contact and respiratory sensitizers according to IL-4 receptor α expression and IL-2 production

    Energy Technology Data Exchange (ETDEWEB)

    Goutet, Michèle, E-mail: michele.goutet@inrs.fr; Pépin, Elsa; Langonné, Isabelle; Huguet, Nelly; Ban, Masarin

    2012-04-15

    Identification of allergenic chemicals is an important occupational safety issue. While several methods exist to identify contact sensitizers, there is currently no validated model to predict the potential of chemicals to act as respiratory sensitizers. Previously, we reported that cytometry analysis of the local immune responses induced in mice dermally exposed to the respiratory sensitizer trimellitic anhydride (TMA 10%) and contact sensitizer dinitrochlorobenzene (DNCB 1%) could identify divergent expression of several immune parameters. The present study confirms, first, that IgE-positive B cells, MHC class II molecules, interleukin (IL)-2, IL-4 and IL-4Rα can differentiate the allergic reactions caused by high doses of strong respiratory (TMA, phthalic anhydride and toluene diisocyanate) and contact sensitizers (DNCB, dinitrofluorobenzene and oxazolone). The second part of the study was designed to test the robustness of these markers when classing the weakly immunogenic chemicals most often encountered. Six respiratory allergens, including TMA (2.5%), five contact allergens, including DNCB (0.25%), and two irritants were compared at doses of equivalent immunogenicity. The results indicated that IL-4Rα and IL-2 can be reliably used to discriminate sensitizers. Respiratory sensitizers induced markedly higher IL-4Rα levels than contact allergens, while irritants had no effect on this parameter. Inversely, contact allergens tended to induce higher percentages of IL-2{sup +}CD8{sup +} cells than respiratory allergens. In contrast, the markers MHC-II, IgE and IL-4 were not able to classify chemicals with low immunogenic potential. In conclusion, IL-4Rα and IL-2 have the potential to be used in classifying a variety of chemical allergens. -- Highlights: ► Identification of chemical allergens is an important occupational safety issue. ► There is currently no model to predict the potential of chemicals to induce asthma. ► We analyze immune responses induced

  1. Identification of contact and respiratory sensitizers according to IL-4 receptor α expression and IL-2 production

    International Nuclear Information System (INIS)

    Goutet, Michèle; Pépin, Elsa; Langonné, Isabelle; Huguet, Nelly; Ban, Masarin

    2012-01-01

    Identification of allergenic chemicals is an important occupational safety issue. While several methods exist to identify contact sensitizers, there is currently no validated model to predict the potential of chemicals to act as respiratory sensitizers. Previously, we reported that cytometry analysis of the local immune responses induced in mice dermally exposed to the respiratory sensitizer trimellitic anhydride (TMA 10%) and contact sensitizer dinitrochlorobenzene (DNCB 1%) could identify divergent expression of several immune parameters. The present study confirms, first, that IgE-positive B cells, MHC class II molecules, interleukin (IL)-2, IL-4 and IL-4Rα can differentiate the allergic reactions caused by high doses of strong respiratory (TMA, phthalic anhydride and toluene diisocyanate) and contact sensitizers (DNCB, dinitrofluorobenzene and oxazolone). The second part of the study was designed to test the robustness of these markers when classing the weakly immunogenic chemicals most often encountered. Six respiratory allergens, including TMA (2.5%), five contact allergens, including DNCB (0.25%), and two irritants were compared at doses of equivalent immunogenicity. The results indicated that IL-4Rα and IL-2 can be reliably used to discriminate sensitizers. Respiratory sensitizers induced markedly higher IL-4Rα levels than contact allergens, while irritants had no effect on this parameter. Inversely, contact allergens tended to induce higher percentages of IL-2 + CD8 + cells than respiratory allergens. In contrast, the markers MHC-II, IgE and IL-4 were not able to classify chemicals with low immunogenic potential. In conclusion, IL-4Rα and IL-2 have the potential to be used in classifying a variety of chemical allergens. -- Highlights: ► Identification of chemical allergens is an important occupational safety issue. ► There is currently no model to predict the potential of chemicals to induce asthma. ► We analyze immune responses induced in mice

  2. Bidirectional modulation of hippocampal gamma (20-80 Hz) frequency activity in vitro via alpha(α)- and beta(β)-adrenergic receptors (AR).

    Science.gov (United States)

    Haggerty, D C; Glykos, V; Adams, N E; Lebeau, F E N

    2013-12-03

    Noradrenaline (NA) in the hippocampus plays an important role in memory function and has been shown to modulate different forms of synaptic plasticity. Oscillations in the gamma frequency (20-80 Hz) band in the hippocampus have also been proposed to play an important role in memory functions and, evidence from both in vitro and in vivo studies, has suggested this activity can be modulated by NA. However, the role of different NA receptor subtypes in the modulation of gamma frequency activity has not been fully elucidated. We have found that NA (30 μM) exerts a bidirectional control on the magnitude of kainate-evoked (50-200 nM) gamma frequency oscillations in the cornu Ammonis (CA3) region of the rat hippocampus in vitro via activation of different receptor subtypes. Activation of alpha-adrenergic receptors (α-AR) reduced the power of the gamma frequency oscillation. In contrast, activation of beta-adrenergic receptors (β-AR) caused an increase in the power of the gamma frequency oscillations. Using specific agonists and antagonists of AR receptor subtypes we demonstrated that these effects are mediated specifically via α1A-AR and β1-AR subtypes. NA activated both receptor subtypes, but the α1A-AR-mediated effect predominated, resulting in a reversible suppression of gamma frequency activity. These results suggest that NA is able to differentially modulate on-going gamma frequency oscillatory activity that could result in either increased or decreased information flow through the hippocampus. Copyright © 2013 IBRO. Published by Elsevier Ltd. All rights reserved.

  3. β2-Adrenergic receptor activation mobilizes intracellular calcium via a non-canonical cAMP-independent signaling pathway.

    Science.gov (United States)

    Galaz-Montoya, Monica; Wright, Sara J; Rodriguez, Gustavo J; Lichtarge, Olivier; Wensel, Theodore G

    2017-06-16

    Beta adrenergic receptors (βARs) are G-protein-coupled receptors essential for physiological responses to the hormones/neurotransmitters epinephrine and norepinephrine which are found in the nervous system and throughout the body. They are the targets of numerous widely used drugs, especially in the case of the most extensively studied βAR, β 2 AR, whose ligands are used for asthma and cardiovascular disease. βARs signal through Gα s G-proteins and via activation of adenylyl cyclase and cAMP-dependent protein kinase, but some alternative downstream pathways have also been proposed that could be important for understanding normal physiological functioning of βAR signaling and its disruption in disease. Using fluorescence-based Ca 2+ flux assays combined with pharmacology and gene knock-out methods, we discovered a previously unrecognized endogenous pathway in HEK-293 cells whereby β 2 AR activation leads to robust Ca 2+ mobilization from intracellular stores via activation of phospholipase C and opening of inositol trisphosphate (InsP 3 ) receptors. This pathway did not involve cAMP, Gα s , or Gα i or the participation of the other members of the canonical β 2 AR signaling cascade and, therefore, constitutes a novel signaling mechanism for this receptor. This newly uncovered mechanism for Ca 2+ mobilization by β 2 AR has broad implications for adrenergic signaling, cross-talk with other signaling pathways, and the effects of βAR-directed drugs. © 2017 by The American Society for Biochemistry and Molecular Biology, Inc.

  4. Fear Memory Recall Potentiates Opiate Reward Sensitivity through Dissociable Dopamine D1 vs. D4 Receptor-Dependent Memory Mechanisms in the Prefrontal Cortex.

    Science.gov (United States)

    Li, Jing Jing; Szkudlarek, Hanna; Renard, Justine; Hudson, Roger; Rushlow, Walter; Laviolette, Steven R

    2018-04-23

    Disturbances in prefrontal cortical (PFC) dopamine (DA) transmission are well-established features of psychiatric disorders involving pathological memory processing, such as post-traumatic stress disorder (PTSD) and opioid addiction. Transmission through PFC DA D4 receptors (D4R) has been shown to potentiate the emotional salience of normally non-salient emotional memories whereas transmission through PFC DA D1 receptors (D1R) has been demonstrated to selectively block recall of reward or aversion-related associative memories. In the present study, using a combination of fear conditioning and opiate reward conditioning in male rats, we examined the role of PFC D4/D1R signaling during the processing of fear-related memory acquisition and recall and subsequent sensitivity to opiate reward memory formation. We report that PFC D4R activation potentiates the salience of normally sub-threshold fear conditioning memory cues and simultaneously potentiates the rewarding effects of systemic or intra-ventral tegmental area (VTA) morphine conditioning cues. In contrast, blocking the recall of salient fear memories with intra-PFC D1R activation, blocks the ability of fear memory recall to potentiate systemic or intra-VTA morphine place preference. These effects were dependent upon dissociable PFC phosphorylation states involving calcium-calmodulin-kinase II (CaMKII-α) or extracellular-signal-related-kinase 1-2 (ERK 1/2), following intra-PFC D4 or D1R activation, respectively. Together, these findings reveal new insights into how aberrant PFC DAergic transmission and associated downstream molecular signaling pathways may modulate fear-related emotional memory processing and concomitantly increase opioid addiction vulnerability. Significance Statement: Post-traumatic stress disorder is highly comorbid with addiction. In this study, we use a translational model of fear memory conditioning to examine how transmission through dopamine D1 or D4 receptors, in the prefrontal cortex

  5. Seasonal dynamics of chemokine receptors and CD62L in subjects with asymptomatic skin sensitization to birch and grass pollen

    DEFF Research Database (Denmark)

    Assing, K; Bødtger, Uffe; Poulsen, L K

    2006-01-01

    BACKGROUND: Asymptomatic skin sensitization (AS) has been shown to be a risk factor for respiratory allergic disease. CCR4, CXCR1 and CD62L have all been assigned a role in the immunopathogenesis of allergy. Memory T-cell expression of CCR4, CXCR1 and CD62L has not hitherto been investigated in s...

  6. Chronically Restricted Sleep Leads to Depression-Like Changes in Neurotransmitter Receptor Sensitivity and Neuroendocrine Stress Reactivity in Rats

    NARCIS (Netherlands)

    Novati, Arianna; Roman, Viktor; Cetin, Timur; Hagewoud, Roelina; den Boer, Johan A.; Luiten, Paul G.M.; Meerlo, Peter

    2008-01-01

    Study Objectives: Frequently disrupted and restricted sleep is a common problem for many people in our Western society. In the long run, insufficient sleep may have repercussions for health and may sensitize individuals to psychiatric diseases. In this context, we applied an animal model of chronic

  7. Two different avian cold-sensitive sensory neurons: Transient receptor potential melastatin 8 (TRPM8)-dependent and -independent activation mechanisms.

    Science.gov (United States)

    Yamamoto, A; Takahashi, K; Saito, S; Tominaga, M; Ohta, T

    2016-12-01

    Sensing the ambient temperature is an important function for survival in animals. Some TRP channels play important roles as detectors of temperature and irritating chemicals. There are functional differences of TRP channels among species. TRPM8 in mammals is activated by cooling compounds and cold temperature, but less information is available on the functional role of TRPM8 in avian species. Here we investigated the pharmacological properties and thermal sensitivities of chicken TRPM8 (cTRPM8) and cold-sensitive mechanisms in avian sensory neurons. In heterologously expressed cTRPM8, menthol and its derivative, WS-12 elicited [Ca 2+ ] i increases, but icilin did not. In chicken sensory neurons, icilin increased [Ca 2+ ] i, in a TRPA1-dependent manner. Icilin selectively stimulated heterologously expressed chicken TRPA1 (cTRPA1). Similar to mammalian orthologue, cTRPM8 was activated by cold. Both heterologous and endogenous expressed cTRPM8 were sensitive to mammalian TRPM8 antagonists. There are two types of cold-sensitive cells regarding menthol sensitivity in chicken sensory neurons. The temperature threshold of menthol-insensitive neurons was significantly lower than that of menthol-sensitive ones. The population of menthol-insensitive neurons was large in chicken but almost little in mammals. The cold-induced [Ca 2+ ] i increases were not abolished by the external Ca 2+ removal or by blockades of PLC-IP 3 pathways and ryanodine channels. The cold stimulation failed to evoke [Ca 2+ ] i increases after intracellular Ca 2+ store-depletion. These results indicate that cTRPM8 acts as a cold-sensor similar to mammals. It is noteworthy that TRPM8-independent cold-sensitive neurons are abundant in chicken sensory neurons. Our results suggest that most of the cold-induced [Ca 2+ ] i increases are mediated via Ca 2+ release from intracellular stores and that these mechanisms may be specific to avian species. Copyright © 2016 Elsevier Ltd. All rights reserved.

  8. Mice expressing a "hyper-sensitive" form of the CB1 cannabinoid receptor (CB1 show modestly enhanced alcohol preference and consumption.

    Directory of Open Access Journals (Sweden)

    David J Marcus

    Full Text Available We recently characterized S426A/S430A mutant mice expressing a desensitization-resistant form of the CB1 receptor. These mice display an enhanced response to endocannabinoids and ∆9-THC. In this study, S426A/S430A mutants were used as a novel model to test whether ethanol consumption, morphine dependence, and reward for these drugs are potentiated in mice with a "hyper-sensitive" form of CB1. Using an unlimited-access, two-bottle choice, voluntary drinking paradigm, S426A/S430A mutants exhibit modestly increased intake and preference for low (6% but not higher concentrations of ethanol. S426A/S430A mutants and wild-type mice show similar taste preference for sucrose and quinine, exhibit normal sensitivity to the hypothermic and ataxic effects of ethanol, and have normal blood ethanol concentrations following administration of ethanol. S426A/S430A mutants develop robust conditioned place preference for ethanol (2 g/kg, morphine (10 mg/kg, and cocaine (10 mg/kg, demonstrating that drug reward is not changed in S426A/S430A mutants. Precipitated morphine withdrawal is also unchanged in opioid-dependent S426A/S430A mutant mice. Although ethanol consumption is modestly changed by enhanced CB1 signaling, reward, tolerance, and acute sensitivity to ethanol and morphine are normal in this model.

  9. Point mutation of a conserved aspartate, D69, in the muscarinic M2 receptor does not modify voltage-sensitive agonist potency.

    Science.gov (United States)

    Ågren, Richard; Sahlholm, Kristoffer; Nilsson, Johanna; Århem, Peter

    2018-01-29

    The muscarinic M 2 receptor (M 2 R) has been shown to display voltage-sensitive agonist binding, based on G protein-activated inward rectifier potassium channel (GIRK) opening and radioligand binding at different membrane voltages. A conserved aspartate in transmembrane segment (TM) II of M 2 R, D69, has been proposed as the voltage sensor. While a recent paper instead presented evidence of tyrosines in TMs III, VI, and VII acting as voltage sensors, these authors were not able to record GIRK channel activation by a D69N mutant M 2 R. In the present study, we succeeded in recording ACh-induced GIRK channel activation by this mutant at -80 and 0 mV. The acetylcholine EC 50 was about 2.5-fold higher at 0 mV, a potency shift very similar to that observed at wild-type M 2 R, indicating that voltage sensitivity persists at the D69N mutant. Thus, our present observations corroborate the notion that D69 is not responsible for voltage sensitivity of the M 2 R. Copyright © 2018 Elsevier Inc. All rights reserved.

  10. Women with multiple chemical sensitivity have increased harm avoidance and reduced 5-HT(1A receptor binding potential in the anterior cingulate and amygdala.

    Directory of Open Access Journals (Sweden)

    Lena Hillert

    Full Text Available Multiple chemical sensitivity (MCS is a common condition, characterized by somatic distress upon exposure to odors. As in other idiopathic environmental intolerances, the underlying mechanisms are unknown. Contrary to the expectations it was recently found that persons with MCS activate the odor-processing brain regions less than controls, while their activation of the anterior cingulate cortex (ACC is increased. The present follow-up study was designed to test the hypotheses that MCS subjects have increased harm avoidance and deviations in the serotonin system, which could render them intolerant to environmental odors. Twelve MCS and 11 control subjects, age 22-44, all working or studying females, were included in a PET study where 5-HT(1A receptor binding potential (BP was assessed after bolus injection of [(11C]WAY100635. Psychological profiles were assessed by the Temperament and Character Inventory and the Swedish universities Scales of Personality. All MCS and 12 control subjects were also tested for emotional startle modulation in an acoustic startle test. MCS subjects exhibited significantly increased harm avoidance, and anxiety compared to controls. They also had a reduced 5-HT(1A receptor BP in amygdala (p = 0.029, ACC (p = 0.005 (planned comparisons, significance level 0.05, and insular cortex (p = 0.003; significance level p<0.005 with Bonferroni correction, and showed an inverse correlation between degree of anxiety and the BP in the amygdala (planned comparison. No group by emotional category difference was found in the startle test. Increased harm avoidance and the observed changes in the 5-HT(1A receptor BP in the regions processing harm avoidance provides a plausible pathophysiological ground for the symptoms described in MCS, and yields valuable information for our general understanding of idiopathic environmental intolerances.

  11. ( sup 125 I)Ifenprodil: a convenient radioligand for binding and autoradiographic studies of the polyamine-sensitive site of the NMDA receptor

    Energy Technology Data Exchange (ETDEWEB)

    Beart, P M; Mercer, L D; Jarrott, B [University of Melbourne, Clinical Pharmacology and Therapeutics Unit, Austin Hospital, Heidelberg, Vic (Australia)

    1991-04-01

    Iodination of ifenprodil, a non-competitive NMDA antagonist, with Na{sup 125}I/Chloramin-T gave a radioligand which bound rapidly and saturably to a single population of sites (dissociation constant 145 nM) in membranes of rat cerebral cortex. In competition studies, specific binding of ({sup 125}I)-ifenprodil was inhibited by analogues of ifenprodil, as well as by spermine and spermidine. Binding was sensitive to Ca{sup 2+}, Mg{sup 2+} and Zn{sup 2+}. ({sup 125}I)-Ifenprodil labelled a population of binding sites, which was topographically distributed in rat forebrain, as shown by autoradiography. ({sup 125}I)-Ifenprodil is a useful radioligand for the investigation of the polyamine site of the N-methyl-D-aspartate (NMDA) receptor-complex. (author).

