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Sample records for rat isolated atria

  1. [Effects of liensinine on haemodynamics in rats and the physiologic properties of isolated rabbit atria].

    Science.gov (United States)

    Wang, J L; Nong, Y; Jing, M X

    1992-01-01

    Liensinine(Lien), an alkaloid extracted from the green seed embryo of Nelumbo nucifera Gaertn, has been shown to have anti-arrhythmic action, its mechanism may be related to blockade of Ca2+, Na+ influx. Lien 3 mg/kg i.v. may temporarily inhibit all parameters of haemodynamics in anesthetized or pithed rats. The inhibitory effects on LVP, +dp/dtmax and SAP in anesthetized rats are slightly stronger than those of quinidine (Qui) 3 mg/kg. Lien 1-30 mg/kg dose-dependently produced these actions. Lien and Qui 12 mg/kg lowered LVP, +dp/dtmax and SAP by 33%, 37%, 29% and 9%, 12%, 9% respectively. While both of them inhibited the other parameters of haemodynamics with nearly equal degrees. The degrees of inhibitory effect of Lien 12 mg/kg on all haemodynamic parameters nearly corresponded to these of verapamil 1 mg/kg. Lien 1-100 mumol/L reduced the contractile force of isolated left atria and the spontaneously beating rate of isolated right atria of rabbits in concentration-dependent manner. These results indicate that the properties of the effect of Lien on haemodynamics may be similar to those of verapamil and different from those of Qui.

  2. Free creatine available to the creatine phosphate energy shuttle in isolated rat atria

    International Nuclear Information System (INIS)

    Savabi, F.

    1988-01-01

    To measure the actual percentage of intracellular free creatine participating in the process of energy transport, the incorporation of [1- 14 C]creatine into the free creatine and phosphocreatine (PCr) pools in spontaneously beating isolated rat atria, under various conditions, was examined. The atria were subjected to three consecutive periods, control, anoxia, and postanoxic recover, in medium containing tracers of [1- 14 C]creatine. The tissue content and specific activity of creatine and PCr were determined at the end of each period. The higher specific activity found for tissue PCr (1.87 times) than creatine, independent of the percentage of total intracellular creatine that was present as free creatine, provides evidence for the existence of two separate pools of free creatine. Analysis of the data shows that in the normal oxygenated state ∼ 9% of the total intracellular creatine is actually free to participate in the process of energy transport (shuttle pool). About 36% of the total creatine is bound to unknown intracellular components and the rest exists as PCr. The creatine that was taken up and the creatine that was released from the breakdown of PCr have much greater access to the site of phosphorylation than the rest of the intracellular creatine. A sharp increase in the specific activity of residual PCr on prolongation of anoxic time was also observed. This provides evidence for a nonhomogeneous pool of PCr, for the most recently formed (radioactive) PCr appeared to be hydrolyzed last

  3. Functional β2-adrenoceptors in rat left atria: effect of foot-shock stress.

    Science.gov (United States)

    Moura, André Luiz de; Hyslop, Stephen; Grassi-Kassisse, Dora M; Spadari, Regina C

    2017-09-01

    Altered sensitivity to the chronotropic effect of catecholamines and a reduction in the β 1 /β 2 -adrenoceptor ratio have previously been reported in right atria of stressed rats, human failing heart, and aging. In this report, we investigated whether left atrial inotropism was affected by foot-shock stress. Male rats were submitted to 3 foot-shock sessions and the left atrial inotropic response, adenylyl cyclase activity, and β-adrenoceptor expression were investigated. Left atria of stressed rats were supersensitive to isoprenaline when compared with control rats and this effect was abolished by ICI118,551, a selective β 2 -receptor antagonist. Schild plot slopes for the antagonism between CGP20712A (a selective β 1 -receptor antagonist) and isoprenaline differed from unity in atria of stressed but not control rats. Atrial sensitivity to norepinephrine, as well as basal and forskolin- or isoprenaline-stimulated adenylyl cyclase activities were not altered by stress. The effect of isoprenaline on adenylyl cyclase stimulation was partially blocked by ICI118,551 in atrial membranes of stressed rats. These findings indicate that foot-shock stress equally affects inotropism and chronotropism and that β 2 -adrenoceptor upregulation contributes to the enhanced inotropic response to isoprenaline.

  4. Isolation of canine coronary sinus musculature from the atria by radiofrequency catheter ablation prevents induction of atrial fibrillation.

    Science.gov (United States)

    Morita, Hiroshi; Zipes, Douglas P; Morita, Shiho T; Wu, Jiashin

    2014-12-01

    The junction between the coronary sinus (CS) musculature and both atria contributes to initiation of atrial tachyarrhythmias. The current study investigated the effects of CS isolation from the atria by radiofrequency catheter ablation on the induction and maintenance of atrial fibrillation (AF). Using an optical mapping system, we mapped action potentials at 256 surface sites in 17 isolated and arterially perfused canine atrial tissues containing the entire musculature of the CS, right atrial septum, posterior left atrium, left inferior pulmonary vein, and vein of Marshal. Rapid pacing from each site before and after addition of acetylcholine (0.5 μmol/L) was applied to induce AF. Epicardial radiofrequency catheter ablation at CS-atrial junctions isolated the CS from the atria. Rapid pacing induced sustained AF in all tissues after acetylcholine. Microreentry within the CS drove AF in 88% of preparations. Reentries associated with the vein of Marshall (29%), CS-atrial junctions (53%), right atrium (65%), and pulmonary vein (76%) (frequently with 2-4 simultaneous circuits) were additional drivers of AF. Radiofrequency catheter ablation eliminated AF in 13 tissues before acetylcholine (Patrial tissue. The results suggest that CS can be a substrate of recurrent AF in patients after pulmonary vein isolation and that CS isolation might help prevent recurrent AF. © 2014 American Heart Association, Inc.

  5. Differential in vivo regulation of TH and DBH mRNA in rat atria by maprotiline and fluoxetine

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    Spasojević Nataša

    2011-01-01

    Full Text Available It is well known that antidepressants affect central monoaminergic neurotransmission and that they also modulate hormone release in peripheral tissues. Repeated maprotiline (a noradrenaline reuptake inhibitor and fluoxetine (a serotonin reuptake inhibitor treatment on gene expression of the catecholamine biosynthetic enzymes were examined in rat atria and ventricles in vivo. Maprotiline decreased the gene expression of tyrosine hydroxylase (TH and dopamineβ-hydroxylase (DBH in the rat atrium. Fluoxetine increased gene expression of TH and DBH, but not of phenylethanolamine N-methyltransferase (PNMT. Chronic application of antidepressants did not change the expression of these enzymes in the ventricles. We conclude that repeated administration of fluoxetine enhances gene transcription of TH and DBH and subsequently stimulates noradrenaline synthesis in rat atria in vivo.

  6. The Effect of Paroxetine on Ouabain-Induced Toxicity in Isolated Guinea Pig Atria

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    Farzaneh Najar

    2011-04-01

    Full Text Available It has been reported that selective serotonin reuptake inhibitors (SSRIs possess some cardiac effects. In the present study we have investigated the effect of paroxetine (PX, a potent SSRI agent, on spontaneously as well as ouabain-induced arrhythmia beating isolated guinea-pig atria. The Guinea-pig heart was rapidly removed; the auricles were dissected out in oxygenated modified Krebs solution. The rate and force of spontaneous contractions were recorded isometrically with a photosensitive transducer. PX (1-16 µg/ml caused a dose-dependent decrease in the rate of contractions (14-70% and contractile force (8-16%. Ouabain alone (1.2 µg/ml produced arrhythmia at 7.2 ± 1.5 min and asystole at 20.1 ± 3.1 min. Pretreatment with PX (4 µg/ml significantly increased the time of arrhythmia onset to 19.8 min. In addition, PX prolonged the duration of action beating from 20.1 ± 3.1 min to 43.1± 2.6 and delayed the occurrence of asystole. The pattern of contractile force by PX + ouabain treatment was more regular than that observed after administration of ouabain alone. The above findings may the probably be due to the inhibition of cardiac Na+ and Ca2+ channels or autonomic nervous system. Results also suggest that PX may reduce the membrane conductance through inhibition of ionic channels to prevent ouabain-induced arrhythmia.

  7. Effect of Mucuna pruriens Seed Extract Pretreatment on the Responses of Spontaneously Beating Rat Atria and Aortic Ring to Naja sputatrix (Javan Spitting Cobra) Venom

    Science.gov (United States)

    Fung, Shin Yee; Tan, Nget Hong; Sim, Si Mui; Aguiyi, John C.

    2012-01-01

    Mucuna pruriens Linn. (velvet bean) has been used by native Nigerians as a prophylactic for snakebite. Rats pretreated with M. pruriens seed extract (MPE) have been shown to protect against the lethal and cardiovascular depressant effects of Naja sputatrix (Javan spitting cobra) venoms, and the protective effect involved immunological neutralization of the venom toxins. To investigate further the mechanism of the protective effect of MPE pretreatment against cobra venom toxicity, the actions of Naja sputatrix venom on spontaneously beating rat atria and aortic rings isolated from both MPE pretreated and untreated rats were studied. Our results showed that the MPE pretreatment conferred protection against cobra venom-induced depression of atrial contractility and atrial rate in the isolated atrial preparations, but it had no effect on the venom-induced contractile response of aortic ring preparation. These observations suggested that the protective effect of MPE pretreatment against cobra venom toxicity involves a direct protective action of MPE on the heart function, in addition to the known immunological neutralization mechanism, and that the protective effect does not involve action on blood vessel contraction. The results also suggest that M. pruriens seed may contain novel cardioprotective agent with potential therapeutic value. PMID:21785646

  8. Effect of Mucuna pruriens Seed Extract Pretreatment on the Responses of Spontaneously Beating Rat Atria and Aortic Ring to Naja sputatrix (Javan Spitting Cobra Venom

    Directory of Open Access Journals (Sweden)

    Shin Yee Fung

    2012-01-01

    Full Text Available Mucuna pruriens Linn. (velvet bean has been used by native Nigerians as a prophylactic for snakebite. Rats pretreated with M. pruriens seed extract (MPE have been shown to protect against the lethal and cardiovascular depressant effects of Naja sputatrix (Javan spitting cobra venoms, and the protective effect involved immunological neutralization of the venom toxins. To investigate further the mechanism of the protective effect of MPE pretreatment against cobra venom toxicity, the actions of Naja sputatrix venom on spontaneously beating rat atria and aortic rings isolated from both MPE pretreated and untreated rats were studied. Our results showed that the MPE pretreatment conferred protection against cobra venom-induced depression of atrial contractility and atrial rate in the isolated atrial preparations, but it had no effect on the venom-induced contractile response of aortic ring preparation. These observations suggested that the protective effect of MPE pretreatment against cobra venom toxicity involves a direct protective action of MPE on the heart function, in addition to the known immunological neutralization mechanism, and that the protective effect does not involve action on blood vessel contraction. The results also suggest that M. pruriens seed may contain novel cardioprotective agent with potential therapeutic value.

  9. Effects of phosphodiesterase inhibitors on atrial dynamics induced by C-type natriuretic peptide in isolated beating rabbit atria

    International Nuclear Information System (INIS)

    Ding Dazhi; Cui Xun; Jin Xiunan; Lan Ying; Liu Liping; Hong Lan

    2010-01-01

    Objective: To investigate the effects of phosphodiesterase inhibitors (PDEI) on atrial dynamics induced by C-type natriuretic peptide (CNP) and the contents of cyclic nucleotide (cAMP, cGMP) in isolated beating rabbit atria. Methods: After the rabbits had been anesthetized, the hearts were removed rapidly. The left auricles were isolated and fixed on the atrial perfusion system. The atrial stroke volume and the pulse pressure were observed by CNP with or without PDEIs pretreatment. The contents of cAMP and cGMP were measured by radioimmunoassay. Results: (1)Compared with control cycle group, CNP (30.0 nmol · L -1 ) obviously decreased the atrial stroke volume and pulse pressure (P 0.05). (2)Compared with control cycle group, IBMX(1000.0 nmol · L -1 ), a non-selective inhibitor of PDE, significantly increased the atrial stroke volume, pulse pressure, cAMP and cGMP contents (P -1 ) plus CNP (30.0 nmol · L -1 )group and IBMX group (P>0.05). (3)Compared with control cycle group, EHNA(30.0 nmol · L -1 ), an inhibitor of PDE2, obviously decreased the atrial stroke volume and pulse pressure (P 0.05). EHNA(30.0 nmol · L -1 ) plus CNP (30.0 nmol · L -1 ) showed similar roles with EHNA only. (4)Compared with control cycle group, milrinone (1.0 nmol · L -1 ), an inhibitor of PDE3, significantly increased the content of cAMP (P 0.05). CNP (30.0 nmol · L -1 ) obviously decreased the atrial stroke volume and pulse pressure (P 0.05). Conclusion: CNP can inhibit atrial dynamics by increasing the content of cGMP, the different inhibitors of PDEs play different roles in the CNP-induced inhibition of atrial dynamics in isolated beating rabbit atria. (authors)

  10. Refractoriness in human atria

    DEFF Research Database (Denmark)

    Skibsbye, Lasse; Jespersen, Thomas; Christ, Torsten

    2016-01-01

    BACKGROUND: Refractoriness of cardiac cells limits maximum frequency of electrical activity and protects the heart from tonic contractions. Short refractory periods support major arrhythmogenic substrates and augmentation of refractoriness is therefore seen as a main mechanism of antiarrhythmic...... drugs. Cardiomyocyte excitability depends on availability of sodium channels, which involves both time- and voltage-dependent recovery from inactivation. This study therefore aims to characterise how sodium channel inactivation affects refractoriness in human atria. METHODS AND RESULTS: Steady......-state activation and inactivation parameters of sodium channels measured in vitro in isolated human atrial cardiomyocytes were used to parameterise a mathematical human atrial cell model. Action potential data were acquired from human atrial trabeculae of patients in either sinus rhythm or chronic atrial...

  11. Features of intrinsic ganglionated plexi in both atria after extensive pulmonary isolation and their clinical significance after catheter ablation in patients with atrial fibrillation.

    Science.gov (United States)

    Kurotobi, Toshiya; Shimada, Yoshihisa; Kino, Naoto; Ito, Kazato; Tonomura, Daisuke; Yano, Kentaro; Tanaka, Chiharu; Yoshida, Masataka; Tsuchida, Takao; Fukumoto, Hitoshi

    2015-03-01

    The features of intrinsic ganglionated plexi (GP) in both atria after extensive pulmonary vein isolation (PVI) and their clinical implications have not been clarified in patients with atrial fibrillation (AF). The purpose of this study was to assess the features of GP response after extensive PVI and to evaluate the relationship between GP responses and subsequent AF episodes. The study population consisted of 216 consecutive AF patients (104 persistent AF) who underwent an initial ablation. We searched for the GP sites in both atria after an extensive PVI. GP responses were determined in 186 of 216 patients (85.6%). In the left atrium, GP responses were observed around the right inferior GP in 116 of 216 patients (53.7%) and around the left inferior GP in 57 of 216 (26.4%). In the right atrium, GP responses were observed around the posteroseptal area: inside the CS in 64 of 216 patients (29.6%), at the CS ostium in 150 of 216 (69.4%), and in the lower right atrium in 45 of 216 (20.8%). The presence of a positive GP response was an independent risk factor for AF recurrence (hazard ratio 4.04, confidence interval 1.48-11.0) in patients with paroxysmal, but not persistent, AF. The incidence of recurrent atrial tachyarrhythmias in patients with paroxysmal AF with a positive GP response was 51% vs 8% in those without a GP response (P = .002). The presence of GP responses after extensive PVI was significantly associated with increased AF recurrence after ablation in patients with paroxysmal AF. Copyright © 2015 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.

  12. Correlations between ANP concentrations in atria, plasma and cerebral structures and sodium chloride preference in Wistar rats

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    Glass H.

    1997-01-01

    Full Text Available We determined whether ANP (atrial natriuretic peptide concentrations, measured by radioimmunoassay, in the ANPergic cerebral regions involved in regulation of sodium intake and excretion and pituitary gland correlated with differences in sodium preference among 40 Wistar male rats (180-220 g. Sodium preference was measured as mean spontaneous ingestion of 1.5% NaCl solution during a test period of 12 days. The relevant tissues included the olfactory bulb (OB, the posterior and anterior lobes of the pituitary gland (PP and AP, respectively, the median eminence (ME, the medial basal hypothalamus (MBH, and the region anteroventral to the third ventricle (AV3V. We also measured ANP content in the right (RA and left atrium (LA and plasma. The concentrations of ANP in the OB and the AP were correlated with sodium ingestion during the preceding 24 h, since an increase of ANP in these structures was associated with a reduced ingestion and vice-versa (OB: r = -0.3649, P<0.05; AP: r = -0.3291, P<0.05. Moreover, the AP exhibited a correlation between ANP concentration and mean NaCl intake (r = -0.4165, P<0.05, but this was not the case for the OB (r = 0.2422. This suggests that differences in sodium preference among individual male rats can be related to variations of AP ANP level. Earlier studies indicated that the OB is involved in the control of NaCl ingestion. Our data suggest that the OB ANP level may play a role mainly in day-to-day variations of sodium ingestion in the individual rat

  13. Isolation of rat adrenocortical mitochondria

    Energy Technology Data Exchange (ETDEWEB)

    Solinas, Paola [Department of Pharmacology, School of Medicine, Case Western Reserve University, Cleveland, OH 44106 (United States); Department of Medicine, Center for Mitochondrial Disease, School of Medicine, Case Western Reserve University, Cleveland, OH 44106 (United States); Fujioka, Hisashi [Electron Microscopy Facility, Department of Pharmacology, Center for Mitochondrial Disease, School of Medicine, Case Western Reserve University, Cleveland, OH 44106 (United States); Tandler, Bernard [Department of Biological Sciences, School of Dental Medicine, Center for Mitochondrial Disease, School of Medicine, Case Western Reserve University, Cleveland, OH 44106 (United States); Hoppel, Charles L., E-mail: charles.hoppel@case.edu [Department of Pharmacology, School of Medicine, Case Western Reserve University, Cleveland, OH 44106 (United States); Department of Medicine, Center for Mitochondrial Disease, School of Medicine, Case Western Reserve University, Cleveland, OH 44106 (United States)

    2012-10-12

    Highlights: Black-Right-Pointing-Pointer A method for isolation of adrenocortical mitochondria from the adrenal gland of rats is described. Black-Right-Pointing-Pointer The purified isolated mitochondria show excellent morphological integrity. Black-Right-Pointing-Pointer The properties of oxidative phosphorylation are excellent. Black-Right-Pointing-Pointer The method increases the opportunity of direct analysis of adrenal mitochondria from small animals. -- Abstract: This report describes a relatively simple and reliable method for isolating adrenocortical mitochondria from rats in good, reasonably pure yield. These organelles, which heretofore have been unobtainable in isolated form from small laboratory animals, are now readily accessible. A high degree of mitochondrial purity is shown by the electron micrographs, as well as the structural integrity of each mitochondrion. That these organelles have retained their functional integrity is shown by their high respiratory control ratios. In general, the biochemical performance of these adrenal cortical mitochondria closely mirrors that of typical hepatic or cardiac mitochondria.

  14. Isolating Lysosomes from Rat Liver.

    Science.gov (United States)

    Pryor, Paul R

    2016-04-01

    This protocol describes the generation of a fraction enriched in lysosomes from rat liver. The lysosomes are rapidly isolated using density-gradient centrifugation with gradient media that retain the osmolarity of the lysosomes such that they are functional and can be used in in vitro assays. © 2016 Cold Spring Harbor Laboratory Press.

  15. Cerveau isolé and pretrigeminal rats.

    Science.gov (United States)

    Zernicki, B; Gandolfo, G; Glin, L; Gottesmann, C

    1984-01-01

    Cortical and hippocampal EEG activity was analysed in 14 cerveau isole and 8 pretrigerninal rats. In the acute stage, waking EEG patterns were absent in the cerveau isole, whereas sleep EEG patterns were absent in the pretrigeminal preparations. However, already on the second day the EEG waking-sleep cycle recovered in the majority of rats. Paradoxically, stimuli directed to the caudal part of preparations evoked stronger cortical and hippocampal EEG arousal than olfactory and visual stimuli. The behavior of the caudal part was observed in 25 preparations. Although in abortive form, the rats did show some locomotor and grooming behavior, and could be fed orally. The peripheral events of paradoxical sleep appeared only on the fourth or fifth day of survival of the cerveau isole rats. It is concluded that the activity of the isolated cerebrum of the rat is similar to that of cat preparations, but that functions of the caudal neuraxis are superior in rats.

  16. DNA isolation from rat tail or ear

    NARCIS (Netherlands)

    Cuppen, E.

    2010-01-01

    This protocol describes a rapid procedure for isolating DNA from rat tail or ear punches. The simplest version of the protocol can be scaled for use in 96-well (deep-well) plates. The quality of the DNA is sufficient for any polymerase chain reaction (PCR)-based genotyping approach.

  17. Comparison of the binding constant (Ksub(D)) of /sup 125/I-labelled 3-(4-iodophenoxy)-1-isopropylaminopropan-2-ol obtained on. beta. -adrenoceptors in guinea-pig myocardial membranes, with its dissociation constants (Ksub(B)) obtained on guinea-pig isolated atria and trachea

    Energy Technology Data Exchange (ETDEWEB)

    O' Donnell, S R [Queensland Univ., Brisbane (Australia). Dept. Of Physiology; Woodcock, E A

    1978-02-01

    The dissociation constant of binding (Ksub(D) of /sup 125/I-labelled 3-(4-iodophenoxy)-isopropylaminopropan-2-ol (IIP) to guinea pig myocardial membrane preparations was 2.2 x 10/sup -8/M. In pharmacological experiments with non-labelled material and 60 min contact time, IIP produced a parallel shift in the orciprenaline concentration-response line on guinea-pig isolated tracheal and atrial preparations. The dissociation constant (Ksub(B) of IIP was 2.9 x 10/sup -8/M on atria (pA/sub 2/ 7.54) and 3.3 x 10/sup -8/M on trachea (PA/sub 2/ 7.48). These values indicate that IIP is not a selective B-adrenoceptor blocking drug. In addition, agreement was found between the affinity constant of this antagonist for B-adrenoceptors as determined by a direct binding study and an indirect pharmacological study.

  18. EFFECT OF ETHANOL ON HEPATOBILIARY TRANSPORT OF CATIONIC DRUGS - A STUDY IN THE ISOLATED-PERFUSED RAT-LIVER, RAT HEPATOCYTES AND RAT MITOCHONDRIA

    NARCIS (Netherlands)

    STEEN, H; MEIJER, DKF; Merema, M.T.

    The effect of ethanol on the hepatic uptake of various cationic drugs was studied in isolated perfused rat livers, isolated rat hepatocytes and isolated rat liver mitochondria. In isolated rat hepatocytes and in isolated perfused rat livers, the uptake of the model organic cation

  19. Photochemical (PUVA) treatment of isolated rat islets

    International Nuclear Information System (INIS)

    Schmidt, S.; Wilke, B.; Kloeting, I.

    1984-01-01

    Isolated rat islets were irradiated with long-wave ultraviolet light alone or in combination with the photosensitizer 8-methoxypsoralen. The influence on specific beta cell functions was determined with the aim to find out experimental conditions which allow the use of such islets for transplantation. Short-term effects: Ultraviolet light affected [ 3 H]leucine incorporation into (pro)insulin (5 J/cm 2 : 53.8 %, 10 J/cm 2 : 41.0 % of the controls) and insulin release was slightly reduced. 8-methoxypsoralen enhanced the irradiation effect. Long-term effects: A restoration of irradiation-affected beta cell function was detected after 5 days of culture unless the dose exceeded 2 J/cm 2 (0.1 μM 8-methoxypsoralen) or 1 J/cm 2 (1 μM 8-methoxypsoralen). After functional restoration islets were used for transplantation experiments. (author)

  20. Photochemical (PUVA) treatment of isolated rat islets

    Energy Technology Data Exchange (ETDEWEB)

    Schmidt, S; Wilke, B; Kloeting, I [Zentralinstitut fuer Diabetes, Karlsburg (German Democratic Republic)

    1984-05-01

    Isolated rat islets were irradiated with long-wave ultraviolet light alone or in combination with the photosensitizer 8-methoxypsoralen. The influence on specific beta cell functions was determined with the aim to find out experimental conditions which allow the use of such islets for transplantation. Short-term effects: Ultraviolet light affected (/sup 3/H)leucine incorporation into (pro)insulin (5 J/cm/sup 2/ : 53.8 %, 10 J/cm/sup 2/ : 41.0 % of the controls) and insulin release was slightly reduced. 8-methoxypsoralen enhanced the irradiation effect. Long-term effects: A restoration of irradiation-affected beta cell function was detected after 5 days of culture unless the dose exceeded 2 J/cm/sup 2/ (0.1 ..mu..M 8-methoxypsoralen) or 1 J/cm/sup 2/ (1 ..mu..M 8-methoxypsoralen). After functional restoration islets were used for transplantation experiments.

  1. Cerveau isolé and pretrigeminal rat preparations.

    Science.gov (United States)

    Zernicki, B; Gandolfo, G; Glin, L; Gottesmann, C

    1985-01-01

    Cortical and hippocampal EEG activity was analysed in cerveau isolé and and pretrigeminal rats. In the acute stage, waking EEG patterns were absent in the cerveau isolé, whereas sleep EGG patterns were absent in the preparations. However, already on the second day the EEG waking sleep cycle recovered in the majority of rats. Paradoxically, stimuli directed to the caudal part of the preparations evoked stronger cortical and hippocampal EEG arousal than olfactory and visual stimuli. The rats exhibited some locomotor and grooming behaviour and could be fed orally. It is concluded that the activity of the isolated cerebrum of the rat is similar to that of cat preparations, but that functions of the caudal neuraxis are superior in rats.

  2. Insulin internalization in isolated rat hepatocytes

    International Nuclear Information System (INIS)

    Galan, J.; Trankina, M.; Noel, R.; Ward, W.

    1990-01-01

    This project was designed to determine whether neomycin, an aminoglycoside antibiotic, has a significant effect upon the pathways of ligand endocytosis in isolated rat hepatocytes. The pathways studied include receptor-mediated endocytosis and fluid-phase endocytosis. Neomycin causes a dose-dependent acceleration of 125 I-insulin internalization. Since fluid-phase endocytosis can also be a significant factor in 125 I-insulin internalization, lucifer yellow (LY), a marker for fluid-phase endocytosis, was incorporated into an assay similar to the 125 I-insulin internalization procedure. In the presence of 5 mM neomycin, a significant increase in LY uptake was evident at 0.2 and 0.4 mg/ml of LY. At 0.8 mg/ml, a decrease in LY uptake was observed. The increased rate of 125 I-insulin internalization in the presence of neomycin was intriguing. Since one action of neomycin is to inhibit phosphoinositidase C, it suggests that the phosphotidylinositol cycle may be involved in ligand internalization by hepatocytes. At low insulin concentrations, receptor-mediated uptake predominates. Fluid-phase uptake can become an important uptake route as insulin concentrations are increased. Since neomycin stimulates fluid-phase endocytosis, it must also be taken into account when measuring ligand internalization

  3. Isolation and identification of two galangin metabolites from rat urine ...

    African Journals Online (AJOL)

    Isolation and identification of two galangin metabolites from rat urine and determination of their in vitro hypolipidemic activity. Xuguang Zhang, Shouqian Cheng, Hailong Li, Xiaopo Zhang, Feng Chen, Youbin Li, Junqing Zhang, Yinfeng Tan ...

  4. NDM 1 Gene Carrying Gram negative Bacteria Isolated from Rats ...

    African Journals Online (AJOL)

    In this study, we screened 56 Gram negative bacteria comprising: 3 isolates of Enterobacter ludwigii, 30 Pseudomonas aeruginosa, 22 Proteus mirabilis, and 1 Aeromonas caviae isolated from oral cavity and rectum of rats captured from commercial poultry houses in Ibadan, Oyo State, Nigeria that were resistant to at least ...

  5. Structure and composition of synaptonemal complexes, isolated from rat spermatocytes

    NARCIS (Netherlands)

    Heyting, C.; Dietrich, A. J.; Redeker, E. J.; Vink, A. C.

    1985-01-01

    Synaptonemal complexes (SCs) (structures involved in chromosome pairing during meiosis) were isolated and purified from rat spermatocytes for the purpose of biochemical and morphological analysis. Spermatocytes were lysed in a medium, containing Triton X-100, EDTA and DTT; the resulting swollen

  6. desensitisation and calcium-sensitivity in the isolated perfused rat ...

    African Journals Online (AJOL)

    Dr Olaleye

    -induced desensitisation to noradrenaline were studied in the isolated perfused rat tail artery. Responses to the activators noradrenaline (NA). (3μM) and potassium chloride (KCl) (100mM) were obtained in Ca2+-buffered saline. Activators ...

  7. Communication: Effect of diperoxovandate on isolated rat heart ...

    African Journals Online (AJOL)

    Diperoxovanadate (DPV), a product of vanadate is gaining importance as a biologically active vanadium compound. The aim of the present study was to evaluate the chronotropic and inotropic activity of DPV using isolated rat heart and to determine the concentration at which it is toxic to the heart. The study was carried out ...

  8. on Isolated Smooth Muscle Preparation in Rats

    African Journals Online (AJOL)

    Samuel Olaleye

    ABSTRACT. This study investigated the receptor effects of methanolic root extract of ... Phytochemical Analysis: Photochemistry of the methanolic extract was ... mounted with resting tension 0.5g in an organ bath containing .... Effects of extra cellular free Ca2+ and 0.5mM ... isolated smooth muscle by high K+ on the other.

  9. [Crabtree effect caused by ketoses in isolated rat hepatocytes].

    Science.gov (United States)

    Martínez, P; Carrascosa, J M; Núñez de Castro, I

    1982-01-01

    Oxygen uptake and glycolytic activity were studied in hepatocytes isolated from fed rats. The addition of fructose or tagatose resulted in a 38% and 31% inhibition of cellular respiration respectively. The addition of 10 mM D-glyceraldehyde caused a slight Crabtree effect. Glucose, L-sorbose, or glycerol failed to modify oxygen consumption. Only incubation in the presence of fructose showed a high aerobic glycolysis measured by lactate production.

  10. Isolation, culture and intraportal transplantation of rat marrow stromal cell

    International Nuclear Information System (INIS)

    Wang Ping; Wang Jianhua; Yan Zhiping; Li Wentao; Lin Genlai; Hu Meiyu; Wang Yanhong

    2004-01-01

    Objective: To observe the tracing and evolution of marrow stromal cell (MSC) after intraportal transplantation into the liver of homogenous rats, and to provide experimental data for MSC differentiation to hepatocyte in vivo. Methods: The MSC was isolated from the leg bone marrow of adult SD rats, and purified by culture-expanded in vitro. Before transplantation, MSC was labeled with DAPI. Then 10 5 MSC were intraportally transplanted into the homogenous rat liver. Rats were killed at 2 hours and 1, 2, 3 and 4 weeks after transplantation. The cryosection samples of liver and lung were observed under fluorescence microscopy. Results: MSC in vitro culture had high ability of proliferation. Except 4 rats were dead because of abdominal bleeding or infection, other recipients were healthy until sacrificed. The implantation cells were detected by identifying the DAPI labeled MSC in the host livers, but not in the host lungs. Conclusion: Intraportal transplanted MSC could immigrate and survive in the host livers at least for 4 weeks. They could immigrate from the small branches of portal veins to hepatic parenchyma

  11. 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.

  12. Differential expression of parvalbumin interneurons in neonatal phencyclidine treated rats and socially isolated rats

    DEFF Research Database (Denmark)

    Kaalund, Sanne Simone; Riise, Jesper; Broberg, Brian

    2013-01-01

    of parvalbumin-positive interneurons (PV(+) interneurons). In this study we examined PV(+) expression in two rat models of cognitive dysfunction in schizophrenia, the environmental social isolation (SI) and pharmacological neonatal phencyclidine (neoPCP) models. Using a stereological method, the optical...

  13. Increased dopaminergic activity in socially isolated rats: an electrophysiological study

    DEFF Research Database (Denmark)

    Fabricius, Katrine; Helboe, Lone; Fink-Jensen, Anders

    2010-01-01

    The development of animal models mimicking symptoms associated with schizophrenia has been a critical step in understanding the neurobiological mechanisms underlying the disease. Long-term social isolation from weaning in rodents, a model based on the neurodevelopmental hypothesis of schizophrenia......, has been suggested to mimic some of the deficits seen in schizophrenic patients. We confirm in the present study that socially isolated rats display an increase in both spontaneous and d-amphetamine-induced locomotor activity, as well as deficits in sensorimotor gating as assessed in a pre......, and a change of firing activity towards a more irregular and bursting firing pattern. Taken together, our findings suggest that the behavioral phenotype induced by social isolation may be driven by an overactive dopamine system....

  14. The performance of atria in two school buildings

    Energy Technology Data Exchange (ETDEWEB)

    Harris, D.J. [Heriot-Watt University, Edinburgh (United Kingdom). Dept. of Building Engineering and Surveying

    1997-10-01

    Atria have become popular additions to many building types in recent years. There is a common misconception that they will automatically result in lower energy consumption, but this is not necessarily the case. Only when designed and used in an appropriate way will atria contribute to energy conservation. In this paper the performance of two school buildings, one incorporating a heat atrium, the other an unheated atrium, was studied. Comparisons between their performance were made with respect to thermal comfort, heating costs, overheating and daylighting. While heating the atrium incurred a cost penalty, it resulted in comfortable conditions in the space for a greater proportion of the time in winter, and consequently created a more useful space. In summer months overheating was likely unless an area of opening vents the equivalent of 10% or more of the floor area is provided in the atrium roof. (author)

  15. Investigation of Thermal Performance for Atria: a Method Overview

    Directory of Open Access Journals (Sweden)

    Moosavi Leila

    2016-01-01

    Full Text Available The importance of low energy design in large buildings has encouraged researchers to implement different methods for predicting a building’s thermal performance. Atria, as energy efficient features, have been implemented to improve the indoor thermal environment in large modern buildings. Though widely implemented, the thorough study of atrium performance is restricted due to its large size, complex thermodynamic behavior and the inaccuracies and limitations of available prediction tools. This study reviews the most common research tools implemented in previous researches on atria thermal performance, to explore the advantages and limitation of different methods for future studies. The methods reviewed are analytical, experimental, computer modelling and a combination of any or all of these methods. The findings showed that CFD (computational fluid dynamic models are the most popular tools of recent due to their higher accuracy, capabilities and user-friendly modification. Although the experimental methods were reliable for predicting atria thermal and ventilation performance, they have mostly been used to provide data for validation of CFD models. Furthermore, coupling CFD with other experimental models could increase the reliability and accuracy of the models and provide a more comprehensive analysis.

  16. Protein phosphorylation in isolated hepatocytes of septic and endotoxemic rats

    International Nuclear Information System (INIS)

    Deaciuc, I.V.; Spitzer, J.A.

    1989-01-01

    The purpose of this study was to investigate possible alterations induced by sepsis and endotoxicosis in the late phase of Ca2+-dependent signaling in rat liver. Hepatocytes isolated from septic or chronically endotoxin (ET)-treated rats were labeled with [32P]H3PO4 and stimulated with various agents. Proteins were resolved by one-dimensional polyacrylamide gel electrophoresis and autoradiographed. Vasopressin (VP)- and phenylephrine (PE)-induced responses were attenuated in both septic and ET-treated rats for cytosolic and membrane proteins compared with their respective controls. Glucagon and 12-O-myristate phorbol-13-acetate (TPA) affected only the phosphorylation of membrane proteins. Glucagon-induced changes in the phosphorylation of membrane proteins were affected by both sepsis and endotoxicosis, whereas TPA-stimulated phosphorylation was lowered only in endotoxicosis. Response to the Ca2+ ionophore A23187 was depressed in septic rats for cytosolic proteins. The phosphorylation of two cytosolic proteins, i.e., 93 and 61 kDa (previously identified as glycogen phosphorylase and pyruvate kinase, respectively), in response to VP, PE, and A23187 was severely impaired by endotoxicosis and sepsis. TPA did not affect the phosphorylation state of these two proteins. The results show that sepsis and endotoxicosis produce perturbations of the phosphorylation step in Ca2+ transmembrane signaling. Such changes can explain alterations of glycogenolysis and gluconeogenesis associated with sepsis and endotoxicosis

  17. Complete inhibition of creatine kinase in isolated perfused rat hearts

    International Nuclear Information System (INIS)

    Fossel, E.T.; Hoefeler, H.

    1987-01-01

    Transient exposure of an isolated isovolumic perfused rat heart to low concentrations (0.5 mM) of perfusate-born iodoacetamide resulted in complete inhibition of creatine kinase and partial inhibition of glyceraldehyde-3-phosphate dehydrogenase in the heart. At low levels of developed pressure, hearts maintained mechanical function, ATP, and creatine phosphate levels at control values. However, iodoacetamide-inhibited hearts were unable to maintain control values of end diastolic pressure or peak systolic pressure as work load increased. Global ischemia resulted in loss of all ATP without loss of creatine phosphate, indicating lack of active creatine kinase. These results indicate that isovolumic perfused rat hearts are able to maintain normal function and normal levels of high-energy phosphates without active creatine kinase at low levels of developed pressure. 31 P-NMR of the heart was carried out

  18. Structural and functional effects of social isolation on the hippocampus of rats with traumatic brain injury.

    Science.gov (United States)

    Khodaie, Babak; Lotfinia, Ahmad Ali; Ahmadi, Milad; Lotfinia, Mahmoud; Jafarian, Maryam; Karimzadeh, Fariba; Coulon, Philippe; Gorji, Ali

    2015-02-01

    Social isolation has significant long-term psychological and physiological consequences. Both social isolation and traumatic brain injury (TBI) alter normal brain function and structure. However, the influence of social isolation on recovery from TBI is unclear. This study aims to evaluate if social isolation exacerbates the anatomical and functional deficits after TBI in young rats. Juvenile male rats were divided into four groups; sham operated control with social contacts, sham control with social isolation, TBI with social contacts, and TBI with social isolation. During four weeks after brain injury in juvenile rats, we evaluated the animal behaviors by T-maze and open-field tests, recorded brain activity with electrocorticograms and assessed structural changes by histological procedures in the hippocampal dentate gyrus, CA1, and CA3 areas. Our findings revealed significant memory impairments and hyperactivity conditions in rats with TBI and social isolation compared to the other groups. Histological assessments showed an increase of the mean number of dark neurons, apoptotic cells, and caspase-3 positive cells in all tested areas of the hippocampus in TBI rats with and without social isolation compared to sham rats. Furthermore, social isolation significantly increased the number of dark cells, apoptotic neurons, and caspase-3 positive cells in the hippocampal CA3 region in rats with TBI. This study indicates the harmful effect of social isolation on anatomical and functional deficits induced by TBI in juvenile rats. Prevention of social isolation may improve the outcome of TBI. Copyright © 2014 Elsevier B.V. All rights reserved.

  19. Reactivity of the isolated perfused rat tail vascular bed

    Directory of Open Access Journals (Sweden)

    A.S. França

    1997-07-01

    Full Text Available Isolated segments of the perfused rat tail artery display a high basal tone when compared to other isolated arteries such as the mesenteric and are suitable for the assay of vasopressor agents. However, the perfusion of this artery in the entire tail has not yet been used for functional studies. The main purpose of the present study was to identify some aspects of the vascular reactivity of the rat tail vascular bed and validate this method to measure vascular reactivity. The tail severed from the body was perfused with Krebs solution containing different Ca2+ concentrations at different flow rates. Rats were anesthetized with sodium pentobarbital (65 mg/kg and heparinized (500 U. The tail artery was dissected near the tail insertion, cannulated and perfused with Krebs solution plus 30 µM EDTA at 36oC and 2.5 ml/min and the procedures were started after equilibration of the perfusion pressure. In the first group a dose-response curve to phenylephrine (PE (0.5, 1, 2 and 5 µg, bolus injection was obtained at different flow rates (1.5, 2.5 and 3.5 ml/min. The mean perfusion pressure increased with flow as well as PE vasopressor responses. In a second group the flow was changed (1.5, 2, 2.5, 3 and 3.5 ml/min at different Ca2+ concentrations (0.62, 1.25, 2.5 and 3.75 mM in the Krebs solution. Increasing Ca2+ concentrations did not alter the flow-pressure relationship. In the third group a similar protocol was performed but the rat tail vascular bed was perfused with Krebs solution containing PE (0.1 µg/ml. There was an enhancement of the effect of PE with increasing external Ca2+ and flow. PE vasopressor responses increased after endothelial damage with air and CHAPS, suggesting an endothelial modulation of the tone of the rat tail vascular bed. These experiments validate the perfusion of the rat tail vascular bed as a method to investigate vascular reactivity

  20. Metabolic variations of fatty acid in isolated rat heart reperfused after a transient global ischemia

    International Nuclear Information System (INIS)

    Huang Gang; Michel Comet; Zhao Huiyang; Zhu Cuiying; Yuan Jimin

    1998-01-01

    Purpose: The fatty acid metabolism and the effect of glucose on it were studied in isolated and reperfused rat heat. Methods: 32 isolated working rat hearts were perfused in Langengdorff device with modified Krebs and were divided into normal and ischemia-reperfused group. Each group was also classified into two subgroups, modified krebs with or without glucose subgroup. 131 I-HA was injected into aorta of isolated working rat heart and then the radio-residue curves were acquired. Results: When the isolated rat hearts were perfused with krebs plus glucose, the catabolism of fatty acid was significantly decreased in normal group, but a remarkable increase of fatty acid catabolism was found in ischemia-reperfused group. While the isolated rat hearts were perfused with krebs without glucose, the catabolism of fatty acid in ischemia-reperfused isolated rat hearts were perfused with krebs without glucose, the catabolism of fatty acid in ischemia-reperfused isolated rat heart was less than that in normal group. Conclusions: Transient ischemia damages the catabolism of myocardial fatty acid in mitochondria in some degree. In normal isolated working rat heart, the principal energy source is glucose. However, the major energy source is switched to catabolism of fatty acid in ischemia-reperfused isolated rat heart. This phenomenon may be related to compensative increase of fatty acid catabolism for replenishing the loss of energy during ischemia

  1. The Effect of Chlorpyrifos on Isolated Thoracic Aorta in Rats

    Directory of Open Access Journals (Sweden)

    Ebru Yıldırım

    2013-01-01

    Full Text Available This study investigated the effect of chlorpyrifos on thoracic aorta and on the level of NO in plasma and aorta. The effect of chlorpyrifos on thoracic aorta in organ bath was determined in 10 rats. Another 45 rats were assigned to 3 groups with 15 rats each: control group 1 received distilled water, control group 2 was given corn oil, and the last group was given 13.5 mg/kg chlorpyrifos dissolved in corn oil every other day for 8 weeks orally. Chlorpyrifos (10−10 M–10−5 M showed no effect on isolated thoracic aorta. Plasma AChE activity was decreased, while LDH, ALT, GGT, and AST activities were increased in chlorpyrifos group compared to control groups. Plasma NO level was increased in chlorpyrifos group compared to control groups. iNOS expression was present in all groups in the cytoplasm of the endothelia and in the smooth muscle cells of aorta. According to semiquantitative histomorphological analysis, iNOS immunopositive reactions were seen in the decreasing order in chlorpyrifos, control 2, and control 1 groups. eNOS immunopositive reactions were observed in the endothelial cell cytoplasm, rarely in the subintimal layer, and the smooth muscle cells of aorta. There were no differences among the groups in terms of eNOS immunostaining. In conclusion, chlorpyrifos induced NO production in aorta following an increase in NOS expression.

  2. The Effect of Chlorpyrifos on Isolated Thoracic Aorta in Rats

    Science.gov (United States)

    Yıldırım, Ebru; Baydan, Emine; Kanbur, Murat; Kul, Oğuz; Çınar, Miyase; Ekici, Hüsamettin; Atmaca, Nurgül

    2013-01-01

    This study investigated the effect of chlorpyrifos on thoracic aorta and on the level of NO in plasma and aorta. The effect of chlorpyrifos on thoracic aorta in organ bath was determined in 10 rats. Another 45 rats were assigned to 3 groups with 15 rats each: control group 1 received distilled water, control group 2 was given corn oil, and the last group was given 13.5 mg/kg chlorpyrifos dissolved in corn oil every other day for 8 weeks orally. Chlorpyrifos (10−10 M–10−5 M) showed no effect on isolated thoracic aorta. Plasma AChE activity was decreased, while LDH, ALT, GGT, and AST activities were increased in chlorpyrifos group compared to control groups. Plasma NO level was increased in chlorpyrifos group compared to control groups. iNOS expression was present in all groups in the cytoplasm of the endothelia and in the smooth muscle cells of aorta. According to semiquantitative histomorphological analysis, iNOS immunopositive reactions were seen in the decreasing order in chlorpyrifos, control 2, and control 1 groups. eNOS immunopositive reactions were observed in the endothelial cell cytoplasm, rarely in the subintimal layer, and the smooth muscle cells of aorta. There were no differences among the groups in terms of eNOS immunostaining. In conclusion, chlorpyrifos induced NO production in aorta following an increase in NOS expression. PMID:23878805

  3. Isolation and purification of rat liver morphine UDP-glucuronosyltransferase

    International Nuclear Information System (INIS)

    Puig, J.F.; Tephly, T.R.

    1986-01-01

    The enhancement of rat liver microsomal morphine (M) and 4-hydroxybiphenyl (4-HBP) UDP-glucuronyltransferase (UDPGT) activities by phenobarbital treatment has been proposed to represent increased activity of a single enzyme form, GT-2. They have separated M and 4-HBP UDPGT activities from Emulgen 911-solubilized microsomes obtained from livers of phenobarbital-treated Wistar rats. A sensitive assay procedure was developed to quantify M-UDPGT and 4-HBP-UDPGT activities using 14 C-UDP-glucuronic acid (UDPGA) and reversed phase C-18 minicolumns whereby the radioactive glucuronides were differentially eluted from labeled UDPGA. Trisacryl DEAE, and chromatofocusing procedures were employed to separate M-UDPGT and 4-HBP-UDPGT in the presence of exogenous phosphatidylcholine (PC). The PC is necessary to stabilize UDPGT activities. M-UDPGT was isolated to apparent homogeneity and displayed a monomeric molecular weight of 56,000 daltons on SDS-PAGE. It reacted with M but not with 4-HBP, bilirubin, p-nitrophenol, testosterone, androsterone, estrone, 4-aminobiphenyl or α-naphthylamine. 4-HBP-UDPGT did not react with M. Therefore, M and 4-HBP glucuronidations are catalyzed by separate enzymes in rat liver microsomes

  4. Isolating the delay component of impulsive choice in adolescent rats

    Directory of Open Access Journals (Sweden)

    Jesse eMcClure

    2014-01-01

    Full Text Available Impulsive choice — the preference for small immediate rewards over larger delayed rewards — has been linked to various psychological conditions ranging from behavioral disorders to addiction. These links highlight the critical need to dissect the various components of this multifaceted behavioral trait. Delay discounting tasks allow researchers to study an important factor of this behavior: how the subjective value of a rewards changes over a delay period. However, existing methods of delay discounting include a confound of modifying reward sizes during the procedure. Here we present a new approach of using a single constant reward size to assess delay discounting. A complementary approach could hold delay constant and assess the utility of changing quantities of a reward. Isolating these behavioral components can advance our ability to explore the behavioral complexity of impulsive choice. We present the methods for isolating delay in detail, and further capitalize on this method by pairing it with a standard peak interval task to test whether individual variation in delay discounting can be explained by differences in perception of time in male and female adolescent rats. We find that rats that were more precise in discriminating time intervals were also less impulsive in their choice. Our data suggest that differences in timing and delay discounting are not causally related, but instead are more likely influenced by a common factor. Further, the mean-level change in our measure between postnatal day 28 and 42 suggests this test may be capturing a developmental change in this factor. In summary, this new method of isolating individual components of impulsive choice (delay or quantity can be efficiently applied in either adolescent or adult animal models and may help elucidate the mechanisms underlying impulsivity and its links to psychological disorders.

  5. Water and nonelectrolyte permeability of isolated rat hepatocytes

    International Nuclear Information System (INIS)

    Alpini, G.; Garrick, R.A.; Jones, M.J.; Nunes, R.; Tavoloni, N.