  12. Overexpression of an Arabidopsis cysteine-rich receptor-like protein kinase, CRK5, enhances abscisic acid sensitivity and confers drought tolerance

    Science.gov (United States)

    Lu, Kai; Liang, Shan; Wu, Zhen; Bi, Chao; Yu, Yong-Tao; Wang, Xiao-Fang; Zhang, Da-Peng

    2016-01-01

    Receptor-like kinases (RLKs) have been reported to regulate many developmental and defense process, but only a few members have been functionally characterized. In the present study, our observations suggest that one of the RLKs, a membrane-localized cysteine-rich receptor-like protein kinase, CRK5, is involved in abscisic acid (ABA) signaling in Arabidopsis thaliana. Overexpression of CRK5 increases ABA sensitivity in ABA-induced early seedling growth arrest and promotion of stomatal closure and inhibition of stomatal opening. Interestingly, and importantly, overexpression of CRK5 enhances plant drought tolerance without affecting plant growth at the mature stages and plant productivity. Transgenic lines overexpressing a mutated form of CRK5, CRK5 K372E with the change of the 372nd conserved amino acid residue from lysine to glutamic acid in its kinase domain, result in wild-type ABA and drought responses, supporting the role of CRK5 in ABA signaling. The loss-of-function mutation of the CRK5 gene does not affect the ABA response, while overexpression of two homologs of CRK5, CRK4 and CRK19, confers ABA responses, suggesting that these CRK members function redundantly. We further showed that WRKY18, WRKY40 and WRKY60 transcription factors repress the expression of CRK5, and that CRK5 likely functions upstream of ABI2 in ABA signaling. These findings help in understanding the complex ABA signaling network. PMID:27406784

  13. Quantitation of alpha 1-adrenergic receptors in porcine uterine and mesenteric arteries

    International Nuclear Information System (INIS)

    Farley, D.B.; Ford, S.P.; Reynolds, L.P.; Bhatnagar, R.K.; Van Orden, D.E.

    1984-01-01

    The activation of vascular alpha-adrenergic receptors may be involved in the control of uterine blood flow. A radioligand binding assay with the use of the alpha 1-adrenergic antagonist 3 H-WB-4101 was established to characterize the alpha-adrenergic receptors in uterine and mesenteric arterial membranes obtained from nonpregnant pigs. Specific binding of 3 H-WB-4101 was rapid, saturable, and exhibited the alpha-adrenergic agonist potency order of (-)-epinephrine inhibition constant [Ki] . 0.6 mumol/L greater than (-)-norepinephrine (Ki . 1.5 mumol/L) much greater than (-)-isoproterenol (Ki . 120 mumol/L). The alpha-adrenergic antagonist phentolamine (Ki . 6.0 nmol/L) was 200 times more potent than the beta-adrenergic antagonist (+/-)-propranolol (Ki . 1,200 nmol/L); the alpha 1-selective antagonist prazosin (Ki . 1.2 nmol/L) was 130 times more potent than the alpha 2-selective antagonist yohimbine (Ki . 160 nmol/L). Scatchard analysis, as well as iterative curve-fitting analysis, demonstrated that 3 H-WB-4101 binding by arterial membranes was to a single class of binding sites. Uterine arteries exhibited greater maximal binding capacity (BMax) than that of mesenteric arteries (47.5 +/- 3.2 versus 30.9 +/- 3.6 fmol per milligram of protein, p less than 0.01), but the uterine artery dissociation constant (Kd) was higher, thus indicating a lower affinity, when compared with mesenteric artery (0.43 +/- 0.04 versus 0.33 +/- 0.04 nmol/L, p less than 0.05)

  14. pectorIs of labetalol in with angina Beneficial effect hypertensive ...

    African Journals Online (AJOL)

    1983-01-15

    Jan 15, 1983 ... The treatment of angina pectoris in patients with arterial hyper- ..... An alternative mechanism whereby labetalol may reduce angina pectoris is .... alpha and beta adrenergic receptor blockade on myocardial cell necrosis after.

  15. Incidence of radiation-induced Graves' disease in patients treated with radioiodine for thyroid autonomy before and after introduction of a high-sensitivity TSH receptor antibody assay

    International Nuclear Information System (INIS)

    Dunkelmann, Simone; Wolf, Ricarda; Koch, Annedore; Kittner, Christian; Groth, Peter; Schuemichen, Carl

    2004-01-01

    Autoimmune hyperthyroidism may occur several months after radioiodine therapy (RIT) for functional thyroid autonomy. Exacerbation of pre-existing subclinical Graves' disease (GD) has been held responsible for this phenomenon. Determination of TSH receptor antibody using solubilised porcine epithelial cell membranes is insensitive and may have failed to diagnose GD in these patients before RIT. Following the introduction of a more sensitive assay, using the human TSH receptor as an antigen, it has been expected that the incidence of radiation-induced GD after RIT for functional thyroid autonomy will be reduced. In a first group of 1,428 patients treated between November 1993 and March 1997 (group I) we used the porcine TRAb assay to exclude GD, while in a second group comprising 1,408 patients treated between January 2000 and December 2001 (group II), GD was excluded using the human TRAb assay. A matched control group of 231 patients was derived from group II. In group I a total of 15 (1.05%) patients developed obvious or suspected radiation-induced GD, while in group II 17 (1.2%) did so; the interval until development of GD was 8.4 and 8.8 months, respectively, after RIT. Serum anti-thyroid peroxidase levels before RIT were elevated in 36.4% of group I patients and 47.1% of group II patients, but in only 5.6% of the control group. Other non-specific signs of mild immunopathy of the thyroid were seen retrospectively in 73.3%, 64.7% and 16.0% of the patients in these three groups, respectively. In conclusion, the introduction of a high-sensitivity TRAb assay did not reduce the incidence of autoimmune hyperthyroidism occurring late after RIT for functional thyroid autonomy, but mild immunopathy of the thyroid is seen more frequently in these patients and seems to be a predisposing factor in the development of radiation-induced GD. (orig.)

  16. Pertussis toxin-sensitive G-protein mediates the alpha 2-adrenergic receptor inhibition of melatonin release in photoreceptive chick pineal cell cultures

    International Nuclear Information System (INIS)

    Pratt, B.L.; Takahashi, J.S.

    1988-01-01

    The avian pineal gland is a photoreceptive organ that has been shown to contain postjunctional alpha 2-adrenoceptors that inhibit melatonin synthesis and/or release upon receptor activation. Physiological response and [32P]ADP ribosylation experiments were performed to investigate whether pertussis toxin-sensitive guanine nucleotide-binding proteins (G-proteins) were involved in the transduction of the alpha 2-adrenergic signal. For physiological response studies, the effects of pertussis toxin on melatonin release in dissociated cell cultures exposed to norepinephrine were assessed. Pertussis toxin blocked alpha 2-adrenergic receptor-mediated inhibition in a dose-dependent manner. Pertussis toxin-induced blockade appeared to be noncompetitive. One and 10 ng/ml doses of pertussis toxin partially blocked and a 100 ng/ml dose completely blocked norepinephrine-induced inhibition. Pertussis toxin-catalyzed [32P]ADP ribosylation of G-proteins in chick pineal cell membranes was assessed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and autoradiography. Membranes were prepared from cells that had been pretreated with 0, 1, 10, or 100 ng/ml pertussis toxin. In the absence of pertussis toxin pretreatment, two major proteins of 40K and 41K mol wt (Mr) were labeled by [32P]NAD. Pertussis toxin pretreatment of pineal cells abolished [32P] radiolabeling of the 40K Mr G-protein in a dose-dependent manner. The norepinephrine-induced inhibition of both cAMP efflux and melatonin release, as assessed by RIA of medium samples collected before membrane preparation, was also blocked in a dose-dependent manner by pertussis toxin. Collectively, these results suggest that a pertussis toxin-sensitive 40K Mr G-protein labeled by [32P]NAD may be functionally associated with alpha 2-adrenergic signal transduction in chick pineal cells

  17. Cardiac Function in Patients with Early Cirrhosis during Maximal Beta-Adrenergic Drive

    DEFF Research Database (Denmark)

    Krag, Aleksander; Bendtsen, Flemming; Dahl, Emilie Kristine

    2014-01-01

    BACKGROUND AND AIM: Cardiac dysfunction in patients with early cirrhosis is debated. We investigated potential cardiac dysfunction by assessing left ventricular systolic performance during a dobutamine stress test in patients with early cirrhosis. PATIENTS AND METHODS: Nineteen patients with Chil...

  18. Mapping genetic variants associated with beta-adrenergic responses in inbred mice.

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    Micha Hersch

    Full Text Available β-blockers and β-agonists are primarily used to treat cardiovascular diseases. Inter-individual variability in response to both drug classes is well recognized, yet the identity and relative contribution of the genetic players involved are poorly understood. This work is the first genome-wide association study (GWAS addressing the values and susceptibility of cardiovascular-related traits to a selective β(1-blocker, Atenolol (ate, and a β-agonist, Isoproterenol (iso. The phenotypic dataset consisted of 27 highly heritable traits, each measured across 22 inbred mouse strains and four pharmacological conditions. The genotypic panel comprised 79922 informative SNPs of the mouse HapMap resource. Associations were mapped by Efficient Mixed Model Association (EMMA, a method that corrects for the population structure and genetic relatedness of the various strains. A total of 205 separate genome-wide scans were analyzed. The most significant hits include three candidate loci related to cardiac and body weight, three loci for electrocardiographic (ECG values, two loci for the susceptibility of atrial weight index to iso, four loci for the susceptibility of systolic blood pressure (SBP to perturbations of the β-adrenergic system, and one locus for the responsiveness of QTc (p<10(-8. An additional 60 loci were suggestive for one or the other of the 27 traits, while 46 others were suggestive for one or the other drug effects (p<10(-6. Most hits tagged unexpected regions, yet at least two loci for the susceptibility of SBP to β-adrenergic drugs pointed at members of the hypothalamic-pituitary-thyroid axis. Loci for cardiac-related traits were preferentially enriched in genes expressed in the heart, while 23% of the testable loci were replicated with datasets of the Mouse Phenome Database (MPD. Altogether these data and validation tests indicate that the mapped loci are relevant to the traits and responses studied.

  19. Severe hyperkalemia as a complication of timolol, a topically applied beta-adrenergic antagonist

    International Nuclear Information System (INIS)

    Swenson, E.R.

    1986-01-01

    Severe hyperkalemia occurred in a patient with radiation pneumonitis and glaucoma shortly after beginning prednisone therapy. There was no evidence of renal failure, diabetes, acidosis, increased potassium intake, or significant tissue trauma. Medications having adverse effects on potassium metabolism were considered, and the patient's use of timolol maleate eyedrops was discontinued. His serum potassium level normalized despite continuation of the prednisone therapy. He became hyperkalemic on rechallenge with timolol and normokalemic following its withdrawal. This case indicates that the potential for beta-blocker-induced hyperkalemia exists even with topical appreciation

  20. Cerebral oxygenation decreases during exercise in humans with beta-adrenergic blockade

    DEFF Research Database (Denmark)

    Seifert, T.; Rasmussen, P.; Secher, Niels H.

    2009-01-01

    AIM: Beta-blockers reduce exercise capacity by attenuated increase in cardiac output, but it remains unknown whether performance also relates to attenuated cerebral oxygenation. METHODS: Acting as their own controls, eight healthy subjects performed a continuous incremental cycle test to exhaustion...... attenuated the increase in cardiac output of consequence for cerebral perfusion and oxygenation. We suggest that a decrease in cerebral oxygenation limits exercise capacity Udgivelsesdato: 2009/7...... with or without administration of the non-selective beta-blocker propranolol. Changes in cerebral blood flow velocity were measured with transcranial Doppler ultrasound and those in cerebral oxygenation were evaluated using near-infrared spectroscopy and the calculated cerebral mitochondrial oxygen tension...

  1. Oxidation of nutrients in bull calves treated with beta-adrenergic agonists

    DEFF Research Database (Denmark)

    Chwalibog, André; Jensen, K; Thorbek, G

    1996-01-01

    Oxidation of protein (OXP), carbohydrate (OXCHO) and fat (OXF) was investigated with 12 growing bulls treated with beta-agonist (L-644, 969) during two 6 weeks trials (Section A and B) at a mean live weight of 195 and 335 kg. Heat production and nutrient oxidation was calculated from gas exchange...

  2. Quantitative protein and fat metabolism in bull calves treated with beta-adrenergic agonist

    DEFF Research Database (Denmark)

    Chwalibog, André; Jensen, K; Thorbek, G

    1996-01-01

    Protein and energy utilization and quantitative retention of protein, fat and energy was investigated with 12 Red Danish bulls during two subsequent 6 weeks trials (Sections A and B) at a mean live weight of 195 and 335 kg respectively. Treatments were control (Group 1) and beta-agonist (L-644...... matter, metabolizable energy and digestible protein was of the same magnitude for all groups. The beta-agonist had no significant effect on protein digestibility and metabolizability of energy, but daily live weight gain was significantly higher in the treated bulls. The utilization of digested protein...

  3. Maintained cerebral metabolic ratio during exercise in patients with beta-adrenergic blockade

    DEFF Research Database (Denmark)

    Gam, Christiane M B; Rasmussen, Peter; Secher, Niels H

    2009-01-01

    patients in oral treatment with propranolol are able to mobilize brain non-oxidative carbohydrate metabolism. METHODS: Incremental cycle ergometry to exhaustion (86 +/- 4.2 W; mean +/- SD) was performed in eight cirrhotic patients instrumented with a catheter in the brachial artery and one retrograde...... in the right internal jugular vein. Healthy subjects form the control group. RESULTS: In beta-blocked cirrhotic patients arterial lactate increased from 1.5 +/- 0.3 to 5.1 +/- 0.8 mM (Pdifference (a-v diff) from -0.01 +/- 0.03 to 0.30 +/- 0.05 mM (P

  4. Functional α7β2 nicotinic acetylcholine receptors expressed in hippocampal interneurons exhibit high sensitivity to pathological level of amyloid β peptides

    Directory of Open Access Journals (Sweden)

    Liu Qiang

    2012-12-01

    Full Text Available Abstract Background β-amyloid (Aβ accumulation is described as a hallmark of Alzheimer’s disease (AD. Aβ perturbs a number of synaptic components including nicotinic acetylcholine receptors containing α7 subunits (α7-nAChRs, which are abundantly expressed in the hippocampus and found on GABAergic interneurons. We have previously demonstrated the existence of a novel, heteromeric α7β2-nAChR in basal forebrain cholinergic neurons that exhibits high sensitivity to acute Aβ exposure. To extend our previous work, we evaluated the expression and pharmacology of α7β2-nAChRs in hippocampal interneurons and their sensitivity to Aβ. Results GABAergic interneurons in the CA1 subregion of the hippocampus expressed functional α7β2-nAChRs, which were characterized by relatively slow whole-cell current kinetics, pharmacological sensitivity to dihydro-β-erythroidine (DHβE, a nAChR β2* subunit selective blocker, and α7 and β2 subunit interaction using immunoprecipitation assay. In addition, α7β2-nAChRs were sensitive to 1 nM oligomeric Aβ. Similar effects were observed in identified hippocampal interneurons prepared from GFP-GAD mice. Conclusion These findings suggest that Aβ modulation of cholinergic signaling in hippocampal GABAergic interneurons via α7β2-nAChRs could be an early and critical event in Aβ-induced functional abnormalities of hippocampal function, which may be relevant to learning and memory deficits in AD.

  5. Bilirubin Increases Insulin Sensitivity in Leptin-Receptor Deficient and Diet-Induced Obese Mice Through Suppression of ER Stress and Chronic Inflammation

    Science.gov (United States)

    Dong, Huansheng; Huang, Hu; Yun, Xinxu; Kim, Do-sung; Yue, Yinan; Wu, Hongju; Sutter, Alton; Chavin, Kenneth D.; Otterbein, Leo E.; Adams, David B.; Kim, Young-Bum

    2014-01-01

    Obesity-induced endoplasmic reticulum (ER) stress causes chronic inflammation in adipose tissue and steatosis in the liver, and eventually leads to insulin resistance and type 2 diabetes (T2D). The goal of this study was to understand the mechanisms by which administration of bilirubin, a powerful antioxidant, reduces hyperglycemia and ameliorates obesity in leptin-receptor-deficient (db/db) and diet-induced obese (DIO) mouse models. db/db or DIO mice were injected with bilirubin or vehicle ip. Blood glucose and body weight were measured. Activation of insulin-signaling pathways, expression of inflammatory cytokines, and ER stress markers were measured in skeletal muscle, adipose tissue, and liver of mice. Bilirubin administration significantly reduced hyperglycemia and increased insulin sensitivity in db/db mice. Bilirubin treatment increased protein kinase B (PKB/Akt) phosphorylation in skeletal muscle and suppressed expression of ER stress markers, including the 78-kDa glucose-regulated protein (GRP78), CCAAT/enhancer-binding protein (C/EBP) homologous protein, X box binding protein (XBP-1), and activating transcription factor 4 in db/db mice. In DIO mice, bilirubin treatment significantly reduced body weight and increased insulin sensitivity. Moreover, bilirubin suppressed macrophage infiltration and proinflammatory cytokine expression, including TNF-α, IL-1β, and monocyte chemoattractant protein-1, in adipose tissue. In liver and adipose tissue of DIO mice, bilirubin ameliorated hepatic steatosis and reduced expression of GRP78 and C/EBP homologous protein. These results demonstrate that bilirubin administration improves hyperglycemia and obesity by increasing insulin sensitivity in both genetically engineered and DIO mice models. Bilirubin or bilirubin-increasing drugs might be useful as an insulin sensitizer for the treatment of obesity-induced insulin resistance and type 2 diabetes based on its profound anti-ER stress and antiinflammatory properties. PMID

  6. Correlation between oxytocin neuronal sensitivity and oxytocin receptor binding: An electrophysiological and autoradiographical study comparing rat and guinea pig hippocampus

    International Nuclear Information System (INIS)

    Raggenbass, M.; Tribollet, E.; Dubois-Dauphin, M.; Dreifuss, J.J.

    1989-01-01

    In transverse hippocampal slices from rat and guinea pig brains, the authors obtained unitary extracellular recordings from nonpyramidal neurones located in or near the stratum pyramidale in the CA1 field and in the transition region between the CA1 and the subiculum. In rats, these neurones responded to oxytocin at 50-1,000 nM by a reversible increase in firing rate. The oxytocin-induced excitation was suppressed by a synthetic structural analogue that acts as a potent, selective antioxytocic on peripheral receptors. Nonpyramidal neurones were also excited by carbachol at 0.5-10 μM. The effect of this compound was postsynaptic and was blocked by the muscarinic antagonist atropine. In guinea pigs, by contrast, nonpyramidal neurones were unaffected by oxytocin, although they were excited by carbachol. Light microscopic autoradiography, carried out using a radioiodinated selective antioxytocic as a ligand, revealed labeling in the subiculum and in the CA1 area of the hippocampus of rats, whereas no oxytocin-binding sites were detected in the hippocampus of guinea pigs. The results indicate (i) that a hippocampal action of oxytocin is species-dependent and (ii) that a positive correlation exists between neuronal responsiveness to oxytocin and the presence in the hippocampus of high-affinity binding sites for this peptide

  7. Stabilization study on a wet-granule tableting method for a compression-sensitive benzodiazepine receptor agonist.

    Science.gov (United States)

    Fujita, Megumi; Himi, Satoshi; Iwata, Motokazu

    2010-03-01

    SX-3228, 6-benzyl-3-(5-methoxy-1,3,4-oxadiazol-2-yl)-5,6,7,8-tetrahydro-1,6-naphthyridin-2(1H)-one, is a newly-synthesized benzodiazepine receptor agonist intended to be developed as a tablet preparation. This compound, however, becomes chemically unstable due to decreased crystallinity when it undergoes mechanical treatments such as grinding and compression. A wet-granule tableting method, where wet granules are compressed before being dried, was therefore investigated as it has the advantage of producing tablets of sufficient hardness at quite low compression pressures. The results of the stability testing showed that the drug substance was chemically considerably more stable in wet-granule compression tablets compared to conventional tablets. Furthermore, the drug substance was found to be relatively chemically stable in wet-granule compression tablets even when high compression pressure was used and the effect of this pressure was small. After investigating the reason for this excellent stability, it became evident that near-isotropic pressure was exerted on the crystals of the drug substance because almost all the empty spaces in the tablets were occupied with water during the wet-granule compression process. Decreases in crystallinity of the drug substance were thus small, making the drug substance chemically stable in the wet-granule compression tablets. We believe that this novel approach could be useful for many other compounds that are destabilized by mechanical treatments.