    1986-01-01

    We have measured the diffusive permeability coefficients of isolated rat hepatocytes to 3 H 2 O, [ 14 C]urea, [ 14 C]erythritol, [ 14 C]mannitol, [ 3 H]sucrose, and [ 3 H]inulin, employing a technique previously developed for erythrocytes (Redwood et al., J. Gen. Physiol 64:706-729, 1974). Diffusion coefficients for the tracer molecules were measured in packed hepatocytes, supernatant fluid, and intracellular medium (lysed hepatocytes) and were calculated assuming one-dimensional semi-infinite diffusion through a homogeneous medium. By applying the series-parallel pathway model, the following permeability coefficients (10(-5) cm/sec) for the hepatocyte plasma membrane were obtained. 3 H 2 O, 98.6 +/- 18.4; [ 14 C]urea, 18.2 +/- 5.3; [ 14 C]erythritol, 4.8 +/- 1.6; [ 14 C]mannitol, 3.1 +/- 1.4; [ 3 H]sucrose, 0; [ 3 H]inulin, 0. These results indicate that isolated rat hepatocytes are highly permeable to water and polar nonelectrolytes, when compared with other transporting epithelia. This relatively high cellular permeability is consistent with a model in which nonelectrolyte permeation is via an aqueous pathway of equivalent pore diameter of 8-12 A. The finding that [ 14 C]erythritol and [ 14 C]mannitol cross the hepatocyte plasma membrane indicates that these molecules enter the bile canaliculus through the transcellular route. Conversely, the failure of [ 3 H]sucrose and [ 3 H]inulin to permeate the hepatocyte in the isolated condition supports the concept that biliary entry of these large carbohydrates, at least that fraction which cannot be accounted for by a vesicular mechanism, must occur via the transjunctional shunt pathway

  6. Expression and function of Kv1.1 potassium channels in human atria from patients with atrial fibrillation.

    Science.gov (United States)

    Glasscock, Edward; Voigt, Niels; McCauley, Mark D; Sun, Qiang; Li, Na; Chiang, David Y; Zhou, Xiao-Bo; Molina, Cristina E; Thomas, Dierk; Schmidt, Constanze; Skapura, Darlene G; Noebels, Jeffrey L; Dobrev, Dobromir; Wehrens, Xander H T

    2015-09-01

    Voltage-gated Kv1.1 channels encoded by the Kcna1 gene are traditionally regarded as being neural-specific with no known expression or intrinsic functional role in the heart. However, recent studies in mice reveal low-level Kv1.1 expression in heart and cardiac abnormalities associated with Kv1.1-deficiency suggesting that the channel may have a previously unrecognized cardiac role. Therefore, this study tests the hypothesis that Kv1.1 channels are associated with arrhythmogenesis and contribute to intrinsic cardiac function. In intra-atrial burst pacing experiments, Kcna1-null mice exhibited increased susceptibility to atrial fibrillation (AF). The atria of Kcna1-null mice showed minimal Kv1 family ion channel remodeling and fibrosis as measured by qRT-PCR and Masson's trichrome histology, respectively. Using RT-PCR, immunocytochemistry, and immunoblotting, KCNA1 mRNA and protein were detected in isolated mouse cardiomyocytes and human atria for the first time. Patients with chronic AF (cAF) showed no changes in KCNA1 mRNA levels relative to controls; however, they exhibited increases in atrial Kv1.1 protein levels, not seen in paroxysmal AF patients. Patch-clamp recordings of isolated human atrial myocytes revealed significant dendrotoxin-K (DTX-K)-sensitive outward current components that were significantly increased in cAF patients, reflecting a contribution by Kv1.1 channels. The concomitant increases in Kv1.1 protein and DTX-K-sensitive currents in atria of cAF patients suggest that the channel contributes to the pathological mechanisms of persistent AF. These findings provide evidence of an intrinsic cardiac role of Kv1.1 channels and indicate that they may contribute to atrial repolarization and AF susceptibility.

  7. Copper uptake and retention in liver parenchymal cells isolated from nutritionally copper-deficient rats

    NARCIS (Netherlands)

    Berg, van den G.J.; de Goeij, J.J.M.; Bock, I.; Gijbels, M.J.J.; Brouwer, A.; Lei, K.Y.; Hendriks, H.F.J.

    1991-01-01

    Copper uptake and retention were studied in primary cultures of liver parenchymal cells isolated from copper-deficient rats. Male Sprague-Dawley rats were fed a copper-deficient diet (<1 mg Cu/kg) for 10 wk. Copper-deficient rats were characterized by low copper concentrations in plasma and liver,

  8. Copper uptake and retention in liver parenchymal cells isolated from nutritionally copper-deficient rats

    NARCIS (Netherlands)

    Berg, G.J. van den; Goeij, J.J.M. de; Bock, I.; Gijbels, M.J.J.; Brouwer, A.; Lei, K.Y.; Hendruiks, H.F.J.

    1991-01-01

    Copper uptake and retention were studied in primary cultures of liver parenchymal cells isolated from copper-deficient rats. Male Sprague-Dawley rats were fed a copper-deficient diet (< 1 mg Cu/kg) for 10 wk. Copper-deficient rats were characterized by low copper concentrations in plasma and liver,

  9. Effect of venlafaxine hydrochloride in different preparations of isolated guinea-pig and rat organ tissues.

    Science.gov (United States)

    Velasco, A; Arruza, A; Maroto, M; Carvajal, A; Fernández del Busto, E; García del Pozo, J

    1999-04-01

    A study was undertaken to know better the effects of venlafaxine hydrochloride on the responses of isolated rat vas deferens to noradrenaline and dopamine, those of isolated rat uterus to serotonin and histamine, and those of isolated guinea-pig ileum to acetylcholine and histamine. Venlafaxine hydrochloride increased the response of rat vas deferens to noradrenaline but not to dopamine. Venlafaxine did not alter the response of rat isolated uterus to serotonin. In rat uterus, venlafaxine did not modify the response to histamine but was able to increase it in guinea-pig ileum. An anticholinergic effect was observed with the lowest concentration tested. Although venlafaxine is a selective serotonine reuptake inhibitor in the central nervous system, serotonin uptake was not seen in the rat uterus. The anticholinergic effects observed in the present study might be consistent with some of the side-effects associated with venlafaxine.

  10. Persepsi Karyawan Tetap Atria Hotel & Conference Malang Atas Pengaruh Keselamatan Dan Kesehatan Kerja Terhadap Motivasi Kerja Dan Kinerja Karyawan (Studi Karyawan Tetap Atria Hotel & Conference Malang)

    OpenAIRE

    Sinaga, Andri Bennydictus

    2015-01-01

    The purpose of this research to know perception permanent workers the Atria Hotel & Conference Malang over the influence of work safety and health to motivation work and employee performance. Data collection done through the distribution of the questionnaire that has been tested validity and reliability .Research locations was conducted in the Atria Hotel & Conference Malang and population used are employees stick with the number of 118 .Number of employees fixed samples this researc...

  11. Isolation of plasma membrane-associated membranes from rat liver.

    Science.gov (United States)

    Suski, Jan M; Lebiedzinska, Magdalena; Wojtala, Aleksandra; Duszynski, Jerzy; Giorgi, Carlotta; Pinton, Paolo; Wieckowski, Mariusz R

    2014-02-01

    Dynamic interplay between intracellular organelles requires a particular functional apposition of membrane structures. The organelles involved come into close contact, but do not fuse, thereby giving rise to notable microdomains; these microdomains allow rapid communication between the organelles. Plasma membrane-associated membranes (PAMs), which are microdomains of the plasma membrane (PM) interacting with the endoplasmic reticulum (ER) and mitochondria, are dynamic structures that mediate transport of proteins, lipids, ions and metabolites. These structures have gained much interest lately owing to their roles in many crucial cellular processes. Here we provide an optimized protocol for the isolation of PAM, PM and ER fractions from rat liver that is based on a series of differential centrifugations, followed by the fractionation of crude PM on a discontinuous sucrose gradient. The procedure requires ∼8-10 h, and it can be easily modified and adapted to other tissues and cell types.

  12. Ciprofloxacin, an antibiotic with cardiac actions on isolated rat hearts

    Directory of Open Access Journals (Sweden)

    Loipa Galán-Martínez

    2018-04-01

    Full Text Available Context: Ciprofloxacin is the most commonly used fluoroquinolone and is prescribed as the antibiotic of choice in the treatment of several microbial infections. Some clinical reports have suggested that ciprofloxacin may induce QT-interval prolongation and Torsades de Pointes arrhythmias. This drug is a weak inhibitor of a rapid component of the cardiac delayed rectifier potassium current IKr, but there are few electrophysiological data available to assess whether ciprofloxacin has the potency to provoke QT prolongation and subsequent Torsades de Pointes arrhythmias. Aims: To evaluate the effect of ciprofloxacin on the contractile and electrical activity of isolated rat hearts. Methods: The Langendorff technique was performed in rat hearts, and the effects of ciprofloxacin (0.001 – 100 μM were measured on the cardiac force of contraction and on the RR, QRS and QTc intervals. The arrhythmogenic potential and the ventricular fibrillation threshold were evaluated with ciprofloxacin. Results: Ciprofloxacin decreased the force of contraction of all hearts studied, in a concentration-dependent manner. The estimated IC50 for the inotropic negative effect was 0.15 ± 0.04 μM. Ciprofloxacin significantly prolonged the QRS complex, QTc and RR interval. Significant arrhythmic effects with ciprofloxacin were shown and the ventricular fibrillation threshold was decreased. Conclusions: These results suggest that ciprofloxacin exerted effects on cardiac Na+, K+ and Ca2+ channels. The actions of ciprofloxacin require further studies at the cellular level. These conclusions may account for clinical data that have been reported previously.

  13. Stabilization of glucocorticoid receptors in isolated rat hepatocytes by radioprotectants

    International Nuclear Information System (INIS)

    Karle, J.M.; Ridder, W.E.; Wright, N.; Olmeda, R.; Nielsen, C.J.

    1986-01-01

    Previous work has shown that glucocorticoid receptors in rat liver homogenate can be stabilized by the addition of MoO 4 plus the sulfhydryl-containing compounds dithiothreitol and WR 1065. The latter is the dephosphorylated, principal metabolite of the radioprotectant WR 2721 (or S-2-(3-aminopropylamino)ethanesphosphorothioic acid). The current work results from applying this knowledge to intact rat hepatocytes. Cells were isolated by collagenase perfusion and incubated in supplemented minimum essential medium at 37 0 C with various concentrations of WR 2721, WR 1065, or vehicle. Samples of these cell suspensions were analyzed at various times for steroid binding capacity by incubating homogenates (27,000 x g supernates) with 50 nM 3 H-triamcinolone acetonide in the presence or absence of excess unlabelled dexamethasone. Concentrations of 10 mM WR 2721 provided marked preservation of the binding capacity (>85% of the initial value at 5 hours) compared to control at 60% of the binding capacity. WR 1065 at 10 mM provided no such protection. This is consistent with the observation that WR 1065 does not pass cell membranes. The authors propose that supplying reducing equivalents to intracellular components such as the glucocorticoid receptor may be one mechanism of the radioprotection afforded by WR 2721

  14. Agmatine Modulation of Noradrenergic Neurotransmission in Isolated Rat Blood Vessels.

    Science.gov (United States)

    Török, Jozef; Zemančíková, Anna

    2016-06-30

    Agmatine, a vasoactive metabolite of L-arginine, is widely distributed in mammalian tissues including blood vessels. Agmatine binding to imidazoline and α₂-adrenoceptors induces a variety of physiological and pharmacological effects. We investigated the effect of agmatine on contractile responses of the rat pulmonary artery and portal vein induced by electrical stimulation of perivascular nerves and by exogenous adrenergic substances. Experiments were performed on isolated segments of rat main pulmonary artery and its extralobular branches, and portal vein suspended in organ bath containing modified Krebs bicarbonate solution and connected to a force-displacement transducer for isometric tension recording. Electrical field stimulation (EFS) produced tetrodotoxin-sensitive contractile responses of pulmonary artery and portal vein. Besides the well known vasorelaxant actions, we found that agmatine also produced a concentration-dependent inhibition of neurogenic contractions induced by EFS in pulmonary arteries; however, the agmatine treatment did not influence the responses to exogenous noradrenaline. The inhibitory effect on EFS-induced contractions was not abolished by the α₂-adrenoceptor antagonist rauwolscine. In portal vein, in contrast, agmatine increased spontaneous mechanical contractions and enhanced the contractions induced by EFS. The results suggest that agmatine can significantly influence vascular function of pulmonary arteries and portal veins by modulating sympathetically mediated vascular contractions by pre- and postsynaptic mechanisms.

  15. Stereological brain volume changes in post-weaned socially isolated rats

    DEFF Research Database (Denmark)

    Fabricius, Katrine; Helboe, Lone; Steiniger-Brach, Björn

    2010-01-01

    Rearing rats in isolation after weaning is an environmental manipulation that leads to behavioural and neurochemical alterations that resemble what is seen in schizophrenia. The model is neurodevelopmental in origin and has been used as an animal model of schizophrenia. However, only a few studies...... Lister Hooded rats isolated from postnatal day 25 for 15 weeks. We observed the expected gender differences in total brain volume with males having larger brains than females. Further, we found that isolated males had significantly smaller brains than group-housed controls and larger lateral ventricles...... than controls. However, this was not seen in female rats. Isolated males had a significant smaller hippocampus, dentate gyrus and CA2/3 where isolated females had a significant smaller CA1 compared to controls. Thus, our results indicate that long-term isolation of male rats leads to neuroanatomical...

  16. [Morphological and electrophysiological changes of the heart atria in necropsy patients with atrial fibrillation - a pilot study].

    Science.gov (United States)

    Matějková, Adéla; Steiner, Ivo

    2014-01-01

    Atrial fibrillation (AF), the most common supraventricular tachycardia, has a morphological base, so called remodelation of atrial myocardium, with its abnormal conduction pattern as a consequence. The remodelation regards electrical, contractile, and structural properties. In this pilot study we attempted to find relations between the myocardial morphological (scarring, amyloidosis, left atrial enlargement) and electrophysiological (ECG characteristics of the P-wave) changes in patients with AF. We examined 40 hearts of necropsy patients - 20 with a history of AF and 20 with no history of AF. Grossly, the heart weight and the size of the left atrium (LA) were evaluated. Histologically, 7 standard sites from the atria were examined. In each specimen, the degree of myocardial scarring and of deposition of isolated atrial amyloid (IAA) were assessed. We failed to show any significant difference in the P-wave pattern between patients with and without AF. Morphologically, however, there were several differences - the patients with AF had significantly heavier hearts, larger left atria, more severely scarred myocardium of the LA and the atrial septum, and more severe deposition of IAA in both atria in comparison to the control group of patients with sinus rhythm. The left atrial distribution of both fibrosis and amyloidosis was irregular. In patients with AF the former was most pronounced in the LA ceiling while the latter in the LA anterior wall. The entire series showed more marked amyloidosis in the left than in the right atrium. An interesting finding was the universal absence of IAA in the sinoatrial node. The knowledge of distribution of atrial myocardial structural changes could be utilized by pathologists in taking specimens for histology and also by cardiologists in targeting the radiofrequency ablation therapy.

  17. A method for isolating identifying and culturing of rat trachea-bronchia epithelial cells

    International Nuclear Information System (INIS)

    Cui Fengmei; Su Shibiao; Nie Jihua; Li Bingyan; Tong Jian

    2005-01-01

    Objective: To explore a method for isolating identifying and culturing the rat trachea-bronchia epithelial cells. Methods: The rat trachea-bronchia epithelial cells were isolated by digestion with pronase and brushing with cell brush, identified using confocul and cultured in entire F12 media with no serum. Results: With this method, cells in high purity and high viability could be obtained, and about 10 6 cells per rat. The cells grow well in entire F12 media with no serum. Conclusion: The method is useful for isolating rate trachea-bronchia epithelial cells and the entire F12 media with no serum is effective for culturing. (authors)

  18. Phosphorus nuclear magnetic resonance in isolated perfused rat pancreas

    International Nuclear Information System (INIS)

    Matsumoto, Takehisa; Kanno, Tomio; Seo, Yoshiteru; Murakami, Masataka; Watari, Hiroshi

    1988-01-01

    Phosphorus nuclear magnetic resonance spectroscopy was applied to measure phosphorus energy metabolites in isolated perfused rat pancreas. The gland was perfused with a modified Krebs-Henseleit solution at room temperature (25 degree C). 31 P resonances of creatine phosphate (PCr), ATP, ADP, inorganic phosphate (P i ) and phosphomonoesters (PMEs) were observed in all the preparations of pancreas. In different individual preparations, the resonance of PCr varied, but those of ATP were almost the same. The initial levels of PCr and ATP in individual preparations, however, remained almost unchanged during perfusion with the standard solution for 2 h. When the perfusion was stopped, the levels of ATP and PCr decreased, while the levels of PME and P i increased. At that time, the P i resonance shfted to a higher magnetic field, indicating that the tissue pH decreased. On reperfusion, the tissue levels of phosphorus compounds and the tissue pH were restored to their initial resting levels. Continuous infusion of 0.1 μM acetylcholine caused marked and sustained increases in the flow of pancreatic juice and protein output. During the stimulation the tissue levels of phosphorus compounds remained unchanged, while the tissue pH was decreased slightly

  19. Anabolic regulation of gluconeogenesis by insulin in isolated rat hepatocytes

    International Nuclear Information System (INIS)

    Mohan, C.; Bessman, S.P.

    1985-01-01

    The role of substrate availability in the regulation of gluconeogenesis in isolated rat hepatocytes was studied using [U- 14 C]alanine as a tracer in the presence of different concentrations of L-alanine in the incubation medium. At low alanine concentrations (0.5 mM) insulin decreased the 14 C incorporation into the glucose pool and increased the incorporation of tracer carbons into the protein and lipid pools and into CO 2 . The net radioactivity lost from the glucose pool was only a small percentage of the total increase in the activity of the protein, lipid, CO 2 , or glycogen pools, supporting the notion that the effect of insulin in diminishing gluconeogenesis is secondary to its effects on pathways using pyruvate. At higher concentrations of alanine (2.5, 5.0, and 10.0 mM) in the incubation medium insulin increased the movement of alanine carbons into protein and glucose. These results were further confirmed by using [U- 14 C]lactate. The increases in observed specific activity of glucose following insulin administration would not be possible if insulin acted by affecting the activity of any enzyme directly involved in the formation or utilization of pyruvate, most of which have been proposed as sites of insulin action. Data presented show that insulin inhibits gluconeogenesis by affecting a change in substrate availability

  20. Stimulation of glucose phosphorylation by fructose in isolated rat hepatocytes.

    Science.gov (United States)

    Van Schaftingen, E; Vandercammen, A

    1989-01-15

    The phosphorylation of glucose was measured by the formation of [3H]H2O from [2-3H]glucose in suspensions of freshly isolated rat hepatocytes. Fructose (0.2 mM) stimulated 2-4-fold the rate of phosphorylation of 5 mM glucose although not of 40 mM glucose, thus increasing the apparent affinity of the glucose phosphorylating system. A half-maximal stimulatory effect was observed at about 50 microM fructose. Stimulation was maximal 5 min after addition of the ketose and was stable for at least 40 min, during which period 60% of the fructose was consumed. The effect of fructose was reversible upon removal of the ketose. Sorbitol and tagatose were as potent as fructose in stimulating the phosphorylation of 5 mM glucose. D-Glyceraldehyde also had a stimulatory effect but at tenfold higher concentrations. In contrast, dihydroxyacetone had no significant effect and glycerol inhibited the detritiation of glucose. Oleate did not affect the phosphorylation of glucose, even in the presence of fructose, although it stimulated the formation of ketone bodies severalfold, indicating that it was converted to its acyl-CoA derivative. These results allow the conclusion that fructose stimulates glucokinase in the intact hepatocyte. They also suggest that this effect is mediated through the formation of fructose 1-phosphate, which presumably interacts with a competitive inhibitor of glucokinase other than long-chain acyl-CoAs.

  1. Concentration of (+/-)-propranolol in isolated, perfused lungs of rat.

    Science.gov (United States)

    Dollery, C T; Junod, A F

    1976-01-01

    1 The metabolism and the accumulation of (+/-)-propranolol have been studied in isolated lungs of the rat, perfused with an artificial medium. 2 Little or no metabolism took place during the perfusion periods (up to 10 minutes). 3 Accumulation was observed with high tissue/medium ratios for substrate concentrations of 0.2 muM to 1 mM; there was evidence for saturability, but no real plateau could be seen. The presence of two binding sites with different affinities was established. 4 Cold greatly inhibited the accumulation process at low substrate concentrations, but had no effect at 1 mM propranolol. 5 Inhibition of accumulation was measured in the presence of imipramine, desmethylimipramine, nortryptiline, chlorpromazine and of Na+-free medium. Cocaine, 5-hydroxytryptamine and noradrenaline had no effect. Lidocaine enhanced the accumulation process. Release of previously bound propranolol was accelerated in the presence of propranolol and imipramine, unaffected by a Na+-free medium and decreased by cold and by lidocaine. 6 Experiments on lung tissue slices yielded qualitatively similar results to those obtained with perfused lungs. Ouabain and KCN had no or little effect on propranolol accumulation. PMID:1276542

  2. Effect of heavy water on isolated rat liver mitochondria

    International Nuclear Information System (INIS)

    Huebner, G.

    1981-01-01

    The rate of O 2 consumption by isolated rat liver mitochondria was determined polarographically with a Clark electrode at 25 0 C in the active (state 3), strongly coupled (state 4) and decoupled state of the mitochondria in media containing H 2 16 O, D 2 16 O or H 2 18 O. The results confirm the value of the D 2 O isotope effect in the form on an O 2 -consumption inhibition. In H 2 18 O no isotope effect has been detected in the state of controlled respiration. In contrast, a strongly marked inverse isotope effect has been found in the active state after ADP addition and in the decoupled state after DNP addition. This inverse isotope effect occurs in reactions involving a preceding equilibrium. According to the chemiosmotic hypothesis of oxidative phosphorylation the formation of hydronium ions is part of this reaction. The equilibrium constant k 2 = 0.9774 for the hydronium ion in H 2 16 O and H 2 18 O implies that the formation of the hydronium ion in H 2 18 O is preferred to that in H 2 16 O. The high inverse H 2 18 O isotope effect respiration shows that the formation of H 3 O + contributes to the vectorial proton transport, probably as a preceding equilibrium, and that in the active state of the respiratory chain this reaction may be the rate-determining step. (author)

  3. Treadmill exercise ameliorates social isolation-induced depression through neuronal generation in rat pups.

    Science.gov (United States)

    Cho, Jung-Wan; Jung, Sun-Young; Lee, Sang-Won; Lee, Sam-Jun; Seo, Tae-Beom; Kim, Young-Pyo; Kim, Dae-Young

    2017-12-01

    Social isolation is known to induce emotional and behavioral changes in animals and humans. The effect of treadmill exercise on depression was investigated using social isolated rat pups. The rat pups in the social isolation groups were housed individually. The rat pups in the exercise groups were forced to run on treadmill for 30 min once a day from postnatal day 21 to postnatal day 34. In order to evaluate depression state of rat pups, forced swimming test was performed. Newly generated cells in the hippocampal dentate gyrus were determined by 5-bromo-2'-deoxyuridine (BrdU) immunohistochemistry. We examined the expression of 5-hydroxytryptamine (5-HT) and tryptophan hydroxylase (TPH) in the dorsal raphe using immunofluorescence. The expression of brain-derived neurotrophic factor (BDNF) and tyrosine kinase B (TrkB) was detected by Western blot analysis. The present results demonstrated that social isolation increased resting time and decreased mobility time. Expression of 5-HT and TPH in the dorsal raphe and expression of BDNF and TrkB in the hippocampus were decreased by social isolation. The number of BrdU-positive cells in the hippocampal dentate gyrus was suppressed by social isolation. Treadmill exercise decreased resting time and increased mobility in the social isolated rat pups. Expression of 5-HT, TPH, BDNF, and TrkB was increased by treadmill exercise. The present results suggested that treadmill exercise may ameliorates social isolation-induced depression through increasing neuronal generation.

  4. Impaired glucocorticoid-mediated HPA axis negative feedback induced by juvenile social isolation in male rats.

    Science.gov (United States)

    Boero, Giorgia; Pisu, Maria Giuseppina; Biggio, Francesca; Muredda, Laura; Carta, Gianfranca; Banni, Sebastiano; Paci, Elena; Follesa, Paolo; Concas, Alessandra; Porcu, Patrizia; Serra, Mariangela

    2018-05-01

    We previously demonstrated that socially isolated rats at weaning showed a significant decrease in corticosterone and adrenocorticotropic hormone (ACTH) levels, associated with an enhanced response to acute stressful stimuli. Here we shown that social isolation decreased levels of total corticosterone and of its carrier corticosteroid-binding globulin, but did not influence the availability of the free active fraction of corticosterone, both under basal conditions and after acute stress exposure. Under basal conditions, social isolation increased the abundance of glucocorticoid receptors, while it decreased that of mineralocorticoid receptors. After acute stress exposure, socially isolated rats showed long-lasting corticosterone, ACTH and corticotrophin releasing hormone responses. Moreover, while in the hippocampus and hypothalamus of group-housed rats glucocorticoid receptors expression increased with time and reached a peak when corticosterone levels returned to basal values, in socially isolated rats expression of glucocorticoid receptors did not change. Finally, social isolation also affected the hypothalamic endocannabinoid system: compared to group-housed rats, basal levels of anandamide and cannabinoid receptor type 1 were increased, while basal levels of 2-arachidonoylglycerol were decreased in socially isolated rats and did not change after acute stress exposure. The present results show that social isolation in male rats alters basal HPA axis activity and impairs glucocorticoid-mediated negative feedback after acute stress. Given that social isolation is considered an animal model of several neuropsychiatric disorders, such as generalized anxiety disorder, depression, post-traumatic stress disorder and schizophrenia, these data could contribute to better understand the alterations in HPA axis activity observed in these disorders. Copyright © 2018 Elsevier Ltd. All rights reserved.

  5. Arterio-venous anastomoses in isolated, perfused rat lungs.

    Science.gov (United States)

    Conhaim, Robert L; Segal, Gilad S; Watson, Kal E

    2016-11-01

    Several studies have suggested that large-diameter (>25 μm) arterio-venous shunt pathways exist in the lungs of rats, dogs, and humans. We investigated the nature of these pathways by infusing specific-diameter fluorescent latex particles (4, 7, 15, 30, or 50 μm) into isolated, ventilated rat lungs perfused at constant pressure. All lungs received the same mass of latex (5 mg), which resulted in infused particle numbers that ranged from 1.7 × 10 7 4 μm particles to 7.5 × 10 4 50 μm particles. Particles were infused over 2 min. We used a flow cytometer to count particle appearances in venous effluent samples collected every 0.5 min for 12 min from the start of particle infusion. Cumulative percentages of infused particles that appeared in the samples averaged 3.17 ± 2.46% for 4 μm diameter particles, but ranged from 0.01% to 0.17% for larger particles. Appearances of 4 μm particles followed a rapid upslope beginning at 30 sec followed by a more gradual downslope that lasted for up to 12 min. All other particle diameters also began to appear at 30 sec, but followed highly irregular time courses. Infusion of 7 and 15 μm particles caused transient but significant perfusate flow reductions, while infusion of all other diameters caused insignificant reductions in flow. We conclude that small numbers of bypass vessels exist that can accommodate particle diameters of 7-to-50 μm. We further conclude that our 4 μm particle data are consistent with a well-developed network of serial and parallel perfusion pathways at the acinar level. Published 2016. This article is a U.S. Government work and is in the public domain in the USA. Physiological Reports published by Wiley Periodicals, Inc. on behalf of The Physiological Society and the American Physiological Society.

  6. Stereological brain volume changes in post-weaned socially isolated rats

    DEFF Research Database (Denmark)

    Fabricius, Katrine; Helboe, Lone; Steiniger-Brach, Björn

    2010-01-01

    Lister Hooded rats isolated from postnatal day 25 for 15 weeks. We observed the expected gender differences in total brain volume with males having larger brains than females. Further, we found that isolated males had significantly smaller brains than group-housed controls and larger lateral ventricles...... have evaluated the neuroanatomical changes in this animal model in comparison to changes seen in schizophrenia. In this study, we applied stereological volume estimates to evaluate the total brain, the ventricular system, and the pyramidal and granular cell layers of the hippocampus in male and female...... than controls. However, this was not seen in female rats. Isolated males had a significant smaller hippocampus, dentate gyrus and CA2/3 where isolated females had a significant smaller CA1 compared to controls. Thus, our results indicate that long-term isolation of male rats leads to neuroanatomical...

  7. K+ transport and membrane potentials in isolated rat parotid acini

    International Nuclear Information System (INIS)

    Nauntofte, B.; Dissing, S.

    1988-01-01

    42K+ transport properties of isolated rat parotid acini were characterized concomitant with measurements of membrane potentials (Em) by means of the fluorescent dye diSC3-(5). In unstimulated acini suspended in a 5 mM K+ buffer, Em was governed by the K+ and Cl- gradients and amounted to about -59 mV, a value that remained unaffected on cholinergic stimulation. In unstimulated acini, 42K+ influx was largely mediated by the Na+-K+ pump, and the residual influxes were mediated by a bumetanide-sensitive component (cotransport system) and by K+ channels. Efflux of 42K+ was largely mediated by a bumetanide-sensitive component and by K+ channels. In the unstimulated state, the cotransport system was mediating K+-K+ exchange without contributing to the net uptake of K+. Within 10 s after stimulation, a approximately 10-fold increase in the acinar K+ conductance (gK) occurred, resulting in a rapid net efflux of K+ that amounted to approximately 3.8 mmol.l cells-1.s-1. Measurements of 42K+ fluxes as a function of the external K+ concentration revealed that in the stimulated state gK increases when external K+ is raised from 0.7 to 10 mM, consistent with an activation of acinar gK by the binding of external K+ to the channel. 42K+ flux ratios as well as the effect of the K+ channel inhibitor from scorpion venom (LQV) suggest that approximately 90% of K+ transport in the stimulated state is mediated by ''maxi'' K+ channels

  8. Transport of cysteate by synaptosomes isolated from rat brain

    International Nuclear Information System (INIS)

    Wilson, D.F.; Pastuszko, A.

    1986-01-01

    Synaptosomes isolated from rat brain were observed to take up cysteic acid by a high affinity transport system (K/sub M = 12.3 +/- 2.1 μM; V/sub m/ = 2.5 n mole/mg protein/minute). This uptake was competitively inhibited by aspartate (K/sub i/ = 13.3 +/- 1.8 μM) and cysteine sulfinate (K/sub i/ = 13.3 +/- 3.3 μM). Addition of extrasynaptosomal cysteate, aspartate or cysteine sulfinate to synaptosomes loaded with [ 35 S] cysteate induced rapid efflux of the cysteate. This efflux was via stoichiometric exchange of amino acids with half maximal rates at 5.0 +/- 1.1 μM aspartate or 8.0 +/- 1.3 μM cysteine sulfinate. Conversely, added extrasynaptosomal cysteate exchanged for endogenous aspartate and glutamate with half maximal rates at 5.0 +/- 0.4 μM cysteate. In the steady state after maximal accumulation of cysteate, the intrasynaptosomal cysteate concentrations exceeded the extrasynaptosomal concentrations by up to 10,000 fold. The measured concentration ratios were the same, within experimental error, as those for aspartate and glutamate. Depolarization, with either high K + or veratridine, of the plasma membrane of synaptosomes loaded with cysteate caused parallel release of cysteate, aspartate and glutamate. It is concluded that neurons transport cysteate, cysteine sulfinate, aspartate and glutamate with the same transport system. This transport system catalyzes homoexchange and heteroexchange as well as net uptake and release of all these amino acids

  9. Saw palmetto is an indirectly acting sympathomimetic in the rat-isolated prostate gland.

    Science.gov (United States)

    Cao, Nga; Haynes, John M; Ventura, Sabatino

    2006-02-01

    To investigate whether saw palmetto that inhibits alpha1-adrenoceptor binding in vitro affects contractility of the rat prostate gland. The effects of a commercially available saw palmetto extract were examined on the contractility of rat-isolated prostate glands. The extract was tested in the presence and absence of phentolamine, prazosin, yohimbine, propranolol, hexamethonium, cocaine, desipramine, nifedipine, guanethidine, atropine, and alpha,beta-methylene ATP to evaluate the mechanism of action. Isolated preparations of rat vas deferens and bladder were used for comparison. Unexpectedly, saw palmetto extract caused contractions of the rat prostate gland that could be attenuated by prazosin, phentolamine, nifedipine, guanethidine, cocaine, and desipramine but not by any of the other pharmacological tools. Similar contractile effects were observed in rat-isolated vas deferens preparations but not in rat-isolated bladder preparations. In the rat prostate gland, saw palmetto extract causes indirect alpha1-adrenoceptor-mediated contractions via the release of noradrenaline from sympathetic neurons. Copyright 2005 Wiley-Liss, Inc.

  10. Draft genome of the emerging pathogen, Kocuria marina, isolated from a wild urban rat

    Directory of Open Access Journals (Sweden)

    Shih Keng Loong

    Full Text Available Kocuria marina has recently emerged as a cause for catheter-related bloodstream infections in patients with underlying health complications. One K. marina strain was recently isolated from the lung tissues of a wild urban rat (Rattus rattus diardii caught during rodent surveillance. Here, we present the draft genome of the first K. marina animal isolate, K. marina TRE150902.

  11. Propranolol inhibits the in vitro conversion of thyroxine into triiodothyronine by isolated rat liver parenchymal cells

    NARCIS (Netherlands)

    van Noorden, C. J.; Wiersinga, W. M.; Touber, J. L.

    1979-01-01

    A model for the in vitro study of the conversion of thyroxine into triiodothyronine using isolated rat liver parenchymal cells is described. Isolated liver cells (mean protein content 18 mg/ml) convert approximately 0.8% of 1.3 microM exogenously added T4 into T3 during thirty minutes incubation.

  12. Immune system stimulation in rats by Lactobacillus sp. isolates from Raffia wine (Raphia vinifera).

    Science.gov (United States)

    Flore, Tiepma N E; François, Zambou N; Félicité, Tchouanguep M

    2010-01-01

    The immune system consists of organs and several cell types. Antigen interaction with these cells induces a cellular immune response mediated by activated cells. The effects of lactic acid bacteria on the systemic immune response and on the secretory immune system are described. The current investigation sets out to examine the possible effects of isolated wine lacto-bacilli upon various hematologic and immunologic parameters in rats. We have fed rats with probiotic isolates from Raffia wine and challenged with castor oil; two control groups were fed with castor oil and others were not. We counted blood cells at the end of the experiment; all isolates seemed to cause a decrease of circulating white blood cells. The percentage of lymphocytes and the total protein in the spleen increased in the treated animals; also a normal aspect of faeces was observed compared to the control. These isolates of Lactobacillus seem to occur to immune cell-mediated responses in rats.

  13. Resistance to Reperfusion Injury Following Short Term Postischemic Administration of Natural Honey in Globally Ischemic Isolated Rat Heart

    OpenAIRE

    Haleh Vaez; Mehrban Samadzadeh; Fahimeh Zahednezhad; Moslem Najafi

    2012-01-01

    Purpose: Results of our previous study revealed that preischemic perfusion of honey before zero flow global ischemia had cardioprotective effects in rat. The present study investigated potential resistance to reperfusion injury following short term postischemic administration of natural honey in globally ischemic isolated rat heart. Methods: Male Wistar rats were divided into five groups (n=10-13). The rat hearts were isolated, mounted on a Langendorff apparatus, allowed to equilibra...

  14. Sex differences in the outcome of juvenile social isolation on HPA axis function in rats.

    Science.gov (United States)

    Pisu, M G; Garau, A; Boero, G; Biggio, F; Pibiri, V; Dore, R; Locci, V; Paci, E; Porcu, P; Serra, M

    2016-04-21

    Women are more likely than men to suffer from anxiety disorders and major depression. These disorders share hyperresponsiveness to stress as an etiological factor. Thus, sex differences in brain arousal systems and their regulation by chronic stress may account for the increased vulnerability to these disorders in women. Social isolation is a model of early life stress that results in neurobiological alterations leading to increased anxiety-like and depressive-like behaviors. Here we investigated the sex difference in the effects of post-weaning social isolation on acute stress sensitivity and behavior in rats. In both sexes, social isolation at weaning reduced basal levels of the neuroactive steroid allopregnanolone in the brain and of corticosterone in plasma. Moreover, acute stress increased plasma corticosterone levels in both group-housed and socially isolated male and female rats; however this effect was greater in male than female rats subjected to social isolation. Intriguingly, group-housed female rats showed no change in plasma and brain levels of allopregnanolone after acute foot-shock stress. The absence of stress-induced effects on allopregnanolone synthesis might be due to the physiologically higher levels of this hormone in females vs. males. Accordingly, increasing allopregnanolone levels in male rats blunted the response to foot-shock stress in these animals. Socially isolated male, but not female, rats also display depressive-like behavior and increased hippocampal brain-derived neurotrophic factor (BDNF). The ovarian steroids could "buffer" the effect of this adverse experience in females on these parameters. Finally, the dexamethasone (DEX) suppression test indicated that the chronic stress associated with social isolation impairs feedback inhibition in both sexes in which an increase in the abundance of glucocorticoid receptors (GRs) in the hippocampus was found. Altogether, these results demonstrate that social isolation affects neuroendocrine

  15. Effects of thapsigargin in isolated rat thoracic aorta

    DEFF Research Database (Denmark)

    Mikkelsen, E O; Thastrup, Ole; Christensen, S B

    1988-01-01

    The effect of thapsigargin (Tg) was studied in rat thoracic aorta. Tg (10(-8)-10(-5) M) had a dual effect on rat aorta. Thus, Tg induced a concentration dependent increase in basal tone in normal physiological salt solution (PSS), while Tg in potassium (K+) precontracted aortic rings caused a con...... A 23187 had an endothelium dependent relaxant effect on rat aorta different from that of carbachol. The results indicate that Tg in vascular smooth muscle acts by stimulating the transmembranal influx of extracellular calcium....

  16. Effects of dehydroepiandrosterone (DHEA) on glucose metabolism in isolated hepatocytes from Zucker rats

    International Nuclear Information System (INIS)

    Finan, A.; Cleary, M.P.

    1986-01-01

    DHEA has been shown to competitively inhibit the pentose phosphate shunt (PPS) enzyme glucose-6-phosphate dehydrogenase (G6PD) when added in vitro to supernatants or homogenates prepared from mammalian tissues. However, no consistent effect on G6PD activity has been determined in tissue removed from DHEA-treated rats. To explore the effects of DHEA on PPS, glucose utilization was measured in hepatocytes from lean and obese male Zucker rats (8 wks of age) following 1 wk of DHEA treatment (0.6% in diet). Incubation of isolated hepatocytes from treated lean Zucker rats with either [1- 14 C] glucose or [6- 14 C] glucose resulted in significant decreases in CO 2 production and total glucose utilization. DHEA-lean rats also had lowered fat pad weights. In obese rats, there was no effect of 1 wk of treatment on either glucose metabolism or fat pad weight. The calculated percent contribution of the PPS to glucose metabolism in hepatocytes was not changed for either DHEA-lean or obese rats when compared to control rats. In conclusion, 1 wk of DHEA treatment lowered overall glucose metabolism in hepatocytes of lean Zucker rats, but did not selectively affect the PPS. The lack of an effect of short-term treatment in obese rats may be due to differences in their metabolism or storage/release of DHEA in tissues in comparison to lean rats

  17. Glucose production and storage in hepatocytes isolated from normal versus diabetic rats

    International Nuclear Information System (INIS)

    Olivieri, M.C.; Dragland-Meserve, C.J.; Parker Botelho, L.H.

    1987-01-01

    The rates of glucose production and storage were compared in hepatocytes isolated from normal versus insulin-resistant diabetic rats. A single low-dose (40 mg/kg) IV injection of streptozotocin to 250 g rats resulted in a Type II diabetic animal model which was hyperglycemic with normal insulin levels. Addition of 8 mM 14 C-lactate and 2 mM pyruvate to hepatocytes resulted in a linear increase in total glucose production ( 14 C-glucose and unlabeled glucose) and incorporation into glycogen measured over 120 min. The rate of gluconeogenesis was estimated from the production of 14 C-glucose and the rate of glycogenolysis was estimated from the production of unlabeled glucose in cells incubated in the presence or absence of 14 C-labelled substrate. There was not significant difference in total glucose production in hepatocytes isolated from normal versus diabetic rats, however, the contribution from gluconeogenesis versus glycogenolysis was significantly different. Following a 1 h incubation of cells from normal rats, 42% of the total glucose production was due to gluconeogenesis and 58% was due to glycogenolysis. In cells from diabetic rats, 83% of total glucose production was from gluconeogenesis and 17% from glycogenolysis. Also, incubation with 14 C-lactate/pyruvate resulted in a 3.3-fold increase in 14 C-glucose incorporation into glycogen in hepatocytes isolated from normal rats compared to diabetic rats. These data suggest that alterations occur in the rate-limiting enzymes responsible for glucose production and storage in hepatocytes isolated from a rat model of insulin-resistant Type II diabetes

  18. Antispasmodic Effects of Yarrow (Achillea Millefolium L.) Extract in the Isolated Ileum of Rat

    OpenAIRE

    Moradi, Mohammad-Taghi; Rafieian-Koupaei, Mahmoud; Imani-Rastabi, Reza; Nasiri, Jafar; Shahrani, Mehrdad; Rabiei, Zahra; Alibabaei, Zahra

    2013-01-01

    Achillea millefolium L. is cultivated in Iran and widely used in traditional medicine for gastrointestinal disorders. The aim of this study was to determine the effect of hydroalcoholic extract of A. millefolium on the contraction and relaxation of isolated ileum in rat. In this experimental study, aerial parts of A. millefolium were extracted by maceration in ethanol 70% for 72h. Terminal portion of ileum in 100 male Wistar rats was dissected and its contractions were recorded isotonically i...

  19. Peptide-evoked release of amylase from isolated acini of the rat parotid gland

    DEFF Research Database (Denmark)

    Goll, R; Poulsen, J H; Schmidt, P

    1994-01-01

    on isolated acini of the rat parotid gland. Furthermore, the occurrence and location of the peptides in the gland was studied. Finally, binding of 125I-BH-SP to isolated acini were studied in order to characterize their tachykinin receptor(s) and their binding kinetics. Only SP, NKA, NPK and VIP stimulated...... of NK1-receptors. Thus, the results of the present study support previous suggestions that the tachykinins and VIP are likely to be involved in amylase secretion in the rat parotid gland....

  20. Effect of UV-B (302 nm) irradiation on isolated rat hepatocytes

    International Nuclear Information System (INIS)

    Lahiri, S.; Habibullah, C.M.; Ayesha, Q.; Khan, A.A.; Srinivas, V.K.; Naithani, R.

    1995-01-01

    The present study aimed to evaluate the effect of UV-B irradiation on the functional integrity, and the metabolic and detoxifying capacity of isolated rat hepatocytes. Isolated rat hepatocytes were irradiated in various doses (400 Jm -2 , 600 Jm -2 , 800 Jm -2 and 1000 Jm -2 ). The cells were assayed for total lactate dehydrogenase, Na + -K + -ATPase, ATPase, ornithine carbamyltransferase activity (OCT) and urea production capacity. Lactate dehydrogenase and Na + -K + -ATPase activity were significantly decreased in all four irradiated groups (P<0.001), whereas viability, OCT and urea production capacity showed no alterations. (au) 22 refs

  1. 45Ca2+movements induced by Ca2+chloride in isolated rat aorta under K+-free conditions

    NARCIS (Netherlands)

    Wermelskirchen, D.; Nebel, U.; Wirth, A.; Wilffert, B.

    1991-01-01

    Increasing the extracellular Ca2+concentration induced a dihydropyridine-insensitive contraction in the isolated rat aorta bathed in K+-free solution. To obtained further insight into the mechanisms of this contraction45Ca2+uptake measurements were carried out with isolated rat aorta. Increasing the

  2. CA-45(2+) MOVEMENTS INDUCED BY CA2+ CHLORIDE IN ISOLATED RAT AORTA UNDER K+-FREE CONDITIONS

    NARCIS (Netherlands)

    WERMELSKIRCHEN, D; NEBEL, U; WIRTH, A; WILFFERT, B

    1991-01-01

    Increasing the extracellular Ca2+ concentration induced a dihydropyridine-insensitive contraction in the isolated rat aorta bathed in K+-free solution. To obtain further insight into the mechanism of this contraction Ca-45(2+) uptake measurements were carried out with isolated rat aorta. Increasing

  3. Routine post-weaning handling of rats prevents isolation rearing-induced deficit in prepulse inhibition

    Directory of Open Access Journals (Sweden)

    M.L.N.M. Rosa

    2005-11-01

    Full Text Available Rats reared under isolation conditions from weaning present a number of behavioral changes compared to animals reared under social conditions (group housing. These changes include deficits in prepulse inhibition (PPI of the startle reflex to a loud sound. PPI refers to the reduction of the magnitude of the startle reflex when a relatively weak stimulus (the prepulse precedes by an appropriate time interval the intense startle-elicing stimulus (the pulse. PPI is useful for studying sensorimotor integration. The present study evaluated the effect of handling on the impairment of PPI induced by isolation-rearing. Male Wistar rats (N = 11-15/group were housed in groups (5 per cage and handled three times a week or isolated (housed individually since weaning (21 days for 10 weeks when they reach approximately 150 g. The isolated rats were divided into "minimally handled" animals (handled once a week for cleaning purposes only or "handled" animals (handled three times a week. This handling consisted of grasping the rat by the tail and moving it to a clean cage (approximately 5 s. A statistically significant reduction (52% in the PPI test was found only in the isolated group with minimal handling while no difference was seen between grouped animals and isolated handled animals. These results indicate that isolation rearing causes disruption in the PPI at adult age, which serves as an index of attention deficit. This change in the sensory processing of information induced by post-weaning isolation can be prevented by handling during the development of the animal.

  4. Routine post-weaning handling of rats prevents isolation rearing-induced deficit in prepulse inhibition.

    Science.gov (United States)

    Rosa, M L N M; Silva, R C B; Moura-de-Carvalho, F T; Brandão, M L; Guimarães, F S; Del Bel, E A

    2005-11-01

    Rats reared under isolation conditions from weaning present a number of behavioral changes compared to animals reared under social conditions (group housing). These changes include deficits in prepulse inhibition (PPI) of the startle reflex to a loud sound. PPI refers to the reduction of the magnitude of the startle reflex when a relatively weak stimulus (the prepulse) precedes by an appropriate time interval the intense startle-elicing stimulus (the pulse). PPI is useful for studying sensorimotor integration. The present study evaluated the effect of handling on the impairment of PPI induced by isolation-rearing. Male Wistar rats (N = 11-15/group) were housed in groups (5 per cage and handled three times a week) or isolated (housed individually) since weaning (21 days) for 10 weeks when they reach approximately 150 g. The isolated rats were divided into "minimally handled" animals (handled once a week for cleaning purposes only) or "handled" animals (handled three times a week). This handling consisted of grasping the rat by the tail and moving it to a clean cage (approximately 5 s). A statistically significant reduction (52%) in the PPI test was found only in the isolated group with minimal handling while no difference was seen between grouped animals and isolated handled animals. These results indicate that isolation rearing causes disruption in the PPI at adult age, which serves as an index of attention deficit. This change in the sensory processing of information induced by post-weaning isolation can be prevented by handling during the development of the animal.

  5. In vitro glucose uptake by isolated rat hemi-diaphragm study of Aegle marmelos Correa root

    Directory of Open Access Journals (Sweden)

    Subban Ravi

    2009-03-01

    Full Text Available The methanol extract of the root of Aegle marmelos, a medicinal plant, was fractionated into eight fractions using column chromatography. The anti-diabetic activity of all the fractions was studied using the glucose uptake by isolated rat hemi-diaphragm in vitro model. Using the bioassay-guided fractionation, two compounds 1 and 2 were isolated by column chromatography and identified as 6-methyl-4-chromanone and skimmianine respectively by NMR and mass spectral methods.

  6. Long term treadmill exercise performed to chronic social isolated rats regulate anxiety behavior without improving learning.