  8. Habituation of the C-start response in larval zebrafish exhibits several distinct phases and sensitivity to NMDA receptor blockade.

    Directory of Open Access Journals (Sweden)

    Adam C Roberts

    Full Text Available The zebrafish larva has been a valuable model system for genetic and molecular studies of development. More recently, biologists have begun to exploit the surprisingly rich behavioral repertoire of zebrafish larvae to investigate behavior. One prominent behavior exhibited by zebrafish early in development is a rapid escape reflex (the C-start. This reflex is mediated by a relatively simple neural circuit, and is therefore an attractive model behavior for neurobiological investigations of simple forms of learning and memory. Here, we describe two forms of short-lived habituation of the C-start in response to brief pulses of auditory stimuli. A rapid form, persisting for ≥1 min but <15 min, was induced by 120 pulses delivered at 0.5-2.0 Hz. A more extended form (termed "short-term habituation" here, which persisted for ≥25 min but <1 h, was induced by spaced training. The spaced training consisted of 10 blocks of auditory pulses delivered at 1 Hz (5 min interblock interval, 900 pulses per block. We found that these two temporally distinguishable forms of habituation are mediated by different cellular mechanisms. The short-term form depends on activation of N-methyl-d-aspartate receptors (NMDARs, whereas the rapid form does not.

  9. Distinct Mechanism of Cysteine Oxidation-Dependent Activation and Cold Sensitization of Human Transient Receptor Potential Ankyrin 1 Channel by High and Low Oxaliplatin

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    Takahito Miyake

    2017-11-01

    Full Text Available Oxaliplatin, a third-generation platinum-based chemotherapeutic agent, displays unique acute peripheral neuropathy triggered or enhanced by cold, and accumulating evidence suggests that transient receptor potential ankyrin 1 (TRPA1 is responsible. TRPA1 is activated by oxaliplatin via a glutathione-sensitive mechanism. However, oxaliplatin interrupts hydroxylation of a proline residue located in the N-terminal region of TRPA1 via inhibition of prolyl hydroxylase (PHD, which causes sensitization of TRPA1 to reactive oxygen species (ROS. Furthermore, PHD inhibition endows cold-insensitive human TRPA1 (hTRPA1 with ROS-dependent cold sensitivity. Since cysteine oxidation and proline hydroxylation regulate its activity, their association with oxaliplatin-induced TRPA1 activation and acquirement of cold sensitivity were investigated in the present study. A high concentration of oxaliplatin (1 mM induced outward-rectifier whole-cell currents and increased the intracellular Ca2+ concentration in hTRPA1-expressing HEK293 cells, but did not increase the probability of hTRPA1 channel opening in the inside-out configuration. Oxaliplatin also induced the rapid generation of hydrogen peroxide, and the resultant Ca2+ influx was prevented in the presence of glutathione and in cysteine-mutated hTRPA1 (Cys641Ser-expressing cells, whereas proline-mutated hTRPA1 (Pro394Ala-expressing cells showed similar whole-cell currents and Ca2+ influx. By contrast, a lower concentration of oxaliplatin (100 μM did not increase the intracellular Ca2+ concentration but did confer cold sensitivity on hTRPA1-expressing cells, and this was inhibited by PHD2 co-overexpression. Cold sensitivity was abolished by the mitochondria-targeting ROS scavenger mitoTEMPO and was minimal in cysteine-mutated hTRPA1 (Cys641Ser or Cys665Ser-expressing cells. Thus, high oxaliplatin evokes ROS-mediated cysteine oxidation-dependent hTRPA1 activation independent of PHD activity, while a lower

  10. Mice Expressing a "Hyper-Sensitive" Form of the Cannabinoid Receptor 1 (CB1 Are Neither Obese Nor Diabetic.

    Directory of Open Access Journals (Sweden)

    David J Marcus

    Full Text Available Multiple lines of evidence implicate the endocannabinoid signaling system in the modulation of metabolic disease. Genetic or pharmacological inactivation of CB1 in rodents leads to reduced body weight, resistance to diet-induced obesity, decreased intake of highly palatable food, and increased energy expenditure. Cannabinoid agonists stimulate feeding in rodents and increased levels of endocannabinoids can disrupt lipid metabolism. Therefore, the hypothesis that sustained endocannabinoid signaling can lead to obesity and diabetes was examined in this study using S426A/S430A mutant mice expressing a desensitization-resistant CB1 receptor. These mice display exaggerated and prolonged responses to acute administration of phytocannabinoids, synthetic cannabinoids, and endocannabinoids. As a consequence these mice represent a novel model for determining the effect of enhanced endocannabinoid signaling on metabolic disease. S426A/S430A mutants consumed equivalent amounts of both high fat (45% and low fat (10% chow control diet compared to wild-type littermate controls. S426A/S430A mutants and wild-type mice fed either high or low fat control diet displayed similar fasting blood glucose levels and normal glucose clearance following a 2 g/kg glucose challenge. Furthermore, S426A/S430A mutants and wild-type mice consumed similar amounts of chow following an overnight fast. While both THC and JZL195 significantly increased food intake two hours after injection, this increase was similar between the S426A/S430A mutant and wildtype control mice Our results indicate that S426A/S430A mutant mice expressing the desensitization-resistant form of CB1 do not exhibit differences in body weight, food intake, glucose homeostasis, or re-feeding following a fast.

  11. The ADP receptor P2Y1 is necessary for normal thermal sensitivity in cutaneous polymodal nociceptors

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    Jankowski Michael P

    2011-02-01

    Full Text Available Abstract Background P2Y1 is a member of the P2Y family of G protein-coupled nucleotide receptors expressed in peripheral sensory neurons. Using ratiometric calcium imaging of isolated dorsal root ganglion neurons, we found that the majority of neurons responding to adenosine diphosphate, the preferred endogenous ligand, bound the lectin IB4 and expressed the ATP-gated ion channel P2X3. These neurons represent the majority of epidermal afferents in hairy skin, and are predominantly C-fiber polymodal nociceptors (CPMs, responding to mechanical stimulation, heat and in some cases cold. Results To characterize the function of P2Y1 in cutaneous afferents, intracellular recordings from sensory neuron somata were made using an ex vivo preparation in which the hindlimb skin, saphenous nerve, DRG and spinal cord were dissected in continuum, and cutaneous receptive fields characterized using digitally-controlled mechanical and thermal stimuli in male wild type mice. In P2Y1-/- mice, CPMs showed a striking increase in mean heat threshold and a decrease in mean peak firing rate during a thermal ramp from 31-52°C. A similar change in mean cold threshold was also observed. Interestingly, mechanical testing of CPMs revealed no significant differences between P2Y1-/- and WT mice. Conclusions These results strongly suggest that P2Y1 is required for normal thermal signaling in cutaneous sensory afferents. Furthermore, they suggest that nucleotides released from peripheral tissues play a critical role in the transduction of thermal stimuli in some fiber types.

  12. Regulating Chondrogenesis of Human Mesenchymal Stromal Cells with a Retinoic Acid Receptor-Beta Inhibitor: Differential Sensitivity of Chondral Versus Osteochondral Development

    Directory of Open Access Journals (Sweden)

    Solvig Diederichs

    2014-05-01

    Full Text Available Aim: Main objective was to investigate whether the synthetic retinoic acid receptor (RAR-β antagonist LE135 is able to drive in vitro chondrogenesis of human mesenchymal stromal cells (MSCs or improve differentiation by suppressing hypertrophic chondrocyte development. Methods: Chondrogenesis of human bone marrow and adipose tissue-derived MSCs was induced in micromass pellet culture for six weeks. Effects of LE135 alone and in combinatorial treatment with TGF-β on deposition of cartilaginous matrix including collagen type II and glycosaminoglycans, on deposition of non-hyaline cartilage collagens type I and X, and on hypertrophy markers including alkaline phosphatase (ALP, indian hedghehog (IHH and matrix metalloproteinase (MMP-13 were assessed. Results: LE135 was no inducer of chondrogenesis and failed to stimulate deposition of collagen type II and glycosaminoglycans. Moreover, addition of LE135 to TGF-β-treated pellets inhibited cartilaginous matrix deposition and gene expression of COL2A1. In contrast, non-hyaline cartilage collagens were less sensitive to LE135 and hypertrophy markers remained unaffected. Conclusion: This demonstrates a differential sensitivity of chondral versus endochondral differentiation pathways to RARβ signaling; however, opposite to the desired direction. The relevance of trans-activating versus trans-repressing RAR signaling, including effects on activator protein (AP-1 is discussed and implications for overcoming current limits of hMSC chondrogenesis are considered.

  13. Regulating chondrogenesis of human mesenchymal stromal cells with a retinoic Acid receptor-Beta inhibitor: differential sensitivity of chondral versus osteochondral development.

    Science.gov (United States)

    Diederichs, Solvig; Zachert, Kerstin; Raiss, Patric; Richter, Wiltrud

    2014-01-01

    Main objective was to investigate whether the synthetic retinoic acid receptor (RAR)-β antagonist LE135 is able to drive in vitro chondrogenesis of human mesenchymal stromal cells (MSCs) or improve differentiation by suppressing hypertrophic chondrocyte development. Chondrogenesis of human bone marrow and adipose tissue-derived MSCs was induced in micromass pellet culture for six weeks. Effects of LE135 alone and in combinatorial treatment with TGF-β on deposition of cartilaginous matrix including collagen type II and glycosaminoglycans, on deposition of non-hyaline cartilage collagens type I and X, and on hypertrophy markers including alkaline phosphatase (ALP), indian hedghehog (IHH) and matrix metalloproteinase (MMP)-13 were assessed. LE135 was no inducer of chondrogenesis and failed to stimulate deposition of collagen type II and glycosaminoglycans. Moreover, addition of LE135 to TGF-β-treated pellets inhibited cartilaginous matrix deposition and gene expression of COL2A1. In contrast, non-hyaline cartilage collagens were less sensitive to LE135 and hypertrophy markers remained unaffected. This demonstrates a differential sensitivity of chondral versus endochondral differentiation pathways to RARβ signaling; however, opposite to the desired direction. The relevance of trans-activating versus trans-repressing RAR signaling, including effects on activator protein (AP)-1 is discussed and implications for overcoming current limits of hMSC chondrogenesis are considered. © 2014 S. Karger AG, Basel.

  14. The receptor tyrosine kinase inhibitor amuvatinib (MP470) sensitizes tumor cells to radio- and chemo-therapies in part by inhibiting homologous recombination

    International Nuclear Information System (INIS)

    Zhao, Helen; Luoto, Kaisa R.; Meng, Alice X.; Bristow, Robert G.

    2011-01-01

    Background and purpose: RAD51 is a key protein involved in homologous recombination (HR) and a potential target for radiation- and chemotherapies. Amuvatinib (formerly known as MP470) is a novel receptor tyrosine kinase inhibitor that targets c-KIT and PDGFRα and can sensitize tumor cells to ionizing radiation (IR). Here, we studied amuvatinib mechanism on RAD51 and functional HR. Materials and methods: Protein and RNA analyses, direct repeat green fluorescent protein (DR-GFP) assay and polysomal fractioning were used to measure HR efficiency and global translation in amuvatinib-treated H1299 lung carcinoma cells. Synergy of amuvatinib with IR or mitomycin c (MMC) was assessed by clonogenic survival assay. Results: Amuvaninib inhibited RAD51 protein expression and HR. This was associated with reduced ribosomal protein S6 phosphorylation and inhibition of global translation. Amuvatinib sensitized cells to IR and MMC, agents that are selectively toxic to HR-deficient cells. Conclusions: Amuvatinib is a promising agent that may be used to decrease tumor cell resistance. Our work suggests that this is associated with decreased RAD51 expression and function and supports the further study of amuvatinib in combination with chemotherapy and radiotherapy.

  15. Effect of cAMP signaling on expression of glucocorticoid receptor, Bim and Bad in glucocorticoid-sensitive and resistant leukemic and multiple myeloma cells.

    Science.gov (United States)

    Dong, Hongli; Carlton, Michael E; Lerner, Adam; Epstein, Paul M

    2015-01-01

    Stimulation of cAMP signaling induces apoptosis in glucocorticoid-sensitive and resistant CEM leukemic and MM.1 multiple myeloma cell lines, and this effect is enhanced by dexamethasone in both glucocorticoid-sensitive cell types and in glucocorticoid-resistant CEM cells. Expression of the mRNA for the glucocorticoid receptor alpha (GR) promoters 1A3, 1B and 1C, expression of mRNA and protein for GR, and the BH3-only proapoptotic proteins, Bim and Bad, and the phosphorylation state of Bad were examined following stimulation of the cAMP and glucocorticoid signaling pathways. Expression levels of GR promoters were increased by cAMP and glucocorticoid signaling, but GR protein expression was little changed in CEM and decreased in MM.1 cells. Stimulation of these two signaling pathways induced Bim in CEM cells, induced Bad in MM.1 cells, and activated Bad, as indicated by its dephosphorylation on ser112, in both cell types. This study shows that leukemic and multiple myeloma cells, including those resistant to glucocorticoids, can be induced to undergo apoptosis by stimulating the cAMP signaling pathway, with enhancement by glucocorticoids, and the mechanism by which this occurs may be related to changes in Bim and Bad expression, and in all cases, to activation of Bad.

  16. Autonomic control of heart rate by metabolically sensitive skeletal muscle afferents in humans

    DEFF Research Database (Denmark)

    Fisher, James P; Seifert, Thomas; Hartwich, Doreen

    2010-01-01

    moderate (PEI-M) and high (PEI-H) intensity isometric handgrip performed at 25% and 40% maximum voluntary contraction, under control (no drug), parasympathetic blockade (glycopyrrolate) and beta-adrenergic blockade (metoprolol or propranalol) conditions, while beat-to-beat HR and BP were continuously...

  17. Trichostatin A (TSA) sensitizes the human prostatic cancer cell line DU145 to death receptor ligands treatment.

    Science.gov (United States)

    Taghiyev, Agshin F; Guseva, Natalya V; Sturm, Mary T; Rokhlin, Oskar W; Cohen, Michael B

    2005-04-01

    The human prostatic carcinoma cell line DU145 has previously been found to be resistant to treatment with TNF-family ligands. However, TRAIL, TNF-alpha and anti-Fas antibodies (Ab) treatment in combination with the histone deacetylase inhibitor Trichostatin A (TSA) converted the phenotype of DU145 from resistant to sensitive. TSA induced 15% cell death but simultaneous treatment with TRAIL, TNF-alpha and anti-Fas Ab resulted in 55%, 70% and 40% cell death, respectively. Simultaneous treatment did not increase the level of TSA-induced histone acetylation, but induced the release of acetylated histones from chromatin into the cytosol. This release was caspase dependent since it was abrogated by Z-VAD-fmk. In addition, treatment with TSA induced caspase-9 activation and resulted in the release of cytochrome c and Smac/DIABLO from mitochondria. To further investigate the role of caspase-9 in TSA-mediated apoptosis we used two different approaches: (1) cells were pretreated with the caspase-9 inhibitor Z-LEHD-fmk, and (2) cells were transfected with a dominant-negative form of caspase-9. Both approaches gave similar results: cells became resistant to treatment with TSA. These data indicate that TSA mediates its effect via the mitochondrial pathway. This was confirmed by examining DU145 overexpressing Bcl-2. These transfectants were resistant to TSA treatment. Taken together, our data shows that only simultaneous treatment with TNF-family ligands and TSA in DU145 resulted in caspase activity sufficient to induce apoptosis. The combination of TSA and TNF-family ligands could potentially be the basis for the treatment of prostate cancer.

  18. The metabolic impact of β-hydroxybutyrate on neurotransmission: Reduced glycolysis mediates changes in calcium responses and KATP channel receptor sensitivity.

    Science.gov (United States)

    Lund, Trine M; Ploug, Kenneth B; Iversen, Anne; Jensen, Anders A; Jansen-Olesen, Inger

    2015-03-01

    Glucose is the main energy substrate for neurons, and ketone bodies are known to be alternative substrates. However, the capacity of ketone bodies to support different neuronal functions is still unknown. Thus, a change in energy substrate from glucose alone to a combination of glucose and β-hydroxybutyrate might change neuronal function as there is a known coupling between metabolism and neurotransmission. The purpose of this study was to shed light on the effects of the ketone body β-hydroxybutyrate on glycolysis and neurotransmission in cultured murine glutamatergic neurons. Previous studies have shown an effect of β-hydroxybutyrate on glucose metabolism, and the present study further specified this by showing attenuation of glycolysis when β-hydroxybutyrate was present in these neurons. In addition, the NMDA receptor-induced calcium responses in the neurons were diminished in the presence of β-hydroxybutyrate, whereas a direct effect of the ketone body on transmitter release was absent. However, the presence of β-hydroxybutyrate augmented transmitter release induced by the KATP channel blocker glibenclamide, thus giving an indirect indication of the involvement of KATP channels in the effects of ketone bodies on transmitter release. Energy metabolism and neurotransmission are linked and involve ATP-sensitive potassium (KATP ) channels. However, it is still unclear how and to what degree available energy substrate affects this link. We investigated the effect of changing energy substrate from only glucose to a combination of glucose and R-β-hydroxybutyrate in cultured neurons. Using the latter combination, glycolysis was diminished, NMDA receptor-induced calcium responses were lower, and the KATP channel blocker glibenclamide caused a higher transmitter release. © 2014 International Society for Neurochemistry.

  19. Overexpression of an Arabidopsis cysteine-rich receptor-like protein kinase, CRK5, enhances abscisic acid sensitivity and confers drought tolerance.

    Science.gov (United States)

    Lu, Kai; Liang, Shan; Wu, Zhen; Bi, Chao; Yu, Yong-Tao; Wang, Xiao-Fang; Zhang, Da-Peng

    2016-09-01

    Receptor-like kinases (RLKs) have been reported to regulate many developmental and defense process, but only a few members have been functionally characterized. In the present study, our observations suggest that one of the RLKs, a membrane-localized cysteine-rich receptor-like protein kinase, CRK5, is involved in abscisic acid (ABA) signaling in Arabidopsis thaliana Overexpression of CRK5 increases ABA sensitivity in ABA-induced early seedling growth arrest and promotion of stomatal closure and inhibition of stomatal opening. Interestingly, and importantly, overexpression of CRK5 enhances plant drought tolerance without affecting plant growth at the mature stages and plant productivity. Transgenic lines overexpressing a mutated form of CRK5, CRK5 (K372E) with the change of the 372nd conserved amino acid residue from lysine to glutamic acid in its kinase domain, result in wild-type ABA and drought responses, supporting the role of CRK5 in ABA signaling. The loss-of-function mutation of the CRK5 gene does not affect the ABA response, while overexpression of two homologs of CRK5, CRK4 and CRK19, confers ABA responses, suggesting that these CRK members function redundantly. We further showed that WRKY18, WRKY40 and WRKY60 transcription factors repress the expression of CRK5, and that CRK5 likely functions upstream of ABI2 in ABA signaling. These findings help in understanding the complex ABA signaling network. © The Author 2016. Published by Oxford University Press on behalf of the Society for Experimental Biology.

  20. Developmental changes in hypothalamic oxytocin and oxytocin receptor mRNA expression and their sensitivity to fasting in male and female rats.

    Science.gov (United States)

    Matsuzaki, Toshiya; Iwasa, Takeshi; Munkhzaya, Munkhsaikhan; Tungalagsuvd, Altankhuu; Kawami, Takako; Murakami, Masahiro; Yamasaki, Mikio; Yamamoto, Yuri; Kato, Takeshi; Kuwahara, Akira; Yasui, Toshiyuki; Irahara, Minoru

    2015-04-01

    Oxytocin (OT) affects the central nervous system and is involved in a variety of social and non-social behaviors. Recently, the role played by OT in energy metabolism and its organizational effects on estrogen receptor alpha (ER-α) during the neonatal period have gained attention. In this study, the developmental changes in the hypothalamic mRNA levels of OT, the OT receptor (OTR), and ER-α were evaluated in male and female rats. In addition, the fasting-induced changes in the hypothalamic mRNA levels of OT and the OTR were evaluated. Hypothalamic explants were taken from postnatal day (PND) 10, 20, and 30 rats, and the mRNA level of each molecule was measured. Hypothalamic OT mRNA expression increased throughout the developmental period in both sexes. The rats' hypothalamic OTR mRNA levels were highest on PND 10 and decreased throughout the developmental period. In the male rats, the hypothalamic mRNA levels of ER-α were higher on PND 30 than on PND 10. On the other hand, no significant differences in hypothalamic ER-α mRNA expression were detected among the examined time points in the female rats, although hypothalamic ER-α mRNA expression tended to be higher on PND 30 than on PND 10. Significant positive correlations were detected between hypothalamic OT and ER-α mRNA expression in both the male and female rats. Hypothalamic OT mRNA expression was not affected by fasting at any of the examined time points in either sex. These results indicate that hypothalamic OT expression is not sensitive to fasting during the developmental period. In addition, as a positive correlation was detected between hypothalamic OT and ER-α mRNA expression, these two molecules might interact with each other to induce appropriate neuronal development. Copyright © 2015 Elsevier Ltd. All rights reserved.

  1. Pilocarpine-Induced Status Epilepticus Increases the Sensitivity of P2X7 and P2Y1 Receptors to Nucleotides at Neural Progenitor Cells of the Juvenile Rodent Hippocampus.

    Science.gov (United States)

    Rozmer, Katalin; Gao, Po; Araújo, Michelle G L; Khan, Muhammad Tahir; Liu, Juan; Rong, Weifang; Tang, Yong; Franke, Heike; Krügel, Ute; Fernandes, Maria José S; Illes, Peter

    2017-07-01

    Patch-clamp recordings indicated the presence of P2X7 receptors at neural progenitor cells (NPCs) in the subgranular zone of the dentate gyrus in hippocampal brain slices prepared from transgenic nestin reporter mice. The activation of these receptors caused inward current near the resting membrane potential of the NPCs, while P2Y1 receptor activation initiated outward current near the reversal potential of the P2X7 receptor current. Both receptors were identified by biophysical/pharmacological methods. When the brain slices were prepared from mice which underwent a pilocarpine-induced status epilepticus or when brain slices were incubated in pilocarpine-containing external medium, the sensitivity of P2X7 and P2Y1 receptors was invariably increased. Confocal microscopy confirmed the localization of P2X7 and P2Y1 receptor-immunopositivity at nestin-positive NPCs. A one-time status epilepticus in rats caused after a latency of about 5 days recurrent epileptic fits. The blockade of central P2X7 receptors increased the number of seizures and their severity. It is hypothesized that P2Y1 receptors after a status epilepticus may increase the ATP-induced proliferation/ectopic migration of NPCs; the P2X7 receptor-mediated necrosis/apoptosis might counteract these effects, which would otherwise lead to a chronic manifestation of recurrent epileptic fits. © The Author 2016. Published by Oxford University Press. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

  2. Studies of the Pro12Ala polymorphism of the peroxisome proliferator-activated receptor-gamma2 (PPAR-gamma2) gene in relation to insulin sensitivity among glucose tolerant caucasians

    DEFF Research Database (Denmark)

    Ek, J; Andersen, G; Urhammer, S A

    2001-01-01

    We examined whether the Pro12-Ala polymorphism of the human peroxisome proliferator-activated receptor-gamma2 (PPAR-gamma2) gene was related to altered insulin sensitivity among glucose-tolerant subjects or a lower accumulated incidence or prevalence of IGT and Type II (non-insulin-dependent) dia......-insulin-dependent) diabetes mellitus among Scandinavian Caucasians....

  3. Novel role of cold/menthol-sensitive transient receptor potential melastatine family member 8 (TRPM8) in the activation of store-operated channels in LNCaP human prostate cancer epithelial cells.

    NARCIS (Netherlands)

    Thebault, S.C.; Lemonnier, L.; Bidaux, G.; Flourakis, M.; Bavencoffe, A.; Gordienko, D.; Roudbaraki, M.; Delcourt, P.; Panchin, Y.; Shuba, Y.; Skryma, R.; Prevarskaya, N.

    2005-01-01

    Recent cloning of a cold/menthol-sensitive TRPM8 channel (transient receptor potential melastatine family member 8) from rodent sensory neurons has provided the molecular basis for the cold sensation. Surprisingly, the human orthologue of rodent TRPM8 also appears to be strongly expressed in the

  4. The in vivo anti-fibrotic function of calcium sensitive receptor (CaSR) modulating poly(p-dioxanone-co-l-phenylalanine) prodrug.

    Science.gov (United States)

    Wang, Bing; Wen, Aiping; Feng, Chengmin; Niu, Lijing; Xiao, Xin; Luo, Le; Shen, Chengyi; Zhu, Jiang; Lei, Jun; Zhang, Xiaoming

    2018-04-13

    In present study, the apoptosis induction and proliferation suppression effects of l-phenylalanine (l-Phe) on fibroblasts were confirmed. The action sites of l-Phe on fibroblasts suppression were deduced to be calcium sensitive receptor (CaSR) which could cause the release of endoplasmic reticulum (ER) Ca 2+ stores; disruption of intracellular Ca 2+ homeostasis triggers cell apoptosis via the ER or mitochondrial pathways. The down-regulation of CaSR were observed after the application of l-Phe, and the results those l-Phe triggered the increasing of intracellular Ca 2+ concentration and calcineurin expression, and then the apoptosis and increasing G1 fraction of fibroblasts have verified our deduction. Hence, l-Phe could be seen as a kind of anti-fibrotic drugs for the crucial participation of fibroblast in the occurrence of fibrosis. And then, poly(p-dioxanone-co-l-phenylalanine) (PDPA) which could prolong the in-vivo anti-fibrotic effect of l-Phe for the sustained release of l-Phe during its degradation could be treated as anti-fibrotic polymer prodrugs. Based on the above, the in vivo anti-fibrotic function of PDPA was evaluated in rabbit ear scarring, rat peritoneum lipopolysaccharide, and rat sidewall defect/cecum abrasion models. PDPA reduced skin scarring and suppressed peritoneal fibrosis and post operation adhesion as well as secretion of transforming growth factor-β1 in injured tissue. These results indicate that PDPA is an effective agent for preventing fibrosis following tissue injury. We have previously demonstrated that poly(p-dioxanone-co-l-phenylalanine) (PDPA) could induce apoptosis to fibroblast and deduced that the inhibitory effect comes from l-phenylalanine. In present study, the inhibition mechanism of l-phenylalanine on fibroblast proliferation was demonstrated. The calcium sensitive receptor (CaSR) was found to be the action site. The CaSR was downregulated after the application of l-phenylalanine, and then the ER Ca 2+ stores were released

  5. Regulation of epidermal growth factor receptor signaling and erlotinib sensitivity in head and neck cancer cells by miR-7.

    Directory of Open Access Journals (Sweden)

    Felicity C Kalinowski

    Full Text Available Elevated expression and activity of the epidermal growth factor receptor (EGFR/protein kinase B (Akt signaling pathway is associated with development, progression and treatment resistance of head and neck cancer (HNC. Several studies have demonstrated that microRNA-7 (miR-7 regulates EGFR expression and Akt activity in a range of cancer cell types via its specific interaction with the EGFR mRNA 3'-untranslated region (3'-UTR. In the present study, we found that miR-7 regulated EGFR expression and Akt activity in HNC cell lines, and that this was associated with reduced growth in vitro and in vivo of cells (HN5 that were sensitive to the EGFR tyrosine kinase inhibitor (TKI erlotinib (Tarceva. miR-7 acted synergistically with erlotinib to inhibit growth of erlotinib-resistant FaDu cells, an effect associated with increased inhibition of Akt activity. Microarray analysis of HN5 and FaDu cell lines transfected with miR-7 identified a common set of downregulated miR-7 target genes, providing insight into the tumor suppressor function of miR-7. Furthermore, we identified several target miR-7 mRNAs with a putative role in the sensitization of FaDu cells to erlotinib. Together, these data support the coordinate regulation of Akt signaling by miR-7 in HNC cells and suggest the therapeutic potential of miR-7 alone or in combination with EGFR TKIs in this disease.

  6. Prion protein is a key determinant of alcohol sensitivity through the modulation of N-methyl-D-aspartate receptor (NMDAR activity.

    Directory of Open Access Journals (Sweden)

    Agnès Petit-Paitel

    Full Text Available The prion protein (PrP is absolutely required for the development of prion diseases; nevertheless, its physiological functions in the central nervous system remain elusive. Using a combination of behavioral, electrophysiological and biochemical approaches in transgenic mouse models, we provide strong evidence for a crucial role of PrP in alcohol sensitivity. Indeed, PrP knock out (PrP(-/- mice presented a greater sensitivity to the sedative effects of EtOH compared to wild-type (wt control mice. Conversely, compared to wt mice, those over-expressing mouse, human or hamster PrP genes presented a relative insensitivity to ethanol-induced sedation. An acute tolerance (i.e. reversion to ethanol inhibition of N-methyl-D-aspartate (NMDA receptor-mediated excitatory post-synaptic potentials in hippocampal slices developed slower in PrP(-/- mice than in wt mice. We show that PrP is required to induce acute tolerance to ethanol by activating a Src-protein tyrosine kinase-dependent intracellular signaling pathway. In an attempt to decipher the molecular mechanisms underlying PrP-dependent ethanol effect, we looked for changes in lipid raft features in hippocampus of ethanol-treated wt mice compared to PrP(-/- mice. Ethanol induced rapid and transient changes of buoyancy of lipid raft-associated proteins in hippocampus of wt but not PrP(-/- mice suggesting a possible mechanistic link for PrP-dependent signal transduction. Together, our results reveal a hitherto unknown physiological role of PrP on the regulation of NMDAR activity and highlight its crucial role in synaptic functions.

  7. Angiotensin type 1 receptors in the subfornical organ mediate the drinking and hypothalamic-pituitary-adrenal response to systemic isoproterenol.

    Science.gov (United States)

    Krause, Eric G; Melhorn, Susan J; Davis, Jon F; Scott, Karen A; Ma, Li Y; de Kloet, Annette D; Benoit, Stephen C; Woods, Stephen C; Sakai, Randall R

    2008-12-01

    Circulating angiotensin II (ANGII) elicits water intake and activates the hypothalamic-pituitary-adrenal (HPA) axis by stimulating angiotensin type 1 receptors (AT1Rs) within circumventricular organs. The subfornical organ (SFO) and the organum vasculosum of the lamina terminalis (OVLT) are circumventricular organs that express AT1Rs that bind blood-borne ANGII and stimulate integrative and effector regions of the brain. The goal of these studies was to determine the contribution of AT1Rs within the SFO and OVLT to the water intake and HPA response to increased circulating ANGII. Antisense oligonucleotides directed against the AT1R [AT1R antisense (AT1R AS)] were administered into the OVLT or SFO. Quantitative receptor autoradiography confirmed that AT1R AS decreased ANGII binding in the SFO and OVLT compared with the scrambled sequence control but did not affect AT1R binding in other nuclei. Subsequently, water intake, ACTH, and corticosterone (CORT) were assessed after administration of isoproterenol, a beta-adrenergic agonist that decreases blood pressure and elevates circulating ANGII. Delivery of AT1R AS into the SFO attenuated water intake, ACTH, and CORT after isoproterenol, whereas similar treatment in the OVLT had no effect. To determine the specificity of this blunted drinking and HPA response, the same parameters were measured after treatment with hypertonic saline, a stimulus that induces drinking independently of ANGII. Delivery of AT1R AS into the SFO or OVLT had no effect on water intake, ACTH, or CORT after hypertonic saline. The results imply that AT1R within the SFO mediate drinking and HPA responses to stimuli that increase circulating ANGII.

  8. Cardiac beta-receptors in experimental Chagas' disease Receptores beta cardíacos na doença de Chagas experimental

    Directory of Open Access Journals (Sweden)

    Julio E. Enders

    1995-02-01

    Full Text Available Experimental Chagas' disease (45 to 90 days post-infection showed serious cardiac alterations in the contractility and in the pharmacological response to beta adrenergic receptors in normal and T. cruzi infected mice (post-acute phase. Chagasic infection did not change the beta receptors density (78.591 ± 3.125 fmol/mg protein and 73.647 ± 2.194 fmol/mg protein for controls but their affinity was significantly diminished (Kd = 7.299 ± 0.426 nM and Kd = 3.759 ± 0.212 nM for the control p Estudaram-se os receptores beta cardíacos de camundongos infectados pelo Trypanosoma cruzi na fase pós-aguda da doença de Chagas para estabelecer em que medida os mesmos contribuem a gerar respostas anômalas às catecolaminas observadas nestes miocardios. Utilizara-se 3-H/DHA para a marcação dos receptores beta cardíacos dos camundongos normais e dos infectados na fase pós-aguda (45 a 90 dias pós-infecção. O número dos sítios de fixação foi similar nos dois grupos, 78.591 ± 3.125 fmol/mg. Proteína nos chagásicos e 73.647 ± 2.194 fmol/mg. Proteína no grupo controle. Em vez disso, a afinidade verificou-se significativamente diminuida no grupo chagásico (Kd = 7.299 ± 0.426 nM respeito do controle (Kd = 3.759 ± 0.212 nM p < 0.001. Os resultados obtidos demonstram que as modificações observadas na estimulação adrenérgica do miocárdio chagásico se correlacionam com a menor afinidade dos receptores beta cardíacos e que estas alterações exerceriam uma parte determinante para as consequências funcionais que são detectadas na fase crônica.

  9. Tomato PYR/PYL/RCAR abscisic acid receptors show high expression in root, differential sensitivity to the abscisic acid agonist quinabactin, and the capability to enhance plant drought resistance.

    Science.gov (United States)

    González-Guzmán, Miguel; Rodríguez, Lesia; Lorenzo-Orts, Laura; Pons, Clara; Sarrión-Perdigones, Alejandro; Fernández, Maria A; Peirats-Llobet, Marta; Forment, Javier; Moreno-Alvero, Maria; Cutler, Sean R; Albert, Armando; Granell, Antonio; Rodríguez, Pedro L

    2014-08-01

    Abscisic acid (ABA) plays a crucial role in the plant's response to both biotic and abiotic stress. Sustainable production of food faces several key challenges, particularly the generation of new varieties with improved water use efficiency and drought tolerance. Different studies have shown the potential applications of Arabidopsis PYR/PYL/RCAR ABA receptors to enhance plant drought resistance. Consequently the functional characterization of orthologous genes in crops holds promise for agriculture. The full set of tomato (Solanum lycopersicum) PYR/PYL/RCAR ABA receptors have been identified here. From the 15 putative tomato ABA receptors, 14 of them could be grouped in three subfamilies that correlated well with corresponding Arabidopsis subfamilies. High levels of expression of PYR/PYL/RCAR genes was found in tomato root, and some genes showed predominant expression in leaf and fruit tissues. Functional characterization of tomato receptors was performed through interaction assays with Arabidopsis and tomato clade A protein phosphatase type 2Cs (PP2Cs) as well as phosphatase inhibition studies. Tomato receptors were able to inhibit the activity of clade A PP2Cs differentially in an ABA-dependent manner, and at least three receptors were sensitive to the ABA agonist quinabactin, which inhibited tomato seed germination. Indeed, the chemical activation of ABA signalling induced by quinabactin was able to activate stress-responsive genes. Both dimeric and monomeric tomato receptors were functional in Arabidopsis plant cells, but only overexpression of monomeric-type receptors conferred enhanced drought resistance. In summary, gene expression analyses, and chemical and transgenic approaches revealed distinct properties of tomato PYR/PYL/RCAR ABA receptors that might have biotechnological implications. © The Author 2014. Published by Oxford University Press on behalf of the Society for Experimental Biology.

  10. Different sensitivities to competitive inhibition of benzodiazepine receptor binding of {sup 11}C-iomazenil and {sup 11}C-flumazenil in rhesus monkey brain

    Energy Technology Data Exchange (ETDEWEB)

    Inoue, Osamu; Hosoi, Rie; Kobayashi, Kaoru [Osaka Univ., Suita (Japan). Medical School; Itoh, Takashi; Gee, A.; Suzuki, Kazutoshi

    2001-04-01

    The in vivo binding kinetics of {sup 11}C-iomazenil were compared with those of {sup 11}C-flumazenil binding in rhesus monkey brain. The monkey was anesthetized with ketamine and intravenously injected with either {sup 11}C-iomazenil or {sup 11}C-flumazenil in combination with the coadministration of different doses of non-radioactive flumazenil (0, 5 and 20 {mu}g/kg). The regional distribution of {sup 11}C-iomazenil in the brain was similar to that of {sup 11}C-flumazenil, but the sensitivity of {sup 11}C-iomazenil binding to competitive inhibition by non-radioactive flumazenil was much less than that of {sup 11}C-flumazenil binding. A significant reduction in {sup 11}C-flumazenil binding in the cerebral cortex was observed with 20 {mu}g/kg of flumazenil, whereas a relatively smaller inhibition of {sup 11}C-iomazenil binding in the same region was observed with the same dose of flumazenil. These results suggest that {sup 11}C-flumazenil may be a superior radiotracer for estimating benzodiazepine receptor occupancy in the intact brain. (author)

  11. Label-free sensitive luminescence biosensor for immunoglobulin G based on Ag6Au6 ethisterone cluster-estrogen receptor α aggregation and graphene.