    Science.gov (United States)

    Cevik, Ozge Selin; Sahin, Leyla; Tamer, Lulufer

    2018-05-01

    The type and duration of exposure to stress is an important influence on emotional and cognitive functions. Learning is the adaptive response of the central nervous system that occurs in hippocampus which affects from environmental factors like exercise. In this study, we investigated effects of long term treadmill exercise on learning and behavior on chronic social isolated rat. Male Wistar rats (n = 32) randomly assigned into four groups: control, exercised, social isolation, social isolation + exercise during postnatal days (PNDs) 21-34. Social isolation protocol was applied during 14 days by placing rat in a cage one by one. Rats were exercised during 5 days, days were chosen randomly for overall 4 weeks (20, 30, 50, 60 min respectively). Finally, learning performance was evaluated by Morris water maze (MWM). Anxiety behavior was evaluated by Open field and elevated plus maze test. At the end of learning and behavior tests, the rats were decapitated to collect blood samples via intracardiac puncture and corticosterone analysis was performed with ELISA method. Animal weights and water consumption did not change significantly but food intake differed among groups. Corticosterone level did not change between groups. The frequency of entering to the target quadrant increased in exercised rat significantly. However, there was no difference in learning and memory in rats. Treadmill exercise reduced anxiety behavior significantly. Taken together these findings may point out that, long term treadmill exercise did not change learning and memory but reduced anxiety level of rat without changing corticosterone level. Copyright © 2018 Elsevier Inc. All rights reserved.

  7. Neural activity in the prelimbic and infralimbic cortices of freely moving rats during social interaction: Effect of isolation rearing

    Science.gov (United States)

    Minami, Chihiro; Shimizu, Tomoko

    2017-01-01

    Sociability promotes a sound daily life for individuals. Reduced sociability is a central symptom of various neuropsychiatric disorders, and yet the neural mechanisms underlying reduced sociability remain unclear. The prelimbic cortex (PL) and infralimbic cortex (IL) have been suggested to play an important role in the neural mechanisms underlying sociability because isolation rearing in rats results in impairment of social behavior and structural changes in the PL and IL. One possible mechanism underlying reduced sociability involves dysfunction of the PL and IL. We made a wireless telemetry system to record multiunit activity in the PL and IL of pairs of freely moving rats during social interaction and examined the influence of isolation rearing on this activity. In group-reared rats, PL neurons increased firing when the rat showed approaching behavior and also contact behavior, especially when the rat attacked the partner. Conversely, IL neurons increased firing when the rat exhibited leaving behavior, especially when the partner left on its own accord. In social interaction, the PL may be involved in active actions toward others, whereas the IL may be involved in passive relief from cautionary subjects. Isolation rearing altered social behavior and neural activity. Isolation-reared rats showed an increased frequency and decreased duration of contact behavior. The increased firing of PL neurons during approaching and contact behavior, observed in group-reared rats, was preserved in isolation-reared rats, whereas the increased firing of IL neurons during leaving behavior, observed in group-reared rats, was suppressed in isolation-reared rats. This result indicates that isolation rearing differentially alters neural activity in the PL and IL during social behavior. The differential influence of isolation rearing on neural activity in the PL and IL may be one of the neural bases of isolation rearing-induced behavior. PMID:28459875

  8. Neural activity in the prelimbic and infralimbic cortices of freely moving rats during social interaction: Effect of isolation rearing.

    Science.gov (United States)

    Minami, Chihiro; Shimizu, Tomoko; Mitani, Akira

    2017-01-01

    Sociability promotes a sound daily life for individuals. Reduced sociability is a central symptom of various neuropsychiatric disorders, and yet the neural mechanisms underlying reduced sociability remain unclear. The prelimbic cortex (PL) and infralimbic cortex (IL) have been suggested to play an important role in the neural mechanisms underlying sociability because isolation rearing in rats results in impairment of social behavior and structural changes in the PL and IL. One possible mechanism underlying reduced sociability involves dysfunction of the PL and IL. We made a wireless telemetry system to record multiunit activity in the PL and IL of pairs of freely moving rats during social interaction and examined the influence of isolation rearing on this activity. In group-reared rats, PL neurons increased firing when the rat showed approaching behavior and also contact behavior, especially when the rat attacked the partner. Conversely, IL neurons increased firing when the rat exhibited leaving behavior, especially when the partner left on its own accord. In social interaction, the PL may be involved in active actions toward others, whereas the IL may be involved in passive relief from cautionary subjects. Isolation rearing altered social behavior and neural activity. Isolation-reared rats showed an increased frequency and decreased duration of contact behavior. The increased firing of PL neurons during approaching and contact behavior, observed in group-reared rats, was preserved in isolation-reared rats, whereas the increased firing of IL neurons during leaving behavior, observed in group-reared rats, was suppressed in isolation-reared rats. This result indicates that isolation rearing differentially alters neural activity in the PL and IL during social behavior. The differential influence of isolation rearing on neural activity in the PL and IL may be one of the neural bases of isolation rearing-induced behavior.

  9. Development of an Assay Based on the Effects of PGBx on the Isolated Perfused Rat Heart and Rat Skeletal Muscle.

    Science.gov (United States)

    1980-09-01

    had no effect on discphe- nol induced alterations in spontaneous heart rate, but did appear to prevent the increase in coronary flow caused by...Phosphorylase a i -24 activity was also the same in each of the groups examined (Table 2-4). DISCUSSION The ability of PGBx to prevent 2,4-dinitrophenol-induced...euthyroid and hyperthyroid rats. Eur. J. Pharmac. 19, 12-17. Aronson, C. E. and Serlick, E. R. (1977a) Effects of chlorpromazine on the isolated

  10. Isolation and Osteogenic Differentiation of Rat Periosteum-derived Cells

    OpenAIRE

    Declercq, Heidi Andrea; De Ridder, Leo Isabelle; Cornelissen, Maria Jozefa

    2005-01-01

    Selection of appropriate cultures having an osteogenic potential is a necessity if cell/biomaterial interactions are studied in long-term cultures. Osteoblastic cells derived from rat long bones or calvaria have the disadvantage of being in an advanced differentiation stage which results in terminal differentiation within 21 days. In this regard, less differentiated periosteum-derived osteoprogenitors could be more suitable.

  11. Relations between fatty acid synthesis, pyruvate concentration and cell concentration of suspensions of isolated rat hepatocytes

    NARCIS (Netherlands)

    Beynen, A.C.; Geelen, M.J.H.

    1984-01-01

    1. 1. The cell concentration of suspensions of isolated rat hepatocytes affects both the rate of pyruvate accumulation in the incubation medium and the rate of fatty acid synthesis. 2. 2. At low cell concentrations pyruvate accumulation is directly related to the cell concentration but levels off

  12. Cell-swelling-induced taurine release from isolated perfused rat liver

    NARCIS (Netherlands)

    Brand, H. S.; Meijer, A. J.; Gustafson, L. A.; Jörning, G. G.; Leegwater, A. C.; Maas, M. A.; Chamuleau, R. A.

    1994-01-01

    Astrocytes and lymphocytes are able to release significant amounts of taurine during periods of hypotonicity to reduce the increase in cell volume. To investigate this mechanism in the liver, we studied the release of free amino acids from isolated perfused rat liver during hypotonicity. The

  13. Veratridine activates a silent sodium-channel in rat isolated aorta

    NARCIS (Netherlands)

    WERMELSKIRCHEN, D; WILFFERT, B; NEBEL, U; LEIDIG, A; WIRTH, A; Peters, Thies

    1992-01-01

    To investigate the existence of silent Na+ channels, isolated rat aorta was treated with veratridine (0.1 mM) and the resulting Ca2+ uptake was determined. After 30-min incubation the total tissue uptake of Ca2+ and Ca2+ uptake increased from 2.325 +/- 0.017 to 2.614 +/- 0.080 nmol/mg wet weight

  14. Plasma protein concentration and control of coronary vascular resistance in isolated rat heart

    NARCIS (Netherlands)

    Avolio, A. P.; Spaan, J. A.; Laird, J. D.

    1980-01-01

    Isolated externally paced (300 beats/min) rat hearts were perfused at constant pressure (70 mmHg) using a modified Krebs-Henseleit solution with (n = 52) and without (n = 15) washed bovine red cells. Albumin concentration varied from 1 to 10 g/dl. With increasing albumin concentration in

  15. CRYOPRESERVATION OF FRESHLY ISOLATED SYNAPTOSOMES PREPARED FROM THE CEREBRAL-CORTEX OF RATS

    NARCIS (Netherlands)

    GLEITZ, J; BEILE, A; WILFFERT, B; TEGTMEIER, F

    In the present study, we established a cryopreservation method for freshly isolated synaptosomes prepared from the cerebral cortex of rats. Freshly prepared synaptosomes were either shock-frozen or frozen under temperature-controlled conditions using a programmable temperature controller. Each group

  16. The central responsiveness of the acute cerveau isolé rat.

    Science.gov (United States)

    User, P; Gottesmann, C

    1982-01-01

    The electrophysiological patterns of the frontal cortex and dorsal hippocampus were studied in the acute cerveau isolé rat. Central and peripheral stimulations were performed in order to modulate these patterns. The results showed that the permanent alternation of high amplitude spindle bursts and low voltage activity in the anterior neocortex of the acute cerveau isolé was influenced neither by olfactory nor by posterior hypothalamic stimulation. In contrast, these two kinds of stimulation easily modulated the continuous low frequency theta rhythm, recorded in the dorsal hippocampus, in terms of amplitude and in overall frequency. This modulation of the theta rhythm in the acute cerveau isolé rat mimics the changes observed when the normal rat comes from the intermediate stage of sleep (as characterized in the the acute intercollicular transected rat by high amplitude spindle bursts at frontal cortex level and low frequency theta activity in the dorsal hippocampus) to rapid sleep. These results further suggest that, during the intermediate stage (as in the cerveau isolé preparation), the hippocampus montonous theta activity appears through a brainstem disinhibitory process releasing the forebrain limbic pacemaker(s). During the following rapid sleep phase, the theta rhythm would be modulated by pontine activity influences acting on the theta generators.

  17. Intermediate stage of sleep and acute cerveau isolé preparation in the rat.

    Science.gov (United States)

    User, P; Gioanni, H; Gottesmann, C

    1980-01-01

    The acute cerveau isole rat shows spindle bursts of large amplitude alternating with low voltage activity in the frontal cortex and continuous theta rhythm in the dorsal hippocampus. These patterns closely resemble an "intermediate" stage of sleep-waking cycle, when the forebrain structures seem to be functionally disconnected from the brainstem.

  18. Early-life Social Isolation Impairs the Gonadotropin-Inhibitory Hormone Neuronal Activity and Serotonergic System in Male Rats

    Directory of Open Access Journals (Sweden)

    Tomoko eSoga

    2015-11-01

    Full Text Available Social isolation in early life deregulates the serotonergic system of the brain, compromising reproductive function. Gonadotropin-inhibitory hormone (GnIH neurons in the dorsomedial hypothalamic nucleus are critical to the inhibitory regulation of gonadotropin-releasing hormone neuronal activity in the brain and release of luteinising hormone by the pituitary gland. Although GnIH responds to stress, the role of GnIH in social isolation-induced deregulation of the serotonin system and reproductive function remains unclear. We investigated the effect of social isolation in early life on the serotonergic–GnIH neuronal system using enhanced green fluorescent protein (EGFP-tagged GnIH-transgenic rats. Socially isolated rats were observed for anxious and depressive behaviours. Using immunohistochemistry, we examined c-Fos protein expression in EGFP–GnIH neurons in 9-week-old adult male rats after 6 weeks post-weaning isolation or group -housing. We also inspected serotonergic fibre juxtapositions in EGFP–GnIH neurons in control and socially isolated male rats. Socially isolated rats exhibited anxious and depressive behaviours. The total number of EGFP–GnIH neurons was the same in control and socially isolated rats, but c-Fos expression in GnIH neurons was significantly reduced in socially isolated rats. Serotonin fibre juxtapositions on EGFP–GnIH neurons was also lower in socially isolated rats. In addition, levels of tryptophan hydroxylase mRNA expression in the dorsal raphe nucleus were significantly attenuated in these rats. These results suggest that social isolation in early life results in lower serotonin levels, which reduce GnIH neuronal activity and may lead to reproductive failure.

  19. Early-Life Social Isolation Impairs the Gonadotropin-Inhibitory Hormone Neuronal Activity and Serotonergic System in Male Rats.

    Science.gov (United States)

    Soga, Tomoko; Teo, Chuin Hau; Cham, Kai Lin; Idris, Marshita Mohd; Parhar, Ishwar S

    2015-01-01

    Social isolation in early life deregulates the serotonergic system of the brain, compromising reproductive function. Gonadotropin-inhibitory hormone (GnIH) neurons in the dorsomedial hypothalamic nucleus are critical to the inhibitory regulation of gonadotropin-releasing hormone neuronal activity in the brain and release of luteinizing hormone by the pituitary gland. Although GnIH responds to stress, the role of GnIH in social isolation-induced deregulation of the serotonin system and reproductive function remains unclear. We investigated the effect of social isolation in early life on the serotonergic-GnIH neuronal system using enhanced green fluorescent protein (EGFP)-tagged GnIH transgenic rats. Socially isolated rats were observed for anxious and depressive behaviors. Using immunohistochemistry, we examined c-Fos protein expression in EGFP-GnIH neurons in 9-week-old adult male rats after 6 weeks post-weaning isolation or group housing. We also inspected serotonergic fiber juxtapositions in EGFP-GnIH neurons in control and socially isolated male rats. Socially isolated rats exhibited anxious and depressive behaviors. The total number of EGFP-GnIH neurons was the same in control and socially isolated rats, but c-Fos expression in GnIH neurons was significantly reduced in socially isolated rats. Serotonin fiber juxtapositions on EGFP-GnIH neurons were also lower in socially isolated rats. In addition, levels of tryptophan hydroxylase mRNA expression in the dorsal raphe nucleus were significantly attenuated in these rats. These results suggest that social isolation in early-life results in lower serotonin levels, which reduce GnIH neuronal activity and may lead to reproductive failure.

  20. Socially isolated rats exhibit changes in dopamine homeostasis pertinent to schizophrenia

    DEFF Research Database (Denmark)

    Fabricius, Katrine; Steiniger-Brach, Björn; Helboe, Lone

    2011-01-01

    Post-weaning social isolation of rats produces an array of behavioral and neurochemical changes indicative of altered dopamine function. It has therefore been suggested that post-weaning social isolation mimics some aspects of schizophrenia. Here we replicate and extent these findings to include...... dopamine levels in the nucleus accumbens, it did cause a significant reduction of basal dopamine release in the prefrontal cortex. In addition, social isolation lead to a significantly larger dopamine response to an amphetamine challenge, in both the nucleus accumbens and the prefrontal cortex compared...

  1. Studies on a novel peptide isolated and purified from rat insulinoma tissue

    Energy Technology Data Exchange (ETDEWEB)

    Al-Akhras, G N

    1987-01-01

    Rat insulinoma peptide (RIP) which appears to be either a fragment of, or an altered rat C-peptide was isolated and purified by dialysis. The purity of this peptide was investigated using polyacrylamide gel electrophoresis with sodium dodecyl sulfate, isoelectric focusing, and high performance liquid chromatography. RIP may contain two peptides similar to each other but differing in their isoelectric points. The molecular weight of RIP was found to be 1982 daltons by fast atoms bombardment mass spectrometry giving a chain length of approximately 22 amino acid residues. From information obtained using radioimmunoassay employing antiserum R901, RIP appears to share a common C-terminus with rat C-peptide. A radioimmunoassay for RIP was developed using the purified RIP as immunogen and for standards and tracers. An indirect enzyme linked immunosorbent assay (ELISA) for rat insulinoma peptide was developed using purified RIP for immunogen and semi-purified RIP as a standard.

  2. DA1 receptors modulation in rat isolated trachea.

    Science.gov (United States)

    Cabezas, Gloria A; Velasco, Manuel

    2010-01-01

    We have previously demonstrated that low dose of inhaled dopamine (0.5-2 microg kg(-1) min(-1)) induces broncodilatacion in patients with acute asthma attack, suggesting that this dopamine effect is mediated by dopaminergic rather than by adrenergic receptors. To understand better these dopamine effect, rat tracheal smooth muscle was used as a model to evaluate the responses of beta2-, alpha1-, alpha2-adrenergic and DA1 and DA2 dopaminergic antagonists. Tracheal rings from male Sprague-Dawley rats (n = 90) were excised and placed in an organ bath containing modified Krebs-Ringer bicarbonate buffer at 37 degrees C, and gassed with O2 (95%) and CO2 (5%). Contractile responses were recorded with an isometric transducer in a polygraph (Letica, Spain). Contraction was induced by accumulative doses of acetylcholine (0.1, 0.3, 1, 3, 10 mM) or by electric field stimulation (10 Hz at 2 milliseconds), and accumulative doses of dopamine were added to the bath. Low concentration (0.1-0.3 mM) elicited a small initial contraction, followed by a marked relaxation. Cholinergic contraction was completely reversed at 6 mM of dopamine. This biphasic dopaminergic response was not blocked by incubation with beta2-adrenergic antagonist propranolol (0.1 microM), alpha1-antagonist, terazosin (0.1 mM), alpha2-antagonist, yohimbine (0.1 mM), or by DA2 antagonist metoclopramide (1-8 mM); DA1 antagonist SCH23390 (0.1 microM) produced a sustained increase of basal tone but did not block initial dopaminergic contraction and partially inhibited bronchodilator effect of dopamine. Dopaminergic relaxation in rat trachea is mediated by DA1 rather than by DA2 receptors; and adrenergic receptors are not involved in such dopamine-induced response. Finally, DA1 antagonist SCH23390 exerts intrinsic contractile activity on airway smooth muscle that deserves further research.

  3. Isolation, separation, and characterization of epithelial and connective cells from rat palate

    Energy Technology Data Exchange (ETDEWEB)

    Terranova, Victor Paul [Univ. of Rochester, NY (United States)

    1979-01-01

    Epithelial and connective tissue cells were isolated from rat palate by sequential collagenase, hyaluronidase and trypsin digestion of the extracellular matrix. Differences between the two populations were noted with respect to total cell protein, total cell water, proline uptake and incorporation, percent collagen synthesized, effects of parathyroid hormone, metabolism of D-valine and cell density. Basal epithelial cells were subsequently separated from the heterogeneous epithelial cell population on shallow linear density gradients by velocity centrifugation. The type of collagen synthesized by the basal epithelial cells was compared to the type of collagen synthesized by the connective tissue cells by means of labeled amino acid incorporation ratios. Cells isolated from the epithelial and connective tissue were compared. From these studies it can be concluded that epithelial and connective tissue cells can be isolated from rat palate as viable and distinct populations with respect to the biochemical parameters examined. Furthermore, subpopulations can be separated and biochemically characterized.

  4. Isomyosin expression in developing chicken atria: a marker for the development of conductive tissue?

    NARCIS (Netherlands)

    de Groot, I. J.; Sanders, E.; Visser, S. D.; Lamers, W. H.; de Jong, F.; Los, J. A.; Moorman, A. F.

    1987-01-01

    Isomyosin expression patterns in embryonic chicken atria during the first two weeks of development were analyzed immunohistochemically. In the 3-days embryonic chicken heart (HH19-20), strong coexpression of both isomyosins can be found as band-like zones at the lateral sides of the sinoatrial

  5. The conducting tissue in the adult chicken atria. A histological and immunohistochemical analysis

    NARCIS (Netherlands)

    de Groot, I. J.; Hardy, G. P.; Sanders, E.; Los, J. A.; Moorman, A. F.

    1985-01-01

    A three-dimensional reconstruction from serial sections of adult chicken heart was made to verify whether Purkinje cells, that can be recognized by a number of well-known histological criteria, form specialized tracts in the adult chicken atria. This reconstruction revealed a loosely arranged

  6. 3D virtual human atria: A computational platform for studying clinical atrial fibrillation.

    Science.gov (United States)

    Aslanidi, Oleg V; Colman, Michael A; Stott, Jonathan; Dobrzynski, Halina; Boyett, Mark R; Holden, Arun V; Zhang, Henggui

    2011-10-01

    Despite a vast amount of experimental and clinical data on the underlying ionic, cellular and tissue substrates, the mechanisms of common atrial arrhythmias (such as atrial fibrillation, AF) arising from the functional interactions at the whole atria level remain unclear. Computational modelling provides a quantitative framework for integrating such multi-scale data and understanding the arrhythmogenic behaviour that emerges from the collective spatio-temporal dynamics in all parts of the heart. In this study, we have developed a multi-scale hierarchy of biophysically detailed computational models for the human atria--the 3D virtual human atria. Primarily, diffusion tensor MRI reconstruction of the tissue geometry and fibre orientation in the human sinoatrial node (SAN) and surrounding atrial muscle was integrated into the 3D model of the whole atria dissected from the Visible Human dataset. The anatomical models were combined with the heterogeneous atrial action potential (AP) models, and used to simulate the AP conduction in the human atria under various conditions: SAN pacemaking and atrial activation in the normal rhythm, break-down of regular AP wave-fronts during rapid atrial pacing, and the genesis of multiple re-entrant wavelets characteristic of AF. Contributions of different properties of the tissue to mechanisms of the normal rhythm and arrhythmogenesis were investigated. Primarily, the simulations showed that tissue heterogeneity caused the break-down of the normal AP wave-fronts at rapid pacing rates, which initiated a pair of re-entrant spiral waves; and tissue anisotropy resulted in a further break-down of the spiral waves into multiple meandering wavelets characteristic of AF. The 3D virtual atria model itself was incorporated into the torso model to simulate the body surface ECG patterns in the normal and arrhythmic conditions. Therefore, a state-of-the-art computational platform has been developed, which can be used for studying multi

  7. Time-dependent changes in rat lymphocyte activity in response to isolation

    International Nuclear Information System (INIS)

    Jessop, J.J.; Bayer, B.M.

    1986-01-01

    The authors have found that isolation of rats, previously adapted to group-housing conditions, resulted in time-dependent changes in mitogenic and cytolytic responses of lymphocytes. A depression (40-60%) of the uptake of 3 H-thymidine by splenic and blood lymphocytes stimulated with either phytohemagglutinin (PHA) or lipopolysaccharide (LPS) was observed during the first 48 hours after transfer of the animals to individual cages. Within 4 days the mitogenic response increased and was comparable to that of animals which had been continuously group-housed. The response continued to increase and by 10 days was enhanced by 2 to 4 fold and remained elevated for at least 8 weeks. Similar changes in activity were observed with both splenic and blood lymphocytes, however, thymic lymphocytes taken from isolated animals demonstrated no change in reactivity to PHA. As with mitogenic responses, the cytolytic activity of splenic lymphocytes was also depressed during the initial days of isolation and as isolation continued, the activity returned to normal and was significantly enhanced (80%) within 5 weeks. These data show that changes in lymphocyte activity are dependent on the duration of exposure to isolated housing conditions and may be a part of the acute, adaptive and chronic phases of the response of rats to the stress of isolation

  8. Changes in vascular reactivity induced by acute hyperthyroidism in isolated rat aortae.

    Science.gov (United States)

    Honda, H; Iwata, T; Mochizuki, T; Kogo, H

    2000-06-01

    Hyperthyroidism was induced by subcutaneous injections of L-thyroxine (T(4)) (500 mg/kg/day) for 3 days in order to study whether adrenergic and muscarinic receptor-mediated vascular responses alter at an early stage of the disease. T(4) treatment was sufficient to induce a significant degree of thyroid weight loss, tachycardia, cardiac hypertrophy, and an elevation in serum T(4) levels. The tension of aortic ring preparations isolated from rats was measured isometrically to investigate the influence of acute hyperthyroidism. The contractions induced by norepinephrine (NE) were significantly suppressed in aortic rings from rats treated with T(4) compared with control rats. N(G)-nitro-L-arginine (L-NOARG), an inhibitor of nitric oxide synthase (NOS), significantly enhanced NE-induced contraction in aortic rings from both control and T(4)-treated rats, and the enhancement was greater in rats treated with T(4) than control rats. The relaxations induced by either acetylcholine (ACh) or sodium nitroprusside (SNP) were also significantly enhanced by T(4) treatment. L-NOARG abolished the relaxation induced by ACh in aortic rings from both control and T(4)-treated rats. L-NOARG shifted SNP-induced relaxation curves of aortic rings from those of control rats to the left, but not with rats treated with T(4). T(4) treatment showed no influence on the amount of endothelial NOS (eNOS) protein. These results suggest that vascular responses alter at an early stage of hyperthyroidism and that it may be due to a modification in the NO system which is independent from the amount of eNOS protein.

  9. Cellular location of rat muscle ferritins and their preferential loss during cell isolation.

    Science.gov (United States)

    Linder, M C; Roboz, M; McKown, M J; Pardridge, W M; Zak, R

    1984-04-10

    Heart and other muscles of the rat contain two forms of ferritin separable in polyacrylamide gel electrophoresis. The cellular location of the fast- and slow-migrating ferritins was investigated using primary cultures of hindlimb skeletal muscle, and isolated myocardial cell populations. Muscle and non-muscle cells were isolated in good yield from hearts of adult rats pretreated with large doses of iron to increase their ferritin content. In virtually all cases, the isolated muscle cells contained traces only of the fast-migrating species and the non-muscle cells contained small amounts of the slow-migrating ferritin. During cell isolation, 90-100% of both ferritins was lost and could be recovered in the perfusates and solutions employed, while one third of the total tissue protein, and a larger percentage of creatine phosphokinase, was recovered in the isolated cells. Primary cultures of thigh muscle from adult rats which had differentiated into multi-nucleated myotubes, were incubated for 1-3 days with chelated iron. These cells contained substantial amounts of the electrophoretically fast migrating ferritin, with its characteristic larger Stokes' radius (determined by quantitative polyacrylamide gel electrophoresis). None of the slow-migrating ferritin species was detected, although hindlimb muscle from iron-treated rats contained both forms. It is concluded that the fast-migrating ferritin of muscle, which is much larger and more asymmetric than other ferritins, is confined to the muscle cell population, while the other form is predominantly or exclusively in the non-muscle cells. Both ferritins are lost preferentially over other proteins during procedures which injure muscle tissue.

  10. Kidney in potassium depletion. II. K+ handling by the isolated perfused rat kidney

    International Nuclear Information System (INIS)

    Hayashi, M.; Katz, A.I.

    1987-01-01

    In a companion paper the authors reported a large increment in Na + -K + -ATPase activity and [ 3 H]ouabain binding the inner stripe of outer medullary collecting tubules from K-depleted rats. To test the hypothesis that the increased number of Na + -K + pumps in these animals may be involved in potassium reabsorption they examined the effect of ouabain on K excretion by isolated, perfused kidneys from rats fed a K-free diet for 3 wk. Kidneys from K-depleted rats retain potassium avidly, both the fractional (FE/sub K/) and absolute K excretion being approximately fivefold lower than in control kidneys. Ouabain (5 mM) increased FE/sub K/ in kidneys from each K-depleted rat; similar results were obtained when kidneys were perfused with low and high potassium concentrations. In contrast, ouabain produced a variable effect in control kidneys, that depended on the perfusate potassium concentration. In K-depleted rats amiloride did not significantly alter K excretion and did not block the ouabain-induced kaliuresis, suggesting that the latter is not due to enhanced secretion secondary to increased distal fluid delivery. These results provide evidence for ouabain-sensitive potassium reabsorption in kidneys of chronically K-depleted rats, and suggest an explanation for the increased Na + -K + -ATPase observed in such animals

  11. Heterogeneous response of isolated adult rat heart cells to insulin

    International Nuclear Information System (INIS)

    Haworth, R.A.; Hunter, D.R.; Berkoff, H.A.

    1984-01-01

    3-O-Methylglucose uptake by Ca2+-resistant adult rat heart cells in suspension was measured, free of artifactual inhibitor-insensitive uptake, and with an accuracy of +/- 1.9% pellet water. (Ca2+-resistant cells are cells which retain their original rod-shaped morphology in the presence of physiological levels of Ca2+.) High levels of insulin (10(-6) M) stimulated the rate of 3-O-methylglucose uptake approximately 10-fold. In the presence of low levels of insulin (3 X 10(-11) M, 10(-10) M) uptake was biphasic; it could not be described by a single exponential function within experimental error, but required the sum of two exponentials. Deviation from a single exponential function was not so great with high levels of insulin (10(-6) M) or no insulin. Cell sugar uptake was also investigated using autoradiography of cells which had accumulated [2-14C]deoxyglucose under similar conditions. This showed considerable heterogeneity of 2-deoxyglucose uptake by cells treated with low levels of insulin, but significantly less heterogeneity of 2-deoxyglucose uptake by cells treated with high levels of insulin. It is concluded that the deviation of 3-O-methylglucose uptake from a single exponential observed at low insulin levels can be accounted for in terms of a heterogeneous response of cells to insulin

  12. Binding of [125I] Concanavalin A to isolated Langerhans islets of rats

    International Nuclear Information System (INIS)

    Prey, N.

    1983-01-01

    Langerhans islets of rats were isolated using Lacy's collagenase technique and were incubated in vitro. The binding of iodine-labelled Concanavalin A to isolated Langerhans islets was investigated. We were unable to decide whether multiple Concanavalin A binding sites are located on the cell membrane, or whether the Concanavalin A binding sites are negatively influenced via a allosteric protein. Although the secretion mechanism induced by sulfony urea is not influenced by Concanavalin A, enhanced binding of Concanavalin A indicates that the region of identification cannot be identical for glucose and sulfonyl urea. (orig./MG) [de

  13. In vitro assessment of cardiac performance after irradiation using an isolated working rat heart preparation

    International Nuclear Information System (INIS)

    Wondergem, J.; Laarse, A. van der; Ravels, F.J.M. van; Wermeskerken, A.-M. van; Verhoeve, H.R.; Graaf, B.W. de; Leer, J.W.H.

    1991-01-01

    The effect of irradiation on cardiac function was assessed using an isolated working rat heart preparation. The animals were given single doses of X-rays in the range 15-30 Gy to their hearts. Cardiac output (CO = aortic flow + coronary flow), heart weight and body weight were followed for a period of 10 months after treatment. Irradiation led to a decrease in cardiac function. This reduction was dose-dependent and progressive with time after treatment. The shape of the Frank-Starling curves constructed for irradiated hearts suggests a loss of contractile function of the myocardium. Coronary flow rates measured in 'working' hearts and in 'Langendorff' hearts were not significantly changed by the irradiation treatment. The isolated working rat heart preparation proved to be a simple and suitable animal model for the investigation of irradiation-induced cardiotoxicity. (author)

  14. Kinetics of the norepinephrine analog [76Br]-meta-bromobenzylguanidine in isolated working rat heart

    International Nuclear Information System (INIS)

    Raffel, David; Loc'h, Christian; Mardon, Karine; Maziere, Bernard; Syrota, Andre

    1998-01-01

    A related set of kinetic studies of the norepinephrine analog [ 76 Br]-meta-bromobenzylguanidine (MBBG) were performed with an isolated working rat heart preparation. A series of constant infusion studies over a wide range of MBBG concentrations allowed estimation of the Michaelis-Menten constants for transport by the neuronal norepinephrine transporter (uptake 1 ) and the extraneuronal uptake system (uptake 2 ). Pharmacological blocking studies with inhibitors of uptake 1 , uptake 2 and vesicular uptake were performed to delineate the relative importance of these norepinephrine handling mechanisms on the kinetics of MBBG in the rat heart. Bolus injection studies were done to assess the ability of compartmental modeling techniques to characterize the kinetics of MBBG. These studies demonstrate that MBBG shares many of the same uptake mechanisms as norepinephrine in the rat heart. PET imaging studies with MBBG would be useful for assessing sympathetic nerve status in the living human heart

  15. Effect of phenytoin on cortical epileptic foci in cerveau isolé rats.

    Science.gov (United States)

    Mares, P

    1994-01-01

    The action of phenytoin was studied in acute experiments in rats with brainstem transection at the midcollicular level. Symmetrical epileptogenic foci were elicited in sensorimotor cortical areas of both hemispheres by local application of penicillin. Seven rats formed a control group, ten animals were pretreated with phenytoin (60 mg/kg i.p., 10 min before penicillin application). Synchronization of interictal discharges in control rats was delayed in comparison to animals with an intact brainstem; phenytoin did not influence this synchronization. Spontaneous transition of interictal into ictal activity was not abolished by phenytoin, i.e. in cerveau isolé preparations phenytoin lost this activity. The loss of anticonvulsant activity was not complete. Ictal episodes were modified; they started as very short ones and their duration progressively increased. Structures localized below the level of transection represent a site of at least one of the mechanisms of phenytoin anticonvulsant action.

  16. Interaction of propionate and carnitine metabolism in isolated rat hepatocytes

    International Nuclear Information System (INIS)

    Brass, E.P.; Beyerinck, R.A.

    1987-01-01

    Propionate (P) and its metabolic products P-CoA and methylmalonyl-CoA can disrupt normal hepatic metabolism. Carnitine (Cn) has been shown to partially restore cellular function in the presence of P. This effect of Cn may result from removal of propionyl groups as propionylcarnitine (P-Cn). The present study examined the kinetics of P-Cn formation in rat hepatocytes, and the consequence of P-Cn formation on P and Cn metabolism. 14 C-P was converted to CO 2 , glucose and P-Cn in the hepatocyte system. Increasing concentrations of Cn up to 10.0 mM increased P-Cn formation from P without affecting CO 2 or glucose formation. Thus, 10.0 mM Cn increased total P metabolism by 40%. Metabolism of P was associated with a decrease in Cn concentration and an increase in short chain acylcarnitines (SCCn). In the absence of added Cn, 60 min incubation with P decreased Cn from 6.8 to 2.5 μM with a corresponding increase in SCCn. This effect of P to deplete free Cn was not seen to the same degree with butyrate in place of P. Similar increases in the formation of SCCn in the presence of P at the expense of free Cn were seen when the incubation Cn concentration was increased to 50 μM or 150 μM. HPLC methodologies to study specific acylcarnitines demonstrated the accumulation of large amounts of P-Cn in the incubations containing P, accounting for the depletion of free Cn

  17. Transcapillary transport of metaiodobenzylguanidine (MIBG) in isolated rat heart

    International Nuclear Information System (INIS)

    DeGrado, Timothy R.; Wang Shuyan

    1998-01-01

    A better understanding of transcapillary transport for tracer metaiodobenzylguanidine (MIBG) is desirable for development of tracer kinetic models that yield meaningful estimates of neuronal uptake function from tissue radioactivity time courses. This study utilized a multiple-indicator approach in Langendorff-perfused rat hearts to define transport mechanisms and determine the capillary permeability-surface area (PSc) over a broad range of flow (F). Multiple injections within the same heart at different flows allowed characterization of the PSc/F relationship within the same heart. The coefficient of variation of E for multiple injections within the same hearts at constant flow was 6±2% (3 to 6 injections in 9 hearts). In 10 hearts (4 to 6 injections per heart), flow was varied between 2.0-16.5 mL/min. PSc was found to be nearly proportional to flow in each heart (r=0.88±0.14; slope = 0.23±0.10; intercept = 11±7 mL/min/g dry). Tissue hypoxia at low flows, as evidenced by enhanced lactate production, did not appear to influence the PSc/F relationship. Pharmacologic blockade of uptake-1 and uptake-2 had negligible affect on E or PSc as compared with flow-matched controls, although tissue retention was markedly reduced. The results show PSc of MIBG to be nearly proportional to flow but independent of specific neuronal and extraneuronal transport mechanisms and tissue hypoxia. The results are consistent with a passive diffusion process across the capillary endothelial barrier. The increase in PSc with increasing flow could reflect capillary recruitment and/or enhanced capillary permeability

  18. Effect of ornithine on ammonia utilization and urea synthesis in isolated hepatocytes from fed rats

    International Nuclear Information System (INIS)

    Garwacki, S.; Wiechetek, M.; Souffrant, W.B.

    1988-01-01

    The effect of ornithine on the ammonia utilization and urea synthesis in hepatocytes isolated from fed male Wistar rats was investigated. On the basis of the 15 N tracer technique, it was found that ornithine stimulated urea synthesis with an increased utilization of the exogenously marked ammonia for urea, but deminished its utilization in other N-metabolic processes. The results also showed that the stimulation of urea synthesis due to ornithine resulted from the utilization of both exogenous and endogenous sources. (author)

  19. Relaxant effect of the ethanol extract of Helichrysum plicatum (Asteraceae) on isolated rat ileum contractions.

    Science.gov (United States)

    Bigovic, Dubravka; Brankovic, Suzana; Kitic, Dusanka; Radenkovic, Mirjana; Jankovic, Teodora; Savikin, Katarina; Zivanovic, Slavoljub

    2010-05-10

    Helichrysum plicatum (Turkish Helichrysum) has been used in folk medicine for the treatment of gastric and hepatic disorders. The aim of the present study was to examine the relaxant activity of an extract of H. plicatum flowers on isolated rat ileum. Segments of ileum of rats were suspended in an organ bath. Cumulative concentrations of H. plicatum ethanol extract induced a relaxant effect on spontaneous rat ileum contractions. H. plicatum extract caused a mean contractile response of 81.68 +/- 6.17% (at a dose of 0.01 mg/mL) and 30.08 +/- 9.07% (at a dose of 1 mg/mL). A similar effect was observed with papaverine (0.01-3 microg/mL). H. plicatum extract (0.01-1 mg/mL) relaxed high K+ (80 mM) precontractions, an effect similar to that caused by papaverine (0.01-3 microg/mL). The plant extract (0.03-0.3 mg/mL) also induced a significant depression of the cumulative concentration response curve for acetylcholine (5-1500 nM) (p Helichrysum plicatum flowers on the isolated rat intestine Extract of H. plicatum can inhibit the spontaneous ileum contractions and contractions induced by acetylcholine, histamine, barium and potassium ions.

  20. Kinetics of reversible-sequestration of leukocytes by the isolated perfused rat lung

    Energy Technology Data Exchange (ETDEWEB)

    Goliaei, B.

    1980-08-01

    The kinetics and morphology of sequestration and margination of rat leukocytes were studied using an isolated perfused and ventilated rat lung preparation. Whole rat blood, bone marrow suspension, or leukocyte suspensions, were used to perfuse the isolated rat lung. The lung was also perfused with latex particle suspensions and the passage of particles through the lung capillaries was studied. When a leukocyte suspension was perfused through the lung in the single-pass mode, the rate of sequestration decreased as more cells were perfused. In contrast, latex particles of a size comparable to that of leukocytes were totally stopped by the lung. When the leukocyte suspension was recirculated through the lung, cells were rapidly removed from circulation until a steady state was reached, after which no net removal of cells by the lung occurred. These results indicate that leukocytes are reversibly sequestered from circulation. The sequestered cells marginated and attached to the luminal surface of the endothelium of post-capillary venules and veins. A mathematical model was developed based on the assumption that the attachment and detachment of leukocytes to blood vessel walls follows first-order kinetics. The model correctly predicts the following characteristics of the system: (a) the kinetics of the sequestration of leukocytes by the lung; (b) the existence of a steady state when a suspension of leukocytes is recirculated through the lung; and (c) the independence of the fraction of cells remaining in circulation from the starting concentration for all values of starting concentration. (ERB)

  1. Action of a new cholinergic agonist, aclatonium napadisilate, on isolated rat pancreatic acini

    International Nuclear Information System (INIS)

    Fujii, M.; Okabayashi, Y.; Nakamura, T.; Tani, S.; Fujisawa, T.; Otsuki, M.

    1990-01-01

    The effect of aclatonium napadisilate, a newly synthesized choline ester, on pancreatic exocrine function was compared with that of the muscarinic agonist carbamylcholine in isolated rat pancreatic acini. Both compounds increased amylase release and 45 Ca 2+ efflux in a dose-dependent fashion, and similarly decreased the binding of [N-methyl- 3 H]scopolamine to isolated rat pancreatic acini. While aclatonium napadisilate was 20-30 times less potent than carbamylcholine in stimulations of amylase release and 45 Ca 2+ efflux, the potency of aclatonium napadisilate in inhibiting [N-methyl- 3 H]scopolamine binding was nearly the same as that of carbamylcholine. These results indicate that aclatonium napadisilate stimulates pancreatic exocrine secretion via muscarinic receptors and Ca 2+ mobilization, and its intrinsic activity is less than carbamylcholine in the isolated rat pancreatic acini. Since aclatonium napadisilate is known to increase motility and peristalsis of the gastrointestinal tract, stimulatory effects of aclatonium napadisilate, shown in the present study, on digestive enzyme secretion from the pancreas may provide additional benefit of aclatonium napadisilate in the treatment of various gastrointestinal disorders

  2. Effects of lysosomal inhibitors on 125I-insulin and 125I-asialofetuin degradation by the isolated, perfused rat liver and isolated rat hepatocytes

    International Nuclear Information System (INIS)

    Ward, W.F.; Moss, A.L.

    1985-01-01

    To further evaluate the role of the lysosomal system in insulin degradation, the authors have compared the effects of inhibitors of lysosomal function on the degradation of 125 I-insulin with 125 I-asialofetuin, a lysosomally targeted molecule, by the intact, perfused rat liver and the isolated rat hepatocyte. The inhibitors employed were chloroquine ( 125 microM), NH 4 Cl (10 mM), and leupeptin (50 micrograms/ml). In the intact, perfused liver the observed inhibition of 125 I-asialofetuin degradation at 30 min was as follows: chloroquine, 38%; NH 4 Cl, 32%; and leupeptin, 86%. Chloroquine also inhibited 125 I-insulin degradation in the intact, perfused liver (29%), but NH 4 Cl and leupeptin had no effect. Using the isolated hepatocyte, the observed values for inhibition of 125I-asialofetuin at 60 min were: chloroquine, 85%; NH 4 Cl, 76%; and leupeptin, 81%. Chloroquine produced a 28% inhibition of 125I-insulin degradation, while NH 4 Cl and leupeptin had no effect. Chloroquine and NH 4 Cl decreased cell-associated radioactivity when isolated hepatocytes were incubated with 125I-asialofetuin (leupeptin had no effect), whereas chloroquine caused a 107% increase in cell-associated radioactivity when 125I-insulin was added to the incubation media (NH 4 Cl and leupeptin had no effect). These results indicate that the effects of chloroquine on insulin degradation are an extralysosomal action and that lysosomes appear not to be involved in the physiologic degradation of the insulin molecule

  3. Neonatal stress tempers vulnerability of acute stress response in adult socially isolated rats

    Directory of Open Access Journals (Sweden)

    Mariangela Serra

    2014-06-01

    Full Text Available Adverse experiences occurred in early life and especially during childhood and adolescence can have negative impact on behavior later in life and the quality of maternal care is considered a critical moment that can considerably influence the development and the stress responsiveness in offspring. This review will assess how the association between neonatal and adolescence stressful experiences such as maternal separation and social isolation, at weaning, may influence the stress responsiveness and brain plasticity in adult rats. Three hours of separation from the pups (3-14 postnatal days significantly increased frequencies of maternal arched-back nursing and licking-grooming by dams across the first 14 days postpartum and induced a long-lasting increase in their blood levels of corticosterone. Maternal separation, which per sedid not modified brain and plasma allopregnanolone and corticosterone levels in adult rats, significantly reduced social isolation-induced decrease of the levels of these hormones. Moreover, the enhancement of corticosterone and allopregnanolone levels induced by foot shock stress in socially isolated animals that were exposed to maternal separation was markedly reduced respect to that observed in socially isolated animals. Our results suggest that in rats a daily brief separation from the mother during the first weeks of life, which per se did not substantially alter adult function and reactivity of hypothalamic-pituitary-adrenal (HPA axis, elicited a significant protection versus the subsequent long-term stressful experience such that induced by social isolation from weaning. Proceedings of the 10th International Workshop on Neonatology · Cagliari (Italy · October 22nd-25th, 2014 · The last ten years, the next ten years in NeonatologyGuest Editors: Vassilios Fanos, Michele Mussap, Gavino Faa, Apostolos Papageorgiou

  4. Altered synthesis of some secretory proteins in pancreatic lobules isolated from streptozotocin-induced diabetic rats

    International Nuclear Information System (INIS)

    Duan, R.D.; Erlanson-Albertsson, C.

    1990-01-01

    The in vitro incorporation of [35S]cysteine into lipase, colipase, amylase, procarboxypeptidase A and B, and the serine proteases and total proteins was studied in pancreatic lobules isolated from normal and diabetic rats with or without insulin treatment. The incorporation of [35S]cysteine into total proteins was 65% greater in pancreatic lobules from diabetic animals than from normal rats. The increased incorporation was partly reversed by insulin treatment (2 U/100 g/day for 5 days) of diabetic rats. The relative rates of biosynthesis for amylase and the procarboxypeptidases in diabetic pancreatic lobules were decreased by 75 and 25%, respectively, after 1 h of incubation, while those for lipase, colipase, and the serine proteases were increased by 90, 85, and 35%, respectively. The absolute rates of synthesis for these enzymes changed in the same direction as the relative rates in diabetic lobules, except that for the procarboxypeptidases, which did not change. The changed rates of biosynthesis for the pancreatic enzymes were reversed by insulin treatment of the diabetic rats. Kinetic studies showed that the incorporation of [35S]cysteine into amylase, lipase, and colipase was linear until up to 2 h of incubation in normal pancreatic lobules, while in the diabetic lobules the incorporation into lipase and colipase was accelerated, reaching a plateau level already after 1 h of incubation. It is concluded that the biosynthesis of pancreatic secretory proteins in diabetic rats is greatly changed both in terms of quantity and kinetics

  5. Quantitative description of the regional mechanics of the left atria by electroanatomical mapping

    International Nuclear Information System (INIS)

    Kuklik, Pawel; Molaee, Payman; Brooks, Anthony G; John, Bobby; Worthley, Stephen G; Sanders, Prashanthan

    2010-01-01

    The left atrium is a complex chamber, which plays an integral role in the maintenance of physiologic hemodynamic and electrical stability of the heart and is involved in many disease states, most commonly atrial fibrillation. Preserving regions of the left atrium that contribute the greatest to atrial mechanical function during curative strategies for atrial fibrillation are important. We present here a new application of the CARTO electroanatomical mapping system in the assessment of the left atria mechanical function. Electroanatomical data were collected in course of the electrophysiological procedure in 11 control patients and 12 patients with paroxysmal atrial fibrillation. The three-dimensional geometry of the left atria was reconstructed in 10 ms intervals and segmented into distinct regions. For each segment, a regional ejection fraction was calculated. We found that anterior, septal and lateral segments have significantly greater regional ejection fraction than atria roof, inferior and posterior segments. Therefore, we hypothesize that in order to minimize the impact on atrial mechanical function, an important determinant of thromboembolic risk, damage should be minimized to these atrial regions

  6. Formation of Cell-To-Cell Connection between Bone Marrow Cells and Isolated Rat Cardiomyocytes in a Cocultivation Model

    Czech Academy of Sciences Publication Activity Database

    Skopalík, J.; Pásek, Michal; Rychtárik, M.; Koristek, Z.; Gabrielová, E.; Sheer, P.; Matejovič, P.; Modrianský, M.; Klabusay, M.

    2014-01-01

    Roč. 5, č. 5 (2014), s. 1000185 ISSN 2157-7013 Institutional support: RVO:61388998 Keywords : bone marrow * mononuclear cells * isolated cardiomyocytes * cocultivation Subject RIV: BO - Biophysics http://omicsonline.org/ open - access /formation-of-celltocell-connection-between-bone-marrow-cells- and -isolated-rat-cardiomyocytes-2157-7013.1000185.php?aid=33364

  7. Long-term voluntary exercise prevents post-weaning social isolation-induced cognitive impairment in rats.

    Science.gov (United States)

    Okudan, Nilsel; Belviranlı, Muaz

    2017-09-30

    This study aimed to determine the effect of exercise on locomotion, anxiety-related behavior, learning, and memory in socially isolated post-weaning rats, as well as the correlation between exercise and the concentration of brain-derived neurotrophic factor (BDNF) and nerve growth factor (NGF) in the hippocampus. Rats were randomly assigned to three groups: the control group; the social isolation group; the social isolation plus exercise (SIE) group. Social isolation conditions, with or without exercise were maintained for 90d, and then multiple behavioral tests, including the open-field test, elevated plus maze test, and Morris water maze (MWM) test were administered. Following behavioral assessment, hippocampal tissue samples were obtained for measurement of BDNF and NGF. There wasn't a significant difference in locomotor activity between the groups (P>0.05). Anxiety scores were higher in the socially isolated group (Psocially isolated rats (Psocial isolation-induced reduction in hippocampal BDNF and NGF content (Psocially isolated post-weaning rats. Copyright © 2017 IBRO. Published by Elsevier Ltd. All rights reserved.