    Science.gov (United States)

    Chen, Nannan; Guo, Wenjing; Lin, Zhixiang; Wei, Qiaohua; Chen, Guonan

    2018-08-01

    A specific and label-free "on-off-on" luminescence biosensor based on a novel heterometallic cluster [Ag 6 Au 6 (ethisterone) 12 ]-estrogen receptor α (Ag 6 Au 6 Eth-ERα) aggregation utilizing graphene oxide (GO) as a quencher to lead a small background signal was firstly constructed to detect immunoglobulin G (IgG) with a simple process and high selectivity. The efficient photoluminescent (PL) Ag 6 Au 6 Eth-ERα aggregation is strongly quenched by GO. In the presence of IgG, the PL of this system will be restored, and perceivable by human eyes under UV lamp excitation (365 nm). The quenching mechanism of GO on Ag 6 Au 6 Eth-ERα and enhancement mechanism of IgG on Ag 6 Au 6 Eth-ERα-GO were investigated in detail. Under the optimum conditions, the biosensor for high sensitive IgG detection expressed a wider linear range of 0.0078-10 ng/mL and a lower detection limit of 0.65 pg/mL with good stability and repeatability, which provided a new approach for label-free IgG detection. Copyright © 2018 Elsevier B.V. All rights reserved.

  12. Dopamine D4 receptor gene and religious affiliation correlate with dictator game altruism in males and not females: evidence for gender-sensitive gene × culture interaction.

    Science.gov (United States)

    Jiang, Yushi; Bachner-Melman, Rachel; Chew, Soo Hong; Ebstein, Richard P

    2015-01-01

    On a large sample of 2288 Han Chinese undergraduates, we investigated how religion and DRD4 are related to human altruistic giving behavior as measured with the Andreoni-Miller Dictator Game. This game enables us to clearly specify (non-)selfishness, efficiency, and fairness motives for sharing. Participants were further classified into religious categories (Christian, Buddhist-Tao, and No Religion) based on self-reports, and genotyped for the dopamine D4 receptor (DRD4) gene exon III VNTR. Our analysis revealed a significant interaction between religion and DRD4 correlated with giving behavior solely among males: Whereas no significant association between religion and sharing decisions was observed in the majority 4R/4R genotype group, a significant difference in giving behavior between Christian and non-Christian males was seen in the non-4R/4R group, with Christian men being overall more altruistic (less selfish and fairer) than non-Christian men. These results support the vantage sensitivity hypothesis regarding DRD4 that the non-4R/4R "susceptibility" genotype is more responsive to a positive environment provided by some religions.

  13. An Aryl Hydrocarbon Receptor from the Salamander Ambystoma mexicanum Exhibits Low Sensitivity to 2,3,7,8-Tetrachlorodibenzo-p-dioxin.

    Science.gov (United States)

    Shoots, Jenny; Fraccalvieri, Domenico; Franks, Diana G; Denison, Michael S; Hahn, Mark E; Bonati, Laura; Powell, Wade H

    2015-06-02

    Structural features of the aryl hydrocarbon receptor (AHR) can underlie species- and population-specific differences in its affinity for 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD). These differences often explain variations in TCDD toxicity. Frogs are relatively insensitive to dioxin, and Xenopus AHRs bind TCDD with low affinity. Weak TCDD binding results from the combination of three residues in the ligand-binding domain: A354 and A370, and N325. Here we sought to determine whether this mechanism of weak TCDD binding is shared by other amphibian AHRs. We isolated an AHR cDNA from the Mexican axolotl (Ambystoma mexicanum). The encoded polypeptide contains identical residues at positions that confer low TCDD affinity to X. laevis AHRs (A364, A380, and N335), and homology modeling predicts they protrude into the binding cavity. Axolotl AHR bound one-tenth the TCDD of mouse AHR in velocity sedimentation analysis, and in transactivation assays, the EC50 for TCDD was 23 nM, similar to X. laevis AHR1β (27 nM) and greater than AHR containing the mouse ligand-binding domain (0.08 nM). Sequence, modeled structure, and function indicate that axolotl AHR binds TCDD weakly, predicting that A. mexicanum lacks sensitivity toTCDD toxicity. We hypothesize that this characteristic of axolotl and Xenopus AHRs arose in a common ancestor of the Caudata and Anura.

  14. Third-generation Ah receptor-responsive luciferase reporter plasmids: amplification of dioxin-responsive elements dramatically increases CALUX bioassay sensitivity and responsiveness.

    Science.gov (United States)

    He, Guochun; Tsutsumi, Tomoaki; Zhao, Bin; Baston, David S; Zhao, Jing; Heath-Pagliuso, Sharon; Denison, Michael S

    2011-10-01

    2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD, dioxin) and related dioxin-like chemicals are widespread and persistent environmental contaminants that produce diverse toxic and biological effects through their ability to bind to and activate the Ah receptor (AhR) and AhR-dependent gene expression. The chemically activated luciferase expression (CALUX) system is an AhR-responsive recombinant luciferase reporter gene-based cell bioassay that has been used in combination with chemical extraction and cleanup methods for the relatively rapid and inexpensive detection and relative quantitation of dioxin and dioxin-like chemicals in a wide variety of sample matrices. Although the CALUX bioassay has been validated and used extensively for screening purposes, it has some limitations when screening samples with very low levels of dioxin-like chemicals or when there is only a small amount of sample matrix for analysis. Here, we describe the development of third-generation (G3) CALUX plasmids with increased numbers of dioxin-responsive elements, and stable transfection of these new plasmids into mouse hepatoma (Hepa1c1c7) cells has produced novel amplified G3 CALUX cell bioassays that respond to TCDD with a dramatically increased magnitude of luciferase induction and significantly lower minimal detection limit than existing CALUX-type cell lines. The new G3 CALUX cell lines provide a highly responsive and sensitive bioassay system for the detection and relative quantitation of very low levels of dioxin-like chemicals in sample extracts.

  15. Systemic modulation of serotonergic synapses via reuptake blockade or 5HT1A receptor antagonism does not alter perithreshold taste sensitivity in rats.

    Science.gov (United States)

    Mathes, Clare M; Spector, Alan C

    2014-09-01

    Systemic blockade of serotonin (5HT) reuptake with paroxetine has been shown to increase sensitivity to sucrose and quinine in humans. Here, using a 2-response operant taste detection task, we measured the effect of paroxetine and the 5HT1A receptor antagonist WAY100635 on the ability of rats to discriminate sucrose, NaCl, and citric acid from water. After establishing individual psychometric functions, 5 concentrations of each taste stimulus were chosen to represent the dynamic portion of the concentration-response curve, and the performance of the rats to these stimuli was assessed after vehicle, paroxetine (7mg/kg intraperitoneally), and WAY100635 (0.3mg/kg subcutaneously; 1mg/kg intravenously) administration. Although, at times, overall performance across concentrations dropped, at most, 5% from vehicle to drug conditions, no differences relative to vehicle were seen on the parameters of the psychometric function (asymptote, slope, or EC50) after drug administration. In contrast to findings in humans, our results suggest that modulation of 5HT activity has little impact on sucrose detectability at perithreshold concentrations in rats, at least at the doses used in this task. In the rat model, the purported paracrine/neurocrine action of serotonin in the taste bud may work in a manner that does not impact overt taste detection behavior. © The Author 2014. Published by Oxford University Press. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  16. Transient receptor potential ion channel Trpm7 regulates exocrine pancreatic epithelial proliferation by Mg2+-sensitive Socs3a signaling in development and cancer

    Directory of Open Access Journals (Sweden)

    Nelson S. Yee

    2011-03-01

    Genetic analysis of pancreatic development has provided new insights into the mechanisms underlying the formation of exocrine pancreatic neoplasia. Zebrafish sweetbread (swd mutants develop hypoplastic acini and dysmorphic ducts in the exocrine pancreas, with impeded progression of cell division cycle and of epithelial growth. Positional cloning and allelic complementation have revealed that the swd mutations affect the transient receptor potential melastatin-subfamily member 7 (trpm7 gene, which encodes a divalent cation-permeable channel with kinase activity. Supplementary Mg2+ partially rescued the exocrine pancreatic defects of the trpm7 mutants by improving cell-cycle progression and growth and repressing the suppressor of cytokine signaling 3a (socs3a gene. The role of Socs3a in Trpm7-mediated signaling is supported by the findings that socs3a mRNA level is elevated in the trpm7 mutants, and antisense inhibition of socs3a expression improved their exocrine pancreatic growth. TRPM7 is generally overexpressed in human pancreatic adenocarcinoma. TRPM7-deficient cells are impaired in proliferation and arrested in the G0-G1 phases of the cell division cycle. Supplementary Mg2+ rescued the proliferative defect of the TRPM7-deficient cells. Results of this study indicate that Trpm7 regulates exocrine pancreatic development via the Mg2+-sensitive Socs3a pathway, and suggest that aberrant TRPM7-mediated signaling contributes to pancreatic carcinogenesis.

  17. Dopamine D4 Receptor Gene and Religious Affiliation Correlate with Dictator Game Altruism in Males and not Females: Evidence for Gender-sensitive Gene x Culture Interaction

    Directory of Open Access Journals (Sweden)

    Yushi eJiang

    2015-09-01

    Full Text Available On a large sample of 2288 Han Chinese undergraduates, we investigated how religion and DRD4 are related to human altruistic giving behavior as measured with the Andreoni-Miller Dictator Game. This game enables us to clearly specify (non-selfishness, efficiency, and fairness motives for sharing. Participants were further classified into religious categories (Christian, Buddhist-Tao, and No Religion based on self-reports, and genotyped for the dopamine D4 receptor (DRD4 gene exon III VNTR. Our analysis revealed a significant interaction between religion and DRD4 correlated with giving behavior solely among males: Whereas no significant association between religion and sharing decisions was observed in the majority 4R/4R genotype group, a significant difference in giving behavior between Christian and non-Christian males was seen in the non-4R/4R group, with Christian men being overall more altruistic (less selfish and fairer than non-Christian men. These results support the vantage sensitivity hypothesis regarding DRD4 that the non-4R/4R ‘susceptibility’ genotype is more responsive to a positive environment provided by some religions.

  18. Stress hormones receptors in the amygdala mediate the effects of stress on the consolidation, but not the retrieval, of a non aversive spatial task.

    Directory of Open Access Journals (Sweden)

    Amir Segev

    Full Text Available This study examined the effects of the arousal level of the rat and exposure to a behavioral stressor on acquisition, consolidation and retrieval of a non-aversive hippocampal-dependent learning paradigm, the object location task. Learning was tested under two arousal conditions: no previous habituation to the experimental context (high novelty stress/arousal level or extensive prior habituation (reduced novelty stress/arousal level. Results indicated that in the habituated rats, exposure to an out-of-context stressor (i.e, elevated platform stress impaired consolidation and retrieval, but not acquisition, of the task. Non-habituated animals under both stressed and control conditions did not show retention of the task. In habituated rats, RU-486 (10 ng/side, a glucocorticoid receptor (GR antagonist, or propranolol (0.75 µg/side, a beta-adrenergic antagonist, injected into the basolateral amygdala (BLA, prevented the impairing effects of the stressor on consolidation, but not on retrieval. The CB1/CB2 receptor agonist WIN55,212-2 (WIN, 5 µg/side microinjected into the BLA did not prevent the effects of stress on either consolidation or retrieval. Taken together the results suggest that: (i GR and β-adrenergic receptors in the BLA mediate the impairing effects of stress on the consolidation, but not the retrieval, of a neutral, non-aversive hippocampal-dependent task, (ii the impairing effects of stress on hippocampal consolidation and retrieval are mediated by different neural mechanisms (i.e., different neurotransmitters or different brain areas, and (iii the effects of stress on memory depend on the interaction between several main factors such as the stage of memory processing under investigation, the animal's level of arousal and the nature of the task (neutral or aversive.

  19. Stress hormones receptors in the amygdala mediate the effects of stress on the consolidation, but not the retrieval, of a non aversive spatial task.

    Science.gov (United States)

    Segev, Amir; Ramot, Assaf; Akirav, Irit

    2012-01-01

    This study examined the effects of the arousal level of the rat and exposure to a behavioral stressor on acquisition, consolidation and retrieval of a non-aversive hippocampal-dependent learning paradigm, the object location task. Learning was tested under two arousal conditions: no previous habituation to the experimental context (high novelty stress/arousal level) or extensive prior habituation (reduced novelty stress/arousal level). Results indicated that in the habituated rats, exposure to an out-of-context stressor (i.e, elevated platform stress) impaired consolidation and retrieval, but not acquisition, of the task. Non-habituated animals under both stressed and control conditions did not show retention of the task. In habituated rats, RU-486 (10 ng/side), a glucocorticoid receptor (GR) antagonist, or propranolol (0.75 µg/side), a beta-adrenergic antagonist, injected into the basolateral amygdala (BLA), prevented the impairing effects of the stressor on consolidation, but not on retrieval. The CB1/CB2 receptor agonist WIN55,212-2 (WIN, 5 µg/side) microinjected into the BLA did not prevent the effects of stress on either consolidation or retrieval. Taken together the results suggest that: (i) GR and β-adrenergic receptors in the BLA mediate the impairing effects of stress on the consolidation, but not the retrieval, of a neutral, non-aversive hippocampal-dependent task, (ii) the impairing effects of stress on hippocampal consolidation and retrieval are mediated by different neural mechanisms (i.e., different neurotransmitters or different brain areas), and (iii) the effects of stress on memory depend on the interaction between several main factors such as the stage of memory processing under investigation, the animal's level of arousal and the nature of the task (neutral or aversive).

  20. m-Acetylanilido-GTP, a novel photoaffinity label for GTP-binding proteins: synthesis and application.

    OpenAIRE

    Zor, T; Halifa, I; Kleinhaus, S; Chorev, M; Selinger, Z

    1995-01-01

    A novel photoaffinity label, m-acetylanilido-GTP (m-AcAGTP), was synthesized and used to identify GTP-binding proteins (G-proteins). This GTP analogue is easily prepared and can be used for photoaffinity labelling of G-proteins without chromatographic purification. In the presence of the beta-adrenergic agonist isoprenaline, it activates turkey erythrocyte adenylate cyclase. This activation persists even when the beta-adrenergic receptor is subsequently blocked by antagonist, indicating that ...

  1. Treatment of essential tremor with arotinolol.

    Science.gov (United States)

    Kuroda, Y; Kakigi, R; Shibasaki, H

    1988-04-01

    We investigated the effect of arotinolol, a new peripherally acting beta-adrenergic blocker, in 15 patients with essential tremor. The patients received 30 mg per day of arotinolol for 8 weeks. Accelerometer readings showed a significant reduction in amplitude of postural tremor after treatment. Action tremor also improved to essentially the same degree as postural tremor. The present findings support the view that the therapeutic effect of beta-blockers in essential tremor is mediated by peripheral beta-adrenergic receptors.

  2. Development of Nano-Liposomal Formulations of Epidermal Growth Factor Receptor Inhibitors and their Pharmacological Interactions on Drug-Sensitive and Drug-Resistant Cancer Cell Lines

    Science.gov (United States)

    Trummer, Brian J.

    A rapidly expanding understanding of molecular derangements in cancer cell function has led to the development of selective, targeted chemotherapeutic agents. Growth factor signal transduction networks are frequently activated in an aberrant fashion, particularly through the activity of receptor tyrosine kinases (RTK). This has spurred an intensive effort to develop receptor tyrosine kinase inhibitors (RTKI) that are targeted to specific receptors, or receptor subfamilies. Chapter 1 reviews the pharmacology, preclinical, and clinical aspects of RTKIs that target the epidermal growth factor receptor (EGFR). EGFR inhibitors demonstrate significant success at inhibiting phosphorylation-based signaling pathways that promote cancer cell proliferation. Additionally RTKIs have physicochemical and structural characteristics that enable them to function as inhibitors of multi-drug resistance transport proteins. Thus EGFR inhibitors and other RTKIs have both on-target and off-target activities that could be beneficial in cancer therapy. However, these agents exert a number of side effects, some of which arise from their hydrophobic nature and large in vivo volume of distribution. Side effects of the EGFR inhibitor gefitinib include skin rash, severe myelotoxicity when combined with certain chemotherapeutic agents, and impairment of the blood brain barrier to xenobiotics. Weighing the preclinical and clinical observations with the EGFR inhibitors, we developed the primary overall hypothesis of this research: that drug-carrier formulations of RTKIs such as the EGFR inhibitors could be developed based on nanoparticulate liposomal carriers. Theoretically, this carrier strategy would ameliorate toxicity and improve the biodistribution and tumor selectivity of these agents. We hypothesized specifically that liposomal formulations could shift the biodistribution of EGFR inhibitors such as gefitinib away from skin, bone marrow, and the blood brain barrier, and toward solid tumors

  3. Comparative influence of propranolol and verapamil on glycemic control and histamine sensitivity associated with L-thyroxine-induced hyperthyroidism - an experimental study.

    Science.gov (United States)

    Bhatt, Parloop A; Makwana, Dharmesh

    2008-02-01

    The present investigation was undertaken to study the comparative effectiveness of beta-adrenergic antagonist propranolol and calcium channel blocker verapamil on L-thyroxine-induced alteration on glycemic control and histamine sensitivity on rats and guinea pigs, respectively. Injection of L-thyroxine sodium every alternate day for 3 weeks in guinea pigs (75 microg/kg, i.p.) and rats (75 mg/kg, s.c.) produced a condition similar to thyrotoxicosis. Verapamil and propranolol administered daily in the third week along with L-thyroxine to two separate groups of hyperthyroid animals reversed thyroxine-induced loss in body weight, reduction in serum TSH levels, and rise in body temperature. Effect on glucose metabolism and insulin sensitivity was studied on rats. Compared to normal rats, L-thyroxine-treated animals showed a state of hyperglycemia, hyperinsulinemia, impaired glucose tolerance, and insulin resistance. Propranolol (10 mg/kg, i.p.) treatment significantly decreased fasting serum glucose levels without affecting serum insulin levels, AUC glucose, and K(ITT) values. Treatment with verapamil (5 mg/kg, i.p.) significantly reduced fasting serum glucose and insulin levels, AUC glucose, and significantly increased K(ITT) values. Effect of propranolol (15 mg/kg, orally) and verapamil (20 mg/kg, orally) treatment on histamine sensitivity was studied on L-thyroxine-treated guinea pigs. Compared to normal guinea pigs, L-thyroxine-treated guinea pigs showed an increased sensitivity to histamine-induced asphyxia. Verapamil treatment reversed this increased histamine sensitivity while propranolol aggravated it. In conclusion, compared to propranolol, verapamil has advantageous effects on glucose metabolism, insulin and histamine sensitivity and could therefore be a valuable addition as an adjunctive therapy option currently available for thyrotoxicosis associated with diabetes and/or anaphylaxis.