  8. Calcium uptake by sarcoplasmic reticulum isolated from hearts of septic rats

    International Nuclear Information System (INIS)

    McDonough, K.H.

    1988-01-01

    Myocardial sarcoplasmic reticulum (SR) plays a critical role in the regulation of the cytosolic calcium fluctuations that occur during the cardiac cycle. One function of the SR is to lower the calcium concentration so that myocardial relaxation and thus ventricular filling can occur. The aim of the present study was to determine if hyperdynamic sepsis induced a decrease in the capacity of SR to take up calcium. This defect would result in decreased ventricular filling and thus decreased cardiac output, as has previously been shown in isolated perfused working hearts removed from septic rats. Therefore, rats were anesthetized with ether, and sepsis was induced by the injection of an aliquot of a fecal homogenate into the peritoneal cavity. Control animals either underwent surgery and received an aliquot of sterilized fecal inoculum (sham) or were untreated (no surgery). On day 2 after surgery, animals were anesthetized with pentobarbital, and hearts were removed, weighted, and SR isolated. The rate of uptake of 45 Ca 2+ by SR from septic rats was not depressed compared to controls but in fact was elevated. Maximum 45 Ca 2+ accumulated by the SR and Ca 2+ -stimulated ATPase activity were similar in SR from control and septic hearts. These results suggest that the contractile dysfunction noted in the myocardium in early sepsis is probably not due to inadequate SR removal of Ca 2+ during diastole

  9. Metabolism of 1-[14C]nitropyrene in isolated perfused rat livers

    International Nuclear Information System (INIS)

    Bond, J.A.; Medinsky, M.A.; Dutcher, J.S.

    1984-01-01

    1-Nitropyrene (1-NP), a constituent of diesel exhaust, is carcinogenic to rats and is a bacterial and mammalian mutagen. Biliary and fecal excretion of 1-NP metabolites are the major routes of excretion in rats, suggesting that hepatic metabolism plays a dominant role in determining the biological fate of 1-NP. The purpose of this investigation was to quantitate 1-[14C]NP metabolites formed in isolated perfused rat livers and excreted in bile from rats. Perfused rat livers displayed a capacity for oxidation, reduction, acetylation, and conjugation of 1-NP (or its metabolites). Reduction of 1-NP followed by N-acetylation was the major metabolic pathway observed in the perfused livers. Acetylaminopyrene (AAP) was the major metabolite detected, with total quantities (150 nmol) accounting for about 60% of the total 1-[14C]NP dose (258 nmol) added to the perfusate. Considerably smaller quantities of aminopyrene and hydroxynitropyrenes were also detected. Livers perfused with 1-[14C]NP excreted about 36 nmol equivalents of 1-[14C]NP (12% of the total 1-NP dose) in bile after 60 min. Some of the biliary metabolites were tentatively identified as metabolites of the mercapturic acid pathway. The spectrum of biliary metabolites was qualitatively identical to that seen in bile from intact rats. Quantities of 14C covalently bound to hepatic macromolecules from perfused livers were 0.4 nmol 1-NP eq/g liver. The data from this study indicate that the liver may be an important site for metabolism of 1-NP

  10. Sulphonylurea drugs reduce hypoxic damage in the isolated perfused rat kidney.

    Science.gov (United States)

    Engbersen, R; Moons, M M; Wouterse, A C; Dijkman, H B; Kramers, C; Smits, P; Russel, F G

    2000-08-01

    Sulphonylurea drugs have been shown to protect against hypoxic damage in isolated proximal tubules of the kidney. In the present study we investigated whether these drugs can protect against hypoxic damage in a whole kidney preparation. Tolbutamide (200 microM) and glibenclamide (10 microM) were applied to the isolated perfused rat kidney prior to changing the gassing from oxygen to nitrogen for 30 min. Hypoxic perfusions resulted in an increased fractional excretion of glucose (FE % glucose 14.3+/-1.5 for hypoxic perfusions vs 4.9+/-1.6 for normoxic perfusions, mean +/- s.e. mean, P<0.05), which could be completely restored by 200 microM tolbutamide (5.7+/-0.4 for tolbutamide vs 14.3+/-1.5 for untreated hypoxic kidneys, P<0.01). Furthermore, tolbutamide reduced the total amount of LDH excreted in the urine (220+/-100 mU for tolbutamide vs. 1220+/-160 mU for untreated hypoxic kidneys, P<0.01). Comparable results were obtained with glibenclamide (10 microM). In agreement with the effect on functional parameters, ultrastructural analysis of proximal tubules showed increased brush border preservation in tolbutamide treated kidneys compared to untreated hypoxic kidneys. We conclude that glibenclamide and tolbutamide are both able to reduce hypoxic damage to proximal tubules in the isolated perfused rat kidney when applied in the appropriate concentrations.

  11. Intake of Mung Bean Protein Isolate Reduces Plasma Triglyceride Level in Rats

    Directory of Open Access Journals (Sweden)

    Nobuhiko Tachibana

    2013-09-01

    Full Text Available ABSTRACTBackground: Mung bean is well known as a starch source, but the physiological effects of mung bean protein have received little attention. In this study, we isolated mung bean protein from de-starched mung bean solutions, and investigated its influence on lipid metabolism. Objective: The aim of this study is to clarify the influence of the lipid metabolism by consumption of mung bean protein isolate (MPIMethods: Diets containing either mung bean protein isolate (MPI or casein were fed to normal rats for 28 days.Results: Both groups ate the same amount of food, but the plasma triglyceride level, relative liver weight and liver lipid contents (cholesterol and triglyceride pool in the MPI group were significantly lower than in the casein group. In the MPI group, the expression of sterol regulatory-element binding factor 1 (SREBF1 mRNA in the liver was significantly different when compared with the casein group. The significantly lower levels of insulin and free fatty acids in the MPI-fed rats may be due to the regulation of genes related to lipid metabolism in the liver.Conclusions: These results suggest that MPI may improve the plasma lipid profile by normalizing insulin sensitivity.Keywords: mung bean, Vigna radiata L., 8S globulin, triglyceride, β-conglycinin, 7S globulin, insulin sensitivity, SREBF1

  12. Arbutus unedo induces endothelium-dependent relaxation of the isolated rat aorta.

    Science.gov (United States)

    Ziyyat, Abderrahim; Mekhfi, Hassane; Bnouham, Mohamed; Tahri, Abdelhafid; Legssyer, Abdelkhaleq; Hoerter, Jacqueline; Fischmeister, Rodolphe

    2002-09-01

    Arbutus unedo L. (Ericaceae) is used in oriental Morocco to treat arterial hypertension. We studied its vasodilator effect and mechanisms of action in vitro. The root aqueous extract of Arbutus (0.25 mg/mL) produced a relaxation of noradrenaline-precontracted ring preparations of rat aorta with intact endothelium. Relaxation by Arbutus did not occur in specimens without endothelium and was inhibited by pretreatment with 100 microM N(G)-methyl-L-arginine (L-NMA), 10 microM methylene blue or 50 microM 1H-[1,2,4] oxadiazolo [4,3-a] quinoxaline-1-one (ODQ) but not by 10 microM atropine. These results suggest that Arbutus produces an endothelium-dependent relaxation of the isolated rat aorta which may be mediated mainly by a stimulation of the endothelial nitric oxide synthase by mechanisms other than activation of muscarinic receptors. Copyright 2002 John Wiley & Sons, Ltd.

  13. Perfusion of the isolated rat brain with (/sup 14/C)-. delta. /sup 1/-tetrahydrocannabinol

    Energy Technology Data Exchange (ETDEWEB)

    Martin, B; Agurell, S [Dept. of Pharmacognosy, Faculty of Pharmacy, BMC, Uppsala (Sweden); Krieglstein, J; Rieger, H

    1977-12-01

    There is controversy over whether ..delta../sup 1/-tetrahydrocannabinol (..delta../sup 1/-THC) or its metabolites is responsible for the behavioural and cardiovascular effects of cannabis. It has been shown that, even in the absence of metabolism, ..delta../sup 1/-THC was capable of altering the EEG of isolated perfused rat brain, and must therefore contribute to the psychoactivity of cannabis. TLC studies showed no evidence for brain metabolism of (/sup 14/C)-..delta../sup 1/-THC, and in particular the 7-hydroxylated metabolite (7-OH-..delta../sup 1/-THC) could not be detected. A disproportionate amount of CNS activity in the rat cannot therefore be attributed to 7-OH-..delta../sup 1/-THC on the basis that it is formed at or near its locus of action.

  14. Perfusion of the isolated rat brain with [14C]-Δ1-tetrahydrocannabinol

    International Nuclear Information System (INIS)

    Martin, B.; Agurell, S.; Krieglstein, J.; Rieger, H.

    1977-01-01

    There is controversy over whether Δ 1 -tetrahydrocannabinol (Δ 1 -THC) or its metabolites is responsible for the behavioural and cardiovascular effects of cannabis. It has been shown that, even in the absence of metabolism, Δ 1 -THC was capable of altering the EEG of isolated perfused rat brain, and must therefore contribute to the psychoactivity of cannabis. TLC studies showed no evidence for brain metabolism of [ 14 C]-Δ 1 -THC, and in particular the 7-hydroxylated metabolite (7-OH-Δ 1 -THC) could not be detected. A disproportionate amount of CNS activity in the rat cannot therefore be attributed to 7-OH-Δ 1 -THC on the basis that it is formed at or near its locus of action. (U.K.)

  15. Effect of interleukin-1 on the biosynthesis of proinsulin and insulin in isolated rat pancreatic islets

    DEFF Research Database (Denmark)

    Hansen, Birgit Sehested; Linde, S; Spinas, G A

    1988-01-01

    Insulin dependent diabetes mellitus (IDDM) is often preceded or associated with lymphocytic infiltration in the islets of Langerhans (insulitis). We recently demonstrated that interleukin-1 (IL-1) produced by activated macrophages exerts a bimodal effect on insulin release and biosynthesis...... in isolated rat islets. In the present study we have further analysed the effect of recombinant human interleukin-1 beta (rIL-1) on the biosynthesis and conversion of proinsulin 1 and 2 in rat islets. By RP-HPLC-analysis of islets labelled with [3H]leucine we found that exposure to 6 ng/ml of IL-1 for 24 h.......1 to 3.4 +/- 0.4, respectively. Pulse-chase experiments with [3H]leucine and [35S]methionine indicated a more marked reduction in the conversion rate of proinsulin-2 compared to that of proinsulin-1. In conclusion these experiments demonstrate that IL-1 inhibits insulin biosynthesis by preferential...

  16. Uncoupling and oxidative stress in liver mitochondria isolated from rats with acute iron overload

    Energy Technology Data Exchange (ETDEWEB)

    Pardo Andreu, G.L. [Centro de Quimica Farmaceutica, Departamento de Investigaciones Biomedicas, Ciudad de La Habana (Cuba); Inada, N.M.; Vercesi, A.E. [Universidade Estadual de Campinas, Departamento de Patologia Clinica, Faculdade de Ciencias Medicas, Campinas, SP (Brazil); Curti, C. [Universidade de Sao Paulo, Departamento de Fisica e Quimica, Faculdade de Ciencias Farmaceuticas de Ribeirao Preto, SP (Brazil)

    2009-01-15

    One hypothesis for the etiology of cell damage arising from iron overload is that its excess selectively affects mitochondria. Here we tested the effects of acute iron overload on liver mitochondria isolated from rats subjected to a single dose of i.p. 500 mg/kg iron-dextran. The treatment increased the levels of iron in mitochondria (from 21{+-}4 to 130{+-}7 nmol/mg protein) and caused both lipid peroxidation and glutathione oxidation. The mitochondria of iron-treated rats showed lower respiratory control ratio in association with higher resting respiration. The mitochondrial uncoupling elicited by iron-treatment did not affect the phosphorylation efficiency or the ATP levels, suggesting that uncoupling is a mitochondrial protective mechanism against acute iron overload. Therefore, the reactive oxygen species (ROS)/H{sup +} leak couple, functioning as a mitochondrial redox homeostatic mechanism could play a protective role in the acutely iron-loaded mitochondria. (orig.)

  17. 31P nuclear magnetic resonance surface coil study of ischemic preconditioned isolated perfused rat heart

    International Nuclear Information System (INIS)

    Yan Yongbin; Luo Xuechun; Zhang Riqing; Wang Xiaoyin; Zuo Lin; Liu Wei

    2000-01-01

    ischemic preconditioning (IPC) will protect the heart from the damage caused by a subsequent long ischemia period. 31 P spectra of isolated perfused rat heart measured by the nuclear magnetic resonance (NMR) surface coil technique can be used to continually, dynamically and noninvasively obtain metabolism information. This paper explores the IPC mechanisms by NMR. This study shows that IPC has no effect on enhancing the ATP and PCr levels during reperfusion but makes significantly slows and smooths the changes of intracellular pH and ATP during ischemia periods. The ATP and PCr recovery rate of the IPC group after ischemia is significantly higher than that of the control group. In conclusion, the above results support that IPC can protect the rat heart by reducing damage during the ischemia period

  18. Isolation and characterization of dental epithelial cells derived from amelogenesis imperfecta rat.

    Science.gov (United States)

    Adiningrat, A; Tanimura, A; Miyoshi, K; Hagita, H; Yanuaryska, R D; Arinawati, D Y; Horiguchi, T; Noma, T

    2016-03-01

    Disruption of the third zinc finger domain of specificity protein 6 (SP6) presents an enamel-specific defect in a rat model of amelogenesis imperfecta (AMI rats). To understand the molecular basis of amelogenesis imperfecta caused by the Sp6 mutation, we established and characterized AMI-derived rat dental epithelial (ARE) cells. ARE cell clones were isolated from the mandibular incisors of AMI rats, and amelogenesis-related gene expression was analyzed by reverse transcription polymerase chain reaction (RT-PCR). Localization of wild-type SP6 (SP6WT) and mutant-type SP6 (SP6AMI) was analyzed by immunocytochemistry. SP6 transcriptional activity was monitored by rho-associated protein kinase 1 (Rock1) promoter activity with its specific binding to the promoter region in dental (G5 and ARE) and non-dental (COS-7) epithelial cells. Isolated ARE cells were varied in morphology and gene expression. Both SP6WT and SP6AMI were mainly detected in nuclei. The promoter analysis revealed that SP6WT and SP6AMI enhanced Rock1 promoter activity in G5 cells but that enhancement by SP6AMI was weaker, whereas no enhancement was observed in the ARE and COS-7 cells, even though SP6WT and SP6AMI bound to the promoter in all instances. ARE cell clones can provide a useful in vitro model to study the mechanism of SP6-mediated amelogenesis imperfecta. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  19. Isolation and identification of previtamin D3 from the skin of rats exposed to ultraviolet irradiation

    International Nuclear Information System (INIS)

    Holick, M.F.; Richtand, N.M.; McNeill, S.C.; Holick, S.A.; Frommer, J.E.; Henley, J.W.; Potts, J.T. Jr.

    1979-01-01

    The process of the photolytic activation of vitamin D precursor(s) in the skin has been elucidated by a detailed analysis of the products formed after ultraviolet light exposure. The photolytic product isolated from the skin of rats exposed to ultraviolet irradiation was identified as previtamin D 3 by several criteria including its characteristic ultraviolet absorption spectrum, mass spectrum, and thermal isomerization to vitamin D 3 , which itself was identified also by mass spectroscopy. Vitamin D 3 per se was not formed by ultraviolet irradiation-vitamin D 3 arises exclusively from the thermal conversion of previtamin D 3 . Detectable amounts of lumisterol 3 or tachysterol 3 were not seen

  20. Phencyclidine increased while isolation rearing did not affect progressive ratio responding in rats: Investigating potential models of amotivation in schizophrenia.

    Science.gov (United States)

    Amitai, Nurith; Powell, Susan B; Young, Jared W

    2017-11-22

    Schizophrenia is a debilitating neurodevelopmental disorder affecting 1% of the global population with heterogeneous symptoms including positive, negative, and cognitive. While treatment for positive symptoms exists, none have been developed to treat negative symptoms. Animal models of schizophrenia are required to test targeted treatments and since patients exhibit reduced effort (breakpoints) for reward in a progressive ratio (PR) task, we examined the PR breakpoints of rats treated with the NMDA receptor antagonist phencyclidine or those reared in isolation - two common manipulations used to induce schizophrenia-relevant behaviors in rodents. In two cohorts, the PR breakpoint for a palatable food reward was examined in Long Evans rats after: 1) a repeated phencyclidine regimen; 2) A subchronic phencyclidine regimen followed by drug washout; and 3) post-weaning social isolation. Rats treated with repeated phencyclidine and those following washout from phencyclidine exhibited higher PR breakpoints than vehicle-treated rats. The breakpoint of isolation reared rats did not differ from those socially reared, despite abnormalities of these rats in other schizophrenia-relevant behaviors. Despite their common use for modeling other schizophrenia-relevant behaviors neither phencyclidine treatment nor isolation rearing recreated the motivational deficits observed in patients with schizophrenia, as measured by PR breakpoint. Other manipulations, and negative symptom-relevant behaviors, require investigation prior to testing putative therapeutics. Copyright © 2017 Elsevier B.V. All rights reserved.

  1. The specific binding of the thyroid hormones to matrix isolated from rat liver nuclei

    International Nuclear Information System (INIS)

    Wilson, B.D.; Albrecht, C.F.; Wium, C.A.

    1982-01-01

    Specific binding sites for the thyroid hormones have been demonstrated in the liver nuclear matrix, a structural framework of the nucleus. When labelled 3,5,3'-tri-iodo-L-thyronine ([ 125 l]T 3 ) is injected into rats, 5% of the total nucleus bound T 3 is bound to the matrix after 1 hour. However, when either isolated nuclei or isolated nuclear matrices were incubated with[ 125 l]T 3 in vitro, a 3- to 7- fold greater number of specific T 3 binding sites were revealed in the nuclear matrix. The properties of the matrix-associated thyroid hormone binding sites were investigated in vitro. These binding sites showed limited capacity and high affinity for T 3 ; the equilibrium association constant (K(a)) was 1,3X10 M -1 and the binding capacity was 20,2 fmol T 3 per 100 μg matrix protein

  2. Huperzine A protects isolated rat brain mitochondria against beta-amyloid peptide.

    Science.gov (United States)

    Gao, Xin; Zheng, Chun Yan; Yang, Ling; Tang, Xi Can; Zhang, Hai Yan

    2009-06-01

    Our previous work in cells and animals showed that mitochondria are involved in the neuroprotective effect of huperzine A (HupA). In this study, the effects of HupA on isolated rat brain mitochondria were investigated. In addition to inhibiting the Abeta(25-35) (40 microM)-induced decrease in mitochondrial respiration, adenosine 5'-triphosphate (ATP) synthesis, enzyme activity, and transmembrane potential, HupA (0.01 or 0.1 microM) effectively prevented Abeta-induced mitochondrial swelling, reactive oxygen species increase, and cytochrome c release. More interestingly, administration of HupA to isolated mitochondria promoted the rate of ATP production and blocked mitochondrial swelling caused by normal osmosis. These results indicate that HupA protects mitochondria against Abeta at least in part by preserving membrane integrity and improving energy metabolism. These direct effects on mitochondria further extend the noncholinergic functions of HupA.

  3. Primary microglia isolation from mixed glial cell cultures of neonatal rat brain tissue.

    Science.gov (United States)

    Tamashiro, Tami T; Dalgard, Clifton Lee; Byrnes, Kimberly R

    2012-08-15

    Microglia account for approximately 12% of the total cellular population in the mammalian brain. While neurons and astrocytes are considered the major cell types of the nervous system, microglia play a significant role in normal brain physiology by monitoring tissue for debris and pathogens and maintaining homeostasis in the parenchyma via phagocytic activity. Microglia are activated during a number of injury and disease conditions, including neurodegenerative disease, traumatic brain injury, and nervous system infection. Under these activating conditions, microglia increase their phagocytic activity, undergo morpohological and proliferative change, and actively secrete reactive oxygen and nitrogen species, pro-inflammatory chemokines and cytokines, often activating a paracrine or autocrine loop. As these microglial responses contribute to disease pathogenesis in neurological conditions, research focused on microglia is warranted. Due to the cellular heterogeneity of the brain, it is technically difficult to obtain sufficient microglial sample material with high purity during in vivo experiments. Current research on the neuroprotective and neurotoxic functions of microglia require a routine technical method to consistently generate pure and healthy microglia with sufficient yield for study. We present, in text and video, a protocol to isolate pure primary microglia from mixed glia cultures for a variety of downstream applications. Briefly, this technique utilizes dissociated brain tissue from neonatal rat pups to produce mixed glial cell cultures. After the mixed glial cultures reach confluency, primary microglia are mechanically isolated from the culture by a brief duration of shaking. The microglia are then plated at high purity for experimental study. The principle and protocol of this methodology have been described in the literature. Additionally, alternate methodologies to isolate primary microglia are well described. Homogenized brain tissue may be separated

  4. Uptake and degradation of natural surfactant by isolated rat granular pneumocytes

    International Nuclear Information System (INIS)

    Fisher, A.B.; Chander, A.; Reicherter, J.

    1987-01-01

    It has been previously shown that isolated granular pneumocytes internalize and degrade dipalmitoylphosphatidylcholine (DPPC) in synthetic lipid vesicles and reutilize degradation products for phosphatidylcholine (PC) synthesis. In this study, the authors evaluated the uptake and degradation of radiolabeled natural surfactant (NS) isolated from lung lavage after perfusing isolated rat lungs with [ 3 H]choline. Uptake of NS by isolated granular pneumocytes was increased approximately fourfold compared with synthetic liposomes, suggesting that physical form or a component (e.g., a protein) of NS plays a role in phospholipid uptake by these cells. Uptake was significantly decreased by metabolic inhibitors, indicating an energy requirement for this process. After 2-h incubation, the pattern of radioactivity in cells compared with NS showed a significant decrease in PC and DSPC and increase in free choline, choline phosphate, and CDP-choline. This pattern of metabolism indicates degradation of PC and metabolic reutilization of products. These studies support the hypothesis that alveolar phospholipids are accumulated and reutilized by granular pneumocytes for surfactant synthesis

  5. Prevention of reperfusion lung injury by lidocaine in isolated rat lung ventilated with higher oxygen levels.

    Directory of Open Access Journals (Sweden)

    Das K

    2003-01-01

    Full Text Available BACKGROUND: Lidocaine, an antiarrhythmic drug has been shown to be effective against post-ischaemic reperfusion injury in heart. However, its effect on pulmonary reperfusion injury has not been investigated. AIMS: We investigated the effects of lidocaine on a postischaemic reperfused rat lung model. MATERIALS AND METHODS: Lungs were isolated and perfused at constant flow with Krebs-Henseilet buffer containing 4% bovine serum albumin, and ventilated with 95% oxygen mixed with 5% CO2. Lungs were subjected to ischaemia by stopping perfusion for 60 minutes followed by reperfusion for 10 minutes. Ischaemia was induced in normothermic conditions. RESULTS: Postischaemic reperfusion caused significant (p < 0.0001 higher wet-to-dry lung weight ratio, pulmonary arterial pressure and peak airway pressure compared to control lungs. Lidocaine, at a dose of 5mg/Kg b.w. was found to significantly (p < 0.0001 attenuate the increase in the wet-to-dry lung weight ratio, pulmonary arterial pressure and peak airway pressure observed in post-ischaemic lungs. CONCLUSION: Lidocaine is effective in preventing post-ischaemic reperfusion injury in isolated, perfused rat lung.

  6. Behavior of lactobacilli isolated from fermented slurry (ben-saalga in gnotobiotic rats.

    Directory of Open Access Journals (Sweden)

    Williams Turpin

    Full Text Available Most bacterial strains, which have been studied so far for their probiotic functions, are extensively used by manufacturers in developed countries. In our work, we sought to study a mix (called BSL comprising three strains belonging to Lactobacillus fermentum, L. paraplantarum and L. salivarius, that were isolated from a traditional African pearl millet based fermented slurry. Our objective was to study this BSL cocktail in gnotobiotic rats, to evaluate their survival and their behavior in the digestive tract conditions. After a single oral inoculation of germfree rats with BSL, the species established stably in the digestive tract with the following hierarchy of abundance: L. salivarius> L. plantarum> L. fermentum. BSL cocktail was metabolically active since it produced 50 mM lactate and it expressed genes involved in binding mechanism in the caecum. Furthermore, the global morphology of the colon epithelium was not disturbed by the BSL cocktail. BSL cocktail did not modify mucus content and host mucus-related genes (MUC1, MUC2, MUC3 or resistin-like molecule β. The cocktail of lactobacilli enhanced the proliferating cell nuclear antigen (PCNA at a level comparable to what was observed in conventional rats. PCNA was involved in proliferation and DNA repair, but the presence of the cocktail did not provoke proliferative events (with Ki67 as indicator, so we suppose BSL may help gut preservation. This work is the first step towards the selection of strains that are derived from traditional fermented food to formulate new probiotic mixture.

  7. Effect of alpha-lipoic acid on the removal of arsenic from arsenic-loaded isolated liver tissues of rat

    Directory of Open Access Journals (Sweden)

    Noor-E-Tabassum

    2006-06-01

    Full Text Available The patient of chronic arsenic toxicity shows oxidative stress. To overcome the oxidative stress, several antioxidants such as beta-carotene, ascorbic acid, α-tocopherol, zinc and selenium had been suggested in the treatment of chronic arsenic toxicity. In the present study universal antioxidant (both water and lipid soluble antioxidant α-lipoic acid was used to examine the effectiveness of reducing the amount of arsenic from arsenic-loaded isolated liver tissues of rat. Isolated liver tissues of Long Evans Norwegian rats were cut into small pieces and incubated first in presence or absence of arsenic and then with different concentrations of α-lipoic acid during the second incubation. α-Lipoic acid decreases the amount of arsenic and malondialdehyde (MDA in liver tissues as well as increases the reduced glutathione (GSH level in dose dependent manner. These results suggest that α-lipoic acid remove arsenic from arsenic-loaded isolated liver tissues of rat.

  8. NADPH- Diaphorase positive cardiac neurons in the atria of mice. A morphoquantitative study

    Directory of Open Access Journals (Sweden)

    Castelucci Patrícia

    2006-02-01

    Full Text Available Abstract Background The present study was conducted to determine the location, the morphology and distribution of NADPH-diaphorase positive neurons in the cardiac nerve plexus of the atria of mice (ASn. This plexus lies over the muscular layer of the atria, dorsal to the muscle itself, in the connective tissue of the subepicardium. NADPH- diaphorase staining was performed on whole-mount preparations of the atria mice. For descriptive purposes, all data are presented as means ± SEM. Results The majority of the NADPH-diaphorase positive neurons were observed in the ganglia of the plexus. A few single neurons were also observed. The number of NADPH-d positive neurons was 57 ± 4 (ranging from 39 to 79 neurons. The ganglion neurons were located in 3 distinct groups: (1 in the region situated cranial to the pulmonary veins, (2 caudally to the pulmonary veins, and (3 in the atrial groove. The largest group of neurons was located cranially to the pulmonary veins (66.7%. Three morphological types of NADPH-diaphorase neurons could be distinguished on the basis of their shape: unipolar cells, bipolar cells and cells with three processes (multipolar cells. The unipolar neurons predominated (78.9%, whereas the multipolar were encountered less frequently (5,3%. The sizes (area of maximal cell profile of the neurons ranged from about 90 μm2to about 220 μm2. Morphometrically, the three types of neurons were similar and there were no significant differences in their sizes. The total number of cardiac neurons (obtained by staining the neurons with NADH-diaphorase method was 530 ± 23. Therefore, the NADPH-diaphorase positive neurons of the heart represent 10% of the number of cardiac neurons stained by NADH. Conclusion The obtained data have shown that the NADPH-d positive neurons in the cardiac plexus of the atria of mice are morphologically different, and therefore, it is possible that the function of the neurons may also be different.

  9. Contrasting cardiovascular properties of the µ-opioid agonists morphine and methadone in the rat.

    Science.gov (United States)

    Tung, Kenneth H; Angus, James A; Wright, Christine E

    2015-09-05

    Morphine and methadone share the property of μ-opioid receptor agonism yet have markedly different cardiovascular actions suggesting additional properties are at play. We investigated the i.v. dose-response relationships of the opioids on cardiovascular metameters in anaesthetised rats in the absence or presence of H1- and H2-receptor antagonism and the μ-opioid antagonist naloxone. In vitro tissue assays were employed to define more clearly cardiac and vascular mechanisms of action. Morphine (9, 30, 90mg/kg i.v.) decreased heart rate (HR) and mean arterial pressure (MAP) - responses that were blocked by naloxone pretreatment (10mg/kg i.v.). In contrast, methadone (3, 10, 30mg/kg i.v.) caused dramatic short-lived (1-3min) bradycardia, hypotension and lengthening of the QT interval before stabilising 5min after i.v. dosing. Only the steady-state responses of HR and MAP were blocked by naloxone. Mepyramine (10mg/kg i.v.) and cimetidine (100mg/kg i.v.) also blocked the naloxone-sensitive components. In isolated small mesenteric arteries precontracted by K(+) 62mM or endothelin-1, methadone (1-30μM) relaxed vessels while morphine (1-100μM) had no effect. Pretreatment with naloxone (10μM), indomethacin (30μM) or nitro-l-arginine (100μM) did not affect the relaxation to methadone. In rat isolated left atria, morphine and methadone inhibited inotropic responses at high concentrations (100μM). In rat papillary muscle and right atria, methadone was more than 30 times more potent at lengthening the refractory period and slowing the atrial rate than morphine. We conclude that methadone is a potent vasodilator agent, possibly through blocking L-type calcium channels. Copyright © 2015 Elsevier B.V. All rights reserved.

  10. Chronic exposure to zinc oxide nanoparticles increases ischemic-reperfusion injuries in isolated rat hearts

    Energy Technology Data Exchange (ETDEWEB)

    Milivojević, Tamara; Drobne, Damjana; Romih, Tea; Mali, Lilijana Bizjak [University of Ljubljana, Department of Biology, Biotechnical Faculty (Slovenia); Marin, Irena; Lunder, Mojca; Drevenšek, Gorazd, E-mail: gorazd.drevensek@mf.uni-lj.si [University of Ljubljana, Institute of Pharmacology and Experimental Toxicology, Faculty of Medicine (Slovenia)

    2016-10-15

    The use of zinc oxide nanoparticles (ZnO NPs) in numerous products is increasing, although possible negative implications of their long-term consumption are not known yet. Our aim was to evaluate the chronic, 6-week oral exposure to two different concentrations of ZnO NPs on isolated rat hearts exposed to ischemic-reperfusion injury and on small intestine morphology. Wistar rats of both sexes (n = 18) were randomly divided into three groups: (1) 4 mg/kg ZnO NPs, (2) 40 mg/kg ZnO NPs, and (3) control. After 6 weeks of treatment, the hearts were isolated, the left ventricular pressure (LVP), the coronary flow (CF), the duration of arrhythmias and the lactate dehydrogenase release rate (LDH) were measured. A histological investigation of the small intestine was performed. Chronic exposure to ZnO NPs acted cardiotoxic dose-dependently. ZnO NPs in dosage 40 mg/kg maximally decreased LVP (3.3-fold) and CF (2.5-fold) and increased the duration of ventricular tachycardia (all P < 0.01) compared to control, whereas ZnO NPs in dosage 4 mg/kg acted less cardiotoxic. Goblet cells in the small intestine epithelium of rats, treated with 40 mg ZnO NPs/kg, were enlarged, swollen and numerous, the intestinal epithelium width was increased. Unexpectedly, ZnO NPs in both dosages significantly decreased LDH. A 6-week oral exposure to ZnO NPs dose-dependently increased heart injuries and caused irritation of the intestinal mucosa. A prolonged exposure to ZnO NPs might cause functional damage to the heart even with exposures to the recommended daily doses, which should be tested in future studies.

  11. Studies into the anxiolytic actions of agomelatine in social isolation reared rats: Role of corticosterone and sex.

    Science.gov (United States)

    Regenass, Wilmie; Möller, Marisa; Harvey, Brian H

    2018-02-01

    Anxiety disorders are severely disabling, while current pharmacological treatments are complicated by delayed onset, low remission rates and side-effects. Sex is also noted to contribute towards illness severity and treatment response. Agomelatine is a melatonin (MT 1 /MT 2 ) agonist and serotonin (5-HT 2C ) antagonist purported to be anxiolytic in clinical and some pre-clinical studies. We undertook a detailed analysis of agomelatine's anxiolytic activity in a neurodevelopmental model of anxiety, the social isolation reared rat. Rats received sub-chronic treatment with vehicle or agomelatine (40 mg/kg per day intraperitoneally at 16:00 h for 16 days), with behaviour analysed in the open field test, social interaction test and elevated plus maze. The contribution of corticosterone and sex was also studied. Social isolation rearing increased locomotor activity and reduced social interaction in the social interaction test, and was anxiogenic in the elevated plus maze in males and females. Agomelatine reversed these behaviours. Male and female social isolation reared rats developed anxiety-like behaviours to a similar degree, although response to agomelatine was superior in male rats. Social isolation rearing decreased plasma corticosterone in both sexes and tended to higher levels in females, although agomelatine did not affect corticosterone in either sex. Concluding, agomelatine is anxiolytic in SIR rats, although correcting altered corticosterone could not be implicated. Sex-related differences in the response to agomelatine are evident.

  12. Social Isolation Modulates CLOCK Protein and Beta-Catenin Expression Pattern in Gonadotropin-Inhibitory Hormone Neurons in Male Rats

    Directory of Open Access Journals (Sweden)

    Chuin Hau Teo

    2017-09-01

    Full Text Available Postweaning social isolation reduces the amplitude of the daily variation of CLOCK protein in the brain and induces lower reproductive activity. Gonadotropin-inhibitory hormone (GnIH acts as an inhibitor in the reproductive system and has been linked to stress. Social isolation has been shown to lower neuronal activity of GnIH-expressing neurons in the dorsomedial hypothalamus (DMH. The exact mechanism by which social isolation may affect GnIH is still unclear. We investigated the impact of social isolation on regulatory cellular mechanisms in GnIH neurons. We examined via immunohistochemistry the expression of CLOCK protein at four different times throughout the day in GnIH cells tagged with enhanced fluorescent green protein (EGFP-GnIH in 9-week-old adult male rats that have been raised for 6 weeks under postweaning social isolation and compared them with group-raised control rats of the same age. We also studied the expression of β-catenin—which has been shown to be affected by circadian proteins such as Bmal1—in EGFP-GnIH neurons to determine whether it could play a role in linking CLOCK in GnIH neurons. We found that social isolation modifies the pattern of CLOCK expression in GnIH neurons in the DMH. Socially isolated rats displayed greater CLOCK expression in the dark phase, while control rats displayed increased CLOCK expression in the light phase. Furthermore, β-catenin expression pattern in GnIH cells was disrupted by social isolation. This suggests that social isolation triggers changes in CLOCK and GnIH expression, which may be associated with an increase in nuclear β-catenin during the dark phase.

  13. Social Isolation Modulates CLOCK Protein and Beta-Catenin Expression Pattern in Gonadotropin-Inhibitory Hormone Neurons in Male Rats.

    Science.gov (United States)

    Teo, Chuin Hau; Soga, Tomoko; Parhar, Ishwar S

    2017-01-01

    Postweaning social isolation reduces the amplitude of the daily variation of CLOCK protein in the brain and induces lower reproductive activity. Gonadotropin-inhibitory hormone (GnIH) acts as an inhibitor in the reproductive system and has been linked to stress. Social isolation has been shown to lower neuronal activity of GnIH-expressing neurons in the dorsomedial hypothalamus (DMH). The exact mechanism by which social isolation may affect GnIH is still unclear. We investigated the impact of social isolation on regulatory cellular mechanisms in GnIH neurons. We examined via immunohistochemistry the expression of CLOCK protein at four different times throughout the day in GnIH cells tagged with enhanced fluorescent green protein (EGFP-GnIH) in 9-week-old adult male rats that have been raised for 6 weeks under postweaning social isolation and compared them with group-raised control rats of the same age. We also studied the expression of β-catenin-which has been shown to be affected by circadian proteins such as Bmal1-in EGFP-GnIH neurons to determine whether it could play a role in linking CLOCK in GnIH neurons. We found that social isolation modifies the pattern of CLOCK expression in GnIH neurons in the DMH. Socially isolated rats displayed greater CLOCK expression in the dark phase, while control rats displayed increased CLOCK expression in the light phase. Furthermore, β-catenin expression pattern in GnIH cells was disrupted by social isolation. This suggests that social isolation triggers changes in CLOCK and GnIH expression, which may be associated with an increase in nuclear β-catenin during the dark phase.

  14. Metabolism in rats of selenium from intrinsically and extrinsically labeled isolated soy protein

    International Nuclear Information System (INIS)

    Mason, A.C.; Weaver, C.M.

    1986-01-01

    Absorption, retention and tissue accumulation by rats of 75 Se from intrinsically labeled isolated soy protein were compared with utilization of 75 Se from the extrinsic sources of [ 75 Se]selenite, [ 75 Se]selenate or [ 75 Se]selenomethionine. Extrinsic sources of selenium were given by gavage or mixed with isolated soy protein. There were no differences in absorption and retention of 75 Se from intrinsically labeled soy diet compared to the three extrinsically labeled soy diets. Of the three extrinsic sources tested, 75 Se from selenate was better absorbed than from selenite or selenomethionine when incorporated into a soy diet. Absorption of 75 Se was significantly lower when given to animals in gavage solution than when mixed with soy diets. After a 14-d test period, retention of 75 Se was the same for all four soy diet groups. In gavaged groups, 75 Se from selenomethionine was retained to a greater extent than 75 Se from selenite. The liver, testes and kidney accumulated more 75 Se from the test meal than did the blood and lungs. In the testes more 75 Se from selenite and selenate was accumulated than from selenomethionine-labeled diets. Selenium absorption from the soy isolate source was very high (86-96%), indicating that, although soy does not normally contain high levels of selenium, the selenium present is well absorbed from this plant source

  15. The effect of curcumin on insulin release in rat-isolated pancreatic islets.

    Science.gov (United States)

    Abdel Aziz, Mohamed T; El-Asmar, Mohamed F; El Nadi, Essam G; Wassef, Mohamed A; Ahmed, Hanan H; Rashed, Laila A; Obaia, Eman M; Sabry, Dina; Hassouna, Amira A; Abdel Aziz, Ahmed T

    2010-08-01

    Curcumin exerts a hypoglycemic action and induces heme-oxygenase-1 (HO-1). We evaluated the effect of curcumin on isolated islets of Langerhans and studied whether its action on insulin secretion is mediated by inducible HO-1. Islets were isolated from rats and divided into control islets, islets incubated in different curcumin concentrations, islets incubated in hemin, islets incubated in curcumin and HO inhibitor, stannous mesoporphyrin (SnMP), islets incubated in hemin and SnMP, islets incubated in SnMP only, and islets incubated in 16.7 mmol/L glucose. Heme-oxygenase activity, HO-1 expression, and insulin estimation was assessed. Insulin secretion, HO-1 gene expression and HO activity were significantly increased in islets incubated in curcumin, hemin, and glucose compared with controls. This increase in insulin secretion was significantly decreased by incubation of islets in SnMP. The action of curcumin on insulin secretion from the isolated islets may be, in part, mediated through increased HO-1 gene expression.

  16. Model-based imaging of cardiac electrical function in human atria

    Science.gov (United States)

    Modre, Robert; Tilg, Bernhard; Fischer, Gerald; Hanser, Friedrich; Messnarz, Bernd; Schocke, Michael F. H.; Kremser, Christian; Hintringer, Florian; Roithinger, Franz

    2003-05-01

    Noninvasive imaging of electrical function in the human atria is attained by the combination of data from electrocardiographic (ECG) mapping and magnetic resonance imaging (MRI). An anatomical computer model of the individual patient is the basis for our computer-aided diagnosis of cardiac arrhythmias. Three patients suffering from Wolff-Parkinson-White syndrome, from paroxymal atrial fibrillation, and from atrial flutter underwent an electrophysiological study. After successful treatment of the cardiac arrhythmia with invasive catheter technique, pacing protocols with stimuli at several anatomical sites (coronary sinus, left and right pulmonary vein, posterior site of the right atrium, right atrial appendage) were performed. Reconstructed activation time (AT) maps were validated with catheter-based electroanatomical data, with invasively determined pacing sites, and with pacing at anatomical markers. The individual complex anatomical model of the atria of each patient in combination with a high-quality mesh optimization enables accurate AT imaging, resulting in a localization error for the estimated pacing sites within 1 cm. Our findings may have implications for imaging of atrial activity in patients with focal arrhythmias.

  17. RNA-sequencing data analysis of uterus in ovariectomized rats fed with soy protein isolate,17B-estradiol and casein

    Science.gov (United States)

    This data file describes the bioinformatics analysis of uterine RNA-seq data comparing genome wide effects of feeding soy protein isolate compared to casein to ovariectomized female rats age 64 days relative to treatment of casein fed rats with 5 ug/kg/d estradiol and relative to rats treated with e...

  18. Inhibition of mirtazapine metabolism by Ecstasy (MDMA) in isolated perfused rat liver model.

    Science.gov (United States)

    Jamshidfar, Sanaz; Ardakani, Yalda H; Lavasani, Hoda; Rouini, Mohammadreza

    2017-06-28

    Nowadays MDMA (3,4-methylendioxymethamphetamine), known as ecstasy, is widely abused among the youth because of euphoria induction in acute exposure. However, abusers are predisposed to depression in chronic consumption of this illicit compound. Mirtazapine (MRZ), an antidepressant agent, may be prescribed in MDMA-induced depression. MRZ is extensively metabolized in liver by CYP450 isoenzymes. 8-hydroxymirtazapine (8-OH) is mainly produced by CYP2D6. N-desmethylmirtazapine (NDES) is generated by CYP3A4. MDMA is also metabolized by the mentioned isoenzymes and demonstrates mechanism-based inhibition (MBI) in association with CYP2D6. Several studies revealed that MDMA showed inhibitory effects on CYP3A4. In the present study, our aim was to evaluate the impact of MDMA on the metabolism of MRZ in liver. Therefore, isolated perfused rat liver model was applied as our model of choice in this assessment. The subjects of the study were categorized into two experimental groups. Rats in the control group received MRZ-containing Krebs-Henselit buffer (1 μg/ml). Rats in the treatment group received aqueous solution of 1 mg/ml MDMA (3 mg/kg) intraperitoneally 1 hour before receiving MRZ. Perfusate samples were analyzed by HPLC. Analyses of perfusate samples showed 80% increase in the parent drug concentrations and 50% decrease in the concentrations of both metabolites in our treatment group compared to the control group. In the treatment group compared to the control group, AUC (0-120) of the parent drug demonstrated 50% increase and AUC (0-120) of 8-OH and NDES showed 70% and 60% decrease, respectively. Observed decrease in metabolic ratios were 83% and 79% for 8-OH and NDES in treatment group compared to control group, respectively. Hepatic clearance (CL h ) and intrinsic clearance (Cl int ) showed 20% and 60% decrease in treatment group compared to control group. All findings prove the inhibitory effects of ecstasy on both CYP2D6 and CYP3A4 hepatic isoenzymes. In

  19. Contribution of social isolation, restraint, and hindlimb unloading to changes in hemodynamic parameters and motion activity in rats.

    Directory of Open Access Journals (Sweden)

    Darya Tsvirkun

    Full Text Available The most accepted animal model for simulation of the physiological and morphological consequences of microgravity on the cardiovascular system is one of head-down hindlimb unloading. Experimental conditions surrounding this model include not only head-down tilting of rats, but also social and restraint stresses that have their own influences on cardiovascular system function. Here, we studied levels of spontaneous locomotor activity, blood pressure, and heart rate during 14 days under the following experimental conditions: cage control, social isolation in standard rat housing, social isolation in special cages for hindlimb unloading, horizontal attachment (restraint, and head-down hindlimb unloading. General activity and hemodynamic parameters were continuously monitored in conscious rats by telemetry. Heart rate and blood pressure were both evaluated during treadmill running to reveal cardiovascular deconditioning development as a result of unloading. The main findings of our work are that: social isolation and restraint induced persistent physical inactivity, while unloading in rats resulted in initial inactivity followed by normalization and increased locomotion after one week. Moreover, 14 days of hindlimb unloading showed significant elevation of blood pressure and slight elevation of heart rate. Hemodynamic changes in isolated and restrained rats largely reproduced the trends observed during unloading. Finally, we detected no augmentation of tachycardia during moderate exercise in rats after 14 days of unloading. Thus, we concluded that both social isolation and restraint, as an integral part of the model conditions, contribute essentially to cardiovascular reactions during head-down hindlimb unloading, compared to the little changes in the hydrostatic gradient.

  20. Cardiovascular effects of a herbicide containing glufosinate and a surfactant: in vitro and in vivo analyses in rats.

    Science.gov (United States)

    Koyama, K; Koyama, K; Goto, K

    1997-08-01

    A herbicide, Basta (BASTA), containing glufosinate ammonium (GLA) as the main component and an anionic surfactant, sodium polyoxyethylene alkylether sulfate (AES), causes hemodynamic changes characterized by a decrease in total vascular resistance with an increase or a decrease in cardiac output in human acute oral poisoning. With a motivation based on these clinical observations, we tried to elucidate the exact component and its mode of action that is mostly responsible for the direct cardiovascular effects of this herbicide formulation, investigating the effects of BASTA, GLA, and AES independently on the cardiovascular system in rats in vitro and in vivo. In isolated right atria beating spontaneously in Krebs-Ringer's solution, BASTA and AES produced negative chronotropic responses in a concentration-dependent manner. In electrically driven isolated left atria, BASTA and AES produced positive inotropic responses concentration dependently but negative inotropic responses at extremely high concentrations. In aortic ring segments, BASTA and AES produced no vasoconstrictive effects but exerted significant vasodilative effects when the aortic ring was precontracted with phenylephrine. These in vitro responses caused by BASTA and AES occurred to a similar degree. On the other hand, the main component, GLA, produced no effects in isolated atria and aortas. In anesthetized rats, relatively low doses of BASTA and AES produced a decrease in blood pressure followed by a slight increase in heart rate, which was presumably due to baroreflex caused by the decrease in blood pressure. At an extremely high dose, BASTA and AES produced a decrease in blood pressure with a marked decrease in heart rate. These in vivo responses to BASTA and AES also occurred to a similar degree. In contrast, the main component, GLA, did not produce any effects on heart rate and blood pressure in anesthetized rats. From these results, we concluded that the effects of BASTA in our in vivo experiments

  1. Isolation of full-length putative rat lysophospholipase cDNA using improved methods for mRNA isolation and cDNA cloning

    International Nuclear Information System (INIS)

    Han, J.H.; Stratowa, C.; Rutter, W.J.

    1987-01-01

    The authors have cloned a full-length putative rat pancreatic lysophospholipase cDNA by an improved mRNA isolation method and cDNA cloning strategy using [ 32 P]-labelled nucleotides. These new methods allow the construction of a cDNA library from the adult rat pancreas in which the majority of recombinant clones contained complete sequences for the corresponding mRNAs. A previously recognized but unidentified long and relatively rare cDNA clone containing the entire sequence from the cap site at the 5' end to the poly(A) tail at the 3' end of the mRNA was isolated by single-step screening of the library. The size, amino acid composition, and the activity of the protein expressed in heterologous cells strongly suggest this mRNA codes for lysophospholipase

  2. Contribution of several amino acids and lactate to gluconeogenesis in hepatocytes isolated from rats fed various diets

    International Nuclear Information System (INIS)

    Kaloyianni, M.; Freedland, R.A.

    1990-01-01

    The contribution under various nutritional regimens of several amino acids and lactate to gluconeogenesis was estimated by measuring the glucose formation from 14C-labeled substrates. Isolated rat hepatocytes were incubated for 60 min in a Krebs-Ringer bicarbonate buffer pH 7.4 containing lactate, pyruvate and all the amino acids at concentrations similar to their physiological levels found in rat plasma, with one precursor labeled in each flask. In all conditions, lactate was the major glucose precursor, providing over 60% of the glucose formed. Glutamine and alanine were the major amino acid precursors of glucose, contributing 9.8% and 10.6% of the glucose formed, respectively, in hepatocytes isolated from starved rats. Serine, glycine and threonine also contributed to gluconeogenesis in the starved liver cells at 2.6, 2.1 and 3.8%, respectively, of the glucose formed. The rate of glucose formation from the isolated hepatocytes of the starved rats and those fed either high protein or high fat was higher than that from rats fed a nonpurified diet

  3. Antidiabetic effects of scoparic acid D isolated from Scoparia dulcis in rats with streptozotocin-induced diabetes.

    Science.gov (United States)

    Latha, Muniappan; Pari, Leelavinothan; Ramkumar, Kunga Mohan; Rajaguru, Palanisamy; Suresh, Thangaraj; Dhanabal, Thangavel; Sitasawad, Sandhya; Bhonde, Ramesh

    2009-01-01

    We evaluated the antihyperglycaemic effect of scoparic acid D (SAD), a diterpenoid isolated from the ethanol extract of Scoparia dulcis in streptozotocin (STZ)-induced diabetic male Wistar rats. SAD was administered orally at a dose of 10, 20 and 40 mg kg(-1) bodyweight for 15 days. At the end of the experimental period, the SAD-treated STZ diabetic rats showed decreased levels of glucose as compared with diabetic control rats. The improvement in blood glucose levels of SAD-treated rats was associated with a significant increase in plasma insulin levels. SAD at a dose of 20 mg kg(-1) bodyweight exhibited a significant effect when compared with other doses. Further, the effect of SAD was tested on STZ-treated rat insulinoma cell lines (RINm5F cells) and isolated islets in vitro. SAD at a dose of 20 microg mL(-1) evoked two-fold stimulation of insulin secretion from isolated islets, indicating its insulin secretagogue activity. Further, SAD protected STZ-mediated cytotoxicity and nitric oxide (NO) production in RINm5F cells. The present study thus confirms the antihyperglycaemic effect of SAD and also demonstrated the consistently strong cytoprotective properties of SAD.

  4. Synergistic Effects of Social Isolation and Morphine Addiction on Reduced Neurogenesis and BDNF Levels and the Resultant Deficits in Cognition and Emotional State in Male Rats.

    Science.gov (United States)

    Famitafreshi, Hamidreza; Karimian, Morteza; Fatima, Sulail

    2016-01-01

    Addiction to drugs of abuse is a devastating condition which results in deterioration of brain function. On the other hand, social isolation also produces cognitive deficits such as learning and memory impairment. This study was designed to evaluate the potential negative synergistic effects of social isolation and morphine addiction on brain functions. One hundred and two Sprague-Dawley rats were randomly divided into four groups for assessing neurogenesis and behaviour: group-housed, isolated, morphine-treated group-housed and morphine-treated isolated groups. Morphine- treated animals received BrdU (50 mg/kg; i.p.) and Morphine (0.75 mg/rat; i.p.) for 14 consecutive days, whereas, control rats received BrdU (50 mg/kg; i.p.) only. At the end of the study, Morris water maze and elevated plus maze tasks were performed to assess spatial working memory and anxiety levels, respectively. Furthermore, neurogenesis and BDNF levels were studied. Reference and working memory was markedly impaired in isolated and morphine-treated isolated rats as compared to group-housed rats and morphine-treated group-housed rats, respectively. Neurogenesis and BDNF levels were reduced in isolated and morphine-treated isolated rats as compared to group-housed rats and morphine-treated group-housed rats, respectively. Furthermore, rats in both isolated groups demonstrated low anxiety levels when compared to group housed groups. Isolation during addiction imparts devastating effects on brain. Thus, socialization of addicts can minimize addiction - induce cognitive deficits and improve neurogenesis.

  5. Insulin and adenosine regulate the phosphatidylcholine concentration in isolated rat adipocyte plasma membranes.

    Science.gov (United States)

    Kiechle, F L; Sykes, E; Artiss, J D

    1995-01-01

    Blockade of adenosine receptors by 3-isobutyl-1-methylxanthine or degradation of endogenous adenosine with adenosine deaminase increased the phosphatidylcholine concentration in isolated rat adipocyte plasma membranes, an effect which was suppressed by the phosphatidylethanolamine methyltransferase inhibitor, S-adenosyl-L-homocysteine, and reversed by the adenosine analogue, N6-(L-phenylisopropyl)-adenosine. For example, the addition of N6-(L-phenylisopropyl)-adenosine to adenosine deaminase pretreated plasma membranes rapidly lowered the concentration of phosphatidylcholine by 171 nmol/mg at 30 seconds compared to control. Insulin-induced stimulation of phospholipid methylation in membranes treated with 3-isobutyl-1-methylxanthine or adenosine deaminase was achieved only after the addition of N6-(L-phenylisopropyl)-adenosine. These results suggest that adenosine receptor occupancy inhibits phospholipid methylation, is required for insulin stimulation of phospholipid methylation, and may perhaps activate a phosphatidylcholine-specific phospholipase C or phospholipase D.

  6. Tannins and catechin gallate mediate the vasorelaxant effect of Arbutus unedo on the rat isolated aorta.

    Science.gov (United States)

    Legssyer, Abdelkhaleq; Ziyyat, Abderrahim; Mekh, Hassane; Bnouham, Mohamed; Herrenknecht, Christine; Roumy, Vincent; Fourneau, Christophe; Laurens, Alain; Hoerter, Jacqueline; Fischmeister, Rodolphe

    2004-11-01

    This study examined the vascular effect of Arbutus leaves (aqueous extract) and described the isolation of several fractions responsible for their vasorelaxant activity. The aqueous extract (AE) of leaves was tested on rat aortic rings precontracted with 0.1 microm noradrenaline. At 10(-2) g/L, AE produced an endothelium dependent relaxation of 66% +/- 5%, (n = 8). The leaves of Arbutus were then extracted successively with different solvents and the methanol extract was the most active. When tannins (primarily condensed tannins) were precipitated from the methanol extract, they showed a strong vasorelaxant activity (87% +/- 4%, n = 5), whereas the elimination of tannins in the methanol extract reduced significantly its vasorelaxant activity (42% +/- 8%, n = 8, p Arbutus is likely to be due to polyphenol compounds, primarily condensed tannins and catechin gallate. Copyright 2004 John Wiley & Sons, Ltd.

  7. Effect of sclerin on amino acid incorporation into mitochondria isolated from rat liver

    International Nuclear Information System (INIS)

    Yamaguchi, Masanori; Satomura, Yukio

    1975-01-01

    Though sclerin (SCL) stimulated amino acid incorporation into the protein fraction of post mitochondrial supernatant of rat liver homogenate, it had no effect on the incorporation into the isolated mitochondria at pH 7.2, despite of its stimulating effect on mitochondrial oxidative phosphorylation. SCL stimulated amino acid incorporation into the mitochondria at pH 6.1, and to some extent maintained the activity on that in mitochondria during aging in hypotonic Tris-HCl buffer (pH 7.2). Since SCL prevented leakage of amino acids from the mitochondria into these buffers, it was suggested that SCL may protect a structure of mitochondrial membrane which appeared to have a significance on transport of amino acids. In liver slices, SCL stimulated amino acid incorporation only into the extra-mitochondrial fraction for the first 3 min, but gradually turned to simulate incorporation into mitochondria within 30 min. (auth.)

  8. Isolation, characterization, and in rats plasma pharmacokinetic study of a new triterpenoid saponin from Dianthus superbus.

    Science.gov (United States)

    Ren, Yina; Xu, Xiaobao; Zhang, Qianlan; Lu, Yongzhuang; Li, Ximin; Zhang, Lin; Tian, Jingkui

    2017-02-01

    One new oleanolic acid triterpenoid saponin, 3-O-β-D-glucopyranosyl olean-11, 13(18)-diene-23,28-dioic acid, (hereafter referred to as DS-1) was isolated from the traditional Chinese medicinal plant Dianthus superbus (D. superbus). DS-1 plays an important role in the bioactivity of D. superbus. Thus, a sensitive, reliable and accurate reversed-phased liquid chromatography with tandem mass spectrometry (LC-MS/MS) in negative ion mode was developed and validated for the quantification and pharmacokinetic study of DS-1 in rats plasma. The pharmacokinetic profile showed that DS-1 was rapidly absorbed and eliminated in plasma, indicating that significant accumulation of the compound in biological specimen is unlikely. In addition, poor absorption into systemic circulation was observed after oral administration of DS-1, resulting in low absolute bioavailability (0.92 %).

  9. Menadione-induced DNA fragmentation without 8-oxo-2'-deoxyguanosine formation in isolated rat hepatocytes

    DEFF Research Database (Denmark)

    Fischer-Nielsen, A; Corcoran, G B; Poulsen, H E

    1995-01-01

    Menadione (2-methyl-1,4-naphthoquinone) induces oxidative stress in cells causing perturbations in the cytoplasm as well as nicking of DNA. The mechanisms by which DNA damage occurs are still unclear, but a widely discussed issue is whether menadione-generated reactive oxygen species (ROS) directly...... damage DNA. In the present study, we measured the effect of menadione on formation of 7,8-dihydro-8-oxo-2'-deoxyguanosine (8-oxodG), an index of oxidative DNA base modifications, and on DNA fragmentation. Isolated hepatocytes from phenobarbital-pretreated rats were exposed to menadione, 25-400 micro......M, for 15, 90 or 180 min with or without prior depletion of reduced glutathione (GSH) by diethyl maleate. Menadione caused profound GSH depletion and internucleosomal DNA fragmentation, which was demonstrated by a prominent fragmentation ladder on agarose gel electrophoresis. We found no oxidative...

  10. Effect of sclerin on amino acid incorporation into mitochondria isolated from rat liver

    Energy Technology Data Exchange (ETDEWEB)

    Yamaguchi, M; Satomura, Y [Osaka City Univ. (Japan). Faculty of Science

    1975-08-01

    Though sclerin (SCL) stimulated amino acid incorporation into the protein fraction of post mitochondrial supernatant of rat liver homogenate, it had no effect on the incorporation into the isolated mitochondria at pH 7.2, despite of its stimulating effect on mitochondrial oxidative phosphorylation. SCL stimulated amino acid incorporation into the mitochondria at pH 6.1, and to some extent maintained the activity on that in mitochondria during aging in hypotonic Tris-HCl buffer (pH 7.2). Since SCL prevented leakage of amino acids from the mitochondria into these buffers, it was suggested that SCL may protect a structure of mitochondrial membrane which appeared to have a significance on transport of amino acids. In liver slices, SCL stimulated amino acid incorporation only into the extra-mitochondrial fraction for the first 3 min, but gradually turned to simulate incorporation into mitochondria within 30 min.

  11. "INHIBITORY EFFECT OF ALUMINIUM ON KCL AND PHENYLEPHRINE INDUCED CONTRACTION IN ISOLATED RAT AORTA"

    Directory of Open Access Journals (Sweden)

    T. Mashhoodi

    2004-10-01

    Full Text Available It has been shown in some investigations that cardiovascular events are the main causes of death in hemodialysis patients. The exact etiology is unknown but some of the articles have reported a relation between aluminium ions in the dialysis solution and cardiovascular disorders. To determine the probable effect of aluminium on vasculature function, in vitro effects of aluminium ion on vasoconstriction induced by KCl (30 mM or phenylephrine (10 µM were investigated using isolated rat aorta. AlCl3 (1-4 mM decreased both KCl and phenylephrine induced contractions in a dose dependent manner (P<0.01. Complete inhibition of the contractions occurred using the higher doses of aluminium. Results of this study suggest that because of inhibitory effects of aluminium on vascular contractions, the probable cardiovascular dysfunction must be considered in aluminium intoxication.

  12. Tissue specific phosphorylation of mitochondrial proteins isolated from rat liver, heart muscle, and skeletal muscle

    DEFF Research Database (Denmark)

    Bak, Steffen; León, Ileana R; Jensen, Ole Nørregaard

    2013-01-01

    -specific phosphorylation sites were identified in tissue-specific enzymes such as those encoded by HMGCS2, BDH1, PCK2, CPS1, and OTC in liver mitochondria, and CKMT2 and CPT1B in heart and skeletal muscle. Kinase prediction showed an important role for PKA and PKC in all tissues but also for proline-directed kinases......Phosphorylation of mitochondrial proteins in a variety of biological processes is increasingly being recognized and may contribute to the differences in function and energy demands observed in mitochondria from different tissues such as liver, heart, and skeletal muscle. Here, we used a combination...... of TiO2 phosphopeptide-enrichment, HILIC fractionation, and LC-MS/MS on isolated mitochondria to investigate the tissue-specific mitochondrial phosphoproteomes of rat liver, heart, and skeletal muscle. In total, we identified 899 phosphorylation sites in 354 different mitochondrial proteins including...

  13. Charge modification of the endothelial surface layer modulates the permeability barrier of isolated rat mesenteric small arteries

    NARCIS (Netherlands)

    van Haaren, Paul M. A.; VanBavel, Ed; Vink, Hans; Spaan, Jos A. E.

    2005-01-01

    We hypothesized that modulation of the effective charge density of the endothelial surface layer ( ESL) results in altered arterial barrier properties to transport of anionic solutes. Rat mesenteric small arteries ( diameter similar to 190 mu m) were isolated, cannulated, perfused, and superfused

  14. KINETIC-ANALYSIS OF SHORT-TERM EFFECTS OF ALPHA-AGONISTS ON GLUCONEOGENESIS IN ISOLATED RAT HEPATOCYTES

    NARCIS (Netherlands)

    Leverve, X. M.; Groen, A. K.; Verhoeven, A. J.; Tager, J. M.

    1985-01-01

    Isolated hepatocytes from fasted rats were perifused with glycerol as gluconeogenic substrate. Stimulation of gluconeogenesis with phenylephrine (10(-5) M) as alpha-adrenergic agonist consisted of two distinct phases. The first phase was a transient stimulation of gluconeogenesis and was accompanied

  15. The impact of short chain fatty acids on GLP-1 and PYY secretion from the isolated perfused rat colon

    DEFF Research Database (Denmark)

    Christiansen, Charlotte Bayer; Gabe, Maria Buur Nordskov; Svendsen, Berit

    2018-01-01

    chain fatty acids (SCFAs) produced by local bacterial fermentation are suggested to activate the colonic free fatty acid receptors FFAR2 (GPR43) and FFAR3 (GPR41), stimulating the colonic L-cells. We used the isolated perfused rat colon as a model of colonic endocrine secretion and studied the effects...

  16. The influence of Poly-Vinyl-Chloride tubing on the isolated perfused rat´s heart.

    NARCIS (Netherlands)

    Meijler, F.L.; Durrer, D.

    1950-01-01

    There are types of poly-vinyl-chloride tubing sold and used for medical and biological purposes which deteriorate heart action in a few minutes. A simple method for testing P.V.C. tubing can be found in the isolated rat's he art perfused according to Langendorff.

  17. Anionic and cationic drug secretion in the isolated perfused rat kidney after neonatal surgical induction of ureteric obstruction.

    NARCIS (Netherlands)

    Gier, R.P.E. de; Feitz, W.F.J.; Masereeuw, R.; Wouterse, A.C.; Smits, D.; Russel, F.G.M.

    2003-01-01

    OBJECTIVE: To study the pathophysiological changes of renal tubular drug transport mechanisms in congenital renal obstruction, by developing a model for perfusing the isolated kidney (IPK) after neonatal surgical induction of partial ureteric obstruction in Hanover Wistar rats. MATERIAL AND METHODS:

  18. Effects of chronic social isolation on Wistar rat behavior and brain plasticity markers.

    Science.gov (United States)

    Djordjevic, Jelena; Djordjevic, Ana; Adzic, Miroslav; Radojcic, Marija B

    2012-01-01

    Chronic stress is a contributing risk factor in the development of psychiatric illnesses, including depressive disorders. The mechanisms of their psychopathology are multifaceted and include, besides others, alterations in the brain plasticity. Previously, we investigated the effects of chronic social stress in the limbic brain structures of Wistar rats (hippocampus, HIPPO, and prefrontal cortex, PFC) and found multiple characteristics that resembled alterations described in some clinical studies of depression. We extended our investigations and followed the behavior of stressed animals by the open field test (OFT) and forced swimming test (FST), and the expression and polysialylation of synaptic plasticity markers, neural cell adhesion molecule (NCAM) and L1, in the HIPPO and PFC. We also determined the adrenal gland mass and plasma corticosterone (CORT) as a terminal part of the hypothalamic-pituitary-adrenal axis activity. Our data indicated that stressed animals avoided the central zone in the OFT and displayed decreased swimming, but prolonged immobility in the FST. The animals exhibited marked hypertrophy of the adrenal gland cortex, in spite of decreased serum CORT. Simultaneously, the stressed animals exhibited an increase in NCAM mRNA expression in the HIPPO, but not in the PFC. The synaptosomal NCAM of the HIPPO was markedly polysialylated, while cortical PSA-NCAM was significantly decreased. The results showed that chronic social isolation of Wistar rats causes both anxiety-like and depression-like behavior. These alterations are parallel with molecular changes in the limbic brain, including diminished NCAM sialylation in the PFC. Together with our previous results, the current observations suggest that a chronic social isolation model may potentially be used to study molecular mechanisms that underlie depressive symptomatology. Copyright © 2012 S. Karger AG, Basel.

  19. Stabilization of mitochondrial membrane potential prevents doxorubicin-induced cardiotoxicity in isolated rat heart

    International Nuclear Information System (INIS)

    Montaigne, David; Marechal, Xavier; Baccouch, Riadh; Modine, Thomas; Preau, Sebastien; Zannis, Konstantinos; Marchetti, Philippe; Lancel, Steve; Neviere, Remi

    2010-01-01

    The present study was undertaken to examine the effects of doxorubicin on left ventricular function and cellular energy state in intact isolated hearts, and, to test whether inhibition of mitochondrial membrane potential dissipation would prevent doxorubicin-induced mitochondrial and myocardial dysfunction. Myocardial contractile performance and mitochondrial respiration were evaluated by left ventricular tension and its first derivatives and cardiac fiber respirometry, respectively. NADH levels, mitochondrial membrane potential and glucose uptake were monitored non-invasively via epicardial imaging of the left ventricular wall of Langendorff-perfused rat hearts. Heart performance was reduced in a time-dependent manner in isolated rat hearts perfused with Krebs-Henseleit solution containing 1 μM doxorubicin. Compared with controls, doxorubicin induced acute myocardial dysfunction (dF/dt max of 105 ± 8 mN/s in control hearts vs. 49 ± 7 mN/s in doxorubicin-treated hearts; *p < 0.05). In cardiac fibers prepared from perfused hearts, doxorubicin induced depression of mitochondrial respiration (respiratory control ratio of 4.0 ± 0.2 in control hearts vs. 2.2 ± 0.2 in doxorubicin-treated hearts; *p < 0.05) and cytochrome c oxidase kinetic activity (24 ± 1 μM cytochrome c/min/mg in control hearts vs. 14 ± 3 μM cytochrome c/min/mg in doxorubicin-treated hearts; *p < 0.05). Acute cardiotoxicity induced by doxorubicin was accompanied by NADH redox state, mitochondrial membrane potential, and glucose uptake reduction. Inhibition of mitochondrial permeability transition pore opening by cyclosporine A largely prevented mitochondrial membrane potential dissipation, cardiac energy state and dysfunction. These results suggest that in intact hearts an impairment of mitochondrial metabolism is involved in the development of doxorubicin cardiotoxicity.

  20. New method of isolation and perfusion of rat pancreas for phosphorus nucletic resonance study

    Energy Technology Data Exchange (ETDEWEB)

    Matsumoto, Takehisa; Kanno, Tomio; Murakami, Masataka; Watari, Hiroshi; Seo, Yoshiteru

    1988-02-01

    Phosphorus nuclear magnetic resonance (/sup 31/P-NMR) was applied to measure phosphorus metabolites in the pancreas. Rat pancreatic gland was isolated and perfused with a modified Krebs-Henseleit solution at room temperature (25 deg C). Removal of the duodenum from the pancreas made it possible to record /sup 31/P-NMR spectra only from the pancreatic tissue. /sup 31/P signals of creatine phosphate (PCr), ATP and inorganic phosphate (Pi) were observed in all the glands. In different individual glands, the Signal intensity of PCr varied, but those of ATP were almost the same. The initial levels of all the phosphorus metabolites in individual glands remained almost unchanged during perfusion with the standard solution for 2 hours. When the perfusion was stopped, signal intensity of ATP and PCr decreased while Pi resonance increased and shifted to a higher magnetic field, indicating tissue acidification. On re-perfusion, each resonance and tissue pH were restored to the respective initial resting levels. Continuous stimulation with 0.3 ..mu..M acetylcholine (ACh) or 0.1 nM CCK-8 caused a markedly larger increase in pancreatic exocrine secretion than that observed in the perfused pancreas which was prepared by the previous method. Continuous stimulation with 0.1 ..mu..M ACh caused a marked and sustained increase in pancreatic exocrine secretion. During the stimulation, the resonances of phosphorus energy metabolites and tissue pH remained almost unchanged. These results indicate that the isolated perfused rat pancreas which is prepared by our new method is a useful preparation for analysis of secretion-metabolism coupling in the exocrine pancreas.

  1. Potentiation by cholinesterase inhibitors of cholinergic activity in rat isolated stomach and colon.

    Science.gov (United States)

    Jarvie, Emma M; Cellek, Selim; Sanger, Gareth J

    2008-01-01

    Acetylcholinesterase (AChE) inhibitors stimulate gastrointestinal (GI) motility and are potential treatments of conditions associated with inadequate GI motility. The ability of itopride to facilitate neuronally (predominantly cholinergic) mediated contractions of rat isolated stomach, evoked by electrical field stimulation (EFS), has been compared with other cholinesterase inhibitors and with tegaserod, a clinically effective prokinetic and non-selective 5-HT(4) receptor agonist which also facilitates GI cholinergic function. Neostigmine greatly increased EFS-evoked contractions over a narrow concentration range (0.01-1 microM; 754+/-337% facilitation at 1 microM); higher concentrations (1, 3 microM) also increased muscle tension. Donepezil increased EFS-evoked contractions gradually over the full range of concentrations (0.01-10 microM; maximum increase 516+/-20% at 10 microM). Itopride increased the contractions even more gradually, rising to 188+/-84% at 10 microM. The butyrylcholinesterase inhibitor iso-OMPA 0.01-10 microM also increased EFS-evoked contractions, to a maximum of 36+/-5.0% at 10 microM, similar to that caused by tegaserod (35+/-5.2% increase at 1 microM). The effects of tegaserod, but not itopride were inhibited by the 5-HT(4) receptor antagonist SB-204070A 0.3 microM. In rat isolated colon, neostigmine was again the most efficacious, causing a defined maximum increase in EFS-evoked contractions (343+/-82% at 10 microM), without changing muscle tension. Maximum increases caused by donepezil and itopride were, respectively, 57.6+/-20 and 43+/-15% at 10 microM. These data indicate that the abilities of different AChE inhibitors to increase GI cholinergic activity differ markedly. Understanding the reasons is essential if AChE inhibitors are to be optimally developed as GI prokinetics.

  2. Toluene metabolism in isolated rat hepatocytes: effects of in vivo pretreatment with acetone and phenobarbital

    Energy Technology Data Exchange (ETDEWEB)

    Smith-Kielland, A.; Ripel, A. (National Inst. of Forensic Toxicology, Oslo (Norway))

    1993-02-01

    Hepatocytes isolated from control, acetone- and phenobarbital-pretreated rats were used to study the metabolic conversion of toluene to benzyl alcohol, benzaldehyde, benzoic acid and hippuric acid at low (<100 [mu]M) and high (100-500 [mu]M) toluene concentrations. The baseline formation rates of toluene metabolites (benzyl alcohol, benzoic acid and hippuric acid) were 2.9[+-]1.7 and 10.0[+-]2.3 nmol/mg cell protein/60 min at low and high toluene concentrations, respectively. In vivo pretreatment of rats with acetone and phenobarbital increased the formation of metabolites: at low toluene concentrations 3- and 5-fold, respectively; at high toluene concentrations no significant increase (acetone) and 8-fold increase (phenobarbital). Apparent inhibition by ethanol, 7 and 60 mM, was most prominent at low toluene concentrations: 63% and 69%, respectively, in control cells; 84% and 91% in acetone-pretreated cells, and 32% (not significant) and 51% in phenobarbital-pretreated cells. Ethanol also caused accumulation of benzyl alcohol. The apparent inhibition by isoniazid was similar to that of ethanol at low toluene concentrations. Control and acetone-pretreated cells were apparently resistant towards metyrapone; the decrease was 49% and 64% in phenobarbital-pretreated cells at low and high toluene concentrations, respectively. In these cells, the decrease in presence of combined ethanol and metyrapone was 95% (low toluene concentrations). 4-Methylpyrazole decreased metabolite formation extensively in all groups. Benzaldehyde was only found in the presence of an aldehyde dehydrogenase inhibitor. Increased ratio benzoic/hippuric acid was observed at high toluene concentrations. These results demonstrate that toluene oxidation may be studied by product formation in isolated hepatocytes. However, the influence of various enzymes in the overall metabolism could not be ascertained due to lack of inhibitor specificity. (orig.).

  3. Ischemia-reperfusion injury in the isolated rat lung. Role of flow and endogenous leukocytes.

    Science.gov (United States)

    Seibert, A F; Haynes, J; Taylor, A

    1993-02-01

    Microvascular lung injury caused by ischemia-reperfusion (IR) may occur via leukocyte-dependent and leukocyte-independent pathways. Leukocyte-endothelial adhesion may be a rate-limiting step in IR lung injury. Leukocyte adhesion to microvascular endothelium occurs when the attractant forces between leukocyte and endothelium are greater than the kinetic energy of the leukocyte and the vascular wall shear rate. We hypothesized (1) that isolated, buffer-perfused rat lungs are not free of endogenous leukocytes, (2) that endogenous leukocytes contribute to IR-induced microvascular injury as measured by the capillary filtration coefficient (Kfc), and (3) that a reduction of perfusate flow rate would potentiate leukocyte-dependent IR injury. Sixty lungs were divided into four groups: (1) low-flow controls, (2) high-flow controls, (3) low-flow IR, and (4) high-flow IR. Microvascular injury was linearly related to baseline perfusate leukocyte concentrations at both low (r = 0.78) and high (r = 0.82) flow rates. Kfc in the high-flow IR group (0.58 +/- 0.03 ml/min/cm H2O/100 g) was less (p Kfc in the low-flow IR group (0.82 +/- 0.07), and in both groups Kfc values were significantly greater than low-flow (0.34 +/- 0.03) and high-flow (0.31 +/- 0.01) control Kfc values after 75 min. Retention of leukocytes in the lung, evaluated by a tissue myeloperoxidase assay, was greatest in the low-flow IR group. We conclude (1) that isolated, buffer-perfused rat lungs contain significant quantities of leukocytes and that these leukocytes contribute to IR lung injury, and (2) that IR-induced microvascular injury is potentiated by low flow.

  4. Antispasmodic effects of yarrow (Achillea millefolium L.) extract in the isolated ileum of rat.

    Science.gov (United States)

    Moradi, Mohammad-Taghi; Rafieian-Koupaei, Mahmoud; Imani-Rastabi, Reza; Nasiri, Jafar; Shahrani, Mehrdad; Rabiei, Zahra; Alibabaei, Zahra

    2013-01-01

    Achillea millefolium L. is cultivated in Iran and widely used in traditional medicine for gastrointestinal disorders. The aim of this study was to determine the effect of hydroalcoholic extract of A. millefolium on the contraction and relaxation of isolated ileum in rat. In this experimental study, aerial parts of A. millefolium were extracted by maceration in ethanol 70% for 72 h. Terminal portion of ileum in 100 male Wistar rats was dissected and its contractions were recorded isotonically in an organ bath containing Tyrode solution (37 °C, pH 7.4) under one gram tension. Acetylcholine (1mM) and KCl (60mM) were used to create isotonic contractions. Propranolol and Nω-Nitro-L-arginine methylester hydrochloride (L-NAME) were used to investigate the mechanisms of action prior to giving the extract to the relevant groups. Data were compared by ANOVA and Turkey's post hoc test.. The results showed that the ileum contraction was induced by KCl and acetylcholine induced contraction was significantly reduced by A. millefolium extract. The cumulative concentrations of A. millefolium relaxed the KCl and acetylcholine induced contractions (n=14, pacetylcholine was not significantly affected neither by propranolol (1µM) nor by L-NAME (100 µM). There was no significant difference in the rate of relaxation by propranolol and L-NAME between the two groups. In conclusion, A. millefolium can inhibit contraction of smooth muscle of ileum in rat, and it can be used for eliminating intestinal spasms. These results suggest that the relaxatory effect of A. millefolium on ileum contractions can be due to the blockade of voltage dependent calcium channels. In addition, the β-adrenoceptors, cholinergic receptors and nitric oxide production are not powerful actors in inhibitory effect of A. millefolium. So, the nitric oxide and adrenergic systems may also be involved in the antispasmodic effect of A. millefolium.

  5. The actions of isoprenaline and mirabegron in the isolated whole rat and guinea pig bladder.

    Science.gov (United States)

    Persyn, Sara; De Wachter, Stefan; Wyndaele, Jean-Jacques; Eastham, Jane; Gillespie, James

    2016-07-01

    β3-adrenoceptor agonists influence overactive bladder in humans and animal models. However, data is emerging that the mode of action of these drugs is complex. The present study explored the actions of the β3-adrenergic agonist mirabegron and the non-selective agonist isoprenaline on the contractile systems in the rat and guinea pig bladder. Intravesical pressure was measured in isolated whole bladders from female adult animals. In both species spontaneous contractile activity was observed. The muscarinic agonist arecaidine produced complex responses consisting of an initial transient pressure rise followed by complex phasic activity. Three contractile elements were identified: intrinsic micro-contractile activity, initial transient response and steady state phasic activity. The intrinsic and steady state activity could be further divided into a baseline pressure with superimposed phasic activity. The effects of isoprenaline and mirabegron were investigated on these elements. In the rat, the micro-contractile activity could be completely inhibited by isoprenaline (full agonist). The arecaidine-induced initial and steady state baseline pressures were partially reduced, while the phasic activity was little affected. In the guinea pig, both the arecaidine-induced baseline pressure and the phasic activity were affected by isoprenaline. Mirabegron didn't produce significant inhibitory effects in any of the contractile elements in either species. These results show that complex contractile systems operate in the rat and guinea pig bladder that can be modulated by β1/β2-adrenoceptor mechanisms. No evidence was obtained for any β3-dependent regulation of contraction. These data support similar data in humans. Therefore the primary site of therapeutic action of β3-adrenergic agonists remains unknown. Copyright © 2016 Elsevier B.V. All rights reserved.

  6. Isolation of three novel rat and mouse papillomaviruses and their genomic characterization.

    Directory of Open Access Journals (Sweden)

    Eric Schulz

    Full Text Available Despite a growing knowledge about the biological diversity of papillomaviruses (PV, only little is known about non-human PV in general and about PV mice models in particular. We cloned and sequenced the complete genomes of two novel PV types from the Norway rat (Rattus norvegicus; RnPV2 and the wood mouse (Apodemus sylvaticus; AsPV1 as well as a novel variant of the recently described MmuPV1 (originally designated as MusPV from a house mouse (Mus musculus; MmuPV1 variant. In addition, we conducted phylogenetic analyses using a systematically representative set of 79 PV types, including the novel sequences. As inferred from concatenated amino acid sequences of six proteins, MmuPV1 variant and AsPV1 nested within the Beta+Xi-PV super taxon as members of the Pi-PV. RnPV2 is a member of the Iota-PV that has a distant phylogenetic position from Pi-PV. The phylogenetic results support a complex scenario of PV diversification driven by different evolutionary forces including co-divergence with hosts and adaptive radiations to new environments. PV types particularly isolated from mice and rats are the basis for new animal models, which are valuable to study PV induced tumors and new treatment options.

  7. Cardiac actions of phencyclidine in isolated guinea pig and rat heart: possible involvement of slow channels

    International Nuclear Information System (INIS)

    Temma, K.; Akera, T.; Ng, Y.C.

    1985-01-01

    The mechanisms responsible for the positive inotropic effect of phencyclidine were studied in isolated preparations of guinea pig and rat heart. In electrically paced left atrial muscle preparations, phencyclidine increased the force of contraction; rat heart muscle preparations were more sensitive than guinea pig heart muscle preparations. The positive inotropic effect of phencyclidine was not significantly reduced by a combination of phentolamine and nadolol; however, the effect was competitively blocked by verapamil in the presence of phentolamine and nadolol. Inhibition of the outward K+ current by tetraethylammonium chloride also produced a positive inotropic effect; however, the effect of tetraethylammonium was reduced by phentolamine and nadolol, and was almost insensitive to verapamil. The inotropic effect of phencyclidine was associated with a marked prolongation of the action potential duration and a decrease in maximal upstroke velocity of the action potential, with no change in the resting membrane potential. The specific [ 3 H]phencyclidine binding observed with membrane preparations from guinea pig ventricular muscle was saturable with a single class of high-affinity binding site. This binding was inhibited by verapamil, diltiazem, or nitrendipine, but not by ryanodine or tetrodotoxin. These results suggest that the positive inotropic effect of phencyclidine results from enhanced Ca 2+ influx via slow channels, either by stimulation of the channels or secondary to inhibition of outward K + currents

  8. The conduction block produced by oxcarbazepine in the isolated rat sciatic nerve: a comparison with lamotrigine.

    Science.gov (United States)

    Guven, Mustafa; Kahraman, Ibrahim; Koc, Filiz; Bozdemir, Hacer; Sarica, Yakup; Gunay, Ismail

    2011-01-01

    Oxcarbazepine is an antiepileptic drug widely used for the treatment of neuropathic pain. In the present study, the effects of oxcarbazepine and lamotrigine on conduction properties in the rat sciatic nerves were examined. The experiments were conducted with in vitro sucrose-gap technique on the isolated wistar rat sciatic nerves. The compound action potentials were obtained by tonic (single) and phasic (10, 40, and 100 Hz) stimulation. Oxcarbazepine produced a significant concentration- and frequency-dependent reduction in the compound action potential amplitude. When the two drugs were applied at concentrations that produced equal levels of tonic (i.e., non-frequency-dependent) conduction block, oxcarbazepine produced the greatest phasic (i.e., frequency-dependent) conduction block, followed by lamotrigine. Oxcarbazepine and lamotrigine reduced the 4-aminopyridine-induced amplitude of delayed depolarization; however, oxcarbazepine had a significantly greater effect than lamotrigine. These results suggest that oxcarbazepine produces more potent frequency-dependent conduction block than lamotrigine, and suppresses the delayed depolarization which contributes to sensory signaling and may play a role in neuropathic pain. The findings provide insight into the mechanisms of action of oxcarbazepine and lamotrigine and may help in the development of novel therapies for neuropathic pain.

  9. Isolated rat dental pulp cell culture and transplantation with an alginate scaffold.

    Science.gov (United States)

    Fujiwara, Shiro; Kumabe, Shunji; Iwai, Yasutomo

    2006-05-01

    Many studies have been conducted on tissue stem cells in the field of regenerative medicine, and cultured dental pulp mesenchymal cells have been reported to secrete dentin matrix. In the present study we used alginate as a scaffold to transplant subcultured rat dental-pulp-derived cells subcutaneously into the back of nude mice. We found that when beta-glycerophosphate was added to the culture medium, the mRNA of the dentin sialophosphoprotein (DSPP) gene coding dentin sialoprotein (DSP) and dentin phosphoprotein (DPP) was expressed, and an increase in alkaline phosphatase, an early marker of odontoblast differentiation, was also demonstrated. Six weeks after implantation, subcutaneous formation of radiopaque calcified bodies was observed in situ. Immunohistochemical and fine structure studies identified expression of type I collagen, type III collagen, and DSP in the mineralizing transplants, and isolated odontoblast-like cells began to form dentin-like hard tissue formation. Scattered autolyzing apoptotic cells were also observed in the transplants. The study showed that subcultured rat dental-pulp-derived cells actively differentiate into odontoblast-like cells and induce calcification in an alginate scaffold.

  10. Relaxant effects of a hydroalcoholic extract of Ruta graveolens on isolated rat tracheal rings

    Directory of Open Access Journals (Sweden)

    Luis Águila

    2015-01-01

    Full Text Available BACKGROUND: Ruta graveolens L. (R. graveolens is a medicinal plant employed in non-traditional medicines that has various therapeutic properties, including anthelmintic, and vasodilatory actions, among others. We evaluated the trachea-relaxant effects of hydroalcoholic extract of R. graveolens against potassium chloride (KCl- and carbachol-induced contraction of rat tracheal rings in an isolated organ bath. RESULTS: The results showed that the airway smooth muscle contraction induced by the depolarizing agent (KCl and cholinergic agonist (carbachol was markedly reduced by R. graveolens in a concentration-dependent manner, with maximum values of 109 ± 7.9 % and 118 ± 2.6 %, respectively (changes in tension expressed as positive percentages of change in proportion to maximum contraction, at the concentration of 45 μg/mL (half-maximal inhibitory concentration IC50: 35.5 μg/mL and 27.8 μg/mL for KCl- and carbachol-induced contraction, respectively. Additionally, the presence of R. graveolens produced rightward parallel displacement of carbachol dose-response curves and reduced over 35 % of the maximum smooth muscle contraction. CONCLUSIONS: The hydroalcoholic extract of R. graveolens exhibited relaxant activity on rat tracheal rings. The results suggest that the trachea-relaxant effect is mediated by a non-competitive antagonistic mechanism. More detailed studies are needed to identify the target of the inhibition, and to determine more precisely the pharmacological mechanisms involved in the observed biological effects.

  11. Parasympathetic denervation increases responses to VIP in isolated rat parotid acini

    International Nuclear Information System (INIS)

    McMillian, M.K.; Talamo, B.R.

    1989-01-01

    Vasoactive intestinal peptide (VIP) is a putative neurotransmitter found in the salivary glands of many species, including the rat parotid gland. Parasympathetic denervation has been reported to deplete VIP in the rat parotid gland and to lead to supersensitivity to this peptide in vivo. We have compared the effects of VIP on acini isolated from parasympathetically denervated and unoperated parotid glands to examine possible supersensitivity to the peptide in vitro. VIP normally produced responses similar to those obtained with a low concentration of the beta adrenergic agonist isoproterenol (ISO), but strikingly different from the effects obtained with the muscarinic agonist carbachol (CARB). In parotid membrane preparations, VIP stimulated adenylate cyclase activity. Dissociated acini treated with VIP showed increases in cAMP accumulation and amylase release which were potentiated by forskolin and also by inhibition of phosphodiesterase. After parasympathetic denervation, maximal effects of VIP on adenylate cyclase, cAMP accumulation and amylase release in intact cells were increased two- to five-fold over contralateral control (or unoperated) parotid responses. The increase in adenylate cyclase-mediated responses after denervation was specific to VIP; there was no increased response nor increased sensitivity of any of these responses to ISO. Specific [125I]VIP binding to parotid acini increased two-fold per gland and three-fold per mg of protein after denervation; this probably explains the observed increases in the response to VIP

  12. Photo-oxidative damage to isolated rat liver mitochondria induced by phenothiazines

    Directory of Open Access Journals (Sweden)

    T. RODRIGUES

    2009-01-01

    Full Text Available

    Photosensitization is a well-known side-effect of phenothiazines that could involve photochemically promoted oxidative damage to mitochondria, leading to the impairment of metabolic functions and apoptosis. In this work, for the first time, we investigated the effects of photoexcited thioridazine (TR, trifluoperazine (TFP and fluphenazine (FP on isolated rat liver mitochondria. Under UV irradiation, the presence of these phenothiazines led to a dose-dependent lack of the respiratory control ratio. These effects were not accompanied by significant swelling and oxidation of protein thiol groups but were accompanied by lipid peroxidation. Lycopene and sorbate, well-known quenchers of singlet oxygen and triplet species, respectively, were ineffective at protecting mitochondrial lipids against the damage promoted by the excited phenothiazines, suggesting that photochemically-produced cation radicals were the prooxidant species. Corroborating this proposal, butylated hydroxytoluene (BHT completely inhibited the lipid peroxidation induced by UV irradiation in the presence of phenothiazines. These novel results make a significant contribution to the understanding of the photochemical properties of phenothiazines in biological systems. Keywords: Trifluoperazine, thioridazine, fluphenazine, rat liver mitochondria, oxidative stress, photochemistry, photodamage, respiratory chain.

  13. Sodium-independent, bicuculline-sensitive [3H]GABA binding to isolated rat hepatocytes

    International Nuclear Information System (INIS)

    Minuk, G.Y.; Bear, C.E.; Sarjeant, E.J.

    1987-01-01

    To determine whether hepatocytes possess specific receptor sites for gamma-aminobutyric acid (GABA), a potent amino acid neurotransmitter, [ 3 H]GABA, was added to sodium-free suspensions of Percoll-purified hepatocytes derived from collagenase-perfused rat livers under various experimental conditions and in the presence or absence of specific GABA receptor agonists (muscimol) and antagonists (bicuculline). The effects of GABA, muscimol, and bicuculline on hepatocyte resting membrane potentials were also determined. Specific binding of [ 3 H]GABA to hepatocytes was a consistent finding. GABA-hepatocyte interactions were reversible and temperature dependent. Muscimol and bicuculline inhibited binding in a dose-dependent manner (IC50, 30 nM and 50 microM, respectively), whereas strychnine (1.0-100 microM), a nonspecific central nervous system stimulant, had no appreciable effect. Both GABA and muscimol (100 microM) caused significant hyperpolarization of hepatocyte resting membrane potential (delta PD 5.4 +/- 3.1 and 22.2 +/- 16.2 mV, respectively, means +/- SD, P less than 0.0005). Bicuculline (100 microM) inhibited the effect of muscimol (P less than 0.05). The results of this study suggest that specific GABA receptor sites exist on the surface of isolated rat hepatocytes. The presence of such sites raises the possibility that, in addition to adrenergic and cholinergic innervation, hepatic function may be influenced by GABA-ergic neurotransmitter mechanisms

  14. Transepithelial transport of PAMAM dendrimers across isolated rat jejunal mucosae in ussing chambers.

    Science.gov (United States)

    Hubbard, Dallin; Ghandehari, Hamidreza; Brayden, David J

    2014-08-11

    Oral delivery remains a challenge for poorly permeable hydrophilic macromolecules. Poly(amido amine) (PAMAM) dendrimers have shown potential for their possible oral delivery. Transepithelial transport of carboxyl-terminated G3.5 and amine-terminated G4 PAMAM dendrimers was assessed using isolated rat jejunal mucosae mounted in Ussing chambers. The 1 mM FITC-labeled dendrimers were added to the apical side of mucosae. Apparent permeability coefficients (Papp) from the apical to the basolateral side were significantly increased for FITC when conjugated to G3.5 PAMAM dendrimer compared to FITC alone. Minimal signs of toxicity were observed when mucosae were exposed to both dendrimers with respect to transepithelial electrical resistance changes, carbachol-induced short circuit current stimulation, and histological changes. [(14)C]-mannitol fluxes were not altered in the presence of 1 mM dendrimers, suggesting that the paracellular pathway was not affected at this concentration in this model. These results give insight into the mechanism of PAMAM dendrimer transepithelial rat jejunal transport, as well as toxicological considerations important for oral drug delivery.

  15. Isolation and characterization of populations of mature and immature rat colonocytes

    International Nuclear Information System (INIS)

    Ahnen, D.J.; Reed, T.A.; Bozdech, J.M.

    1988-01-01

    A nonenzymatic method is described for the isolation of viable populations of mature and immature rat colonocytes. Histology was used to monitor colonocyte dissociation and to systematically characterize the amount of cross-contamination between populations of mature luminal cells and immature crypt cells. The mature coloncytes were 87 ± 9% pure with respect to contamination from cells from the lower half of the colonic crypt, and the immature populations were 98% pure with respect to contamination with cells from the upper half of the colonic crypt. Neither population contained significant numbers of cells from the lamina propria. Cell viability and synthetic function were maintained from 10-12 h in short-term culture. Alkaline phosphatase activity was 1.59 ± 0.01-fold higher in the mature cells than in the immature cells, and in vivo [ 3 H]thymidine incorporation was 2.9 ± 0.4-fold greater in the immature than the mature populations. These studies demonstrate that highly enriched populations of mature and immature rat colonocytes that maintain viability and synthetic function in short-term culture can be prepared. The intrinsic rate of protein synthesis is higher in immature colonocytes, and a shift to synthesis of a higher percentage of fucoproteins occurs during colonocyte differentiation. In contrast to result in the small intestine, only modest gradients of differentiation markers and cell surface protein expression were observed between mature and immature colonocytes

  16. Effects Of The Direct Renin Inhibitor Aliskiren On Oxidative Stress In Isolated Rat Heart

    Directory of Open Access Journals (Sweden)

    Plecevic Sasa

    2015-09-01

    Full Text Available Increased activity of the renin-angiotensin-aldosterone system (RAAS plays a significant role in the development and progression of various cardio-metabolic diseases, such as hypertension, atherosclerosis and heart failure. Aliskiren is the newest antihypertensive drug and the first orally active direct renin inhibitor to become available for clinical use. This study investigated the acute and direct effects of Aliskiren on different parameters of oxidative stress on isolated rat heart. The hearts of male Wistar albino rats (n = 24, 8 per experimental group, age 8 weeks, body mass 180–200 g, were excised and retrogradely perfused according to the Langendorfftechnique at a gradually increasing perfusion pressure (40-120 cmH2O. Markers of oxidative stress (NO2−, TBARS, H2O2 and O2− were measured spectrophotometrically after perfusion with three different concentrations of Aliskiren (0.1 μM, 1 μM, and 10 μM. The results demonstrated possible dose-dependent cardioprotective properties of Aliskiren, particularly with higher CPP. Lipid peroxidation (TBARS levels decreased with the highest dose of Aliskiren and higher CPP, and the same trend was observed in nitrite (NO2− and hydrogen peroxide (H2O2 levels. These findings indicate that the acute effects of Aliskiren do not likely promote the production of reactive oxygen species upon higher pressure with the highest dose. Aliskiren may exert beneficial effects on oxidative stress biomarkers.

  17. Diabetes and thyroid hormones affect connexin-43 and PKC-ε expression in rat heart atria

    Czech Academy of Sciences Publication Activity Database

    Mitašíková, M.; Lin, H.; Soukup, Tomáš; Imanaga, I.; Tribulová, N.

    2009-01-01

    Roč. 58, č. 2 (2009), s. 211-217 ISSN 0862-8408 R&D Projects: GA MŠk(CZ) LC554; GA ČR(CZ) GA304/05/0327; GA ČR(CZ) GA304/08/0256 Grant - others:EC(XE) LSH-CT-2004-511978; VEGA(SK) 2/6064/27; APVV(SK) 51-059505 Institutional research plan: CEZ:AV0Z50110509 Keywords : diabetes * triiodothyronine * atrial fibrillation Subject RIV: ED - Physiology Impact factor: 1.430, year: 2009

  18. Failure of isolated rat tibial periosteal cells to 5 alpha reduce testosterone to 5 alpha-dihydrotestosterone

    International Nuclear Information System (INIS)

    Turner, R.T.; Bleiberg, B.; Colvard, D.S.; Keeting, P.E.; Evans, G.; Spelsberg, T.C.