  4. Transcript Levels of Androgen Receptor Variant 7 and Ubiquitin-Conjugating Enzyme 2C in Hormone Sensitive Prostate Cancer and Castration-Resistant Prostate Cancer.

    Science.gov (United States)

    Lee, Chan Ho; Ku, Ja Yoon; Ha, Jung Min; Bae, Sun Sik; Lee, Jeong Zoo; Kim, Choung-Soo; Ha, Hong Koo

    2017-01-01

    This study is designed to identify the androgen receptor variant 7 (AR-V7) status, clinical significance of AR-V7 in hormone sensitive prostate cancer (HSPC). Then, we evaluated AR-V7 and changes of its target gene, ubiquitin-conjugating enzyme E2C (UBE2C) which is an anaphase-promoting complex/cyclosome (APC/C)-specific ubiquitin-conjugating enzyme, in castration-resistant prostate cancer (CRPC) in serial tumor biopsies from patients receiving androgen deprivation therapy. We used RT-PCR and Q-PCR assay to evaluate AR-V7, androgen receptor full length (AR-FL), and UBE2C in tumor biopsies from patients with HSPC and CRPC. We examined associations between mRNA expression of AR-V7 and clinicopathologic factors. Furthermore, to identify other potential genes involved in the development of CRPC, RNA sequencing was conducted, using paired prostate cancer (PCa) tissues obtained immediately prior to treatment and at the time of therapeutic resistance. A total of 13 HSPC patients and three CRPC patients were enrolled. Neither a high Gleason score (score of 8 and 9) nor a high risk of PCa (a high risk of locally advanced PCa according to NCCN guidelines) was correlated with mRNA expression of AR-V7 in HSPC (P = 0.153 and P = 0.215). The mRNA expression of AR-FL, but not AR-V7, was significantly associated with the mRNA expression of UBE2C level in HSPC (P = 0.007). However, increased expression of AR-V7, not AR-FL, paralleled increased expression of UBE2C in the CRPC specimens (P = 0.03). AR-V7 expression status before ADT was likely related to shorter CRPC development in patients treating ADT. The result of the RNA-sequencing analysis using serial samples from the same patient before and after castration demonstrated an increased level of the PI3K regulatory subunit 1 (P = 0.018). Our study revealed the role of UBE2C as a marker of the androgen signaling pathway in PCa. Differential gene expression analysis using serial samples from the same patient

  5. Enhanced cerebral uptake of receptor ligands by modulation of P-glycoprotein function in the blood-brain barrier

    NARCIS (Netherlands)

    Doze, P; Van Waarde, A; Elsinga, P H; Hendrikse, N H; Vaalburg, W

    Low cerebral uptake of some therapeutic drugs can be enhanced by modulation of P-glycoprotein (P-gp), an ATP-driven drug efflux pump at the blood-brain barrier (BBB). We investigated the possibility of increasing cerebral uptake of the beta-adrenergic ligands S-1'-[(18)F]-fluorocarazolol (FCAR) and

  6. Neonatal co-lesion by DSP-4 and 5,7-DHT produces adulthood behavioral sensitization to dopamine D(2) receptor agonists.

    Science.gov (United States)

    Nowak, Przemysław; Nitka, Dariusz; Kwieciński, Adam; Jośko, Jadwiga; Drab, Jacek; Pojda-Wilczek, Dorota; Kasperski, Jacek; Kostrzewa, Richard M; Brus, Ryszard

    2009-01-01

    To assess the possible modulatory effects of noradrenergic and serotoninergic neurons on dopaminergic neuronal activity, the noradrenergic and serotoninergic neurotoxins DSP-4 N-(2-chlorethyl)-N-ethyl-2-bromobenzylamine (50.0 mg/kg, sc) and 5,7-dihydroxytryptamine (5,7-DHT) (37.5 microg icv, half in each lateral ventricle), respectively, were administered toWistar rats on the first and third days of postnatal ontogeny, and dopamine (DA) agonist-induced behaviors were assessed in adulthood. At eight weeks, using an HPLC/ED technique, DSP-4 treatment was associated with a reduction in NE content of the corpus striatum (> 60%), hippocampus (95%), and frontal cortex (> 85%), while 5,7-DHT was associated with an 80-90% serotonin reduction in the same brain regions. DA content was unaltered in the striatum and the cortex. In the group lesioned with both DSP-4 and 5,7-DHT, quinpirole-induced (DA D(2) agonist) yawning, 7-hydroxy-DPAT-induced (DA D(3) agonist) yawning, and apomorphine-induced (non-selective DA agonist) stereotypies were enhanced. However, SKF 38393-induced (DA D(1) agonist) oral activity was reduced in the DSP-4 + 5,7-DHT group. These findings demonstrate that DA D(2)- and D(3)-agonist-induced behaviors are enhanced while DA D(1)-agonist-induced behaviors are suppressed in adult rats in which brain noradrenergic and serotoninergic innervation of the brain has largely been destroyed. This study indicates that noradrenergic and serotoninergic neurons have a great impact on the development of DA receptor reactivity (sensitivity).

  7. The presence of a membrane-bound progesterone receptor sensitizes the estradiol-induced effect on the proliferation of human breast cancer cells.

    Science.gov (United States)

    Neubauer, Hans; Yang, Yang; Seeger, Harald; Fehm, Tanja; Cahill, Michael A; Tong, Xiaowen; Ruan, Xiangyan; Mueck, Alfred O

    2011-08-01

    Breast cancer risk is still an important topic regarding hormone therapy as well as oral contraception. Evidence that progestogens may play a crucial role is accumulating. Progesterone receptor membrane component 1 (PGRMC1) expressed in breast cancer may be important in tumorigenesis and thus may increase breast cancer risk. The aim of this project was to investigate the influence of different estradiol (E2) concentrations and the addition of two progestogens on MCF-7 breast cancer cells overexpressing PGRMC1. MCF-7 cells were stably transfected with PGRMC1 expression plasmid (MCF-7/PGRMC1-3HA [WT-12]). To test the effects of E2 and progestogens on cell proliferation, MCF-7 and WT-12 cells were stimulated with different concentrations of E2 (10 and 10 M) alone and in combination with progesterone and medroxyprogesterone acetate (each 10 M). E2 elicited a concentration-dependent proliferative effect on both cell lines, which was much more pronounced in WT-12 cells (50% vs 200%). This effect could be completely abrogated by the addition of the E2 antagonist fulvestrant. Addition of progesterone had no influence on the E2-induced effect, whereas medroxy-progesterone acetate enhanced the E2-induced effect at a low E2 concentration, which was, again, more pronounced in the WT-12 cells. The figures were between 20% and 40% in MCF-7 and between 60% and 250% in WT-12 cells. Overexpression of PGRMC1 sensitizes the proliferative response of the MCF-7 breast cancer cell line to estradiol. The effect of progestogens on breast cancer tumorigenesis may depend on the specific progestogen used for hormone therapy or oral contraception.

  8. Advanced oxidation protein products sensitized the transient receptor potential vanilloid 1 via NADPH oxidase 1 and 4 to cause mechanical hyperalgesia

    Directory of Open Access Journals (Sweden)

    Ruoting Ding

    2016-12-01

    Full Text Available Oxidative stress is a possible pathogenesis of hyperalgesia. Advanced oxidation protein products (AOPPs, a new family of oxidized protein compounds, have been considered as a novel marker of oxidative stress. However, the role of AOPPs in the mechanism of hyperalgesia remains unknown. Our study aims to investigate whether AOPPs have an effect on hyperalgesia and the possible underlying mechanisms. To identify the AOPPs involved, we induced hyperalgesia in rats by injecting complete Freund’s adjuvant (CFA in hindpaw. The level of plasma AOPPs in CFA-induced rats was 1.6-fold in comparison with what in normal rats (P<0.05. After intravenous injection of AOPPs-modified rat serum albumin (AOPPs-RSA in Sprague-Dawley rats, the paw mechanical thresholds, measured by the electronic von Frey system, significantly declined. Immunofluorescence staining indicated that AOPPs increased expressions of NADPH oxidase 1 (Nox1, NADPH oxidase 4 (Nox4, transient receptor potential vanilloid 1 (TRPV1 and calcitonin gene-related peptide (CGRP in the dorsal root ganglia (DRG tissues. In-vitro studies were performed on primary DRG neurons which were obtained from both thoracic and lumbar DRG of rats. Results indicated that AOPPs triggered reactive oxygen species (ROS production in DRG neurons, which were significantly abolished by ROS scavenger N-acetyl-l-cysteine (NAC and small-interfering RNA (siRNA silencing of Nox1 or Nox4. The expressions of Nox1, Nox4, TRPV1 and CGRP were significantly increased in AOPPs-induced DRG neurons. And relevant siRNA or inhibitors notably suppressed the expressions of these proteins and the calcium influxes in AOPPs-induced DRG neurons. In conclusion, AOPPs increased significantly in CFA-induced hyperalgesia rats and they activated Nox1/Nox4-ROS to sensitize TRPV1-dependent Ca2+ influx and CGRP release which led to inducing mechanical hyperalgesia.

  9. Adrenergic effects on renal secretion of epidermal growth factor in the rat

    DEFF Research Database (Denmark)

    Poulsen, Steen Seier; Nexø, Ebba

    1985-01-01

    Urinary epidermal growth factor (EGF) has been demonstrated recently to originate from the kidneys. The present study was undertaken to investigate the adrenergic and cholinergic influence on secretion of renal EGF. beta-Adrenergic agonists increased the level of urinary EGF, while propranolol......, a beta-adrenergic blocking agent, decreased basal and beta-adrenergic stimulated total output of urinary EGF. Acetylcholine and the anticholinergic agent atropine had no effect on the output of EGF in urine. Also chemical sympathectomy induced by 6-hydroxydopamine reduced the urinary output of EGF. None...... of the experimental groups had a median serum concentration above the detection limit of the assay. The present study shows that secretion of renal EGF is under the influence of the sympathetic nervous system and release of EGF is stimulated by activation of beta-adrenergic receptors in the kidneys....

  10. The Combination of Marketed Antagonists of α1b-Adrenergic and 5-HT2A Receptors Inhibits Behavioral Sensitization and Preference to Alcohol in Mice: A Promising Approach for the Treatment of Alcohol Dependence.

    Directory of Open Access Journals (Sweden)

    Fabrice Trovero

    Full Text Available Alcohol-dependence is a chronic disease with a dramatic and expensive social impact. Previous studies have indicated that the blockade of two monoaminergic receptors, α1b-adrenergic and 5-HT2A, could inhibit the development of behavioral sensitization to drugs of abuse, a hallmark of drug-seeking and drug-taking behaviors in rodents. Here, in order to develop a potential therapeutic treatment of alcohol dependence in humans, we have blocked these two monoaminergic receptors by a combination of antagonists already approved by Health Agencies. We show that the association of ifenprodil (1 mg/kg and cyproheptadine (1 mg/kg (α1-adrenergic and 5-HT2 receptor antagonists marketed as Vadilex ® and Periactine ® in France, respectively blocks behavioral sensitization to amphetamine in C57Bl6 mice and to alcohol in DBA2 mice. Moreover, this combination of antagonists inhibits alcohol intake in mice habituated to alcohol (10% v/v and reverses their alcohol preference. Finally, in order to verify that the effect of ifenprodil was not due to its anti-NMDA receptors property, we have shown that a combination of prazosin (0.5 mg/kg, an α1b-adrenergic antagonist, Mini-Press ® in France and cyproheptadine (1 mg/kg could also reverse alcohol preference. Altogether these findings strongly suggest that combined prazosin and cyproheptadine could be efficient as a therapy to treat alcoholism in humans. Finally, because α1b-adrenergic and 5-HT2A receptors blockade also inhibits behavioral sensitization to psychostimulants, opioids and tobacco, it cannot be excluded that this combination will exhibit some efficacy in the treatment of addiction to other abused drugs.

  11. Impact of the putative cancer stem cell markers and growth factor receptor expression on the sensitivity of ovarian cancer cells to treatment with various forms of small molecule tyrosine kinase inhibitors and cytotoxic drugs

    OpenAIRE

    Puvanenthiran, Soozana; Essapen, Sharadah; Seddon, Alan M.; Modjtahedi, Helmout

    2016-01-01

    Increased expression and activation of human epidermal growth factor receptor (EGFR) and HER-2 have been reported in numerous cancers. The aim of this study was to determine the sensitivity of a large panel of human ovarian cancer cell lines (OCCLs) to treatment with various forms of small molecule tyrosine kinase inhibitors (TKIs) and cytotoxic drugs. The aim was to see if there was any association between the protein expression of various biomarkers including three putative ovarian cancer s...

  12. The flinders sensitive line rats, a genetic model of depression, show abnormal serotonin receptor mRNA expression in the brain that is reversed by 17beta-estradiol.

    Science.gov (United States)

    Osterlund, M K; Overstreet, D H; Hurd, Y L

    1999-12-10

    The possible link between estrogen and serotonin (5-HT) in depression was investigated using a genetic animal model of depression, the Flinders Sensitive Line (FSL) rats, in comparison to control Flinders Resistant Line rats. The mRNA levels of the estrogen receptor (ER) alpha and beta subtypes and the 5-HT(1A) and 5-HT(2A) receptors were analyzed in several limbic-related areas of ovariectomized FSL and FRL rats treated with 17beta-estradiol (0.15 microg/g) or vehicle. The FSL animals were shown to express significantly lower levels of the 5-HT(2A) receptor transcripts in the perirhinal cortex, piriform cortex, and medial anterodorsal amygdala and higher levels in the CA 2-3 region of the hippocampus. The only significant difference between the rat lines in ER mRNA expression was found in the medial posterodorsal amygdala, where the FSL rats showed lower ERalpha expression levels. Overall, estradiol treatment increased 5-HT(2A) and decreased 5-HT(1A) receptor mRNA levels in several of the examined regions of both lines. Thus, in many areas, estradiol was found to regulate the 5-HT receptor mRNA expression in the opposite direction to the alterations found in the FSL rats. These findings further support the implication of 5-HT receptors, in particular the 5-HT(2A) subtype, in the etiology of affective disorders. Moreover, the ability of estradiol to regulate the expression of the 5-HT(1A) and 5-HT(2A) receptor genes might account for the reported influence of gonadal hormones in mood and depression.

  13. Direct control of peripheral lipid deposition by CNS GLP-1 receptor signaling is mediated by the sympathetic nervous system and blunted in diet-induced obesity.

    Science.gov (United States)

    Nogueiras, Ruben; Pérez-Tilve, Diego; Veyrat-Durebex, Christelle; Morgan, Donald A; Varela, Luis; Haynes, William G; Patterson, James T; Disse, Emmanuel; Pfluger, Paul T; López, Miguel; Woods, Stephen C; DiMarchi, Richard; Diéguez, Carlos; Rahmouni, Kamal; Rohner-Jeanrenaud, Françoise; Tschöp, Matthias H

    2009-05-06

    We investigated a possible role of the central glucagon-like peptide (GLP-1) receptor system as an essential brain circuit regulating adiposity through effects on nutrient partitioning and lipid metabolism independent from feeding behavior. Both lean and diet-induced obesity mice were used for our experiments. GLP-1 (7-36) amide was infused in the brain for 2 or 7 d. The expression of key enzymes involved in lipid metabolism was measured by real-time PCR or Western blot. To test the hypothesis that the sympathetic nervous system may be responsible for informing adipocytes about changes in CNS GLP-1 tone, we have performed direct recording of sympathetic nerve activity combined with experiments in genetically manipulated mice lacking beta-adrenergic receptors. Intracerebroventricular infusion of GLP-1 in mice directly and potently decreases lipid storage in white adipose tissue. These effects are independent from nutrient intake. Such CNS control of adipocyte metabolism was found to depend partially on a functional sympathetic nervous system. Furthermore, the effects of CNS GLP-1 on adipocyte metabolism were blunted in diet-induced obese mice. The CNS GLP-1 system decreases fat storage via direct modulation of adipocyte metabolism. This CNS GLP-1 control of adipocyte lipid metabolism appears to be mediated at least in part by the sympathetic nervous system and is independent of parallel changes in food intake and body weight. Importantly, the CNS GLP-1 system loses the capacity to modulate adipocyte metabolism in obese states, suggesting an obesity-induced adipocyte resistance to CNS GLP-1.

  14. Bone stroma-derived cells change coregulators recruitment to androgen receptor and decrease cell proliferation in androgen-sensitive and castration-resistant prostate cancer cells

    Energy Technology Data Exchange (ETDEWEB)

    Villagran, Marcelo A.; Gutierrez-Castro, Francisco A.; Pantoja, Diego F.; Alarcon, Jose C.; Fariña, Macarena A.; Amigo, Romina F.; Muñoz-Godoy, Natalia A. [Molecular Endocrinology and Oncology Laboratory, University of Concepcion, Concepcion (Chile); Pinilla, Mabel G. [Department of Medical Specialties, School of Medicine, University of Concepcion, Concepcion (Chile); Peña, Eduardo A.; Gonzalez-Chavarria, Ivan; Toledo, Jorge R.; Rivas, Coralia I.; Vera, Juan C. [Department of Physiopathology, School of Biological Sciences, University of Concepcion, Concepcion (Chile); McNerney, Eileen M. [Molecular Endocrinology and Oncology Laboratory, University of Concepcion, Concepcion (Chile); Onate, Sergio A., E-mail: sergio.onate@udec.cl [Molecular Endocrinology and Oncology Laboratory, University of Concepcion, Concepcion (Chile); Department of Medical Specialties, School of Medicine, University of Concepcion, Concepcion (Chile); Department of Urology, State University of New York at Buffalo, NY (United States)

    2015-11-27

    Prostate cancer (CaP) bone metastasis is an early event that remains inactive until later-stage progression. Reduced levels of circulating androgens, due to andropause or androgen deprivation therapies, alter androgen receptor (AR) coactivator expression. Coactivators shift the balance towards enhanced AR-mediated gene transcription that promotes progression to androgen-resistance. Disruptions in coregulators may represent a molecular switch that reactivates latent bone metastasis. Changes in AR-mediated transcription in androgen-sensitive LNCaP and androgen-resistant C4-2 cells were analyzed for AR coregulator recruitment in co-culture with Saos-2 and THP-1. The Saos-2 cell line derived from human osteosarcoma and THP-1 cell line representing human monocytes were used to display osteoblast and osteoclast activity. Increased AR activity in androgen-resistant C4-2 was due to increased AR expression and SRC1/TIF2 recruitment and decreased SMRT/NCoR expression. AR activity in both cell types was decreased over 90% when co-cultured with Saos-2 or THP-1 due to dissociation of AR from the SRC1/TIF2 and SMRT/NCoR coregulators complex, in a ligand-dependent and cell-type specific manner. In the absence of androgens, Saos-2 decreased while THP-1 increased proliferation of LNCaP cells. In contrast, both Saos-2 and THP-1 decreased proliferation of C4-2 in absence and presence of androgens. Global changes in gene expression from both CaP cell lines identified potential cell cycle and androgen regulated genes as mechanisms for changes in cell proliferation and AR-mediated transactivation in the context of bone marrow stroma cells. - Highlights: • Decreased corepressor expression change AR in androgen-resistance prostate cancer. • Bone stroma-derived cells change AR coregulator recruitment in prostate cancer. • Bone stroma cells change cell proliferation in androgen-resistant cancer cells. • Global gene expression in CaP cells is modified by bone stroma cells in co

  15. Bone stroma-derived cells change coregulators recruitment to androgen receptor and decrease cell proliferation in androgen-sensitive and castration-resistant prostate cancer cells

    International Nuclear Information System (INIS)

    Villagran, Marcelo A.; Gutierrez-Castro, Francisco A.; Pantoja, Diego F.; Alarcon, Jose C.; Fariña, Macarena A.; Amigo, Romina F.; Muñoz-Godoy, Natalia A.; Pinilla, Mabel G.; Peña, Eduardo A.; Gonzalez-Chavarria, Ivan; Toledo, Jorge R.; Rivas, Coralia I.; Vera, Juan C.; McNerney, Eileen M.; Onate, Sergio A.