    1990-01-01

    Periosteal cells were isolated from tibiae of adult male rats after collagenase treatment. Northern blot analysis of total cytoplasmic RNA extracted from the isolated periosteal cells was positive for expression of genes encoding the osteoblast marker proteins osteocalcin (BGP) and pre-pro-alpha 2(I) chain of type 1 precollagen. The isolated periosteal cells were incubated with 1 nM [3H]testosterone [( 3 H]T) for up to 240 minutes and the reaction products separated by high-performance liquid chromatography. [ 3 H]5 alpha-dihydrotestosterone [( 3 H]DHT) was not detected in extracts of periosteal cell incubations. In contrast, [ 3 H]DHT was produced in a time-dependent manner by cells from seminal vesicles. These results suggest that testosterone 5 alpha-reductase activity is not expressed by osteoblasts in rat tibial periosteum and that the anabolic effects of androgens in this tissue are not mediated by locally produced DHT

  19. Study of the antioxidant effects of Eremostachys laciniata rhizome extracts in isolated rat hepatocytes

    Directory of Open Access Journals (Sweden)

    Haleh Vaez

    2015-09-01

    Full Text Available Eremostachys laciniata, having rich flavonoid content, is expected to have a considerable antioxidant effect. In this study We used ACMS (Accelerated cytotoxic or protective mechanism screening technique to evaluate the possible antioxidant effect of E. laciniata rhizome against oxidative cell damages induced by different types of oxidative stress such as iron-8-hydroxyquinolin (IQ complex and copper in freshly isolated liver cells. The extracts were prepared with n-hexane, dichloromethane and methanol. Hepatocytes were isolated from male Sprague-Dawley rats by a two-step collagenase perfusion. Cell viability was measured by trypan blue exclusion method. DPPH (2, 2-diphenyl-1-picrylhydrazyl assay was used to evaluate the antioxidant activity. ROS formation was measured by using DCFDA (2, 7-dichlorofluorescin diacetate probe, mitochondrial membrane potential (MMP was assessed by rhodamine 123 fluorescence and lipid peroxidation was determined by thiobarbituric acid reactive substances (TBARS assay. The MET extract was demonstrated to possess a significant radical scavenging activity (RC50%=0.212. Unlike MET extract, the n-hexane and dichloromethane extracts showed toxic effects in cell suspensions. The MET extract significantly decreased cell death and ROS formation induced by IQ complex and copper and demonstrated protective effects against copper-induced mitochondrial membrane potential collapse and lipid peroxidation. The protection induced by MET extract can be attributed to antioxidant characteristics of the phenylethanoids content.

  20. Regional Morphology and Transport of PAMAM Dendrimers Across Isolated Rat Intestinal Tissue.

    Science.gov (United States)

    Hubbard, Dallin; Bond, Tanner; Ghandehari, Hamidreza

    2015-12-01

    Intestinal permeability of PAMAM dendrimers has been observed, giving rationale for their use in oral drug delivery as potential carriers of associated molecules. This study assessed the apparent permeability coefficients (Papp) of dendrimers across isolated rat intestinal regional mucosae, along with estimation of the maximum non-toxic concentration. Caco-2 monolayers were also used to assess the comparative Papp values between isolated mucosae and cell culture models. Concentrations from 0.1 to 10 mM of anionic and cationic dendrimers were tested in mucosae to assess their Papp, membrane TEER, [(14)C]-mannitol Papp, and histology. 0.1 mM concentrations of dendrimers were assessed over 120 min in Caco-2 cell monolayers as concentrations above that were cytotoxic. Jejunal transport of dendrimers was higher than transport in colonic epithelium. Monolayer Papp values of dendrimers were comparable to those of jejunal mucosae. Mucosae exposed to dendrimer concentrations of 10 mM for 120 min caused significant reduction in TEER and changes in tissue morphology; however, G3.5 was the only analogue that caused significant TEER reduction and morphological changes at 1 mM concentrations. Transport in jejunal mucosae appears to be the greatest indicating that the small intestinal will be the most likely region to target for oral drug delivery using PAMAM dendrimers. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  1. Oxaliplatin-induced Oxidative Stress Provokes Toxicity in Isolated Rat Liver Mitochondria.

    Science.gov (United States)

    Tabassum, Heena; Waseem, Mohammad; Parvez, Suhel; Qureshi, M Irfan

    2015-11-01

    Oxaliplatin is a widely employed platinum-derived chemotherapeutic agent commonly used for the treatment of colorectal cancer. Unfortunately, the benefit of this important drug is compromised by severe side effects such as neuropathy, ototoxicity, gastrointestinal toxicity, and hematological toxicity. Recently, few studies have also suggested the occurrence of hepatotoxicity in oxaliplatin-treated patients. Mitochondria have emerged as targets for anticancer drugs in various kinds of toxicity including hepatotoxicity that can lead to neoplastic disease. Oxidative stress is a well-established biomarker of mitochondrial toxicity. The purpose of this study was to investigate the dose-dependent damage caused by oxaliplatin on isolated liver mitochondria under in vitro conditions. The study was conducted in mitochondria isolated from liver of Wistar rats. Oxaliplatin was incubated with mitochondria in a dose-dependent manner under in vitro conditions. Oxidative stress indexes, non-enzymatic and enzymatic antioxidants were evaluated, looking at the overall armamentarium against the toxicity induced by oxaliplatin. Oxaliplatin caused a significant rise in the mitochondrial oxidative stress indexes lipid peroxidation and protein carbonyl. Alterations in the levels of non-enzymatic antioxidants and activities of enzymatic antioxidants were also observed. Oxidative stress plays an important role in the mitochondrial toxicity of oxaliplatin. The integrity of the hepatic tissue is compromised by the reactive oxygen species-mediated lipid peroxidation and protein carbonyl formation. Copyright © 2015 IMSS. Published by Elsevier Inc. All rights reserved.

  2. Static inflation attenuates ischemia/reperfusion injury in an isolated rat lung in situ.

    Science.gov (United States)

    Kao, Shang Jyh; Wang, David; Yeh, Diana Yu-Wung; Hsu, Kang; Hsu, Yung Hsiang; Chen, Hsing I

    2004-08-01

    Ischemia (I)/reperfusion (R) lung injury is an important clinical issue in lung transplantation. In the present study, we observed the effects of lung static inflation, different perfusates, and ventilatory gas with nitrogen or oxygen on the I/R-induced pulmonary damage. A total of 96 male Sprague-Dawley rats were used. The lung was isolated in situ. In an isolated lung, the capillary filtration coefficient (Kfc), lung weight gain (LWG), lung weight (LW)/body weight (BW) ratio, and protein concentration in BAL fluid (PCBAL) were measured or calculated to evaluate the degree of lung injury. Histologic examinations with hematoxylin-eosin staining were performed. I/R caused lung injury, as reflected by increases in Kfc, LWG, LW/BW, and PCBAL. The histopathologic picture revealed the presence of hyaline membrane formation and the infiltration of inflammatory cells. These values were significantly attenuated by static lung inflation. The I/R lung damage appeared to be less in the lung perfused with whole blood than in the lung perfused with an isotonic solution. Therapy with ventilatory air (ie, nitrogen or oxygen) did not alter the I/R lung damage. The data suggest that lung inflation is protective to I/R injury, irrespective of the type of ventilatory air used for treatment. The preservation of the lung for transplantation is better kept at a static inflation state and perfused with whole blood instead of an isotonic physiologic solution.

  3. Reproducible insulin secretion from isolated rat pancreas preparations using an organ bath.

    Science.gov (United States)

    Morita, Asuka; Ouchi, Motoshi; Terada, Misao; Kon, Hiroe; Kishimoto, Satoko; Satoh, Keitaro; Otani, Naoyuki; Hayashi, Keitaro; Fujita, Tomoe; Inoue, Ken-Ichi; Anzai, Naohiko

    2018-02-09

    Diabetes mellitus is a lifestyle-related disease that is characterized by inappropriate or diminished insulin secretion. Ex vivo pharmacological studies of hypoglycemic agents are often conducted using perfused pancreatic preparations. Pancreas preparations for organ bath experiments do not require cannulation and are therefore less complex than isolated perfused pancreas preparations. However, previous research has generated almost no data on insulin secretion from pancreas preparations using organ bath preparations. The purpose of this study was to investigate the applicability of isolated rat pancreas preparations using the organ bath technique in the quantitative analysis of insulin secretion from β-cells. We found that insulin secretion significantly declined during incubation in the organ bath, whereas it was maintained in the presence of 1 µM GLP-1. Conversely, amylase secretion exhibited a modest increase during incubation and was not altered in the presence of GLP-1. These results demonstrate that the pancreatic organ bath preparation is a sensitive and reproducible method for the ex vivo assessment of the pharmacological properties of hypoglycemic agents.

  4. Active Oxygen Metabolites and Thromboxane in Phorbol Myristate Acetate Toxicity to the Isolated, Perfused Rat Lung.

    Science.gov (United States)

    Carpenter, Laurie Jean

    When administered intravenously or intratracheally to rats, rabbits and sheep, phorbol myristate acetate (PMA) produces changes in lung morphology and function are similar to those seen in humans with the adult respiratory distress syndrome (ARDS). Therefore, it is thought that information about the mechanism of ARDS development can be gained from experiments using PMA-treated animals. Currently, the mechanisms by which PMA causes pneumotoxicity are unknown. Results from other studies in rabbits and in isolated, perfused rabbit lungs suggest that PMA-induced lung injury is mediated by active oxygen species from neutrophils (PMN), whereas studies in sheep and rats suggest that PMN are not required for the toxic response. The role of PMN, active oxygen metabolites and thromboxane (TxA_2) in PMA-induced injury to isolated, perfused rat lungs (IPLs) was examined in this thesis. To determine whether PMN were required for PMA to produce toxicity to the IPL, lungs were perfused for 30 min with buffer containing various concentrations of PMA (in the presence or absence of PMN). When concentrations >=q57 ng/ml were added to medium devoid of added PMN, perfusion pressure and lung weight increased. When a concentration of PMA (14-28 ng/ml) that did not by itself cause lungs to accumulate fluid was added to the perfusion medium containing PMN (1 x 10 ^8), perfusion pressure increased, and lungs accumulated fluid. These results indicate that high concentrations of PMA produce lung injury which is independent of PMN, whereas injury induced by lower concentrations is PMN-dependent. To examine whether active oxygen species were involved in mediating lung injury induced by PMA and PMN, lungs were coperfused with the oxygen radical scavengers SOD and/or catalase. Coperfusion with either or both of these enzymes totally protected lungs against injury caused by PMN and PMA. These results suggest that active oxygen species (the hydroxyl radical in particular), mediate lung injury in

  5. Atrial arrhythmia in ageing spontaneously hypertensive rats: unraveling the substrate in hypertension and ageing.

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    Dennis H Lau

    Full Text Available BACKGROUND: Both ageing and hypertension are known risk factors for atrial fibrillation (AF although the pathophysiological contribution or interaction of the individual factors remains poorly understood. Here we aim to delineate the arrhythmogenic atrial substrate in mature spontaneously hypertensive rats (SHR. METHODS: SHR were studied at 12 and 15 months of age (n = 8 per group together with equal numbers of age-matched normotensive Wistar-Kyoto control rats (WKY. Electrophysiologic study was performed on superfused isolated right and left atrial preparations using a custom built high-density multiple-electrode array to determine effective refractory periods (ERP, atrial conduction and atrial arrhythmia inducibility. Tissue specimens were harvested for structural analysis. RESULTS: COMPARED TO WKY CONTROLS, THE SHR DEMONSTRATED: Higher systolic blood pressure (p<0.0001, bi-atrial enlargement (p<0.05, bi-ventricular hypertrophy (p<0.05, lower atrial ERP (p = 0.008, increased atrial conduction heterogeneity (p = 0.001 and increased atrial interstitial fibrosis (p = 0.006 & CD68-positive macrophages infiltration (p<0.0001. These changes resulted in higher atrial arrhythmia inducibility (p = 0.01 and longer induced AF episodes (p = 0.02 in 15-month old SHR. Ageing contributed to incremental bi-atrial hypertrophy (p<0.01 and atrial conduction heterogeneity (p<0.01 without affecting atrial ERP, fibrosis and arrhythmia inducibility. The limited effect of ageing on the atrial substrate may be secondary to the reduction in CD68-positive macrophages. CONCLUSIONS: Significant atrial electrical and structural remodeling is evident in the ageing spontaneously hypertensive rat atria. Concomitant hypertension appears to play a greater pathophysiological role than ageing despite their compounding effect on the atrial substrate. Inflammation is pathophysiologically linked to the pro-fibrotic changes in the hypertensive atria.

  6. A Simple and Reproducible Method to Prepare Membrane Samples from Freshly Isolated Rat Brain Microvessels.

    Science.gov (United States)

    Brzica, Hrvoje; Abdullahi, Wazir; Reilly, Bianca G; Ronaldson, Patrick T

    2018-05-07

    The blood-brain barrier (BBB) is a dynamic barrier tissue that responds to various pathophysiological and pharmacological stimuli. Such changes resulting from these stimuli can greatly modulate drug delivery to the brain and, by extension, cause considerable challenges in the treatment of central nervous system (CNS) diseases. Many BBB changes that affect pharmacotherapy, involve proteins that are localized and expressed at the level of endothelial cells. Indeed, such knowledge on BBB physiology in health and disease has sparked considerable interest in the study of these membrane proteins. From a basic science research standpoint, this implies a requirement for a simple but robust and reproducible method for isolation of microvessels from brain tissue harvested from experimental animals. In order to prepare membrane samples from freshly isolated microvessels, it is essential that sample preparations be enriched in endothelial cells but limited in the presence of other cell types of the neurovascular unit (i.e., astrocytes, microglia, neurons, pericytes). An added benefit is the ability to prepare samples from individual animals in order to capture the true variability of protein expression in an experimental population. In this manuscript, details regarding a method that is utilized for isolation of rat brain microvessels and preparation of membrane samples are provided. Microvessel enrichment, from samples derived, is achieved by using four centrifugation steps where dextran is included in the sample buffer. This protocol can easily be adapted by other laboratories for their own specific applications. Samples generated from this protocol have been shown to yield robust experimental data from protein analysis experiments that can greatly aid the understanding of BBB responses to physiological, pathophysiological, and pharmacological stimuli.

  7. SPASMOLYTIC ACTIVITY OF THE AQUEOUS AND ETHANOL CELERY LEAVES (APIUM GRAVEOLENS L. EXTRACTS ON THE CONTRACTION OF ISOLATED RAT ILEUM

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    Suzana Branković

    2015-06-01

    Full Text Available Celery (Apium graveolens L. is a plant species in the family Apiaceae, which has been used in traditional medicine for the treatment of gastrointestinal diseases. This study investigated the effects of aqueous and ethanol extracts from celery leaves on intestinal contractility. Air-dried and powdered leaves were extracted with distilled water and 96% ethanol, respectively. The activities of the extracts on the smooth muscle contractions were evaluated using isolated rat ileum model. The isolated rat ileum was mounted in a 10ml tissue bath. The results suggest that the cumulative concentrations of the extracts of celery statistically significantly inhibited spontaneous rat ileum contractions (p<0.01. The extracts dose-dependently reduced the contractile effects of acetylcholine on the isolated ileum (p<0.05. Ethanol extract exhibited significantly greater relaxant activity than the aqueous extract (p<0.05. These results suggest that the aqueous and ethanol extracts of celery leaves can produce the inhibition of the spontaneous rat ileum contractions and contractions induced by acetylcholine. These data indicate that celery extracts act as intestinal smooth muscle relaxants, which justifies their use in gastrointestinal disorders.

  8. Effects of toluene on protein synthesis and the interaction with ethanol in hepatocytes isolated from fed and fasted rats

    International Nuclear Information System (INIS)

    Smith-Kielland, A.; Ripel, Aa.; Gadeholt, G.

    1989-01-01

    The effects of three different concentrations (about 20, 100 and 1000 μM) of toluene on protein synthesis were studied in hepatocytes isolated from fed and fasted rats after 60 and 120 min. of incubation. The interaction between ethanol (60 mM) and the low and high toluene concentrations were also tested. To measure protein synthesis, 14 C-valine was used as the precursor amino acid. Total valine concentration was 2 mM to ensure near-constant specific radioactivity of precursor. Toluene concentrations were measured by head-space gas chromatography. Protein synthesis was unchanged in the presence of low toluene concentrations. Intermediate toluene concentration decreased protein synthesis by about 20% and high toluene concentration decreased protein synthesis by about 60%. Protein synthesis was similar in cells from fed and fasted rats. Ethanol alone inhibited protein synthesis by 20-30%, more in fasted than in fed rats. Toluene and ethanol in combination inhibited protein synthesis additively. The high toluene concentration with or without ethanol appeared to inhibit synthesis/secretion of export proteins in hepatocytes from fasted rats. In conclusion, our study indicates that toluene in relatively high concentrations inhibits general protein synthesis in isolated rat hepatocytes. Toluene and ethanol seems to inhibit protein synthesis additively. (author)

  9. Effects of toluene on protein synthesis and the interaction with ethanol in hepatocytes isolated from fed and fasted rats

    Energy Technology Data Exchange (ETDEWEB)

    Smith-Kielland, A.; Ripel, Aa.; Gadeholt, G.

    1989-01-01

    The effects of three different concentrations (about 20, 100 and 1000 ..mu..M) of toluene on protein synthesis were studied in hepatocytes isolated from fed and fasted rats after 60 and 120 min. of incubation. The interaction between ethanol (60 mM) and the low and high toluene concentrations were also tested. To measure protein synthesis, /sup 14/C-valine was used as the precursor amino acid. Total valine concentration was 2 mM to ensure near-constant specific radioactivity of precursor. Toluene concentrations were measured by head-space gas chromatography. Protein synthesis was unchanged in the presence of low toluene concentrations. Intermediate toluene concentration decreased protein synthesis by about 20% and high toluene concentration decreased protein synthesis by about 60%. Protein synthesis was similar in cells from fed and fasted rats. Ethanol alone inhibited protein synthesis by 20-30%, more in fasted than in fed rats. Toluene and ethanol in combination inhibited protein synthesis additively. The high toluene concentration with or without ethanol appeared to inhibit synthesis/secretion of export proteins in hepatocytes from fasted rats. In conclusion, our study indicates that toluene in relatively high concentrations inhibits general protein synthesis in isolated rat hepatocytes. Toluene and ethanol seems to inhibit protein synthesis additively.

  10. Alterations to prepulse inhibition magnitude and latency in adult rats following neonatal treatment with domoic acid and social isolation rearing.

    Science.gov (United States)

    Marriott, Amber L; Tasker, R Andrew; Ryan, Catherine L; Doucette, Tracy A

    2016-02-01

    Deficits in perceptual, informational, and attentional processing are consistently identified as a core feature in schizophrenia and related neuropsychiatric disorders. Neonatal injections of low doses of the AMPA/kainate agonist domoic acid (DOM) have previously been shown to alter various aspects of perceptual and attentional processing in adult rats. The current study investigated the effects of combined neonatal DOM treatment with isolation rearing on prepulse inhibition behaviour and relevant neurochemical measures, to assess the usefulness of these paradigms in modeling neurodevelopmental disorders. Daily subcutaneous injections of DOM (20 μg/kg) or saline were administered to male and female rat pups from postnatal days (PND) 8-14. After weaning, rats were either housed alone or in groups of 4. Both the magnitude and latency of prepulse inhibition were determined in adulthood (approximately 4.5 months of age) and post-mortem brain tissue was assayed using Western blot. Social isolation alone significantly lowered PPI magnitude in male (but not female) rats while DOM treatment appeared to make animals refractory to this effect. Combining social isolation and DOM treatment caused an additive decrease in PPI startle latency. No statistically significant differences were found in the expression of D1, D2, TH, GAD65 or GAD67 protein in either the prefrontal cortex or hippocampus, although some tendencies toward differences were noted. We conclude that both neonatal low-dose DOM and social isolation affect prepulse inhibition in rats but that each paradigm exerts these effects through different neuronal signalling systems. Copyright © 2015 Elsevier B.V. All rights reserved.

  11. The Effects Of L-Arginine And L-Name On Coronary Flow And Oxidative Stress In Isolated Rat Hearts

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    Sobot Tanja

    2015-12-01

    Full Text Available The aim of this experimental study was to assess the effects of the acute administration of L-arginine alone and in combination with L-NAME (a non-selective NO synthase inhibitor on the coronary flow and oxidative stress markers in isolated rat hearts. The experimental study was performed on hearts isolated from Wistar albino rats (n=12, male, 8 weeks old, body mass of 180-200 g. Retrograde perfusion of the isolated preparations was performed using a modified method according to the Langendorff technique with a gradual increase in the perfusion pressure (40–120 cmH2O. The following values were measured in the collected coronary effluents: coronary flow, released nitrites (NO production marker, superoxide anion radical and the index of lipid peroxidation (measured as thiobarbiturate reactive substances. The experimental protocol was performed under controlled conditions, followed by the administration of L-arginine alone (1 mmol and L-arginine (1 mmol + L-NAME (30 μmol. The results indicated that L-arginine did not significantly increase the coronary flow or the release of NO, TBARS and the superoxide anion radical. These effects were partially blocked by the joint administration of L-arginine + L-NAME, which indicated their competitive effect. Hence, the results of our study do not demonstrate significant effects of L-arginine administration on the coronary flow and oxidative stress markers in isolated rat hearts.

  12. Effects of resocialization on post-weaning social isolation-induced abnormal aggression and social deficits in rats.

    Science.gov (United States)

    Tulogdi, Aron; Tóth, Máté; Barsvári, Beáta; Biró, László; Mikics, Eva; Haller, József

    2014-01-01

    As previously shown, rats isolated from weaning develop abnormal social and aggressive behavior characterized by biting attacks targeting vulnerable body parts of opponents, reduced attack signaling, and increased defensive behavior despite increased attack counts. Here we studied whether this form of violent aggression could be reversed by resocialization in adulthood. During the first weak of resocialization, isolation-reared rats showed multiple social deficits including increased defensiveness and decreased huddling during sleep. Deficits were markedly attenuated in the second and third weeks. Despite improved social functioning in groups, isolated rats readily showed abnormal features of aggression in a resident-intruder test performed after the 3-week-long resocialization. Thus, post-weaning social isolation-induced deficits in prosocial behavior were eliminated by resocialization during adulthood, but abnormal aggression was resilient to this treatment. Findings are compared to those obtained in humans who suffered early social maltreatment, and who also show social deficits and dysfunctional aggression in adulthood. © 2013 Wiley Periodicals, Inc.

  13. Effects of stress on catecholamine stores in central and peripheral tissues of long-term socially isolated rats.

    Science.gov (United States)

    Dronjak, S; Gavrilovic, L

    2006-06-01

    Both the peripheral sympatho-adrenomedullary and central catecholaminergic systems are activated by various psycho-social and physical stressors. Catecholamine stores in the hypothalamus, hippocampus, adrenal glands, and heart auricles of long-term socially isolated (21 days) and control 3-month-old male Wistar rats, as well as their response to immobilization of all 4 limbs and head fixed for 2 h and cold stress (4 degrees C, 2 h), were studied. A simultaneous single isotope radioenzymatic assay based on the conversion of catecholamines to the corresponding O-methylated derivatives by catechol-O-methyl-transferase in the presence of S-adenosyl-l-(3H-methyl)-methionine was used. The O-methylated derivatives were oxidized to 3H-vanilline and the radioactivity measured. Social isolation produced depletion of hypothalamic norepinephrine (about 18%) and hippocampal dopamine (about 20%) stores and no changes in peripheral tissues. Immobilization decreased catecholamine stores (approximately 39%) in central and peripheral tissues of control animals. However, in socially isolated rats, these reductions were observed only in the hippocampus and peripheral tissues. Cold did not affect hypothalamic catecholamine stores but reduced hippocampal dopamine (about 20%) as well as norepinephrine stores in peripheral tissues both in control and socially isolated rats, while epinephrine levels were unchanged. Thus, immobilization was more efficient in reducing catecholamine stores in control and chronically isolated rats compared to cold stress. The differences in rearing conditions appear to influence the response of adult animals to additional stress. In addition, the influence of previous exposure to a stressor on catecholaminergic activity in the brainstem depends on both the particular catecholaminergic area studied and the properties of additional acute stress. Therefore, the sensitivity of the catecholaminergic system to habituation appears to be tissue-specific.

  14. Effects of stress on catecholamine stores in central and peripheral tissues of long-term socially isolated rats

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    Dronjak S.

    2006-01-01

    Full Text Available Both the peripheral sympatho-adrenomedullary and central catecholaminergic systems are activated by various psycho-social and physical stressors. Catecholamine stores in the hypothalamus, hippocampus, adrenal glands, and heart auricles of long-term socially isolated (21 days and control 3-month-old male Wistar rats, as well as their response to immobilization of all 4 limbs and head fixed for 2 h and cold stress (4ºC, 2 h, were studied. A simultaneous single isotope radioenzymatic assay based on the conversion of catecholamines to the corresponding O-methylated derivatives by catechol-O-methyl-transferase in the presence of S-adenosyl-l-(³H-methyl-methionine was used. The O-methylated derivatives were oxidized to ³H-vanilline and the radioactivity measured. Social isolation produced depletion of hypothalamic norepinephrine (about 18% and hippocampal dopamine (about 20% stores and no changes in peripheral tissues. Immobilization decreased catecholamine stores (approximately 39% in central and peripheral tissues of control animals. However, in socially isolated rats, these reductions were observed only in the hippocampus and peripheral tissues. Cold did not affect hypothalamic catecholamine stores but reduced hippocampal dopamine (about 20% as well as norepinephrine stores in peripheral tissues both in control and socially isolated rats, while epinephrine levels were unchanged. Thus, immobilization was more efficient in reducing catecholamine stores in control and chronically isolated rats compared to cold stress. The differences in rearing conditions appear to influence the response of adult animals to additional stress. In addition, the influence of previous exposure to a stressor on catecholaminergic activity in the brainstem depends on both the particular catecholaminergic area studied and the properties of additional acute stress. Therefore, the sensitivity of the catecholaminergic system to habituation appears to be tissue-specific.

  15. Niacinamide mitigated the acute lung injury induced by phorbol myristate acetate in isolated rat's lungs

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    Lin Chia-Chih

    2012-03-01

    Full Text Available Abstract Background Phorbol myristate acetate (PMA is a strong neutrophil activator and has been used to induce acute lung injury (ALI. Niacinamide (NAC is a compound of B complex. It exerts protective effects on the ALI caused by various challenges. The purpose was to evaluate the protective effects of niacinamide (NAC on the PMA-induced ALI and associated changes. Methods The rat's lungs were isolated in situ and perfused with constant flow. A total of 60 isolated lungs were randomized into 6 groups to received Vehicle (DMSO 100 μg/g, PMA 4 μg/g (lung weight, cotreated with NAC 0, 100, 200 and 400 mg/g (lung weight. There were 10 isolated lungs in each group. We measured the lung weight and parameters related to ALI. The pulmonary arterial pressure and capillary filtration coefficient (Kfc were determined in isolated lungs. ATP (adenotriphosphate and PARP [poly(adenosine diphophate-ribose polymerase] contents in lung tissues were detected. Real-time PCR was employed to display the expression of inducible and endothelial NO synthases (iNOS and eNOS. The neutrophil-derived mediators in lung perfusate were determined. Results PMA caused increases in lung weight parameters. This agent produced pulmonary hypertension and increased microvascular permeability. It resulted in decrease in ATP and increase in PARP. The expression of iNOS and eNOS was upregulated following PMA. PMA increased the neutrophil-derived mediators. Pathological examination revealed lung edema and hemorrhage with inflammatory cell infiltration. Immunohistochemical stain disclosed the presence of iNOS-positive cells in macrophages and endothelial cells. These pathophysiological and biochemical changes were diminished by NAC treatment. The NAC effects were dose-dependent. Conclusions Our results suggest that neutrophil activation and release of neutrophil-derived mediators by PMA cause ALI and associated changes. NO production through the iNOS-producing cells plays a detrimental

  16. Niacinamide mitigated the acute lung injury induced by phorbol myristate acetate in isolated rat's lungs.

    Science.gov (United States)

    Lin, Chia-Chih; Hsieh, Nan-Kuang; Liou, Huey Ling; Chen, Hsing I

    2012-03-01

    Phorbol myristate acetate (PMA) is a strong neutrophil activator and has been used to induce acute lung injury (ALI). Niacinamide (NAC) is a compound of B complex. It exerts protective effects on the ALI caused by various challenges. The purpose was to evaluate the protective effects of niacinamide (NAC) on the PMA-induced ALI and associated changes. The rat's lungs were isolated in situ and perfused with constant flow. A total of 60 isolated lungs were randomized into 6 groups to received Vehicle (DMSO 100 μg/g), PMA 4 μg/g (lung weight), cotreated with NAC 0, 100, 200 and 400 mg/g (lung weight). There were 10 isolated lungs in each group. We measured the lung weight and parameters related to ALI. The pulmonary arterial pressure and capillary filtration coefficient (Kfc) were determined in isolated lungs. ATP (adenotriphosphate) and PARP [poly(adenosine diphophate-ribose) polymerase] contents in lung tissues were detected. Real-time PCR was employed to display the expression of inducible and endothelial NO synthases (iNOS and eNOS). The neutrophil-derived mediators in lung perfusate were determined. PMA caused increases in lung weight parameters. This agent produced pulmonary hypertension and increased microvascular permeability. It resulted in decrease in ATP and increase in PARP. The expression of iNOS and eNOS was upregulated following PMA. PMA increased the neutrophil-derived mediators. Pathological examination revealed lung edema and hemorrhage with inflammatory cell infiltration. Immunohistochemical stain disclosed the presence of iNOS-positive cells in macrophages and endothelial cells. These pathophysiological and biochemical changes were diminished by NAC treatment. The NAC effects were dose-dependent. Our results suggest that neutrophil activation and release of neutrophil-derived mediators by PMA cause ALI and associated changes. NO production through the iNOS-producing cells plays a detrimental role in the PMA-induced lung injury. ATP is beneficial

  17. Isolation of Trichophyton mentogrophytes var mentogrophytes from naturally infected laboratory albino rats: experimental infection and treatment in rabbits

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    N. A. Issa

    2009-01-01

    Full Text Available The present study demonstrated for the first time the occurrence of dermatophytosis in naturally infected rats and from asymptomatic and from breeding boxes of white rats kept in animal housing of college of Veterinary Medicine, University of Dohuk, Iraq. The prevalence rate of infection was (28%, clinically infected rats characterized by appearance of scaly ovoid type lesions with crusty edge and patch of hair loss mostly seen on the back, neck and face of the infected rats, itching was reported in some rats. Only one species of the trichophyton, T. mentogrophytes var mentogrophytes was isolated with growth rate (85.71% of samples collected from clinically infected rats, and (28.57% from asymptomatic and from breeding cages, the growth was observed within the 21 days at 25ºC on Sabouraud's Dextrose Agar. Lacto phenol cotton blue staining slides of T. mentogrophytes var mentogrophytes revealed both microconidia and macroconidia. Microconidia found in numerous numbers often in dense cluster which were hyaline, smooth walled and predominantly spherical to sub spherical in shape, varying numbers of chlamydoconidia. Spiral hyphae and smooth, thin walled clavate shaped multicelled macroconidia were also present. The study also dealt with experimental infection in rabbits with T. mentogrophytes var mentogrophytes and treated by two drugs, natural herbal preparation of acidic pomegranate (Punica granatum fruit and synthetic nystatine ointment. The complete recovery of lesions was recorded after 14 days and 21 days of topical application of a pomegranate and nystatine ointment for 5 successive days respectively.

  18. Peroxynitrite-induced relaxation in isolated rat aortic rings and mechanisms of action

    International Nuclear Information System (INIS)

    Li Jianfeng; Li Wenyan; Altura, Bella T.; Altura, Burton M.

    2005-01-01

    The present study was designed to evaluate the effects of peroxynitrite (ONOO - ), the product of superoxide and nitric oxide, on isolated segments of rat aorta. In the absence of any vasoactive agent, ONOO - (from 10 -8 to 10 -4 M) failed to alter the basal tension. In phenylephrine (PE; 5 x 10 -7 M)-precontracted rat aortic rings (RAR), ONOO - elicited concentration-dependent relaxation at concentrations of from 10 -8 to 10 -4 M. The effective concentrations producing approximately 50% of maximal relaxation (ED 5 ) to ONOO - were 1.84 x 10 -5 M and 1.96 x 10 -5 M in intact and denuded RAR, respectively (P > 0.05). No significant differences in the relaxation responses were found between RAR with or without endothelium (P > 0.05). The presence of either 5 μM methylene blue (MB) or 5 μM 1H-[1,2,4]oxadiazolo-[4,3-α]quinoxalin-1-one (ODQ) significantly inhibited the relaxations induced by ONOO - . Sildenafil (10 -7 M), on the other hand, significantly potentiated the ONOO - -induced relaxations. Tetraethylammonium chloride (T-2265) significantly decreased the ONOO - -induced relaxations in a concentration-dependent manner. However, ONOO - had no effect on RAR precontracted by high KCL (40 mM, n = 6, P > 0.05). Addition of calyculin A also significantly decreased the ONOO - -induced relaxation in a dose-dependent manner. Furthermore, ONOO - significantly inhibited calcium-induced contractions of K + -depolarized aortic rings in a concentration-related manner. Lastly, a variety of other pharmacological agents and antagonists including L-NMMA, L-arginine, indomethacin, atropine, naloxone, diphenhydramine, cimetine, glibenclamide, haloperidol, superoxide dismutase (SOD), and catalase did not influence the relaxant effects of ONOO - on RAR. Our new results suggest that ONOO - -triggered relaxation on rat aortic rings is mediated by elevation of cGMP levels, membrane hyperpolarization via K + -channel activation, activation of myosin phosphatase activity, and

  19. Chronic social isolation suppresses proplastic response and promotes proapoptotic signalling in prefrontal cortex of Wistar rats.

    Science.gov (United States)

    Djordjevic, Ana; Adzic, Miroslav; Djordjevic, Jelena; Radojcic, Marija B

    2010-08-15

    Successful adaptation to stress involves synergized actions of glucocorticoids and catecholamines at several levels of the CNS, including the prefrontal cortex (PFC). Inside the PFC, hormonal signals trigger concerted actions of transcriptional factors, such as glucocorticoid receptor (GR) and nuclear factor kappa B (NFkappaB), culminating in a balanced, proadaptive expression of their common genes, such as proplastic NCAM and/or apoptotic Bax and Bcl-2. In the present study, we hypothesized that chronic stress may compromise the balance between GR and NFkappaB signals and lead to an altered/maladaptive expression of their cognate genes in the PFC. Our results obtained with Wistar rats exposed to chronic social isolation indicated alterations of the GR relative to the NFkappaB, in favor of the GR, in both the cytoplasmic and the nuclear compartments of the PFC. Although these alterations did not affect the induction of proplastic NCAM gene, they decreased the NCAM sialylation necessary for plastic response and caused marked relocation of the mitochondrial membrane antiapoptotic Bcl-2 protein to its cytoplasmic form. Moreover, the compromised PSA-NCAM plastic response found under chronic stress was sustained after exposure of animals to the subsequent acute stress, whereas the proapoptotic signals were further emphasized. It is concluded that chronic social isolation of Wistar animals leads to a maladaptive response of the PFC, considering the diminishment of its plastic potential and potentiating of apoptosis. Such conditions in the PFC are likely to compromise its ability to interact with other CNS structures, such as the hippocampus, which is necessary for successful adaptation to stress. (c) 2010 Wiley-Liss, Inc.

  20. Mitochondrial apoptotic pathway activation in the atria of heart failure patients due to mitral and tricuspid regurgitation.

    Science.gov (United States)

    Chang, Jen-Ping; Chen, Mien-Cheng; Liu, Wen-Hao; Lin, Yu-Sheng; Huang, Yao-Kuang; Pan, Kuo-Li; Ho, Wan-Chun; Fang, Chih-Yuan; Chen, Chien-Jen; Chen, Huang-Chung

    2015-08-01

    Apoptosis occurs in atrial cardiomyocytes in mitral and tricuspid valve disease. The purpose of this study was to examine the respective roles of the mitochondrial and tumor necrosis factor-α receptor associated death domain (TRADD)-mediated death receptor pathways for apoptosis in the atrial cardiomyocytes of heart failure patients due to severe mitral and moderate-to-severe tricuspid regurgitation. This study comprised eighteen patients (7 patients with persistent atrial fibrillation and 11 in sinus rhythm). Atrial appendage tissues were obtained during surgery. Three purchased normal human left atrial tissues served as normal controls. Moderately-to-severely myolytic cardiomyocytes comprised 59.7±22.1% of the cardiomyocytes in the right atria and 52.4±12.9% of the cardiomyocytes in the left atria of mitral and tricuspid regurgitation patients with atrial fibrillation group and comprised 58.4±24.8% of the cardiomyocytes in the right atria of mitral and tricuspid regurgitation patients with sinus rhythm. In contrast, no myolysis was observed in the normal human adult left atrial tissue samples. Immunohistochemical analysis showed expression of cleaved caspase-9, an effector of the mitochondrial pathways, in the majority of right atrial cardiomyocytes (87.3±10.0%) of mitral and tricuspid regurgitation patients with sinus rhythm, and right atrial cardiomyocytes (90.6±31.4%) and left atrial cardiomyocytes (70.7±22.0%) of mitral and tricuspid regurgitation patients with atrial fibrillation. In contrast, only 5.7% of cardiomyocytes of the normal left atrial tissues showed strongly positive expression of cleaved caspase-9. Of note, none of the atrial cardiomyocytes in right atrial tissue in sinus rhythm and in the fibrillating right and left atria of mitral and tricuspid regurgitation patients, and in the normal human adult left atrial tissue samples showed cleaved caspase-8 expression, which is a downstream effector of TRADD of the death receptor pathway

  1. Tezosentan reduces the microvascular filtration coefficient in isolated lungs from rats subjected to cecum ligation and puncture.

    Science.gov (United States)

    Kuklin, Vladimir; Sovershaev, Mikhail; Andreasen, Thomas; Skogen, Vegard; Ytrehus, Kirsti; Bjertnaes, Lars

    2005-01-01

    We recently demonstrated that the non-selective endothelin-1 (ET-1) receptor blocker tezosentan antagonizes ovine acute lung injury (ALI) following infusion of endotoxin or ET-1 by reducing the enhanced lung microvascular pressure, although we could not exclude the possibility of a simultaneous decline in microvascular permeability. In the present study, our aim was to find out if tezosentan reverses the rise in microvascular filtration coefficient (Kfc) in rat lungs that have been isolated and perfused 12 h after cecum ligation and puncture (CLP) or infusion of ET-1. Wistar rats (n = 42) were subjected to CLP. Postoperatively, rats were randomized to a CLP group (n = 7) and a CLP + tezosentan group (n = 7); the latter received tezosentan 30 mg/kg. A sham-operated group (n = 5) underwent laparotomy without CLP. Twelve hours postoperatively, the lungs were isolated and perfused with blood from similarly treated rats that also were used to assess plasma concentration of ET-1 and protein kinase Calpha (PKCalpha) in lung tissue. Additionally, isolated blood perfused lungs from healthy rats were randomized to a control group (n = 8), an ET-1 group (n = 7) subjected to pulmonary arterial injection of ET-1 10 nM, and an ET-1 + tezosentan group (n = 7) that received tezosentan 30 mg/kg. All lung preparations received papaverine 0.1 microg/kg added to the perfusate for vasoplegia. Pulmonary hemodynamic variables, Kfc and lung compliance (CL) were assessed. After CLP, the plasma concentration of ET-1 increased. Papaverine abolished the vasoconstrictor response to ET-1 and the pulmonary vascular pressures remained close to baseline throughout the experiments. Both CLP and injection of ET-1 caused significant changes in Kfc and CL that were prevented in tezosentan-treated rats. Compared to sham-operated animals, CLP increased the content of PKCalpha by 50% and 70% in the cytosolic and the membrane fractions of lung tissue homogenates, respectively. Tezosentan prevented the

  2. A new iridoid and effect on the rat aortic vascular smooth muscle cell proliferation of isolated compounds from Buddleja officinalis.

    Science.gov (United States)

    Tai, Bui Huu; Nhiem, Nguyen Xuan; Quang, Tran Hong; Ngan, Nguyen Thi Thanh; Tung, Nguyen Huu; Kim, Yohan; Lee, Jung-Jin; Myung, Chang-Seon; Cuong, Nguyen Manh; Kim, Young Ho

    2011-06-01

    A new iridoid, named methylscutelloside (1) together with 19 known compounds belonging to the iridoids (2-4), monoterpenoids (5), flavonoids (6-8), triterpenoids (9-14), and phenylethanoids (15-20) were isolated from the flowers of Buddleja officinalis. Their chemical structures were elucidated on the basis of physicochemical properties, and by spectroscopic methods including 1D, 2D NMR, and MS. All isolated compounds were tested in vitro for their effects on the proliferation of rat aortic vascular smooth muscle cells (VSMCs). Among them, iridoids were the main active components and showed significant inhibitory effects on PDGF-BB-induced proliferation in rat aortic VSMCs. Copyright © 2011 Elsevier Ltd. All rights reserved.

  3. 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

  4. Resistance to Reperfusion Injury Following Short Term Postischemic Administration of Natural Honey in Globally Ischemic Isolated Rat Heart

    Science.gov (United States)

    Vaez, Haleh; Samadzadeh, Mehrban; Zahednezhad, Fahimeh; Najafi, Moslem

    2012-01-01

    Purpose: Results of our previous study revealed that preischemic perfusion of honey before zero flow global ischemia had cardioprotective effects in rat. The present study investigated potential resistance to reperfusion injury following short term postischemic administration of natural honey in globally ischemic isolated rat heart. Methods: Male Wistar rats were divided into five groups (n=10-13). The rat hearts were isolated, mounted on a Langendorff apparatus, allowed to equilibrate for 30 min then subjected to 30 min global ischemia. In the control group, the hearts were reperfused with drug free normal Krebs-Henseleit (K/H) solution before ischemia and during 120 min reperfusion. In the treatment groups, reperfusion was initiated with K/H solution containing different concentration of honey (0.25, 0.5, 1 and 2%) for 15 min and was resumed until the end of 120 min with normal K/H solution. Results: In the control group, VEBs number was 784±199, while in honey concentration of 0.25, 0.5, 1 and 2%, it decreased to 83±23 (Phoney. In the control group, the infarct size was 54.1±7.8%, however; honey (0.25, 0.5, 1 and 2%) markedly lowered the value to 12.4±2.4, 12.7±3.3, 11.3±2.6 and 7.9±1.7 (Phoney in global ischemia showed protective effects against ischemia/reperfusion (I/R) injuries in isolated rat heart. Antioxidant and radical scavenging activity, lipoperoxidation inhibition, reduction of necrotized tissue, presence of rich energy sources, various type of vitamins, minerals and enzymes and formation of NO-contain metabolites may probably involve in those cardioprotective effects. PMID:24312792

  5. Enduring increases in anxiety-like behavior and rapid nucleus accumbens dopamine signaling in socially isolated rats.

    Science.gov (United States)

    Yorgason, Jordan T; España, Rodrigo A; Konstantopoulos, Joanne K; Weiner, Jeffrey L; Jones, Sara R

    2013-03-01

    Social isolation (SI) rearing, a model of early life stress, results in profound behavioral alterations, including increased anxiety-like behavior, impaired sensorimotor gating and increased self-administration of addictive substances. These changes are accompanied by alterations in mesolimbic dopamine function, such as increased dopamine and metabolite tissue content, increased dopamine responses to cues and psychostimulants, and increased dopamine neuron burst firing. Using voltammetric techniques, we examined the effects of SI rearing on dopamine transporter activity, vesicular release and dopamine D2-type autoreceptor activity in the nucleus accumbens core. Long-Evans rats were housed in group (GH; 4/cage) or SI (1/cage) conditions from weaning into early adulthood [postnatal day (PD) 28-77]. After this initial housing period, rats were assessed on the elevated plus-maze for an anxiety-like phenotype, and then slice voltammetry experiments were performed. To study the enduring effects of SI rearing on anxiety-like behavior and dopamine terminal function, another cohort of similarly reared rats was isolated for an additional 4 months (until PD 174) and then tested. Our findings demonstrate that SI rearing results in lasting increases in anxiety-like behavior, dopamine release and dopamine transporter activity, but not D2 activity. Interestingly, GH-reared rats that were isolated as adults did not develop the anxiety-like behavior or dopamine changes seen in SI-reared rats. Together, our data suggest that early life stress results in an anxiety-like phenotype, with lasting increases in dopamine terminal function. © 2013 Federation of European Neuroscience Societies and Blackwell Publishing Ltd.

  6. The relaxant effect induced by Allium sativum L. bulb aqueous extract on rat isolated trachea

    Science.gov (United States)

    Fehri, Badreddine; Ahmed, Mueen K.K.; Aiache, Jean-Marc

    2011-01-01

    Background: Garlic plays an important role in complementary and alternative medicine. Most people believe in and use herbal products even when they have not been as thoroughly researched as garlic. Garlic is also known for its beneficial effects on the cardiovascular system. Materials and Methods: The relaxant effect of Allium sativum L. bulb aqueous extract (ASBAE) containing 0.06%-0.10% of allicin was studied on isolated smooth muscle of trachea of rats precontracted using acetylcholine (10−5 M). Results: It was found that ASBAE induced a dose-dependent relaxation with recorded EC 50 values of 71.87 ± 5.90 µg/mL (n = 7). Pretreatments with mepyramine (10−7 M), methysergide (10−7 M), caffeine (10−6 M), theophylline (10−6 M), nifedipine (10−6 M), and dipyridamole (10−6 M) did not alter ASBAE concentration-response curves. In turn, concentration-response curves to ASBAE were significantly shifted toward right in the presence of aspirin (3.10−3 M), indomethacin (10−6 M), prazosin (10−6 M), and propranolol (10−7 M). Conclusion: It is suggested that the recorded relaxation results are due to the release of prostaglandins E 1 and E 2 consecutively to α- and β-adrenoreceptor stimulation. PMID:21472073

  7. The Toxicity Mechanisms of Action of Aβ25–35 in Isolated Rat Cardiac Myocytes

    Directory of Open Access Journals (Sweden)

    Beiru Zhang

    2014-08-01

    Full Text Available β-Amyloid (Aβ is deposited in neurons and vascular cells of the brain and is characterized as a pathologic feature of Alzheimer’s disease (AD. Recently studies have reported that there is an association between cardiovascular risk factors and AD, however the mechanism of this association is still uncertain. In this study we observed Aβ had an effect on cardiovascular cells. We represent as a major discovery that Aβ25–35 had toxicity on isolated rat cardiac myocytes by impacting the cytoskeleton assembly and causing ER stress, ultimately contributing to the apoptosis of the myocytes. Importantly, the activation of ER stress and subsequent cellular dysfunction and apoptosis by Aβ25–35 was regulated by the MAPK pathway, which could be prevented by inhibition of p38 via pharmacological inhibitors. It was noteworthy that Aβ25–35 played a critical role in cardiac myocytes, suggesting that Alzheimer’s disease (AD had a relation with the heart and understanding of these associations in future will help search for effective treatment strategies.

  8. Calcium and osmotic stimulation in renin release from isolated rat glomeruli

    DEFF Research Database (Denmark)

    Skøtt, O

    1986-01-01

    of the RR rate preceding the stimulus. Removal of calcium stimulated the RR by 10 times (n = 5, p less than 0.001) and a subsequent decrease in osmolality of 20 mOsm/kg stimulated the RR proportionally to that observed in the series containing 2 mM calcium. A decrease in osmolality was able to stimulate RR......The effects of changes in osmolality and calcium concentration on renin release (RR) from isolated superfused rat glomeruli were studied. The undisturbed RR followed a first order fall with a half-time of about 100 min (n = 45). Changes in the osmolality between 270 and 350 mOsm/kg resulted in dose......-dependent changes in the RR rates. Hypoosmotic treatment stimulated the RR transiently, whereas hyperosmotic treatment produced a sustained inhibition. The dose-response relationship was log-linear between 270 and 320 mOsm/kg. A decrease in osmolality of 20 mOsm/kg gave proportional increases in RR irrespectively...

  9. Acute effects of nandrolone decanoate on oxidative stress in isolated rat heart

    Directory of Open Access Journals (Sweden)

    Jevđević Maja

    2015-01-01

    Full Text Available Abuse of anabolic-androgenic steroids (AAS produces side effects in different tissues, with oxidative stress linked to their pathophysiology, being involved in fibrosis, cellular proliferation, and tumorigenesis. The aim of this study was to examine the acute effects of nandrolone decanoate (ND on oxidative stress in isolated rat heart. The hearts of male Wistar albino were excised and perfused according to the Langendorff technique at gradually increasing coronary perfusion pressures (40-120 cmH2O. The hearts were perfused with ND at doses of 1, 10 and 100 μM. Oxidative stress markers, including the index of lipid peroxidation (thiobarbituric acid reactive substances (TBARS, nitric oxide (nitrites; NO2-, the superoxide anion radical (O2- and hydrogen peroxide (H2O2 were measured in the coronary venous effluent. Our results showed that acute effects of ND do not promote the production of reactive oxygen species (ROS. Our finding pointed out that the highest concentration of ND may even possess some anti-oxidative potential, which should be examined further.

  10. Transcriptome analysis of amoeboid and ramified microglia isolated from the corpus callosum of rat brain

    Directory of Open Access Journals (Sweden)

    Parakalan Rangarajan

    2012-06-01

    Full Text Available Abstract Background Microglia, the resident immune cells of the central nervous system (CNS, have two distinct phenotypes in the developing brain: amoeboid form, known to be amoeboid microglial cells (AMC and ramified form, known to be ramified microglial cells (RMC. The AMC are characterized by being proliferative, phagocytic and migratory whereas the RMC are quiescent and exhibit a slow turnover rate. The AMC transform into RMC with advancing age, and this transformation is indicative of the gradual shift in the microglial functions. Both AMC and RMC respond to CNS inflammation, and they become hypertrophic when activated by trauma, infection or neurodegenerative stimuli. The molecular mechanisms and functional significance of morphological transformation of microglia during normal development and in disease conditions is not clear. It is hypothesized that AMC and RMC are functionally regulated by a specific set of genes encoding various signaling molecules and transcription factors. Results To address this, we carried out cDNA microarray analysis using lectin-labeled AMC and RMC isolated from frozen tissue sections of the corpus callosum of 5-day and 4-week old rat brain respectively, by laser capture microdissection. The global gene expression profiles of both microglial phenotypes were compared and the differentially expressed genes in AMC and RMC were clustered based on their functional annotations. This genome wide comparative analysis identified genes that are specific to AMC and RMC. Conclusions The novel and specific molecules identified from the trancriptome explains the quiescent state functioning of microglia in its two distinct morphological states.

  11. Ultrastructural changes in the isolated rat kidney induced by conjugated bilirubin and bile acids.

    Science.gov (United States)

    Gollan, J L; Billing, B H; Huang, S N

    1976-10-01

    The effects of bilirubin and bile acids on the ultrastructure of proximal renal tubules have been studied using an isolated rat kidney preparation, perfused with a protein-free dextran medium. Control kidneys perfused for 1 h had a normal glomerular filtration rate and effective renal plasma flow; the ultrastructure of proximal tubular cells was well preserved, with normal mitochondria, nuclear and plasma membranes, and microvilli of the brush border. When conjugated bilirubin, prepared from human hepatic bile, was added to the perfusion medium (5-0-7-5 mg/100 ml), marked alterations were observed in some cells, particularly with regard to the mitochondria and plasma membranes. These changes were greatly diminished by the inclusion of bovine albumin in the medium, indicating that the unbound fraction was primarily responsible for the tubular damage. The addition of taurocholate (450 muM), taurochenodeoxycholate (550 muM) or taurolithocholate (250 muM, bound to albumin) also produced plasma membrane changes, but only slight abnormalities were seen in the mitochondria and other structures. These ultrastructural observations support the concept that the elevated plasma levels of conjugated bilirubin and to a lesser extent bile acids are related to the renal failure associated with obstructive jaundice.

  12. Effect of parathyroid hormone and calcium ions on substrate oxidation by isolated glomeruli of the rat.

    Science.gov (United States)

    Wang, M S; Kurokawa, K

    1981-11-05

    Effect of Ca2+ and parathyroid hormone (PTH) on 14 CO2 production from certain metabolic substrates by isolated glomeruli of rat kidney were examined. Increasing calcium concentration in the incubation medium inhibited 14CO2 production from 14C-labeled alpha-ketoglutarate and succinate, stimulated 14CO2 production from [1-14C]glucose and [1-14C]glutamate, but was without effect on that from [6-14C]glucose. PTH in the presence but not in the absence of Ca2+ inhibited 14CO2 production from labeled alpha-ketoglutarate and glutamate but not from labeled glucose. Additions of cyclic AMP as well as hormonal agents known to act directly on the glomureli, such as histamine, epinephrine, prostaglandin E2, vasopressin, angiotensin II and insulin, did not alter 14 CO2 production from labeled alpha-ketoglutarate. These data show the presence of calcium-dependent inhibitory actions on PTH on oxidation of alpha-ketoglutarate and glutamate which may be independent of cyclic AMP. These metabolic effects of PTH may underlie the alteration in the glomerular ultrafiltration coefficient and glomerular filtration induced by the hormone.

  13. Incorporation of radioactive amino acids into protein in isolated rat hepatocytes

    International Nuclear Information System (INIS)

    Seglin, P.O.

    1976-01-01

    The incorporation of radioactivity from a 14 C-labelled amino acid mixture (algal protein hydrolysate) into protein in isolated rat hepatocytes has been studied. The incorporation rate declined with increasing cell concentration, an effect which could be explained by isotope consumption, partly (and largely) by isotope dilution due to the formation of non-labelled amino acids by the cells. At a high extracellular amino acid concentration, the rate of incorporation into protein became independent of cell concentration because the isotope dilution effect was now quantitatively insignificant. The time course of protein labelling at various cell concentrations correlated better with the intracellular than with the extracellular amino acid specific activity, suggesting that amino acids for protein synthesis were taken from an intracellular pool. With increasing extracellular amino acid concentrations, both the intracellular amino acid concentration, the intracellular radioactivity and the rate of incorporation into protein increased. Protein labelling exhibited a distinct time lag at high amino acid concentrations, presumable reflecting the time-dependent expansion of the intracellular amino acid pool. The gradual increase in the rate of protein labelling could be due either to an increased intracellular specific activity, or to a real stimulation of protein synthesis by amino acids, depending on whether the total intracellular amino acid pool or just the expandable compartment is the precursor pool for protein synthesis

  14. Digitonin abolishes free 2-deoxy-D-glucose accumulation in isolated rat adipocytes

    International Nuclear Information System (INIS)

    Thompson, K.; Kleinzeller, A.

    1986-01-01

    The hypothesis that accumulation against sizable chemical gradients of free (non-phosphorylated) 2-deoxy-D-glucose (2dGlc) in isolated rat adipocytes results from an intracellular compartmentation of free hexose was investigated. Cells exposed to 20 μg/ml digitonin for 10' demonstrated an increased plasma membrane permeability indexed by increased L-glucose entry rates and cellular (presumably cytosolic) protein and K + loss. Functional integrity of intracellular organelles was indicated by the ability of the cells to support ATP-driven 45 Ca 2+ -uptake. Equilibrium 3-O-methylglucose (3-O-MG, a non-accumulated hexose) levels were unaffected. These data suggest a specific permeabilizing action of digitonin at the plasma membrane having no effect on intracellular organelles or passively distributed solutes. Upon addition of digitonin, free 2dGlc fell from 66.5 +/- 8.9 to 7.4 +/- 2.3 pmol/10 5 cells, a value not significantly different from 3-O-MG levels. The gradient of 2dGlc-phosphate was also abolished, as was the increased steady-state free 2dGlc levels induced by insulin. The data argue against a compartmentation model as either the mechanism of adipocyte sugar accumulation or the basis of the steady-state free 2dGlc increase seen with insulin and suggest that an intact plasma membrane is essential to the process

  15. Studies on the uptake of 14C-neostigmine in the isolated rat diaphragm

    International Nuclear Information System (INIS)

    Helleberg, L.

    1976-01-01

    The uptake process of 14 C-neostigmine in striated muscles was studied using the isolated rat diaphragm. Hemidiaphragms were incubated with 3x10 -7 M 14 C-neostigmine at 37deg in Krebs-Ringer solution containing 11 mM glucose and aerated with oxygen:carbon dioxide (95:5 v/v %). The uptake, which is expressed as the muscle-to-medium concentration ratio, was 1.41, after 3 hours, after which the rate of uptake diminished and became equal to that of inulin. The uptake which showed partial saturation, was decreased by some tertiary and quarternary amines, metabolic inhibitors, potassium and in an atmosphere of nitrogen. Neostigmine accumulated in all parts of the muscle without preference for the end plate zone. The half-time for the efflux was about 30 min. The phrenic nerve-diaphragm preparation became desensitized to the effect of 3x10 -7 M neostigmine after 2-3 hours. It is suggested that the uptake of neostigmine is mediated via a specialized carrier transport system. (author)

  16. Antidiarrheal Activity of 19-Deoxyicetexone Isolated from Salvia ballotiflora Benth in Mice and Rats

    Directory of Open Access Journals (Sweden)

    Ernesto Sánchez-Mendoza

    2013-07-01

    Full Text Available The antidiarrheal properties of 19-deoxyicetexone, a diterpenoid isolated from Salvia ballotiflora were evaluated on castor oil-, arachidonic acid (AA- and prostaglandin (PGE2-induced diarrhea in rodent models. The structure of 19-deoxyicetexone was determined by X-ray crystallography, mass spectrometry (EI-MS, as well as ultraviolet (UV-Vis, infrared (FT-IR and nuclear magnetic resonance (NMR spectroscopies. This compound significantly and dose-dependently reduced frequency of stooling in castor oil-induced diarrhea, and at dose of 25 mg/kg it also inhibited diarrhea induced with AA, while it had no effect on PGE2-induced diarrhea. This compound at doses of 25 mg/kg also diminished castor oil-induced enteropooling and intestinal motility, and inhibited the contraction of the rats’ ileum induced by carbachol chloride at a concentration of 100 µg/mL. 19-Deoxyicetexone did not present acute toxicity at doses of 625 mg/kg. Its antidiarrheal activity may be due to increased reabsorption of NaCl and water and inhibition of the release of prostaglandins, gastrointestinal motility and fluid accumulation in the intestinal tracts of rats. These findings suggest that 19-deoxyicetexone may be used in the treatment of diarrhea, although more studies must be carried out to confirm this.

  17. Effect of ADH on rubidium transport in isolated perfused rat cortical collecting tubules

    International Nuclear Information System (INIS)

    Schafer, J.A.; Troutman, S.L.

    1986-01-01

    Unidirectional fluxes of 86Rb+ were measured as an indicator of potassium transport in isolated rat cortical collecting tubules perfused and bathed at 38 degrees C with isotonic solutions in which Rb+ replaced K+. Under control conditions the lumen-to-bath flux (Jl----b) was significantly less than the bath-to-lumen flux (Jb----l), indicating net Rb+ secretion. Net secretion increased approximately 180% after addition of 100 microU/ml of arginine vasopressin (ADH) to the bathing solution, due to a rapid and reversible increase in Jb----l from 4.6 +/- 0.8 to 9.0 +/- 1.9 pmol X min-1 X mm-1 with no significant change in Jl----b. The ADH effect was completely inhibited by 2 mM luminal Ba2+. The average transepithelial voltage (Ve) was not significantly different from zero in the control period but became lumen negative (-5 to -10 mV) after ADH. With 10(-5) M amiloride in the lumen Ve was lumen positive (+2 to +4 mV) and was unaltered by ADH or Ba2+, yet ADH produced a significant but attentuated increase in Jb----l with no change in Jl----b. The results indicate that ADH augments net K+ secretion either by an increase in the Ba2+-sensitive conductance of the apical membrane or by an increase in the electrochemical potential driving force for net Rb+ secretion through this pathway

  18. Vasopressin-induced constriction of the isolated rat occipital artery is segment dependent.

    Science.gov (United States)

    Chelko, Stephen P; Schmiedt, Chad W; Lewis, Tristan H; Lewis, Stephen J; Robertson, Tom P

    2013-01-01

    Circulating factors delivered to the nodose ganglion (NG) by the occipital artery (OA) have been shown to affect vagal afferent activity, and thus the contractile state of the OA may influence blood flow to the NG. OA were isolated and bisected into proximal and distal segments relative to the external carotid artery. Bisection highlighted stark differences between maximal contractile responses and OA sensitivity. Specifically, maximum responses to vasopressin and the V1 receptor agonist were significantly higher in distal than proximal segments. Distal segments were significantly more sensitive to 5-hydroxytryptamine (5-HT) and the 5-HT2 receptor agonist than proximal segments. Angiotensin II (AT)2, V2 and 5-HT(1B/1D) receptor agonists did not elicit vascular responses. Additionally, AT1 receptor agonists elicited mild, yet not significantly different maximal responses between segments. The results of this study are consistent with contractile properties of rat OA being mediated via AT1, V1 and 5-HT2 receptors and dependent upon the OA segment. Furthermore, vasopressin-induced constriction of the OA, regardless of a bolus dose or a first and second concentration-response curve, retained this unique segmental difference. We hypothesize that these segmental differences may be important in the regulation of blood flow through the OA in health and disease. © 2013 S. Karger AG, Basel.

  19. Vasopressin-induced constriction of the isolated rat occipital artery is segment-dependent

    Science.gov (United States)

    Chelko, Stephen P.; Schmiedt, Chad W.; Lewis, Tristan H.; Lewis, Stephen J.; Robertson, Tom P.

    2014-01-01

    Background Circulating factors delivered to the nodose ganglion (NG) by the occipital artery (OA) have shown to affect vagal afferent activity, and thus the contractile state of the OA may influence blood flow to the NG. Methods OA were isolated and bisected into proximal and distal segments, relative to the external carotid artery. Results Bisection, highlighted stark differences between maximal contractile responses and OA sensitivity. Specifically, maximum responses to vasopressin and the V1 receptor agonist, were significantly higher in distal than proximal segments. Distal segments were significantly more sensitive to 5-HT and the 5-HT2 receptor agonist than proximal segments. AT2, V2 and 5-HT1B/1D receptor agonists did not elicit vascular responses. Additionally, AT1 receptor agonists elicited mild, yet not significantly different maximal responses between segments. Conclusion The results of this study are consistent with contractile properties of rat OA being mediated via AT1, V1 and 5-HT2 receptors, and are dependent upon the OA segment. Furthermore, vasopressin-induced constriction of the OA, regardless of a bolus dose or a first and second concentration response curve retained this unique segmental difference and therefore we hypothesize this may be a pathophysiological response in the regulation of blood flow through the OA. PMID:24192548

  20. beta-Methyl-15-p-iodophenylpentadecanoic acid metabolism and kinetics in the isolated rat heart.

    Science.gov (United States)

    DeGrado, T R; Holden, J E; Ng, C K; Raffel, D M; Gatley, S J

    1989-01-01

    The use of 15-p-iodophenyl-beta-methyl-pentadecanoic acid (beta Me-IPPA) as an indicator of long chain fatty acid (LCFA) utilization in nuclear medicine studies was evaluated in the isolated, perfused, working rat heart. Time courses of radioactivity (residue curves) were obtained following bolus injections of both beta Me-IPPA and its straight chain counterpart 15-p-iodophenyl-pentadecanoic acid (IPPA). IPPA kinetics clearly indicated flow independent impairment of fatty acid oxidation caused by the carnitine palmitoyltransferase I inhibitor 2[5(4-chlorophenyl)pentyl]oxirane-2-carboxylate (POCA). In contrast, beta Me-IPPA kinetics were insensitive to changes in fatty acid oxidation rate and net utilization of long chain fatty acid. Analysis of radiolabeled species in coronary effluent and heart homogenates showed the methylated fatty acid to be readily incorporated into complex lipids but a poor substrate for oxidation. POCA did not significantly alter metabolism of the tracer, suggesting that the tracer is poorly metabolized beyond beta Me-IPPA-CoA in the oxidative pathway.

  1. β-methyl-15-p-iodophenylpentadecanoic acid metabolism and kinetics in the isolated rat heart

    International Nuclear Information System (INIS)

    DeGrado, T.R.; Holden, J.E.; Ng, C.K.; Raffel, D.M.; Gatley, S.J.

    1989-01-01

    The use of 15-p-iodophenyl-β-methyl-pentadecanoic acid (βMe-IPPA) as an indicator of long chain fatty acid (LCFA) utilization in nuclear medicine studies was evaluated in the isolated, perfused, working rat heart. Time courses of radioactivity (residue curves) were obtained following bolus injections of both βMe-IPPA and its straight chain counterpart 15-p-iodophenyl-pentadecanoic acid (IPPA). IPPA kinetics clearly indicated flow independent impairment of fatty acid oxidation caused by the carnitine palmitoyltransferase I inhibitor 2[5(4-chlorophenyl)pentyl]oxirane-2-carboxylate (POCA). In contrast, βMe-IPPA kinetics were insensitive to changes in fatty acid oxidation rate and net utilization of long chain fatty acid. Analysis of radiolabeled species in coronary effluent and heart homogenates showed the methylated fatty acid to be readily incorporated into complex lipids but a poor substrate for oxidation. POCA did not significantly alter metabolism of the tracer, suggesting that the tracer is poorly metabolized beyond βMe-IPPA-CoA in the oxidative pathway. (orig.)

  2. beta. -methyl-15-p-iodophenylpentadecanoic acid metabolism and kinetics in the isolated rat heart

    Energy Technology Data Exchange (ETDEWEB)

    DeGrado, T.R.; Holden, J.E.; Ng, C.K.; Raffel, D.M.; Gatley, S.J.

    1989-02-01

    The use of 15-p-iodophenyl-..beta..-methyl-pentadecanoic acid (..beta..Me-IPPA) as an indicator of long chain fatty acid (LCFA) utilization in nuclear medicine studies was evaluated in the isolated, perfused, working rat heart. Time courses of radioactivity (residue curves) were obtained following bolus injections of both ..beta..Me-IPPA and its straight chain counterpart 15-p-iodophenyl-pentadecanoic acid (IPPA). IPPA kinetics clearly indicated flow independent impairment of fatty acid oxidation caused by the carnitine palmitoyltransferase I inhibitor 2(5(4-chlorophenyl)pentyl)oxirane-2-carboxylate (POCA). In contrast, ..beta..Me-IPPA kinetics were insensitive to changes in fatty acid oxidation rate and net utilization of long chain fatty acid. Analysis of radiolabeled species in coronary effluent and heart homogenates showed the methylated fatty acid to be readily incorporated into complex lipids but a poor substrate for oxidation. POCA did not significantly alter metabolism of the tracer, suggesting that the tracer is poorly metabolized beyond ..beta..Me-IPPA-CoA in the oxidative pathway.

  3. Biliary excretion of ouabain in isolated perfused rat liver after treatment with microsomal enzyme inducers

    International Nuclear Information System (INIS)

    Nevasaari, K.; Alakare, B.; Kaerki, N.T.

    1976-01-01

    The effect of pretreatment with spironolactone, phenobarbital and 3,4-benzpyrene on biliary excretion of ouabain was studied in isolated perfused rat liver system after a single dose of 3 H-ouabain. Spironolactone pretreatment (100 mg/kg intraperitoneally for 4 days) changed the time course of the excretion, thus accelerating the transport of ouabain into the bile. Phenobarbital pretreatment (75 mg/kg intraperitoneally for 4 days) enhanced bile flow and increased biliary excretion of ouabain only after 15 min. At longer time periods the increase in bile flow diluted the bile level of ouabain there being no difference in the amounts excreted into the bile between the treated and untreated groups. 3,4-benzpyrene pretreatment (20 mg/kg intraperitoneally for 4 days) was without efffect on biliary excretion of ouabain. The results suggest that spironolactone differs from phenobarbital in its enhancing effect on biliary excretion of ouabain, possibly through a specific effect on an unknown hepatic transport mechanism. (author)

  4. Binding and functional effects of atrial natriuretic factor in isolated rat kidney

    International Nuclear Information System (INIS)

    Suzuki, M.; Almeida, F.A.; Nussenzveig, D.R.; Sawyer, D.; Maack, T.

    1987-01-01

    A new methodological approach was developed to study the relationship between specific binding and dose-response curves of the renal effects of atrial natriuretic factor (ANF) in isolated perfused rat kidneys (IK). IK were perfused with 125 I-labeled and unlabeled ANF 1-28 to determine the following: (1) distribution, capacity (C max ), and apparent affinity (S 50 ) of specific binding of ANF 1-28 in cortex, outer medulla, and papilla and (2) dose-response curves of the effects of ANF 1-28 on renal hemodynamics and excretion of fluid and electrolytes. The kidney had a very high density of high-affinity binding sites for ANF. Cortex had >90% of total binding sites whereas papilla had <2% of total binding sites with a 10-fold lower apparent affinity than in cortex. ANF-induced increases in glomerular filtration rate and excretion of fluid and electrolytes were detectable at 10-100 pM and maximal effects occurred at 1-10 nM ANF. Below 1 nM there was no dissociation between the renal hemodynamic and natriuretic effects of ANF. There was a close agreement between dose-response and binding curves of ANF to cortex. Results demonstrates that binding site occupancy in kidney cortex and renal effects of ANF occur at near physiological concentrations of the hormone

  5. Penile erection responses of Nigella sativa seed extract on isolated rat corpus cavernosum

    Science.gov (United States)

    Aminyoto, M.; Ismail, S.

    2018-04-01

    Nigella sativa L. (NS) from Ranunculaceae family is known as black cumin in Indonesia. The seed has been used as an aphrodisiac in ethnobotanical studies and reported to have pharmacological activities such as antihypertensive through the relaxant effect of vascular smooth muscles but the direct effect to the blood vessels of the corpus cavernosum is still unknown. The purpose of this study was to examine the response of NS seed extract on penile erection in vitro. NS seeds were macerated in ethanol solvent for three days in room temperature and repeated for two times. Penile erection responses was assessed using isolated rat corpus cavernosum in Krebs-Henseleit solution, temperature 37°C, pH 7.4, aerated with carbogen gas. After acclimation, corpus cavernosum was contracted with a phenylephrine solution. Ethanolic extract of NS seeds or control solution were given after reaching the plateu phase of the highest contraction. This study showed that the contraction response of the corpus cavernosum decreased after addition of NS extract and this action was increased with the addition of the extract concentration. This study concluded that NS seed ethanol extract affects the penile erection response directly through the relaxation of blood vessels in the corpus cavernosum.

  6. Isoproterenol attenuates high vascular pressure-induced permeability increases in isolated rat lungs.

    Science.gov (United States)

    Parker, J C; Ivey, C L

    1997-12-01

    To separate the contributions of cellular and basement membrane components of the alveolar capillary barrier to the increased microvascular permeability induced by high pulmonary venous pressures (Ppv), we subjected isolated rat lungs to increases in Ppv, which increased capillary filtration coefficient (Kfc) without significant hemorrhage (31 cmH2O) and with obvious extravasation of red blood cells (43 cmH2O). Isoproterenol (20 microM) was infused in one group (Iso) to identify a reversible cellular component of injury, and residual blood volumes were measured to assess extravasation of red blood cells through ruptured basement membranes. In untreated lungs (High Ppv group), Kfc increased 6.2 +/- 1.3 and 38.3 +/- 15.2 times baseline during the 31 and 43 cmH2O Ppv states. In Iso lungs, Kfc was 36.2% (P Kfc increases at moderate Ppv, possibly because of an endothelial effect, but it did not affect red cell extravasation at higher vascular pressures.

  7. Effects of rocuronium and vecuronium on initial rundown of endplate potentials in the isolated phrenic nerve diaphragm preparation of rats

    OpenAIRE

    Li, Jun; Liu, Yong-Qin; Zhang, Han-Ting

    2013-01-01

    Rocuronium and vecuronium, two non-depolarizing neuromuscular blockers, have been widely used in surgery procedures. However, their electrophysiological properties need to be more widely explored. We examined the effects of rocuronium and vecuronium on initial rundown of endplate potential amplitudes in the non-uniform stretched muscle preparation of the rat isolated phrenic nerve diaphragm. More specifically, the endplate potentials were recorded with one microelectrode from a single endplat...

  8. Metabolism in the isolated rat heart: comparison of 125I-BMIPP with 125I-IPPA

    International Nuclear Information System (INIS)

    Chen Shaoliang; Cheng Aiping; Xu Lanwen; Qiao Weiwei

    2008-01-01

    Objective: The fatty acid metabolism in myocardium is recently one of the most interesting subjects in nuclear cardiology. The purpose of this study was to clarify the metabolic fate of 125 I-labeled 15-(p-iodophenyl)-3-(R, S)-methyl-pentadecanoic acid ( 125 I-BMIPP) and 15-(p-[ 125 I] iodophenyl) pentadecanoic acid ( 125 I-IPPA) by means of isolated rat hearts. Methods: Ten isolated rat hearts were prepared and perfused with 125 I-BMIPP (5 rats) or 125 I-IPPA (5 rats) for 3 h following a basic perfusion of 30 min. After perfusion, the radioactivity in the recirculated buffer was measured. The metabolites in the buffer were then extracted and analyzed using high performance liquid chromatography (HPLC) and thin-layer chromatography (TLC). Results: At the beginning (5 rain) of 125 I-BMIPP perfusion, the main radioactive peak appeared on HPLC at 37 min, which remained after 3 h perfusion. Several small peaks eluting were found before the parent peak at 30, 26, 21, 16, 12 and 9 min, respectively. At the beginning (5 min) of 125 I-IPPA perfusion, the main peak appeared on HPLC at 33 min, which disappeared after 3 h. Conclusions: 125 I-BMIPP strongly inhibited beta-oxidation, therefore appeared suitable for myocardial metabolic imaging. 125 I-IPPA was metabolized rapidly. (authors)

  9. The role of tryptophan 2,3-dioxygenase in the hormonal control of tryptophan metabolism in isolated rat liver cells. Effects of glucocorticoids and experimental diabetes.

    OpenAIRE

    Salter, M; Pogson, C I

    1985-01-01

    The metabolism of L-tryptophan by isolated liver cells prepared from control, adrenalectomized, glucocorticoid-treated, acute-diabetic, chronic-diabetic and insulin-treated chronic-diabetic rats was studied. Liver cells from adrenalectomized rats metabolized tryptophan at rates comparable with the minimum diurnal rates of controls, but different from rates determined for cells from control rats 4h later. Administration of dexamethasone phosphate increased the activity of tryptophan 2,3-dioxyg...

  10. Influence of fasting on the myocardial metabolsim of [123I] 16-iodohexadecenoic acid (IHA): a study on isolated rat heart

    International Nuclear Information System (INIS)

    Ghezzi, C.; Bontemps, L.; Demaison, L.; Dubois, F.; Comet, M.; Cuchet, P.

    1986-01-01

    IHA has been proposed for the study of myocardial metabolism by external detection. This requires numerical data on the iodinated fatty acid metabolism of the myocardium which can be derived from an analysis of the time activity curve. We developed a mathematical 4-compartment model for this purpose with compartments 0, 1, 2 and 3 representing vascular IHA, intracellular IHA, esterified forms and iodide, respectively. To validate this model it was applied to the study of the effect of fasting on rat myocardial metabolism. Two groups of rats were used, one fed ad lib. and the other fasted for 36 hours. After a bolus injection of IHA into the perfused rat coronaries myocardial time activity curves were recorded for 30 minutes and the activity distribution in the 4 compartments was simulated. Then intracellular activity in perfused rat heart homogenates was determined at different intervals p.i.. Measured and computed values were found to agree well in all compartments. A 36-hour fast was associated with increased uptake and accelerated β-oxidation, while esterification was unchanged. In conclusion, the proposed mathematical model helps to demonstrate even discrete changes of myocardial fatty acid metabolism in the isolated rat heart. Our results, once again, document the excellent suitability of IHA for assessing myocardial metabolism. (Author)

  11. The cardiac proteome in patients with congenital ventricular septal defect: A comparative study between right atria and right ventricles.

    Science.gov (United States)

    Bond, A R; Iacobazzi, D; Abdul-Ghani, S; Ghorbel, M T; Heesom, K J; George, S J; Caputo, M; Suleiman, M-S; Tulloh, R M

    2018-03-20

    Right ventricle (RV) remodelling occurs in neonatal patients born with ventricular septal defect (VSD). The presence of a defect between the two ventricles allows for shunting of blood from the left to right side. The resulting RV hypertrophy leads to molecular remodelling which has thus far been largely investigated using right atrial (RA) tissue. In this study we used proteomic and phosphoproteomic analysis in order to determine any difference between the proteomes for RA and RV. Samples were therefore taken from the RA and RV of five infants (0.34 ± 0.05 years, mean ± SEM) with VSD who were undergoing cardiac surgery to repair the defect. Significant differences in protein expression between RV and RA were seen. 150 protein accession numbers were identified which were significantly lower in the atria, whereas none were significantly higher in the atria compared to the ventricle. 19 phosphorylation sites (representing 19 phosphoproteins) were also lower in RA. This work has identified differences in the proteome between RA and RV which reflect differences in contractile activity and metabolism. As such, caution should be used when drawing conclusions based on analysis of the RA and extrapolating to the hypertrophied RV. RV hypertrophy occurs in neonatal patients born with VSD. Very little is known about how the atria responds to RV hypertrophy, especially at the protein level. Access to tissue from age-matched groups of patients is very rare, and we are in the unique position of being able to get tissue from both the atria and ventricle during reparative surgery of these infants. Our findings will be beneficial to future research into heart chamber malformations in congenital heart defects. Copyright © 2018. Published by Elsevier B.V.

  12. Dietary red palm oil supplementation reduces myocardial infarct size in an isolated perfused rat heart model

    Directory of Open Access Journals (Sweden)

    Esterhuyse Adriaan J

    2010-06-01

    Full Text Available Abstract Background and Aims Recent studies have shown that dietary red palm oil (RPO supplementation improves functional recovery following ischaemia/reperfusion in isolated hearts. The main aim of this study was to investigate the effects of dietary RPO supplementation on myocardial infarct size after ischaemia/reperfusion injury. The effects of dietary RPO supplementation on matrix metalloproteinase-2 (MMP2 activation and PKB/Akt phosphorylation were also investigated. Materials and methods Male Wistar rats were divided into three groups and fed a standard rat chow diet (SRC, a SRC supplemented with RPO, or a SRC supplemented with sunflower oil (SFO, for a five week period, respectively. After the feeding period, hearts were excised and perfused on a Langendorff perfusion apparatus. Hearts were subjected to thirty minutes of normothermic global ischaemia and two hours of reperfusion. Infarct size was determined by triphenyltetrazolium chloride staining. Coronary effluent was collected for the first ten minutes of reperfusion in order to measure MMP2 activity by gelatin zymography. Results Dietary RPO-supplementation decreased myocardial infarct size significantly when compared to the SRC-group and the SFO-supplemented group (9.1 ± 1.0% versus 30.2 ± 3.9% and 27.1 ± 2.4% respectively. Both dietary RPO- and SFO-supplementation were able to decrease MMP2 activity when compared to the SRC fed group. PKB/Akt phosphorylation (Thr 308 was found to be significantly higher in the dietary RPO supplemented group when compared to the SFO supplemented group at 10 minutes into reperfusion. There was, however, no significant changes observed in ERK phosphorylation. Conclusions Dietary RPO-supplementation was found to be more effective than SFO-supplementation in reducing myocardial infarct size after ischaemia/reperfusion injury. Both dietary RPO and SFO were able to reduce MMP2 activity, which suggests that MMP2 activity does not play a major role in

  13. Analysing the impact of reflectance distributions and well geometries on vertical surface daylight levels in atria for overcast skies

    Energy Technology Data Exchange (ETDEWEB)

    Du, Jiangtao; Sharples, Steve [School of Architecture, University of Sheffield, Crookesmoor Building, Conduit Road, Sheffield S10 1FL (United Kingdom)

    2010-07-15

    This study investigated the impacts of different diffuse reflectance distributions and well geometries on vertical daylight factors and vertical internally reflected components in atria. Two forms of reflectance distribution patterns of wall surface were examined: horizontal and vertical reflectance band variation. The square atrium models studied have a broader WI range of 0.25-2.0, which represent shallow, medium and high atria. Radiance, a powerful package based on backward ray tracing technique, was used for the simulations of vertical daylight levels. The results show that different reflectance distributions of square atrium walls do have an impact on the vertical daylight factors and vertical internally reflected components under overcast sky condition. The impact relates to the orientation of the band with different reflectance distributions on the wall. Compared with the vertical band surface, the horizontal band surface has a much more complicated effect. The horizontal distributions of the reflectances significantly affects the vertical daylight levels at the locations more than 30% atrium height on the wall. For an atrium with a height more than 1/2 the width, the effect tends to increase with the increasing well index. The vertical distributions of the reflectance, nevertheless, do not substantially take effect on the vertical daylight levels in atria except for some special reflectance distribution patterns. (author)

  14. Effect of immobilization stress on gene expression of catecholamine biosynthetic enzymes in heart auricles of socially isolated rats

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    L. Gavrilovic

    2009-12-01

    Full Text Available Chronic stress is associated with the development of cardiovascular diseases. The sympathoneural system plays an important role in the regulation of cardiac function both in health and disease. In the present study, the changes in gene expression of the catecholamine biosynthetic enzymes tyrosine hydroxylase (TH, dopamine-β-hydroxylase (DBH and phenylethanolamine N-methyltransferase (PNMT and protein levels in the right and left heart auricles of naive control and long-term (12 weeks socially isolated rats were investigated by Taqman RT-PCR and Western blot analysis. The response of these animals to additional immobilization stress (2 h was also examined. Long-term social isolation produced a decrease in TH mRNA level in left auricles (about 70% compared to the corresponding control. Expression of the DBH gene was markedly decreased both in the right (about 62% and left (about 81% auricles compared to the corresponding control, group-maintained rats, whereas PNMT mRNA levels remained unchanged. Exposure of group-housed rats to acute immobilization for 2 h led to a significant increase of mRNA levels of TH (about 267%, DBH (about 37% and PNMT (about 60% only in the right auricles. Additional 2-h immobilization of individually housed rats did not affect gene expression of these enzymes in either the right or left auricle. Protein levels of TH, DBH and PNMT in left and right heart auricles were unchanged either in both individually housed and immobilized rats. The unchanged mRNA levels of the enzymes examined after short-term immobilization suggest that the catecholaminergic system of the heart auricles of animals previously exposed to chronic psychosocial stress was adapted to maintain appropriate cardiovascular homeostasis.

  15. AICAR stimulation metabolome widely mimics electrical contraction in isolated rat epitrochlearis muscle.

    Science.gov (United States)

    Miyamoto, Licht; Egawa, Tatsuro; Oshima, Rieko; Kurogi, Eriko; Tomida, Yosuke; Tsuchiya, Koichiro; Hayashi, Tatsuya

    2013-12-15

    Physical exercise has potent therapeutic and preventive effects against metabolic disorders. A number of studies have suggested that 5'-AMP-activated protein kinase (AMPK) plays a pivotal role in regulating carbohydrate and lipid metabolism in contracting skeletal muscles, while several genetically manipulated animal models revealed the significance of AMPK-independent pathways. To elucidate significance of AMPK and AMPK-independent signals in contracting skeletal muscles, we conducted a metabolomic analysis that compared the metabolic effects of 5-aminoimidazole-4-carboxamide-1-β-D-ribonucleoside (AICAR) stimulation with the electrical contraction ex vivo in isolated rat epitrochlearis muscles, in which both α1- and α2-isoforms of AMPK and glucose uptake were equally activated. The metabolomic analysis using capillary electrophoresis time-of-flight mass spectrometry detected 184 peaks and successfully annotated 132 small molecules. AICAR stimulation exhibited high similarity to the electrical contraction in overall metabolites. Principal component analysis (PCA) demonstrated that the major principal component characterized common effects whereas the minor principal component distinguished the difference. PCA and a factor analysis suggested a substantial change in redox status as a result of AMPK activation. We also found a decrease in reduced glutathione levels in both AICAR-stimulated and contracting muscles. The muscle contraction-evoked influences related to the metabolism of amino acids, in particular, aspartate, alanine, or lysine, are supposed to be independent of AMPK activation. Our results substantiate the significance of AMPK activation in contracting skeletal muscles and provide novel evidence that AICAR stimulation closely mimics the metabolomic changes in the contracting skeletal muscles.

  16. Measurement of the efficacy of 2% lipid in reversing bupivacaine- induced asystole in isolated rat hearts

    Science.gov (United States)

    2014-01-01

    Background The reversal efficacy of 2% lipid emulsion in cardiac asystole induced by different concentrations of bupivacaine is poorly defined and needs to be determined. Methods Forty-two male Sprague–Dawley rats were randomly divided into seven groups: B40, B60, B80, B100, B120, B140 and B160, n = 6. The Langendorff isolated heart perfusion model was used, which consisted of a balanced perfusion with Krebs-Henseleit solution for 25 minutes and a continuous infusion of 100 μmol/L bupivacaine until asystole had been induced for 3 minutes. The hearts in the seven groups were perfused with Krebs-Henseleit solution containing a 2% lipid emulsion, and 40, 60, 80, 100, 120, 140 or 160 μmol/L bupivacaine, respectively. Cardiac recovery was defined as a spontaneous and regular rhythm with a rate-pressure product > 10% of the baseline value for more than 1 minute. Our primary outcome was the rate-pressure product 25 minutes after cardiac recovery. Other cardiac function parameters were also recorded. Results All groups demonstrated cardiac recovery. During the recovery phase, heart rate, rate-pressure product, the maximum left ventricular pressure rise and decline in heart rate in the B120-B160 groups was significantly lower than those in the B40-B80 groups (P bupivacaine and the reversal effects of a 2% lipid emulsion showed a typical transoid S-shaped curve, R2 = 0.9983, IC50 value was 102.5 μmol/L (95% CI: 92.44 - 113.6). Conclusions There is a concentration-response relationship between the concentrations of bupivacaine and the reversal effects of 2% lipid emulsion. PMID:25089118

  17. Effects of 31 FDA approved small-molecule kinase inhibitors on isolated rat liver mitochondria.

    Science.gov (United States)

    Zhang, Jun; Salminen, Alec; Yang, Xi; Luo, Yong; Wu, Qiangen; White, Matthew; Greenhaw, James; Ren, Lijun; Bryant, Matthew; Salminen, William; Papoian, Thomas; Mattes, William; Shi, Qiang

    2017-08-01

    The FDA has approved 31 small-molecule kinase inhibitors (KIs) for human use as of November 2016, with six having black box warnings for hepatotoxicity (BBW-H) in product labeling. The precise mechanisms and risk factors for KI-induced hepatotoxicity are poorly understood. Here, the 31 KIs were tested in isolated rat liver mitochondria, an in vitro system recently proposed to be a useful tool to predict drug-induced hepatotoxicity in humans. The KIs were incubated with mitochondria or submitochondrial particles at concentrations ranging from therapeutic maximal blood concentrations (Cmax) levels to 100-fold Cmax levels. Ten endpoints were measured, including oxygen consumption rate, inner membrane potential, cytochrome c release, swelling, reactive oxygen species, and individual respiratory chain complex (I-V) activities. Of the 31 KIs examined only three including sorafenib, regorafenib and pazopanib, all of which are hepatotoxic, caused significant mitochondrial toxicity at concentrations equal to the Cmax, indicating that mitochondrial toxicity likely contributes to the pathogenesis of hepatotoxicity associated with these KIs. At concentrations equal to 100-fold Cmax, 18 KIs were found to be toxic to mitochondria, and among six KIs with BBW-H, mitochondrial injury was induced by regorafenib, lapatinib, idelalisib, and pazopanib, but not ponatinib, or sunitinib. Mitochondrial liability at 100-fold Cmax had a positive predictive power (PPV) of 72% and negative predictive power (NPV) of 33% in predicting human KI hepatotoxicity as defined by product labeling, with the sensitivity and specificity being 62% and 44%, respectively. Similar predictive power was obtained using the criterion of Cmax ≥1.1 µM or daily dose ≥100 mg. Mitochondrial liability at 1-2.5-fold Cmax showed a 100% PPV and specificity, though the NPV and sensitivity were 32% and 14%, respectively. These data provide novel mechanistic insights into KI hepatotoxicity and indicate that

  18. Adrenaline in pro-oxidant conditions elicits intracellular survival pathways in isolated rat cardiomyocytes

    International Nuclear Information System (INIS)

    Costa, Vera Marisa; Silva, Renata; Ferreira, Rita; Amado, Francisco; Carvalho, Felix; Bastos, Maria Lourdes de; Albuquerque Carvalho, Rui; Carvalho, Marcia; Remiao, Fernando

    2009-01-01

    In several pathologic conditions, like cardiac ischemia/reperfusion, the sustained elevation of plasma and interstitial catecholamine levels, namely adrenaline (ADR), and the generation of reactive oxygen species (ROS) are hallmarks. The present work aimed to investigate in cardiomyocytes which intracellular signalling pathways are altered by ADR redox ability. To mimic pathologic conditions, freshly isolated calcium tolerant cardiomyocytes from adult rat were incubated with ADR alone or in the presence of a system capable of generating ROS [(xanthine with xanthine oxidase) (X/XO)]. ADR elicited a pro-oxidant signal with generation of reactive species, which was largely magnified by the ROS generating system. However, no change in cardiomyocytes viability was observed. The pro-oxidant signal promoted the translocation to the nucleus of the transcription factors, Heat shock factor-1 (HSF-1) and Nuclear factor-κB (NF-κB). In addition, proteasome activity was compromised in the experimental groups where the generation of reactive species occurred. The decrease in the proteasome activity of the ADR group resulted from its redox sensitivity, since the activity was recovered by adding the ROS scavenger, tiron. Proteasome inhibition seemed to elicit an increase in HSP70 levels. Furthermore, retention of mitochondrial cytochrome c and inhibition of caspase 3 activity were observed by X/XO incubation in presence or absence of ADR. In conclusion, in spite of all the insults inflicted to the cardiomyocytes, they were capable to activate intracellular responses that enabled their survival. These mechanisms, namely the pathways altered by catecholamine proteasome inhibition, should be further characterized, as they could be of relevance in the ischemia preconditioning and the reperfusion injury

  19. Assessment of Cardiovascular Apoptosis in the Isolated Rat Heart by Magnetic Resonance Molecular Imaging

    Directory of Open Access Journals (Sweden)

    Karl-Heinz Hiller

    2006-04-01

    Full Text Available Apoptosis, an active process of cell self-destruction, is associated with myocardial ischemia. The redistribution of phosphatidylserine (PS from the inner to the outer leaflet of the cell membrane is an early event in apoptosis. Annexin V, a protein with high specificity and tight binding to PS, was used to identify and localize apoptosis in the ischemic heart. Fluorescein-labeled annexin V has been used routinely for the assessment of apoptosis in vitro. For the detection of apoptosis in vivo, positron emission tomography and single-photon emission computed tomography have been shown to be suitable tools. In view of the relatively low spatial resolution of nuclear imaging techniques, we developed a high-resolution contrast-enhanced magnetic resonance imaging (MRI method that allows rapid and noninvasive monitoring of apoptosis in intact organs. Instead of employing superparamagnetic iron oxide particles linked to annexin V, a new T1 contrast agent was used. To this effect, annexin V was linked to gadolinium diethylenetriamine pentaacetate (Gd-DTPA-coated liposomes. The left coronary artery of perfused isolated rat hearts was ligated for 30 min followed by reperfusion. T1 and T2* images were acquired by using an 11.7-T magnet before and after intracoronary injection of Gd-DTP-labeled annexin V to visualize apoptotic cells. A significant increase in signal intensity was visible in those regions containing cardiomyocytes in the early stage of apoptosis. Because labeling of early apoptotic cell death in intact organs by histological and immunohistochemical methods remains challenging, the use of Gd-DTPA-labeled annexin V in MRI is clearly an improvement in rapid targeting of apoptotic cells in the ischemic and reperfused myocardium.

  20. Analysis of agonist dissociation constants as assessed by functional antagonism in guinea pig left atria

    International Nuclear Information System (INIS)

    Molenaar, P.; Malta, E.

    1986-01-01

    In electrically driven guinea pig left atria, positive inotropic responses to (-)-isoprenaline and the selective beta 1-adrenoceptor agonist RO363 were obtained in the absence and in the presence of the functional antagonists adenosine, carbachol, gallopamil, nifedipine, and Ro 03-7894. Each of the functional antagonists reduced the maximum response to both agonists and produced nonparallel rightward shifts in the cumulative concentration effect curves. For both agonists, dissociation constants (KA) were calculated using the equation described by Furchgott (1966) for irreversible antagonism. For RO363, which is a partial agonist with high agonist activity, the equations outlined for functional interaction by Mackay (1981) were also employed to calculate KA values. The KA values obtained by each method were compared with the dissociation constants (KD) for the two agonists determined from their ability to displace the radioligand (-)-[ 125 I]iodocyanopindolol from beta 1-adrenoceptors in guinea pig left atrial membrane preparations. The estimates of KA varied substantially from KD values. The KD values were taken as more accurate estimates of the true values for the dissociation constants because a high degree of correlation exists between pKD and pD2 values for a number of other beta-adrenoceptor agonists that behave as partial agonists and between pKD and pKB values for a number of beta-adrenoceptor antagonists. Thus, it appears that there are serious limitations in the current theory for using functional antagonism as a means of obtaining agonist dissociation constants

  1. A method for the isolation and culture of adult rat retinal pigment epithelial (RPE cells to study retinal diseases

    Directory of Open Access Journals (Sweden)

    Janosch Peter Heller

    2015-11-01

    Full Text Available Diseases such as age-related macular degeneration (AMD affect the retinal pigment epithelium (RPE and lead to the death of the epithelial cells and ultimately blindness. RPE transplantation is currently a major focus of eye research and clinical trials using human stem cell-derived RPE cells are ongoing. However, it remains to be established to which extent the source of RPE cells for transplantation affects their therapeutic efficacy and this needs to be explored in animal models. Autotransplantation of RPE cells has attractions as a therapy, but existing protocols to isolate adult RPE cells from rodents are technically difficult, time-consuming, have a low yield and are not optimized for long-term cell culturing. Here, we report a newly devised protocol which facilitates reliable and simple isolation and culture of RPE cells from adult rats. Incubation of a whole rat eyeball in 20 U/ml papain solution for 50 minutes yielded 4 x 104 viable RPE cells. These cells were hexagonal and pigmented upon culture. Using immunostaining, we demonstrated that the cells expressed RPE cell-specific marker proteins including cytokeratin 18 and RPE65, similar to RPE cells in vivo. Additionally, the cells were able to produce and secrete Bruch’s membrane matrix components similar to in vivo situation. Similarly, the cultured RPE cells adhered to isolated Bruch’s membrane as has previously been reported. Therefore, the protocol described in this article provides an efficient method for the rapid and easy isolation of high quantities of adult rat RPE cells. This provides a reliable platform for studying the therapeutic targets, testing the effects of drugs in a preclinical setup and to perform in vitro and in vivo transplantation experiments to study retinal diseases.

  2. Effect of selenium and vitamin E deficiencies on the fate of arachidonic acid in rat isolated lungs

    International Nuclear Information System (INIS)

    Uotila, P.; Puustinen, T.

    1985-01-01

    The fate of exogenous 14 C-arachidonic acid ( 14 C-AA) was investigated in the isolated lungs of rats fed selenium and vitamin E deficient diet or diets supplemented with selenium and/or vitamin E. When 80 nmol of 14 C-AA was infused into the pulmonary circulation most of the infused 14 C-AA was found in different phospholipid and neutral lipid fractions of the perfused lungs. Only less than ten percent of the infused radioactivity was recovered in the perfusion effluent. The amount of arachidonate metabolites in the perfusion effluent was negligible, and most of the radioactivity in the perfusion effluent consisted of unmetabolized arachidonate. Selenium deficiency had no significant effect on the distribution of 14 C-AA in different lung lipid fractions. However, in the lungs of vitamin E deficient rats the amount of radioactivity was slightly increased in the neutral lipid fraction, which was due to the increased amount of 14 C-AA in the diacylglycerols. The amount of radioactivity was increased especially in the 1,3-diacylglycerols. The amount of radioactivity was increased especially in the 1,3-diacylglycerols. The amount of 14 C-AA in the triacylglycerols and in different phospholipids was not significantly changed. The present study might indicate that selenium deficiency has no significant effect on the fate of exogenous arachidonic acid in isolated rat lungs, and that vitamin E deficiency would slightly increase the amount of arachidonic acid in the diacylglycerols

  3. Effect of Propafenone on the Contractile Activity of Latissimus Dorsi Muscle Isolated in an Organ Chamber: Experimental Study in Rats

    Directory of Open Access Journals (Sweden)

    Ricardo Simões

    2002-03-01

    Full Text Available OBJECTIVE: To study the effect of propafenone on the contractile function of latissimus dorsi muscle isolated from rats in an organ chamber. METHODS: We studied 20 latissimus dorsi muscles of Wistar rats and divided them into 2 groups: group I (n=10, or control group - we studied the feasibility of muscle contractility; group II (n=10, in which the contralateral muscles were grouped - we analyzed the effect of propafenone on muscle contractility. After building a muscle ring, 8 periods of sequential 2-minute baths were performed, with intervals of preprogrammed electrical stimulation using a pacemaker of 50 stimuli/min. In group II, propafenone, at the concentration of 9.8 µg/mL, was added to the bath in period 2 and withdrawn in period 4. RESULTS: In group I, no significant depression in muscle contraction occurred up to period 5 (p>0.05. In group II, a significant depression occurred in all periods, except between the last 2 periods (p0.05. CONCLUSION: Propafenone had a depressing effect on the contractile function of latissimus dorsi muscle isolated from rats and studied in an organ chamber.