    2015-01-01

    Prostate cancer (CaP) bone metastasis is an early event that remains inactive until later-stage progression. Reduced levels of circulating androgens, due to andropause or androgen deprivation therapies, alter androgen receptor (AR) coactivator expression. Coactivators shift the balance towards enhanced AR-mediated gene transcription that promotes progression to androgen-resistance. Disruptions in coregulators may represent a molecular switch that reactivates latent bone metastasis. Changes in AR-mediated transcription in androgen-sensitive LNCaP and androgen-resistant C4-2 cells were analyzed for AR coregulator recruitment in co-culture with Saos-2 and THP-1. The Saos-2 cell line derived from human osteosarcoma and THP-1 cell line representing human monocytes were used to display osteoblast and osteoclast activity. Increased AR activity in androgen-resistant C4-2 was due to increased AR expression and SRC1/TIF2 recruitment and decreased SMRT/NCoR expression. AR activity in both cell types was decreased over 90% when co-cultured with Saos-2 or THP-1 due to dissociation of AR from the SRC1/TIF2 and SMRT/NCoR coregulators complex, in a ligand-dependent and cell-type specific manner. In the absence of androgens, Saos-2 decreased while THP-1 increased proliferation of LNCaP cells. In contrast, both Saos-2 and THP-1 decreased proliferation of C4-2 in absence and presence of androgens. Global changes in gene expression from both CaP cell lines identified potential cell cycle and androgen regulated genes as mechanisms for changes in cell proliferation and AR-mediated transactivation in the context of bone marrow stroma cells. - Highlights: • Decreased corepressor expression change AR in androgen-resistance prostate cancer. • Bone stroma-derived cells change AR coregulator recruitment in prostate cancer. • Bone stroma cells change cell proliferation in androgen-resistant cancer cells. • Global gene expression in CaP cells is modified by bone stroma cells in co

  16. Transferrin receptor-targeted pH-sensitive micellar system for diminution of drug resistance and targetable delivery in multidrug-resistant breast cancer

    Directory of Open Access Journals (Sweden)

    Gao W

    2017-02-01

    Full Text Available Wei Gao,1 Guihua Ye,1 Xiaochuan Duan,1 Xiaoying Yang,1 Victor C Yang1,2 1Tianjin Key Laboratory on Technologies Enabling Development of Clinical Therapeutics and Diagnostics (Theranostics, School of Pharmacy, Tianjin Medical University, Tianjin, People’s Republic of China; 2Department of Pharmaceutical Sciences, College of Pharmacy, University of Michigan, Ann Arbor, MI, USA Abstract: The emergence of drug resistance is partially associated with overproduction of transferrin receptor (TfR. To overcome multidrug resistance (MDR and achieve tumor target delivery, we designed a novel biodegradable pH-sensitive micellar system modified with HAIYPRH, a TfR ligand (7pep. First, the polymers poly(l-histidine-coupled polyethylene glycol-2000 (PHIS-PEG2000 and 7pep-modified 1,2-distearoyl-sn-glycero-3-phosphoethanolamine-polyethylene glycol-2000 (7pep-DSPE-PEG2000 were synthesized, and the mixed micelles were prepared by blending of PHIS-PEG2000 and 1,2-distearoyl-sn-glycero-3-phosphoethanolamine-polyethylene glycol-2000 (DSPE-PEG2000 or 7pep-DSPE-PEG2000 (7-pep HD micelles. The micelles exhibited good size uniformity, high encapsulation efficiency, and a low critical micelle concentration. By changing the polymer ratio in the micellar formulation, the pH response range was specially tailored to pH ~6.0. When loaded with antitumor drug doxorubicin (DOX, the micelle showed an acid pH-triggering drug release profile. The cellular uptake and cytotoxicity study demonstrated that 7-pep HD micelles could significantly enhance the intracellular level and antitumor efficacy of DOX in multidrug-resistant cells (MCF-7/Adr, which attributed to the synergistic effect of poly(l-histidine-triggered endolysosom escape and TfR-mediated endocytosis. Most importantly, the in vivo imaging study confirmed the targetability of 7-pep HD micelles to MDR tumor. These findings indicated that 7-pep HD micelles would be a promising drug delivery system in the treatment of drug

  17. Prenatal exposure to an NMDA receptor antagonist, MK-801 reduces density of parvalbumin-immunoreactive GABAergic neurons in the medial prefrontal cortex and enhances phencyclidine-induced hyperlocomotion but not behavioral sensitization to methamphetamine in postpubertal rats.

    Science.gov (United States)

    Abekawa, Tomohiro; Ito, Koki; Nakagawa, Shin; Koyama, Tsukasa

    2007-06-01

    Neurodevelopmental deficits of parvalbumin-immunoreactive gamma-aminobutyric acid (GABA)ergic interneurons in prefrontal cortex have been reported in schizophrenia. Glutamate influences the proliferation of this type of interneuron by an N-methyl-D-aspartate (NMDA)-receptor-mediated mechanism. The present study hypothesized that prenatal blockade of NMDA receptors would disrupt GABAergic neurodevelopment, resulting in differences in effects on behavioral responses to a noncompetitive NMDA antagonist, phencyclidine (PCP), and a dopamine releaser, methamphetamine (METH). GABAergic neurons were immunohistochemically stained with parvalbumin antibody. Psychostimulant-induced hyperlocomotion was measured using an infrared sensor. Prenatal exposure (E15-E18) to the NMDA receptor antagonist MK-801 reduced the density of parvalbumin-immunoreactive neurons in rat medial prefrontal cortex on postnatal day 63 (P63) and enhanced PCP-induced hyperlocomotion but not the acute effects of METH on P63 or the development of behavioral sensitization. Prenatal exposure to MK-801 reduced the number of parvalbumin-immunoreactive neurons even on postnatal day 35 (P35) and did not enhance PCP-induced hyperlocomotion, the acute effects of METH on P35, or the development of behavioral sensitization to METH. These findings suggest that prenatal blockade of NMDA receptors disrupts GABAergic neurodevelopment in medial prefrontal cortex, and that this disruption of GABAergic development may be related to the enhancement of the locomotion-inducing effect of PCP in postpubertal but not juvenile offspring. GABAergic deficit is unrelated to the effects of METH. This GABAergic neurodevelopmental disruption and the enhanced PCP-induced hyperlocomotion in adult offspring prenatally exposed to MK-801 may prove useful as a new model of the neurodevelopmental process of pathogenesis of treatment-resistant schizophrenia via an NMDA-receptor-mediated hypoglutamatergic mechanism.

  18. Antihistamines suppress upregulation of histidine decarboxylase gene expression with potencies different from their binding affinities for histamine H1 receptor in toluene 2,4-diisocyanate-sensitized rats

    Directory of Open Access Journals (Sweden)

    Hiroyuki Mizuguchi

    2016-04-01

    Full Text Available Antihistamines inhibit histamine signaling by blocking histamine H1 receptor (H1R or suppressing H1R signaling as inverse agonists. The H1R gene is upregulated in patients with pollinosis, and its expression level is correlated with the severity of nasal symptoms. Here, we show that antihistamine suppressed upregulation of histidine decarboxylase (HDC mRNA expression in patients with pollinosis, and its expression level was correlated with that of H1R mRNA. Certain antihistamines, including mepyramine and diphenhydramine, suppress toluene-2,4-diisocyanate (TDI-induced upregulation of HDC gene expression and increase HDC activity in TDI-sensitized rats. However, d-chlorpheniramine did not demonstrate any effect. The potencies of antihistamine suppressive effects on HDC mRNA elevation were different from their H1R receptor binding affinities. In TDI-sensitized rats, the potencies of antihistamine inhibitory effects on sneezing in the early phase were related to H1R binding. In contrast, the potencies of their inhibitory effects on sneezing in the late phase were correlated with those of suppressive effects on HDC mRNA elevation. Data suggest that in addition to the antihistaminic and inverse agonistic activities, certain antihistamines possess additional properties unrelated to receptor binding and alleviate nasal symptoms in the late phase by inhibiting synthesis and release of histamine by suppressing HDC gene transcription.

  19. Dissociation of thirst and sodium appetite in the furo/cap model of extracellular dehydration and a role for N-methyl-D-aspartate receptors in the sensitization of sodium appetite

    Science.gov (United States)

    Hurley, Seth. W.; Johnson, Alan Kim

    2015-01-01

    Depletion of extracellular fluids motivates many animals to seek out and ingest water and sodium. Animals with a history of extracellular dehydration display enhanced sodium appetite and in some cases thirst. The progressive increase in sodium intake induced by repeated sodium depletions is known as sensitization of sodium appetite. Administration of the diuretic and natriuretic drug, furosemide, along with a low dose of captopril (furo/cap), elicits thirst and a rapid onset of sodium appetite. In the present studies the furo/cap model was used to explore the physiological mechanisms of sensitization of sodium appetite. However, when thirst and sodium appetite were measured concurrently in the furo/cap model, individual rats exhibited sensitization of either thirst or sodium appetite. In subsequent studies, thirst and sodium appetite were dissociated by offering either water prior to sodium or sodium before water. When water and sodium intake were dissociated in time, the furo/cap model reliably produced sensitization of sodium appetite. It is likely that neuroplasticity mediates this sensitization. Glutamatergic N-methyl-d-aspartate receptor (NMDA-R) activation is critical for the development of most forms of neuroplasticity. Therefore, we hypothesized that integrity of NMDA-R function is necessary for the sensitization of sodium appetite. Pharmacological blockade of NMDA-Rs with systemic administration of MK-801 (0.15mg/kg) prevented the sensitization of fluid intake in general when water and sodium were offered concurrently, and prevented sensitization of sodium intake specifically when water and sodium intake were dissociated. The involvement of NMDA-Rs provides support for the possibility that sensitization of sodium appetite is mediated by neuroplasticity. PMID:24341713

  20. Betaxolol, a selective beta(1)-adrenergic receptor antagonist, diminishes anxiety-like behavior during early withdrawal from chronic cocaine administration in rats.

    Science.gov (United States)

    Rudoy, C A; Van Bockstaele, E J

    2007-06-30

    Anxiety has been indicated as one of the main symptoms of the cocaine withdrawal syndrome in human addicts and severe anxiety during withdrawal may potentially contribute to relapse. As alterations in noradrenergic transmission in limbic areas underlie withdrawal symptomatology for many drugs of abuse, the present study sought to determine the effect of cocaine withdrawal on beta-adrenergic receptor (beta(1) and beta(2)) expression in the amygdala. Male Sprague Dawley rats were administered intraperitoneal (i.p.) injections of cocaine (20 mg/kg) once daily for 14 days. Two days following the last cocaine injection, amygdala brain regions were micro-dissected and processed for Western blot analysis. Results showed that beta(1)-adrenergic receptor, but not beta(2)-adrenergic receptor expression was significantly increased in amygdala extracts of cocaine-withdrawn animals as compared to controls. This finding motivated further studies aimed at determining whether treatment with betaxolol, a highly selective beta(1)-adrenergic receptor antagonist, could ameliorate cocaine withdrawal-induced anxiety. In these studies, betaxolol (5 mg/kg via i.p. injection) was administered at 24 and then 44 h following the final chronic cocaine administration. Anxiety-like behavior was evaluated using the elevated plus maze test approximately 2 h following the last betaxolol injection. Following behavioral testing, betaxolol effects on beta(1)-adrenergic receptor protein expression were examined by Western blotting in amygdala extracts from rats undergoing cocaine withdrawal. Animals treated with betaxolol during cocaine withdrawal exhibited a significant attenuation of anxiety-like behavior characterized by increased time spent in the open arms and increased entries into the open arms compared to animals treated with only saline during cocaine withdrawal. In contrast, betaxolol did not produce anxiolytic-like effects in control animals treated chronically with saline. Furthermore

  1. The nicotinic α6 subunit gene determines variability in chronic pain sensitivity via cross-inhibition of P2X2/3 receptors

    DEFF Research Database (Denmark)

    Wieskopf, Jeffrey S; Mathur, Jayanti; Limapichat, Walrati

    2015-01-01

    expression levels of Chrna6, which encodes the α6 subunit of the nicotinic acetylcholine receptor (nAChR), as highly associated with allodynia. We confirmed the importance of α6* (α6-containing) nAChRs by analyzing both gain- and loss-of-function mutants. We find that mechanical allodynia associated...... with neuropathic and inflammatory injuries is significantly altered in α6* mutants, and that α6* but not α4* nicotinic receptors are absolutely required for peripheral and/or spinal nicotine analgesia. Furthermore, we show that Chrna6's role in analgesia is at least partially due to direct interaction and cross...

  2. Dominant portion of thyrotropin-releasing hormone receptor is excluded from lipid domains. Detergent-resistant and detergent-sensitive pools of TRH receptor and Gq alpha/G11 alpha protein

    Czech Academy of Sciences Publication Activity Database

    Rudajev, Vladimír; Novotný, Jiří; Hejnová, Lucie; Milligan, G.; Svoboda, Petr

    2005-01-01

    Roč. 138, č. 2 (2005), s. 111-125 ISSN 0021-924X R&D Projects: GA MŠk(CZ) LC554 Grant - others:GA-(GB) Wellcome Trust Institutional research plan: CEZ:AV0Z50110509 Keywords : TRH receptor * lipid domains * trimeric G proteins Subject RIV: CE - Biochemistry Impact factor: 1.827, year: 2005

  3. Sensitizing pigment in the fly

    International Nuclear Information System (INIS)

    Vogt, K.; Kirschfeld, K.

    1983-01-01

    The sensitizing pigment hypothesis for the high UV sensitivity in fly photoreceptors (R1-6) is further substantiated by measurements of the polarisation sensitivity in the UV. The quantum yield of the energy transfer from sensitizing pigment to rhodopsin was estimated by electrophysiological measurements of the UV sensitivity and the rhabdomeric absorptance (at 490 nm) in individual receptor cells. The transfer efficiency is >=0.75 in receptors with an absorptance in the rhabdomeres of 0.55-0.95. This result suggests that the sensitizing pigment is bound in some way to the rhodopsin. A ratio of two molecules of sensitizing pigment per one rhodopsin is proposed. (orig.)

  4. Nociceptin/orphanin FQ peptide receptor agonist Ac-RYYRWKKKKKKK-NH2 (ZP120) induces antinatriuresis in rats by stimulation of amiloride-sensitive sodium reabsorption

    DEFF Research Database (Denmark)

    van Deurs, Ulla S K; Hadrup, Niels; Petersen, Jørgen Søberg

    2008-01-01

    receptors are expressed in the distal convoluted tubules, the connecting tubules, and the collecting ducts. Using clearance techniques, we evaluated renal excretory function during acute administration of ZP120 (1 nmol/kg/min) in chronically catheterized, conscious rats (n = 8/group). To examine...

  5. [3H]WB4101 labels the 5-HT1A serotonin receptor subtype in rat brain. Guanine nucleotide and divalent cation sensitivity

    International Nuclear Information System (INIS)

    Norman, A.B.; Battaglia, G.; Creese, I.

    1985-01-01

    In the presence of a 30 nM prazosin mask, [ 3 H]-2-(2,6-dimethoxyphenoxyethyl) aminomethyl-1,4-benzodioxane ([ 3 H]WB4101) can selectively label 5-HT1 serotonin receptors. Serotonin exhibits high affinity (Ki = 2.5 nM) and monophasic competition for [ 3 H] WB4101 binding in cerebral cortex. We have found a significant correlation (r = 0.96) between the affinities of a number of serotonergic and nonserotonergic compounds at [ 3 H]WB4101-binding sites in the presence of 30 nM prazosin and [ 3 H] lysergic acid diethylamide ([ 3 H]LSD)-labeled 5-HT1 serotonin receptors in homogenates of rat cerebral cortex. Despite similar pharmacological profiles, distribution studies indicate that, in the presence of 5 mM MgSO4, the Bmax of [ 3 H]WB4101 is significantly lower than the Bmax of [ 3 H]LSD in various brain regions. WB4101 competition for [ 3 H] LSD-labeled 5-HT1 receptors fits best to a computer-derived model assuming two binding sites, with the KH for WB4101 being similar to the KD of [ 3 H]WB4101 binding derived from saturation experiments. This suggests that [ 3 H]WB4101 labels only one of the subtypes of the 5-HT1 serotonin receptors labeled by [ 3 H]LSD. The selective 5-HT1A serotonin receptor antagonist, spiperone, and the selective 5-HT1A agonist, 8-hydroxy-2-(di-n-propylamino) tetraline, exhibit high affinity and monophasic competition for [ 3 H]WB4101 but compete for multiple [ 3 H]LSD 5-HT1 binding sites. These data indicate that [ 3 H]WB4101 selectively labels the 5-HT1A serotonin receptor, whereas [ 3 H] LSD appears to label both the 5-HT1A and the 5-HT1B serotonin receptor subtypes. The divalent cations, Mn2+, Mg2+, and Ca2+ were found to markedly increase the affinity and Bmax of [ 3 H]WB4101 binding in cerebral cortex. Conversely, the guanine nucleotides guanylylimidodiphosphate and GTP, but not the adenosine nucleotide ATP, markedly reduce the Bmax of [ 3 H]WB4101 binding

  6. Glycyrrhetic acid synergistically enhances β₂-adrenergic receptor-Gs signaling by changing the location of Gαs in lipid rafts.

    Directory of Open Access Journals (Sweden)

    Qian Shi

    Full Text Available Glycyrrhetic acid (GA exerts synergistic anti-asthmatic effects via a β₂-adrenergic receptor (β₂AR-mediated pathway. Cholesterol is an important component of the structure and function of lipid rafts, which play critical roles in the β₂AR-Gs-adenylate cyclase (AC-mediated signaling pathway. Owing to the structural similarities between GA and cholesterol, we investigated the possibility that GA enhances β₂AR signaling by altering cholesterol distribution. Azide-terminal GA (ATGA was synthesized and applied to human embryonic kidney 293 (HEK293 cells expressing fusion β₂AR, and the electron spin resonance (ESR technique was utilized. GA was determined to be localized predominantly on membrane and decreased their cholesterol contents. Thus, the fluidity of the hydrophobic region increased but not the polar surface of the cell membrane. The conformations of membrane proteins were also changed. GA further changed the localization of Gαs from lipid rafts to non-raft regions, resulting the binding of β₂AR and Gαs, as well as in reduced β₂AR internalization. Co-localization of β₂AR, Gαs, and AC increased isoproterenol-induced cAMP production and cholesterol reloading attenuated this effect. A speculation wherein GA enhances beta-adrenergic activity by increasing the functional linkage between the subcomponents of the membrane β₂AR-protein kinase A (PKA signaling pathway was proposed. The enhanced efficacy of β₂AR agonists by this novel mechanism could prevent tachyphylaxis.

  7. The metabolic impact of β-hydroxybutyrate on neurotransmission: Reduced glycolysis mediates changes in calcium responses and KATP channel receptor sensitivity

    DEFF Research Database (Denmark)

    Lund, Trine Meldgaard; Ploug, K.B.; Iversen, Anne

    2015-01-01

    -hydroxybutyrate might change neuronal function as there is a known coupling between metabolism and neurotransmission. The purpose of this study was to shed light on the effects of the ketone body β-hydroxybutyrate on glycolysis and neurotransmission in cultured murine glutamatergic neurons. Previous studies have shown...... an effect of β-hydroxybutyrate on glucose metabolism, and the present study further specified this by showing attenuation of glycolysis when β-hydroxybutyrate was present in these neurons. In addition, the NMDA receptor-induced calcium responses in the neurons were diminished in the presence of β...... to a combination of glucose and R-β-hydroxybutyrate in cultured neurons. Using the latter combination, glycolysis was diminished, NMDA receptor-induced calcium responses were lower, and the KATP channel blocker glibenclamide caused a higher transmitter release....

  8. Combined receptor antagonist stimulation of the hypothalamic-pituitary-adrenal axis test identifies impaired negative feedback sensitivity to cortisol in obese men.

    Science.gov (United States)

    Mattsson, Cecilia; Reynolds, Rebecca M; Simonyte, Kotryna; Olsson, Tommy; Walker, Brian R

    2009-04-01

    Hypothalamic-pituitary-adrenal (HPA) axis dysregulation may underlie disorders including obesity, depression, cognitive decline, and the metabolic syndrome. Conventional tests of HPA axis negative feedback rely on glucocorticoid receptor (GR) agonists such as dexamethasone but do not test feedback by endogenous cortisol, potentially mediated by both GR and mineralocorticoid receptors (MR). The objective of the study was to use a combination of GR (RU38486, mifepristone) and MR (spironolactone) antagonists to explore the poorly understood activation of the HPA axis that occurs in obesity. This was a double-blind, placebo-controlled, randomized, crossover study. The study was conducted at a clinical research facility. Participants included 15 lean (body mass index 22.0 +/- 1.6 kg/m(2)) and 16 overweight/obese (body mass index 30.1 +/- 3.5 kg/m(2)) men. Subjects attended on four occasions for blood and saliva sampling every 30 min between 1800 and 2200 h. At 1100 and 1600 h before visits, subjects took 200 mg spironolactone, 400 mg RU38486, 200 mg spironolactone + 400 mg RU38486, or placebo orally. Serum cortisol levels after drug or placebo were measured. Cortisol levels did not differ between lean and obese after placebo. Spironolactone and RU38486 alone had modest effects, increasing cortisol by less than 50% in both groups. However, combined spironolactone plus RU38486 elevated cortisol concentrations substantially, more so in lean than obese men [2.9- (0.3) vs. 2.2 (0.3)-fold elevation, P = 0.002]. Combined receptor antagonist stimulation of the HPA axis reveals redundancy of MR and GR in negative feedback in humans. Obese men have impaired responses to combined receptor antagonist stimulation, suggesting impaired negative feedback by endogenous cortisol. Such an approach may be useful to dissect abnormal HPA axis control in neuropsychiatric and other disorders.

  9. Insulin receptors

    International Nuclear Information System (INIS)

    Kahn, C.R.; Harrison, L.C.

    1988-01-01

    This book contains the proceedings on insulin receptors. Part A: Methods for the study of structure and function. Topics covered include: Method for purification and labeling of insulin receptors, the insulin receptor kinase, and insulin receptors on special tissues

  10. Glucagon and plasma catecholamines during beta-receptor blockade in exercising man

    DEFF Research Database (Denmark)

    Galbo, H; Holst, Janett; Christensen, N J

    1976-01-01

    Seven men ran at 60% of individual maximal oxygen uptake to exhaustion during beta-adrenergic blockade with propranolol (P), during lipolytic blockade with nicotinic acid (N), or without drugs (C). The total work times (83 +/- 9 (P), 122 +/- 8 (N), 166 +/- 10 (C) min, mean and SE) differed signif...... determinants for the exercise-induced glucagon secretion in man. It is suggested that decreased glucose availability enhances the secretion of glucagon and epinephrine during prolonged exercise....

  11. 4-IBP, a σ1 Receptor Agonist, Decreases the Migration of Human Cancer Cells, Including Glioblastoma Cells, In Vitro and Sensitizes Them In Vitro and In Vivo to Cytotoxic Insults of Proapoptotic and Proautophagic Drugs

    Directory of Open Access Journals (Sweden)

    Veronique Mégalizzi

    2007-05-01

    Full Text Available Although the molecular function of cr receptors has not been fully defined and the natural ligand(s is still not known, there is increasing evidence that these receptors and their ligands might play a significant role in cancer biology. 4-(N-tibenzylpiperidin-4-yl-4iodobenzamide (4-IBP, a selective σ1, agonist, has been used to investigate whether this compound is able to modify: 1 in vitro the migration and proliferation of human cancer cells; 2 in vitro the sensitivity of human glioblastoma cells to cytotoxic drugs; and 3 in vivo in orthotopic glioblastoma and non-small cell lung carcinoma (NSCLC models the survival of mice coadministered cytotoxic agents. 4-IBP has revealed weak anti proliferative effects on human U373-MG glioblastoma and C32 melanoma cells but induced marked concentration-dependent decreases in the growth of human A549 NSCLC and PC3 prostate cancer cells. The compound was also significantly antimigratory in all four cancer cell lines. This may result, at least in U373-MG cells, from modifications to the actin cytoskeleton. 4-IBP modified the sensitivity of U373-MG cells in vitro to proapoptotic lomustin and proautophagic temozolomide, and markedly decreased the expression of two proteins involved in drug resistance: glucosylceramide synthase and Rho guanine nucleotide dissociation inhibitor. In vivo, 4-IBP increased the antitumor effects of temozolomide and irinotecan in immunodeficient mice that were orthotopically grafted with invasive cancer cells.

  12. Non-invasive screening for Alzheimer's disease by sensing salivary sugar using Drosophila cells expressing gustatory receptor (Gr5a) immobilized on an extended gate ion-sensitive field-effect transistor (EG-ISFET) biosensor.

    Science.gov (United States)

    Lau, Hui-Chong; Lee, In-Kyu; Ko, Pan-Woo; Lee, Ho-Won; Huh, Jeung-Soo; Cho, Won-Ju; Lim, Jeong-Ok

    2015-01-01

    Body fluids are often used as specimens for medical diagnosis. With the advent of advanced analytical techniques in biotechnology, the diagnostic potential of saliva has been the focus of many studies. We recently reported the presence of excess salivary sugars, in patients with Alzheimer's disease (AD). In the present study, we developed a highly sensitive, cell-based biosensor to detect trehalose levels in patient saliva. The developed biosensor relies on the overexpression of sugar sensitive gustatory receptors (Gr5a) in Drosophila cells to detect the salivary trehalose. The cell-based biosensor was built on the foundation of an improved extended gate ion-sensitive field-effect transistor (EG-ISFET). Using an EG-ISFET, instead of a traditional ion-sensitive field-effect transistor (ISFET), resulted in an increase in the sensitivity and reliability of detection. The biosensor was designed with the gate terminals segregated from the conventional ISFET device. This design allows the construction of an independent reference and sensing region for simultaneous and accurate measurements of samples from controls and patients respectively. To investigate the efficacy of the cell-based biosensor for AD screening, we collected 20 saliva samples from each of the following groups: participants diagnosed with AD, participants diagnosed with Parkinson's disease (PD), and a control group composed of healthy individuals. We then studied the response generated from the interaction of the salivary trehalose of the saliva samples and the Gr5a in the immobilized cells on an EG-ISFET sensor. The cell-based biosensor significantly distinguished salivary sugar, trehalose of the AD group from the PD and control groups. Based on these findings, we propose that salivary trehalose, might be a potential biomarker for AD and could be detected using our cell-based EG-ISFET biosensor. The cell-based EG-ISFET biosensor provides a sensitive and direct approach for salivary sugar detection and

  13. Prevention of adenosine A2A receptor activation diminishes beat-to-beat alternation in human atrial myocytes.

    Science.gov (United States)

    Molina, Cristina E; Llach, Anna; Herraiz-Martínez, Adela; Tarifa, Carmen; Barriga, Montserrat; Wiegerinck, Rob F; Fernandes, Jacqueline; Cabello, Nuria; Vallmitjana, Alex; Benitéz, Raúl; Montiel, José; Cinca, Juan; Hove-Madsen, Leif

    2016-01-01

    Atrial fibrillation (AF) has been associated with increased spontaneous calcium release from the sarcoplasmic reticulum and linked to increased adenosine A2A receptor (A2AR) expression and activation. Here we tested whether this may favor atrial arrhythmogenesis by promoting beat-to-beat alternation and irregularity. Patch-clamp and confocal calcium imaging was used to measure the beat-to-beat response of the calcium current and transient in human atrial myocytes. Responses were classified as uniform, alternating or irregular and stimulation of Gs-protein coupled receptors decreased the frequency where a uniform response could be maintained from 1.0 ± 0.1 to 0.6 ± 0.1 Hz; p < 0.01 for beta-adrenergic receptors and from 1.4 ± 0.1 to 0.5 ± 0.1 Hz; p < 0.05 for A2ARs. The latter was linked to increased spontaneous calcium release and after-depolarizations. Moreover, A2AR activation increased the fraction of non-uniformly responding cells in HL-1 myocyte cultures from 19 ± 3 to 51 ± 9 %; p < 0.02, and electrical mapping in perfused porcine atria revealed that adenosine induced electrical alternans at longer cycle lengths, doubled the fraction of electrodes showing alternation, and increased the amplitude of alternations. Importantly, protein kinase A inhibition increased the highest frequency where uniform responses could be maintained from 0.84 ± 0.12 to 1.86 ± 0.11 Hz; p < 0.001 and prevention of A2AR-activation with exogenous adenosine deaminase selectively increased the threshold from 0.8 ± 0.1 to 1.2 ± 0.1 Hz; p = 0.001 in myocytes from patients with AF. In conclusion, A2AR-activation promotes beat-to-beat irregularities in the calcium transient in human atrial myocytes, and prevention of A2AR activation may be a novel means to maintain uniform beat-to-beat responses at higher beating frequencies in patients with atrial fibrillation.

  14. Association of the AMPA receptor-related postsynaptic density proteins GRIP and ABP with subsets of glutamate-sensitive neurons in the rat retina.

    Science.gov (United States)

    Gábriel, Robert; de Souza, Sunita; Ziff, Edward B; Witkovsky, Paul

    2002-07-22

    We used specific antibodies against two postsynaptic density proteins, GRIP (glutamate receptor interacting protein) and ABP (AMPA receptor-binding protein), to study their distribution in the rat retina. In the central nervous system, it has been shown that both proteins bind strongly to the AMPA glutamate receptor (GluR) 2/3 subunits, but not other GluRs, through a set of three PDZ domains. Western blots detected a single GRIP protein that was virtually identical in retina and brain, whereas retinal ABP corresponded to only one of three ABP peptides found in brain. The retinal distributions of GluR2/3, GRIP, and ABP immunoreactivity (IR) were similar but not identical. GluR2/3 immunoreactivity (IR) was abundant in both plexiform layers and in large perikarya. ABP IR was concentrated in large perikarya but was sparse in the plexiform layers, whereas GRIP IR was relatively more abundant in the plexiform layers than in perikarya. Immunolabel for these three antibodies consisted of puncta ABP IR was examined by double labeling subclasses of retinal neuron with characteristic marker proteins, e.g., calbindin. GRIP, ABP, and GluR2/3 IR were detected in horizontal cells, dopaminergic and glycinergic AII amacrine cells and large ganglion cells. Immunolabel was absent in rod bipolar and weak or absent in cholinergic amacrine cells. By using the tyramide method of signal amplification, a colocalization of GluR2/3 was found with either GRIP or ABP in horizontal cell terminals, and perikarya of amacrine and ganglion cells. Our results show that ABP and GRIP colocalize with GluR2/3 in particular subsets of retinal neuron, as was previously established for certain neurons in the brain. Copyright 2002 Wiley-Liss, Inc.

  15. Mutation of a zinc-binding residue in the glycine receptor α1 subunit changes ethanol sensitivity in vitro and alcohol consumption in vivo.

    Science.gov (United States)

    McCracken, Lindsay M; Blednov, Yuri A; Trudell, James R; Benavidez, Jillian M; Betz, Heinrich; Harris, R Adron

    2013-02-01

    Ethanol is a widely used drug, yet an understanding of its sites and mechanisms of action remains incomplete. Among the protein targets of ethanol are glycine receptors (GlyRs), which are potentiated by millimolar concentrations of ethanol. In addition, zinc ions also modulate GlyR function, and recent evidence suggests that physiologic concentrations of zinc enhance ethanol potentiation of GlyRs. Here, we first built a homology model of a zinc-bound GlyR using the D80 position as a coordination site for a zinc ion. Next, we investigated in vitro the effects of zinc on ethanol action at recombinant wild-type (WT) and mutant α1 GlyRs containing the D80A substitution, which eliminates zinc potentiation. At D80A GlyRs, the effects of 50 and 200 mM ethanol were reduced as compared with WT receptors. Also, in contrast to what was seen with WT GlyRs, neither adding nor chelating zinc changed the magnitude of ethanol enhancement of mutant D80A receptors. Next, we evaluated the in vivo effects of the D80A substitution by using heterozygous Glra1(D80A) knock-in (KI) mice. The KI mice showed decreased ethanol consumption and preference, and they displayed increased startle responses compared with their WT littermates. Other behavioral tests, including ethanol-induced motor incoordination and strychnine-induced convulsions, revealed no differences between the KI and WT mice. Together, our findings indicate that zinc is critical in determining the effects of ethanol at GlyRs and suggest that zinc binding at the D80 position may be important for mediating some of the behavioral effects of ethanol action at GlyRs.

  16. Current knowledge on the sensitivity of the 68Ga-somatostatin receptor positron emission tomography and the SUVmax reference range for management of pancreatic neuroendocrine tumours

    OpenAIRE

    Virgolini, Irene; Gabriel, Michael; Kroiss, Alexander; von Guggenberg, Elisabeth; Prommegger, Rupert; Warwitz, Boris; Nilica, Bernhard; Roig, llanos Geraldo; Rodrigues, Margarida; Uprimny, Christian

    2016-01-01

    Physiologically increased pancreatic uptake at the head/uncinate process is observed in more than one-third of patients after injection of one of the three 68Ga-labelled octreotide-based peptides used for somatostatin (sst) receptor (r) imaging. There are minor differences between these 68Ga-sstr-binding peptides in the imaging setting. On 68Ga-sstr-imaging the physiological uptake can be diffuse or focal and usually remains stable over time. Differences in the maximal standardised uptake val...

  17. Persistent gating deficit and increased sensitivity to NMDA receptor antagonism after puberty in a new mouse model of the human 22q11.2 microdeletion syndrome

    DEFF Research Database (Denmark)

    Didriksen, Michael; Fejgin, Kim; Nilsson, Simon R O

    2016-01-01

    BACKGROUND: The hemizygous 22q11.2 microdeletion is a common copy number variant in humans. The deletion confers high risk for neurodevelopmental disorders, including autism and schizophrenia. Up to 41% of deletion carriers experience psychotic symptoms. METHODS: We present a new mouse model (Df...... displayed increased amplitude of loudness-dependent auditory evoked potentials. Prefrontal cortex and dorsal striatal elevations of the dopamine metabolite DOPAC and increased dorsal striatal expression of the AMPA receptor subunit GluR1 was found. The Df(h22q11)/+ mice did not deviate from wild-type mice...

  18. Persistent gating deficit and increased sensitivity to NMDA receptor antagonism after puberty in a new mouse model of the human 22q11.2 microdeletion syndrome

    DEFF Research Database (Denmark)

    Didriksen, Michael; Fejgin, Kim; Nilsson, Simon R O

    2017-01-01

    Background: The hemizygous 22q11.2 microdeletion is a common copy number variant in humans. The deletion confers high risk for neurodevelopmental disorders, including autism and schizophrenia. Up to 41% of deletion carriers experience psychotic symptoms. Methods: We present a new mouse model (Df...... displayed increased amplitude of loudness-dependent auditory evoked potentials. Prefrontal cortex and dorsal striatal elevations of the dopamine metabolite DOPAC and increased dorsal striatal expression of the AMPA receptor subunit GluR1 was found. The Df(h22q11)/+ mice did not deviate from wild-type mice...

  19. Functional characterization of mutants in the transmembrane domains of the rat P2X7 receptor that regulate pore conductivity and agonist sensitivity

    Czech Academy of Sciences Publication Activity Database

    Jindřichová, Marie; Bhattacharya, Anirban; Rupert, Marian; Škopek, Petr; Obšil, T.; Zemková, Hana

    2015-01-01

    Roč. 133, č. 6 (2015), s. 815-827 ISSN 0022-3042 R&D Projects: GA ČR(CZ) GPP304/12/P371; GA ČR(CZ) GBP304/12/G069; GA MŠk(CZ) EE2.3.30.0025; GA MŠk(CZ) ED1.1.00/02.0109 Institutional support: RVO:67985823 Keywords : ATP * purinergic receptor channel * P2X7 * pore dilation * YO-PRO-1 uptake Subject RIV: ED - Physiology Impact factor: 3.842, year: 2015

  20. P2Y purinoceptor and nucleotide receptor-induced relaxation of precontracted bovine aortic collateral artery rings: differential sensitivity to suramin and indomethacin.

    Science.gov (United States)

    Wilkinson, G F; McKechnie, K; Dainty, I A; Boarder, M R

    1994-02-01

    We have examined a series of adenine nucleotides and UTP for their ability to cause relaxation of precontracted bovine aortic collateral artery rings. The overall rank order of agonist potency for relaxation was 2-methylthioadenosine 5'-triphosphate (2MeSATP) > adenosine 5'-O-(3-thiotriphosphate) (ATP gamma S) > UTP > ADP > ATP. These responses were endothelium-dependent. Interaction studies showed that responses to the selective P2Y purinoceptor agonist 2MeSATP, and to ADP, were mediated by different <