  4. The uptake and metabolism of cystamine and taurine by isolated, ventilated and perfused rat and rabbit lungs

    International Nuclear Information System (INIS)

    Sharma, R.; Kodavanti, U.P.; Smith, L.L.; Mehendale, H.M.

    1991-01-01

    Cystamine has been reported to be taken up by the lung slices and metabolized to taurine via hypotaurine through enzymatic processes. The objective of these studies was to determine whether intact isolated, ventilated and perfused rat and rabbit lungs also posses similar characteristics. The lungs were isolated from male New Zealand white rabbits and S-D rats and perfused with 20 μM [ 14 C] cystamine (Sp. Act., 16.4 mCi/mmol) for 60 min and 30 min, respectively. Cystamine and its metabolites in lung as well as in perfusate were separated by TLC and quantitated using scintillation spectrometry. Similar experiments were also conducted with 20 μM taurine to investigate its fate in perfused lungs. Significant pulmonary uptake of cystamine and taurine occurred during perfusion. Cystamine was metabolized to [ 14 C] hypotaurine and [ 14 C] taurine. No further metabolism of taurine was evident in rat or rabbit lungs. Inclusion of 1 nM GSH did not significantly alter the ability of lungs to sequester cystamine, but the metabolism of hypotaurine to taurine was decreased. It was evident that cystamine was metabolized to taurine by perfused lungs in the same way as in lung slices

  5. Does N-acetylcysteine have an effect on acetylcholine-induced contractions and histopathological changes on isolated rat ileum?

    International Nuclear Information System (INIS)

    Koc, E.; Yavuzer, Sema A.; Ocakcioglu, B.; Ergun, A.; Can, B.; Saran, Y.

    2007-01-01

    Objective was to investigate the action of N-acetyllcysteine (NAC) on rat isolated ileal contractility and to determine the effects of NAC on histopathological changes on ileal tissue. The study took place at the Faculty of Medicine, Ankara University, Ankara, Turkey, January 2003. Adult Wistar rats were used in all experiments. Two groups were designed. The experimental group, to which NAC 0.5 g/Kg/day was administered orally by adding to their water for 7 days, and the control group to which only saline was administered. At the end of experimental periods, one cm pieces of terminal ileum segments were removed for testing ileal contractility, and one cm pieces of ileum segments were removed for histopathological experiments. The acetylcholine (ACh)-induced contraction was recorded, and the ileal tissue examined using light and electron microscopic techniques for histopathological changes. The average peak amplitude of Ach-induced contraction recorded in standard tyrode solution of the experimental group was decreased significantly when compared to the control group in standard and calcium-free tyrode solution. On histopathological findings, there were swollen mitochondria with disturbed cristae in ileal muscle. Our data suggest that the NAC in the present experiment decreased the ACh-induced contractility on rat-isolated ileum. (author)

  6. Hydroxyl radicals' production and ECG parameters during ischemia and reperfusion in rat, guinea pig and rabbit isolated heart.

    Science.gov (United States)

    Paulova, Hana; Stracina, Tibor; Jarkovsky, Jiri; Novakova, Marie; Taborska, Eva

    2013-06-01

    Ischemic and reperfusion injury is a serious condition related to numerous biochemical and electrical abnormalities of the myocardium. It has been repeatedly studied in various animal models. In this study, the production of hydroxyl radicals and electrophysiological parameters were compared in three species. Rat, guinea pig and rabbit isolated hearts were perfused according to Langendorff under strictly identical conditions. The heart rate and arrhythmia were monitored during ischemia and reperfusion periods at defined time intervals; the production of hydroxyl radical was determined by HPLC as 2.5-dihydroxybenzoic acid (2.5-DHBA) formed by salicylic acid hydroxylation. Relationship between arrhythmias and production of 2.5-DHBA was studied. The inter-species differences were observed in timing of arrhythmias onset and their severity, and in the production of 2.5-DHBA in both ischemia and reperfusion. The most considerable changes were observed in rats, where arrhythmias appeared early and with highest severity during ischemia on one side and the regular rhythm was restored early and completely during reperfusion. The corresponding changes in the production of 2.5-DHBA were observed. It can be concluded that rat isolated heart is the most suitable model for evaluation of ischemia/reperfusion injury under given experimental conditions.

  7. Frequent combination of antimicrobial multiresistance and extraintestinal pathogenicity in Escherichia coli isolates from urban rats (Rattus norvegicus) in Berlin, Germany.

    Science.gov (United States)

    Guenther, Sebastian; Bethe, Astrid; Fruth, Angelika; Semmler, Torsten; Ulrich, Rainer G; Wieler, Lothar H; Ewers, Christa

    2012-01-01

    Urban rats present a global public health concern as they are considered a reservoir and vector of zoonotic pathogens, including Escherichia coli. In view of the increasing emergence of antimicrobial resistant E. coli strains and the on-going discussion about environmental reservoirs, we intended to analyse whether urban rats might be a potential source of putatively zoonotic E. coli combining resistance and virulence. For that, we took fecal samples from 87 brown rats (Rattus norvegicus) and tested at least three E. coli colonies from each animal. Thirty two of these E. coli strains were pre-selected from a total of 211 non-duplicate isolates based on their phenotypic resistance to at least three antimicrobial classes, thus fulfilling the definition of multiresistance. As determined by multilocus sequence typing (MLST), these 32 strains belonged to 24 different sequence types (STs), indicating a high phylogenetic diversity. We identified STs, which frequently occur among extraintestinal pathogenic E. coli (ExPEC), such as STs 95, 131, 70, 428, and 127. Also, the detection of a number of typical virulence genes confirmed that the rats tested carried ExPEC-like strains. In particular, the finding of an Extended-spectrum beta-lactamase (ESBL)-producing strain which belongs to a highly virulent, so far mainly human- and avian-restricted ExPEC lineage (ST95), which expresses a serogroup linked with invasive strains (O18:NM:K1), and finally, which produces an ESBL-type frequently identified among human strains (CTX-M-9), pointed towards the important role, urban rats might play in the transmission of multiresistant and virulent E. coli strains. Indeed, using a chicken infection model, this strain showed a high in vivo pathogenicity. Imagining the high numbers of urban rats living worldwide, the way to the transmission of putatively zoonotic, multiresistant, and virulent strains might not be far ahead. The unforeseeable consequences of such an emerging public health

  8. Short-term isolation increases social interactions of male rats: A parametric analysis

    NARCIS (Netherlands)

    Niesink, R.J.M.; Ree, J.M. van

    1982-01-01

    Frequencies of social interactions were higher in pairs of short-term individually housed male Wistar rats as compared to group-housed animals. This was most pronounced when an individually housed rat and a group-housed conspecific were tested together in the morning under red light conditions.

  9. Failure of isolated rat tibial periosteal cells to 5 alpha reduce testosterone to 5 alpha-dihydrotestosterone

    Energy Technology Data Exchange (ETDEWEB)

    Turner, R.T.; Bleiberg, B.; Colvard, D.S.; Keeting, P.E.; Evans, G.; Spelsberg, T.C. (Mayo Clinic, Rochester, MN (USA))

    1990-07-01

    Periosteal cells were isolated from tibiae of adult male rats after collagenase treatment. Northern blot analysis of total cytoplasmic RNA extracted from the isolated periosteal cells was positive for expression of genes encoding the osteoblast marker proteins osteocalcin (BGP) and pre-pro-alpha 2(I) chain of type 1 precollagen. The isolated periosteal cells were incubated with 1 nM (3H)testosterone (({sup 3}H)T) for up to 240 minutes and the reaction products separated by high-performance liquid chromatography. ({sup 3}H)5 alpha-dihydrotestosterone (({sup 3}H)DHT) was not detected in extracts of periosteal cell incubations. In contrast, ({sup 3}H)DHT was produced in a time-dependent manner by cells from seminal vesicles. These results suggest that testosterone 5 alpha-reductase activity is not expressed by osteoblasts in rat tibial periosteum and that the anabolic effects of androgens in this tissue are not mediated by locally produced DHT.

  10. The Evidence for Altered BDNF Expression in the Brain of Rats Reared or Housed in Social Isolation: A Systematic Review

    Directory of Open Access Journals (Sweden)

    Jana Murínová

    2017-05-01

    Full Text Available There is evidence that development and maintenance of neural connections are disrupted in major mental disorders, which indicates that neurotrophic factors could play a critical role in their pathogenesis. Stress is a well-established risk factor for psychopathology and recent research suggests that disrupted signaling via brain-derived neurotrophic factor (BDNF may be involved in mediating the negative effects of stress on the brain. Social isolation of rats elicits chronic stress and is widely used as an animal model of mental disorders such as schizophrenia and depression. We carried out a systematic search of published studies to review current evidence for an altered expression of BDNF in the brain of rats reared or housed in social isolation. Across all age groups (post-weaning, adolescent, adult, majority of the identified studies (16/21 reported a decreased expression of BDNF in the hippocampus. There are far less published data on BDNF expression in other brain regions. Data are also scarce to assess the behavioral changes as a function of BDNF expression, but the downregulation of BDNF seems to be associated with increased anxiety-like symptoms. The reviewed data generally support the putative involvement of BDNF in the pathogenesis of stress-related mental illness. However, the mechanisms linking chronic social isolation, BDNF expression and the elicited behavioral alterations are currently unknown.

  11. The metabolism of aflatoxin B1 by hepatocytes isolated from rats following the in vivo administration of some xenobiotics

    International Nuclear Information System (INIS)

    Metcalfe, S.A.; Neal, G.E.

    1983-01-01

    Isolated rat hepatocytes, an intact cellular system capable of performing phase I and phase II metabolism, have been used to investigate metabolism of aflatoxin B1. These cells were found to metabolise [ 14 C]aflatoxin B1 to aflatoxins M1 and Q1, and to radiolabelled polar material, presumably conjugates, as analysed by h.p.l.c., t.l.c. and radioactive determination. In vivo administration of the mixed function oxidase inducers, phenobarbitone and 3-methylcholanthrene, resulted in enhanced hepatocyte phase I (microsomal) metabolism of aflatoxin B1. In contrast to metabolism of AFB1 by in vitro subcellular systems increased production of polar material (conjugated metabolites) derived from [ 14 C]aflatoxin B1 was also detected in hepatocytes isolated from these pretreated animals. Formation of aflatoxin Q1 by isolated hepatocytes appeared to be mediated by cytochrome P450-linked enzymes whereas cytochrome P448-linked enzymes were apparently involved in aflatoxin M1 production. Chronic feeding of aflatoxin B1 to rats enhanced hepatocyte production of conjugated material only and did not elevate cellular cytochrome P450 levels, thus suggesting that aflatoxin B1 is not an inducer of its own primary metabolism

  12. Phylogenetic relationship of the Brazilian isolates of the rat lungworm Angiostrongylus cantonensis (Nematoda: Metastrongylidae employing mitochondrial COI gene sequence data

    Directory of Open Access Journals (Sweden)

    Monte Tainá CC

    2012-11-01

    Full Text Available Abstract Background The rat lungworm Angiostrongylus cantonensis can cause eosinophilic meningoencephalitis in humans. This nematode’s main definitive hosts are rodents and its intermediate hosts are snails. This parasite was first described in China and currently is dispersed across several Pacific islands, Asia, Australia, Africa, some Caribbean islands and most recently in the Americas. Here, we report the genetic variability among A. cantonensis isolates from different geographical locations in Brazil using mitochondrial cytochrome c oxidase subunit I (COI gene sequences. Methods The isolates of A. cantonensis were obtained from distinct geographical locations of Brazil. Genomic DNAs were extracted, amplified by polymerase reaction, purified and sequenced. A partial sequence of COI gene was determined to assess their phylogenetic relationship. Results The sequences of A. cantonensis were monophyletic. We identified a distinct clade that included all isolates of A. cantonensis from Brazil and Asia based on eight distinct haplotypes (ac1, ac2, ac3, ac4, ac5, ac6, ac7 and ac8 from a previous study. Interestingly, the Brazilian haplotype ac5 is clustered with isolates from Japan, and the Brazilian haplotype ac8 from Rio de Janeiro, São Paulo, Pará and Pernambuco states formed a distinct clade. There is a divergent Brazilian haplotype, which we named ac9, closely related to Chinese haplotype ac6 and Japanese haplotype ac7. Conclusion The genetic variation observed among Brazilian isolates supports the hypothesis that the appearance of A. cantonensis in Brazil is likely a result of multiple introductions of parasite-carrying rats, transported on ships due to active commerce with Africa and Asia during the European colonization period. The rapid spread of the intermediate host, Achatina fulica, also seems to have contributed to the dispersion of this parasite and the infection of the definitive host in different Brazilian regions.

  13. Phylogenetic relationship of the Brazilian isolates of the rat lungworm Angiostrongylus cantonensis (Nematoda: Metastrongylidae) employing mitochondrial COI gene sequence data

    Science.gov (United States)

    2012-01-01

    Background The rat lungworm Angiostrongylus cantonensis can cause eosinophilic meningoencephalitis in humans. This nematode’s main definitive hosts are rodents and its intermediate hosts are snails. This parasite was first described in China and currently is dispersed across several Pacific islands, Asia, Australia, Africa, some Caribbean islands and most recently in the Americas. Here, we report the genetic variability among A. cantonensis isolates from different geographical locations in Brazil using mitochondrial cytochrome c oxidase subunit I (COI) gene sequences. Methods The isolates of A. cantonensis were obtained from distinct geographical locations of Brazil. Genomic DNAs were extracted, amplified by polymerase reaction, purified and sequenced. A partial sequence of COI gene was determined to assess their phylogenetic relationship. Results The sequences of A. cantonensis were monophyletic. We identified a distinct clade that included all isolates of A. cantonensis from Brazil and Asia based on eight distinct haplotypes (ac1, ac2, ac3, ac4, ac5, ac6, ac7 and ac8) from a previous study. Interestingly, the Brazilian haplotype ac5 is clustered with isolates from Japan, and the Brazilian haplotype ac8 from Rio de Janeiro, São Paulo, Pará and Pernambuco states formed a distinct clade. There is a divergent Brazilian haplotype, which we named ac9, closely related to Chinese haplotype ac6 and Japanese haplotype ac7. Conclusion The genetic variation observed among Brazilian isolates supports the hypothesis that the appearance of A. cantonensis in Brazil is likely a result of multiple introductions of parasite-carrying rats, transported on ships due to active commerce with Africa and Asia during the European colonization period. The rapid spread of the intermediate host, Achatina fulica, also seems to have contributed to the dispersion of this parasite and the infection of the definitive host in different Brazilian regions. PMID:23130987

  14. Phylogenetic relationship of the Brazilian isolates of the rat lungworm Angiostrongylus cantonensis (Nematoda: Metastrongylidae) employing mitochondrial COI gene sequence data.

    Science.gov (United States)

    Monte, Tainá C C; Simões, Raquel O; Oliveira, Ana Paula M; Novaes, Clodoaldo F; Thiengo, Silvana C; Silva, Alexandre J; Estrela, Pedro C; Maldonado, Arnaldo

    2012-11-06

    The rat lungworm Angiostrongylus cantonensis can cause eosinophilic meningoencephalitis in humans. This nematode's main definitive hosts are rodents and its intermediate hosts are snails. This parasite was first described in China and currently is dispersed across several Pacific islands, Asia, Australia, Africa, some Caribbean islands and most recently in the Americas. Here, we report the genetic variability among A. cantonensis isolates from different geographical locations in Brazil using mitochondrial cytochrome c oxidase subunit I (COI) gene sequences. The isolates of A. cantonensis were obtained from distinct geographical locations of Brazil. Genomic DNAs were extracted, amplified by polymerase reaction, purified and sequenced. A partial sequence of COI gene was determined to assess their phylogenetic relationship. The sequences of A. cantonensis were monophyletic. We identified a distinct clade that included all isolates of A. cantonensis from Brazil and Asia based on eight distinct haplotypes (ac1, ac2, ac3, ac4, ac5, ac6, ac7 and ac8) from a previous study. Interestingly, the Brazilian haplotype ac5 is clustered with isolates from Japan, and the Brazilian haplotype ac8 from Rio de Janeiro, São Paulo, Pará and Pernambuco states formed a distinct clade. There is a divergent Brazilian haplotype, which we named ac9, closely related to Chinese haplotype ac6 and Japanese haplotype ac7. The genetic variation observed among Brazilian isolates supports the hypothesis that the appearance of A. cantonensis in Brazil is likely a result of multiple introductions of parasite-carrying rats, transported on ships due to active commerce with Africa and Asia during the European colonization period. The rapid spread of the intermediate host, Achatina fulica, also seems to have contributed to the dispersion of this parasite and the infection of the definitive host in different Brazilian regions.

  15. Effect of phenobarbital pretreatment on benzene biotransformation in the rat. Pt. 2. 9. 000 g supernatant and isolated perfused liver versus living rat

    Energy Technology Data Exchange (ETDEWEB)

    Gut, I.; Hatle, K.; Zizkova, L.

    1981-03-01

    Factors responsible for different quantitative effect of phenobarbital (PB) pretreatment on benzene metabolism to phenol in vivo and in vitro were studied in male Wistar rats. A more than 4-fold increase of benzene metabolism was observed with 9,000 g supernatant of liver homogenate, 2.8- to 4-fold increase with isolated perfused liver; phenol formation in vivo after oral benzene was increased by PB 2-fold, but only shortly following benzene administration and the enhancement rapidly diminished to 1.15-fold increase in the total excreted phenol. Benzene concentrations in 9,000 g supernatant incubations were 2 mM, those with isolated perfused livers were up to 4 mM, but those in blood in vivo were below 0.3 mM; the effect of PB induction in vivo disappeared along with decreasing benzene and increasing phenol blood concentrations which surpassed benzene 2-3 h after oral benzene administration. The effect of benzene concentration on the manifestation of PB induction is also supported by almost a 2-fold increased phenol formation in PB rats over controls in vivo after repeated administration of benzene. The elimination of radioactive metabolites of orally administered benzene-/sup 14/C, in urine was markedly inhibited by intraperitoneal administration of phenol, but not by pyrocatechol, resorcinol or hydroquinol suggesting that phenol might inhibit benzene metabolism in vivo especially when its concentration exceeds that of benzene.

  16. The uptake and overflow of radiolabelled β-adrenoceptor blocking agents by the isolated vas deferens of the rat

    International Nuclear Information System (INIS)

    Lewis, M.J.

    1977-01-01

    A comparison of uptake into and overflow from the isolated vas deferens of the rat has been made between [ 3 H]-noradrenaline ([ 3 H]-NA), [ 14 C]-D-sorbitol and three radio-labelled β-adrenoceptor blocking agents, [ 14 C]-practolol, [ 14 C]-(+-)-propranolol and [ 3 H]-penbutolol. The accumulation of [ 3 H]-NA after 30 min incubation was reduced by desmethylimipramine (DMI) 1 x 10 -8 M and was also reduced in vasa from rats pretreated with 6-hydroxydopamine (6-OHDA). This was not so with [ 14 C]-D-sorbitol. 6-OHDA pretreatment of the rats reduced the uptake of [ 3 H]-penbutolol after 30 min incubation but not that of [ 14 C]-propranolol or [ 14 C]-practolol. DMI 1 x 10 -8 M did not alter the tissue uptake of [ 14 C]-propanolol, [ 14 C]-practolol or [ 3 H]-penbutolol. Electrical stimulation of vasa preloaded with [ 3 H]-NA caused a significantly greater increase in [ 3 H]-NA overflow than during the resting, unstimulated periods. No such increase in overflow was observed with [ 14 C]-sorbitol or any of the three β-adrenoceptor blocking agents used. The β-adrenoceptor blocking agent penbutolol was shown to possess adrenergic neurone blocking activity in the isolated vas deferens of the rat. It is concluded that any effect that practolol or (+-)-propranolol have on noradrenergic neurones is brought about without the need for these drugs to gain access to the interior of the neurone. (author)

  17. Resistance to Reperfusion Injury Following Short Term Postischemic Administration of Natural Honey in Globally Ischemic Isolated Rat Heart

    Directory of Open Access Journals (Sweden)

    Haleh Vaez

    2012-08-01

    Full Text Available Purpose: Results of our previous study revealed that preischemic perfusion of honey before zero flow global ischemia had cardioprotective effects in rat. The present study investigated potential resistance to reperfusion injury following short term postischemic administration of natural honey in globally ischemic isolated rat heart. Methods: Male Wistar rats were divided into five groups (n=10-13. The rat hearts were isolated, mounted on a Langendorff apparatus, allowed to equilibrate for 30 min then subjected to 30 min global ischemia. In the control group, the hearts were reperfused with drug free normal Krebs-Henseleit (K/H solution before ischemia and during 120 min reperfusion. In the treatment groups, reperfusion was initiated with K/H solution containing different concentration of honey (0.25, 0.5, 1 and 2% for 15 min and was resumed until the end of 120 min with normal K/H solution. Results: In the control group, VEBs number was 784±199, while in honey concentration of 0.25, 0.5, 1 and 2%, it decreased to 83±23 (P<0.001, 138±48 (P<0.01, 142±37 (P<0.001 and 157±40 (P<0.01, respectively. Number and duration of VT and time spent in reversible VF were also reduced by honey. In the control group, the infarct size was 54.1±7.8%, however; honey (0.25, 0.5, 1 and 2% markedly lowered the value to 12.4±2.4, 12.7±3.3, 11.3±2.6 and 7.9±1.7 (P<0.001, respectively. Conclusion: Postischemic administration of natural honey in global ischemia showed protective effects against ischemia/reperfusion (I/R injuries in isolated rat heart. Antioxidant and radical scavenging activity, lipoperoxidation inhibition, reduction of necrotized tissue, presence of rich energy sources, various type of vitamins, minerals and enzymes and formation of NO-contain metabolites may probably involve in those cardioprotective effects.

  18. Effect of prolonged incubation with copper on endothelium-dependent relaxation in rat isolated aorta

    Science.gov (United States)

    Chiarugi, Alberto; Pitari, Giovanni Mario; Costa, Rosa; Ferrante, Margherita; Villari, Loredana; Amico-Roxas, Matilde; Godfraind, Théophile; Bianchi, Alfredo; Salomone, Salvatore

    2002-01-01

    We investigated the effects of prolonged exposure to copper (Cu2+) on vascular functioning of isolated rat aorta. Aortic rings were exposed to CuSO4 (3–24 h) in Dulbecco's modified Eagle medium with or without 10% foetal bovine serum (FBS) and then challenged with vasoconstrictors or vasodilators in the absence of Cu2+. Exposure to 2 μM Cu2+ in the absence of FBS did not modify the response to phenylephrine (PE) or acetylcholine (ACh) in aortic rings incubated for 24 h. Identical exposure in the presence of FBS increased the contractile response to 1 μM PE by 30% (P<0.05) and impaired the relaxant response to 3 μM ACh or 1 μM A23187 (ACh, from 65.7±7.1 to 6.2±1.1%, n=8; A23187, from 74.6±8.2 to 12.0±0.8%, n=6; P<0.01 for both). Cu2+ exposure did not affect the relaxant response to NO-donors. Impairment of vasorelaxation appeared 3 h after incubation with 2 μM Cu2+ and required 12 h to attain a steady state. Vasorelaxation to ACh was partially restored by 1 mM tiron (intracellular scavenger of superoxide ions; maximum relaxation 34.2±6.4%, n=10, P<0.01 vs Cu2+ alone), whereas catalase, superoxide dismutase or cycloheximide were ineffective. Twenty-four hour-exposure to 2 μM Cu2+ did not affect endothelium integrity or eNOS expression, and increased the Cu content in arterial rings from 6.8±1.1 to 18.9±2.9 ng mg−1 wet weight, n=8; P<0.01. Our results show that, in the presence of FBS, prolonged exposure to submicromolar concentrations of Cu2+ impaired endothelium-dependent vasorelaxation in aortic rings, probably through an intracellular generation of superoxide ions. PMID:12163352

  19. Adrenaline and reactive oxygen species elicit proteome and energetic metabolism modifications in freshly isolated rat cardiomyocytes

    International Nuclear Information System (INIS)

    Costa, Vera Marisa; Silva, Renata; Tavares, Ludgero Canario; Vitorino, Rui; Amado, Francisco; Carvalho, Felix; Bastos, Maria de Lourdes; Carvalho, Marcia; Carvalho, Rui Albuquerque; Remiao, Fernando

    2009-01-01

    The sustained elevation of plasma and interstitial catecholamine levels, namely adrenaline (ADR), and the generation of reactive oxygen species (ROS) are well recognized hallmarks of several cardiopathologic conditions, like cardiac ischemia/reperfusion (I/R) and heart failure (HF). The present work aimed to investigate the proteomics and energetic metabolism of cardiomyocytes incubated with ADR and/or ROS. To mimic pathologic conditions, freshly isolated calcium-tolerant cardiomyocytes from adult rat were incubated with ADR alone or in the presence of a system capable of generating ROS [(xanthine with xanthine oxidase) (XXO)]. Two-dimensional electrophoresis with matrix-assisted laser desorption/ionization and time-of-flight mass spectrometer analysis were used to define protein spot alterations in the cardiomyocytes incubated with ADR and/or ROS. Moreover, the energetic metabolism and the activity of mitochondrial complexes were evaluated by nuclear magnetic resonance and spectrophotometric determinations, respectively. The protein extract was mainly constituted by cardiac mitochondrial proteins and the alterations found were included in five functional classes: (i) structural proteins, notably myosin light chain-2; (ii) redox regulation proteins, in particular superoxide dismutase (SOD); (iii) energetic metabolism proteins, encompassing ATP synthase alpha chain and dihydrolipoyllysine-residue acetyltransferase component of pyruvate dehydrogenase complex; (iv) stress response proteins, like the heat shock proteins; and (v) regulatory proteins, like cytochrome c and voltage-dependent anion channel 1. The XXO system elicited alterations in cardiac contractile proteins, as they showed high levels of cleavage, and also altered energetic metabolism, through increased lactate and alanine levels. The cardiomyocytes incubation with ADR resulted in an accentuated increase in mitochondrial complexes activity and the decrease in alanine/lactate ratio, thus reflecting a high

  20. ß-adrenergic regulation of ion transport in pancreatic ducts: Patch-clamp study of isolated rat pancreatic ducts

    DEFF Research Database (Denmark)

    Novak, I

    1998-01-01

    BACKGROUND & AIMS: In the intact pancreas, bicarbonate secretion is thought to be controlled by a number of regulators, including adrenergic agonists. The aim of this study was to investigate the effects of adrenergic agonists on pancreatic ducts, which are the site of bicarbonate secretion....... METHODS: Small intralobular ducts were isolated from rat pancreas and studied in vitro by the whole-cell patch clamp technique. Cell membrane voltages and currents were indicators of cellular ion transport. In some ducts, intracellular Ca2+ activity was measured by fluorescence optical methods. RESULTS...

  1. Vascular, but not luminal, activation of FFAR1 (GPR40) stimulates GLP-1 secretion from isolated perfused rat small intestine

    DEFF Research Database (Denmark)

    Christensen, Louise Wulff; Kuhre, Rune Ehrenreich; Janus, Charlotte

    2015-01-01

    -protein-cou- pled receptor, FFAR1 (previously GPR40), expressed on L cells and activated by long-chain fatty acids (LCFAs) is a potential target. A link between FFAR1 activation and GLP-1 secretion has been demonstrated in cellular models and small-molecule FFAR1 agonists have been developed. In this study, we exam......- ined the effect of FFAR1 activation on GLP-1 secretion using isolated, per- fused small intestines from rats, a physiologically relevant model allowing distinction between direct and indirect effects of FFAR1 activation. The endogenous FFAR1 ligand, linoleic acid (LA), and four synthetic FFAR1 ago...

  2. Comparison of the vasodilator responses of isolated human and rat middle meningeal arteries to migraine related compounds

    DEFF Research Database (Denmark)

    Grände, Gustaf; Labruijere, Sieneke; Haanes, Kristian Agmund

    2014-01-01

    , telcagepant) were applied to the isolated arteries, and both induced a significant decrease of the effect of exogenously administrated CGRP. In experiments on rat middle meningeal arteries, pre-contracted with PGF2α, similar tendencies were seen. When the pre-contraction was switched to K+ in a separate...... series of experiments, CGRP and sildenafil significantly relaxed the arteries. CONCLUSIONS: Still no definite answer can be given as to why pain is experienced during an attack of migraine. No clear correlation was found between the efficacy of a substance as a meningeal artery vasodilator in human...

  3. Effect of high fat and high sugar diet on insulin binding and insulin action in isolated rat adipocytes

    OpenAIRE

    岡﨑,悟

    1987-01-01

    To clarify on a cellular basis the mechanism of the diabetogenic effect of the westernized diet, insulin binding, insulin stimulated 3-o-methylglucose uptake and glucose oxidation were studied in isolated adipocytes from rats fed experimental diets : low fat-no sugar diet (energy ratio of 10% fat, 70% starch, a model of the traditional Japanese diet), high fat-high sugar diet (40% fat, 20% starch, 20% sugar, a model of the westernized diet), low fat-high sugar diet (10% fat, 50% starch, 20% s...

  4. Effect of triiodothyronine and insulin on glucose metabolism in tissue explants and isolated adipocytes from lean and obese Zucker rats

    International Nuclear Information System (INIS)

    Bailey, J.W.

    1985-01-01

    Glucose metabolism in adipocytes from 6 week old lean and obese Zucker rats were sensitive to direct and chronic treatment with insulin and triidothyronine (T 3 ). Insulin had a large stimulatory effect on glucose metabolism in acutely isolated adipocytes. This effect was greater in the lean than in the obese. Fatty acid, CO 2 , and glycerol-glyceride formation from radiolabeled glucose was elevated in the obese over the leans. Pretreatment of isolated adipocytes with pharmacological concentrations of T 3 for 30 minutes prior to the measurement of glucose metabolism had a greater effect on lean than obese adipocytes. The presence of insulin was required to observe the acute effects of T 3 . A 2-hour exposure to physiological levels of T 3 in the presence of insulin in both lean and obese adipocytes decreased lipogenesis. In the absence of insulin, a 2 hour pretreatment with physiological levels of T 3 in tissue from a euthyroid animal produced increased lipogenesis

  5. Isolated flavonoids from Ficus racemosa stem bark possess antidiabetic, hypolipidemic and protective effects in albino Wistar rats.

    Science.gov (United States)

    Keshari, Amit K; Kumar, Ghanendra; Kushwaha, Priya S; Bhardwaj, Monika; Kumar, Pranesh; Rawat, Atul; Kumar, Dinesh; Prakash, Anand; Ghosh, Balaram; Saha, Sudipta

    2016-04-02

    Ficus racemosa (FR) has been used for thousands of years in Ayurvedic system of medicine in India and is closely associated with prevention, treatment and cure of various human ailments like obesity and diabetes. It is popularly known as gular. A vast and wide range of chemical compounds like polyphenols, friedelane-type triterpenes, norfriedelane type triterpene, eudesmane-type sesquiterpene including various glycosides had been isolated from this plant. However, no detail studies related to isolation of flavonoids has been reported previously with their antidiabetic, hypolipidemic and toxicological consequences. The present study was undertaken to evaluate antidiabetic, hypolipidemic and toxicological assessments of flavonoids isolated from Ficus racemosa (FR) stem bark. We isolated four flavonoids from stem bark of FR and structures were confirmed by Infrared spectroscopy (IR), Nuclear Magnetic Resonance (NMR) (both 1D and 2D), mass spectroscopy (MS). Later, these flavonoids were administered to streptozotocin (STZ) rats once in a day for a period of seven days at 100mg/kg dose. We measured blood glucose level and body weight changes at different days (1st, 3rd, 5th and 7th days). Serum lipid profiles were also estimated to investigate the hypolipidemic potential of flavonoids in the similar experiment. Various oxidative stress parameters in pancreas and liver and hepatic biomarker enzymes in plasma were also determined to investigate the toxicity potential of isolated flavonoids. Finally, we performed docking studies to find out the mechanism of action. Our results collectively suggested that four flavonoids reduced blood glucose level and restored body weight, signifying antidiabetic action. There were reduction of other lipid profile parameters and increase of high density lipoprotein (HDL) during administration of flavonoids, also signifying hypolipidemic action. Various oxidative stress biomarkers and hepatic enzymes levels were also normalized with respect

  6. Selenium bioavailability from soy protein isolate and tofu in rats fed a torula yeast-based diet.

    Science.gov (United States)

    Yan, Lin; Graef, George L; Reeves, Philip G; Johnson, LuAnn K

    2009-12-23

    Selenium (Se) is an essential nutrient, and soy is a major plant source of dietary protein to humans. The United States produces one-third of the world's soybeans, and the Se-rich Northern Plains produce a large share of the nation's soybeans. The present study used a rat model to determine the bioavailability of Se from a protein isolate and tofu (bean curd) prepared from a soybean cultivar we recently developed specifically for food grade markets. The soybean seeds contained 2.91 mg Se/kg. Male Sprague-Dawley rats were depleted of Se by feeding them a 30% Torula yeast-based diet containing 5 microg Se/kg; after 56 days, they were replenished of Se for an additional 50 days by feeding them the same diet supplemented with 20, 30, or 40 microg Se/kg from soy protein isolate or tofu. l-Selenomethionine (SeMet) was used as a reference. Selenium bioavailability was determined on the basis of the responses of Se-dependent enzyme activities and tissue Se contents, comparing those responses for each soy product to those for SeMet using a slope-ratio method. Dietary supplementation with the protein isolate or tofu resulted in dose-dependent increases in glutathione peroxidase activities in blood and liver and thioredoxin reductase activity in liver, as well as dose-dependent increases in the Se contents of plasma, liver, muscle, and kidneys. These responses indicated an overall bioavailability of approximately 97% for Se from both the protein isolate and tofu, relative to SeMet. These results demonstrate that Se from this soybean cultivar is highly bioavailable in this model and that high-Se soybeans can be good dietary sources of Se.

  7. Pro-arrhythmogenic effects of atrial fibrillation-induced electrical remodelling: insights from the three-dimensional virtual human atria.

    Science.gov (United States)

    Colman, Michael A; Aslanidi, Oleg V; Kharche, Sanjay; Boyett, Mark R; Garratt, Clifford; Hancox, Jules C; Zhang, Henggui

    2013-09-01

    Chronic atrial fibrillation (AF) is associated with structural and electrical remodelling in the atria, which are associated with a high recurrence of AF. Through biophysically detailed computer modelling, this study investigated mechanisms by which AF-induced electrical remodelling promotes and perpetuates AF. A family of Courtemanche-Ramirez-Nattel variant models of human atrial cell action potentials (APs), taking into account of intrinsic atrial electrophysiological properties, was modified to incorporate various experimental data sets on AF-induced changes of major ionic channel currents (ICaL, IKur, Ito, IK1, IKs, INaCa) and on intracellular Ca(2+) handling. The single cell models for control and AF-remodelled conditions were incorporated into multicellular three-dimensional (3D) atrial tissue models. Effects of the AF-induced electrical remodelling were quantified as the changes of AP profile, AP duration (APD) and its dispersion across the atria, and the vulnerability of atrial tissue to the initiation of re-entry. The dynamic behaviour of re-entrant excitation waves in the 3D models was characterised. In our simulations, AF-induced electrical remodelling abbreviated atrial APD non-uniformly across the atria; this resulted in relatively short APDs co-existing with marked regional differences in the APD at junctions of the crista terminalis/pectinate muscle, pulmonary veins/left atrium. As a result, the measured tissue vulnerability to re-entry initiation at these tissue junctions was increased. The AF-induced electrical remodelling also stabilized and accelerated re-entrant excitation waves, leading to rapid and sustained re-entry. Under the AF-remodelled condition, re-entrant scroll waves in the 3D model degenerated into persistent and erratic wavelets, leading to fibrillation. In conclusion, realistic 3D atrial tissue models indicate that AF-induced electrical remodelling produces regionally heterogeneous and shortened APD; these respectively facilitate

  8. Small-conductance calcium-activated potassium (SK) channels contribute to action potential repolarization in human atria

    DEFF Research Database (Denmark)

    Skibsbye, Lasse; Poulet, Claire; Diness, Jonas Goldin

    2014-01-01

    (+) currents by ∼15% and prolonged action potential duration (APD), but no effect was observed in myocytes from AF patients. In trabeculae muscle strips from right atrial appendages of SR patients, both compounds increased APD and effective refractory period, and depolarized the resting membrane potential......, while only NS8593 induced these effects in tissue from AF patients. SK channel inhibition did not alter any electrophysiological parameter in human interventricular septum tissue. CONCLUSIONS: SK channels are present in human atria where they participate in repolarization. SK2 and SK3 were down...

  9. Differential uptake of FDG and DG during post-ischaemic reperfusion in the isolated, perfused rat heart

    Energy Technology Data Exchange (ETDEWEB)

    Garlick, P.B.; Medina, R.A.; Southworth, R.; Marsden, P.K. [Department of Radiological Sciences, Guy' s, King' s and St. Thomas' School of Medicine, London (United Kingdom)

    1999-10-01

    Fluorine-18 2-fluoro-2-deoxyglucose (FDG) and 2-deoxyglucose (DG) are widely used as tracers of glucose uptake in the myocardium. Although there is agreement that the two analogues behave similarly to glucose under control conditions, there is growing evidence that some interventions (e.g. insulin stimulation or ischaemia/reperfusion) cause differential changes in their behaviour. The addition of a two-surface coil nuclear magnetic resonance (NMR) probe and a dual-perfusion cannula to our recently developed PET and NMR dual-acquisition (PANDA) system allows us to collect PET (FDG) images and phosphorus-31 NMR (2-deoxyglucose-6-phosphate) spectra simultaneously from each independently perfused coronary bed of the heart. We have used this technique to study the effect of regional ischaemia/reperfusion on FDG and DG uptake in the isolated, perfused rat heart. During control perfusion, FDG uptake was almost identical in both coronary beds. When one coronary bed was made ischaemic, FDG uptake ceased on that side but continued on the control side. Reperfusion failed to restore FDG uptake. In contrast, NMR spectra showed that, during reperfusion, the uptake and phosphorylation of DG did not differ between the two coronary beds. The results thus demonstrate that regional myocardial ischaemia/reperfusion has different effects on the uptake of FDG and DG in the isolated, perfused rat heart. (orig.)

  10. Differential uptake of FDG and DG during post-ischaemic reperfusion in the isolated, perfused rat heart

    International Nuclear Information System (INIS)

    Garlick, P.B.; Medina, R.A.; Southworth, R.; Marsden, P.K.

    1999-01-01

    Fluorine-18 2-fluoro-2-deoxyglucose (FDG) and 2-deoxyglucose (DG) are widely used as tracers of glucose uptake in the myocardium. Although there is agreement that the two analogues behave similarly to glucose under control conditions, there is growing evidence that some interventions (e.g. insulin stimulation or ischaemia/reperfusion) cause differential changes in their behaviour. The addition of a two-surface coil nuclear magnetic resonance (NMR) probe and a dual-perfusion cannula to our recently developed PET and NMR dual-acquisition (PANDA) system allows us to collect PET (FDG) images and phosphorus-31 NMR (2-deoxyglucose-6-phosphate) spectra simultaneously from each independently perfused coronary bed of the heart. We have used this technique to study the effect of regional ischaemia/reperfusion on FDG and DG uptake in the isolated, perfused rat heart. During control perfusion, FDG uptake was almost identical in both coronary beds. When one coronary bed was made ischaemic, FDG uptake ceased on that side but continued on the control side. Reperfusion failed to restore FDG uptake. In contrast, NMR spectra showed that, during reperfusion, the uptake and phosphorylation of DG did not differ between the two coronary beds. The results thus demonstrate that regional myocardial ischaemia/reperfusion has different effects on the uptake of FDG and DG in the isolated, perfused rat heart. (orig.)

  11. Toxicity of thallium on isolated rat liver mitochondria: the role of oxidative stress and MPT pore opening.

    Science.gov (United States)

    Eskandari, M R; Mashayekhi, Vida; Aslani, Majid; Hosseini, Mir-Jamal

    2015-02-01

    Thallium(I) is a highly toxic heavy metal; however, up to now, its mechanisms are poorly understood. The authors' previous studies showed that this compound could induce reactive oxygen species (ROS) formation, reduced glutathione (GSH) oxidation, membrane lipid peroxidation, and mitochondrial membrane potential (MMP) collapse in isolated rat hepatocyte. Because the liver is the storage site of thallium, it seems that the liver mitochondria are one of the important targets for hepatotoxicity. In this investigation, the effects of thallium on mitochondria were studied to investigate its mechanisms of toxicity. Mitochondria were isolated from rat liver and incubated with different concentrations of thallium (25-200 µM). Thallium(I)-treated mitochondria showed a marked elevation in oxidative stress parameters accompanied by MMP collapse when compared with the control group. These results showed that different concentrations of thallium (25-200 µM) induced a significant (P thallium(I)-induced liver toxicity is a result of the disruptive effect of this metal on the mitochondrial respiratory complexes (I, II, and IV), which are the obvious causes of metal-induced ROS formation and ATP depletion. The latter two events, in turn, trigger cell death signaling via opening of mitochondrial permeability transition pore and cytochrome c expulsion. © 2013 Wiley Periodicals, Inc.

  12. Tocotrienols and Whey Protein Isolates Substantially Increase Exercise Endurance Capacity in Diet -Induced Obese Male Sprague-Dawley Rats

    Science.gov (United States)

    Aguila, Jay; McConell, Glenn K.; McAinch, Andrew J.; Mathai, Michael L.

    2016-01-01

    Background and Aims Obesity and impairments in metabolic health are associated with reductions in exercise capacity. Both whey protein isolates (WPIs) and vitamin E tocotrienols (TCTs) exert favorable effects on obesity-related metabolic parameters. This research sought to determine whether these supplements improved exercise capacity and increased glucose tolerance in diet-induced obese rats. Methods Six week old male rats (n = 35) weighing 187 ± 32g were allocated to either: Control (n = 9), TCT (n = 9), WPI (n = 8) or TCT + WPI (n = 9) and placed on a high-fat diet (40% of energy from fat) for 10 weeks. Animals received 50mg/kg body weight and 8% of total energy intake per day of TCTs and/or WPIs respectively. Food intake, body composition, glucose tolerance, insulin sensitivity, exercise capacity, skeletal muscle glycogen content and oxidative enzyme activity were determined. Results Both TCT and WPI groups ran >50% longer (2271 ± 185m and 2195 ± 265m respectively) than the Control group (1428 ± 139m) during the run to exhaustion test (Pexercise endurance (2068 ± 104m). WPIs increased the maximum in vitro activity of beta-hydroxyacyl-CoA in the soleus muscle (Pexercise endurance by 50% in sedentary, diet-induced obese rats. These positive effects of TCTs and WPIs were independent of body weight, adiposity or glucose tolerance. PMID:27058737

  13. Effect of soy protein isolate in the diet on retention by the rat of iron from radiolabeled test meals

    International Nuclear Information System (INIS)

    Thompson, D.B.; Erdman, J.W. Jr.

    1984-01-01

    The influence of soy protein isolate (SPI) in the diet on whole-body retention of extrinsically radiolabeled iron from test meals containing or not containing SPI was evaluated in marginally iron-deficient weanling rats. In experiment 1 SPI was compared with casein in a 2 X 2 factorial design: diets and test meals were either SPI-based or casein-based. Diets were fed for 13 days prior to the test meal and for 7 days subsequent to the test meal. Rats fed the SPI-based diet retained less iron from test meals than did rats fed the casein-based diet (66.1 vs. 74.8%, P less than 0.01). Experiment 2 showed that an SPI-based diet fed during the final 4 days of a 14-day pre-test meal period and subsequent to the test meal led to less iron retention compared to a casein-based diet. In addition to the observed diet effect, experiment 1 showed that iron retention was less from an SPI-based test meal than from a casein-based test meal, confirming previous reports of adverse effects of SPI on iron retention. The present experiments show that SPI can adversely affect from retention in two ways: by its presence in the diet before and after a test meal, and by its presence in a test meal

  14. Gou-teng (from Uncaria rhynchophylla Miquel)-induced endothelium-dependent and -independent relaxations in the isolated rat aorta.

    Science.gov (United States)

    Kuramochi, T; Chu, J; Suga, T

    1994-01-01

    Gou-teng is a drug used for treatment of hypertension in Chinese medicine. Its antihypertensive action has been previously confirmed in the spontaneously hypertensive rat (SHR). Here, its vasorelaxing effect and the mechanisms of actions were studied in vitro. Gou-teng extract (GTE) relaxed the norepinephrine (NE)-precontracted aortic ring preparations isolated from Wistar Kyoto rats (WKY) with and without intact endothelium; the latter was significantly less sensitive than the former. The GTE-induced endothelium-dependent relaxation was significantly inhibited by NG-monomethyl-L-arginine (NMMA) in a dose-dependent manner while indomethacin did not affect the relaxation. Atropine inhibited the acetylcholine (ACh)-induced endothelium-dependent relaxation but did not the GTE-induced one. Furthermore, once GTE was applied, the following NE-induced contraction was significantly reduced even after repeated washout. NMMA effectively reduced and rather reversed this residual effect of GTE. From these results, it is concluded that GTE relaxes the NE-precontracted rat aorta through endothelium-dependent and, to lesser extent, -independent mechanisms. The endothelium-dependent component would be mediated by EDRF/NO pathway in which the muscarinic cholinoceptors were not involved. Thus, GTE appears to be a potent and long-lasting vasodilator mainly through EDRF/NO release.

  15. Evidence that the periaqueductal gray matter mediates the facilitation of panic-like reactions in neonatally-isolated adult rats.

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    Jeyce Willig Quintino-dos-Santos

    Full Text Available Plenty of evidence suggests that childhood separation anxiety (CSA predisposes the subject to adult-onset panic disorder (PD. As well, panic is frequently comorbid with both anxiety and depression. The brain mechanisms whereby CSA predisposes to PD are but completely unknown in spite of the increasing evidence that panic attacks are mediated at midbrain's dorsal periaqueductal gray matter (DPAG. Accordingly, here we examined whether the neonatal social isolation (NSI, a model of CSA, facilitates panic-like behaviors produced by electrical stimulations of DPAG of rats as adults. Eventual changes in anxiety and depression were also assessed in the elevated plus-maze (EPM and forced-swimming test (FST respectively. Male pups were subjected to 3-h daily isolations from post-natal day 2 (PN2 until weaning (PN21 allotting half of litters in individual boxes inside a sound-attenuated chamber (NSI, n = 26 whilst siblings (sham-isolated rats, SHAM, n = 27 and dam were moved to another box in a separate room. Non-handled controls (CTRL, n = 18 remained undisturbed with dams until weaning. As adults, rats were implanted with electrodes into the DPAG (PN60 and subjected to sessions of intracranial stimulation (PN65, EPM (PN66 and FST (PN67-PN68. Groups were compared by Fisher's exact test (stimulation sites, likelihood ratio chi-square tests (stimulus-response threshold curves and Bonferroni's post hoc t-tests (EPM and FST, for P<0.05. Notably, DPAG-evoked panic-like responses of immobility, exophthalmus, trotting, galloping and jumping were markedly facilitated in NSI rats relative to both SHAM and CTRL groups. Conversely, anxiety and depression scores either did not change or were even reduced in neonatally-handled groups relative to CTRL, respectively. Data are the first behavioral evidence in animals that early-life separation stress produces the selective facilitation of panic-like behaviors in adulthood. Most importantly, results implicate

  16. Effects of Scirpusin B, a polyphenol in passion fruit seeds, on the coronary circulation of the isolated perfused rat heart

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    Yutaka Matsumoto, Nozomi Gotoh, Shoko Sano, Kenkichi Sugiyama, Tatsuhiko Ito, Yohei Abe, Yumi Katano, Akira Ishihata

    2014-07-01

    Full Text Available Objective: Piceatannol, a polyphenol which is contained in passion fruits seed, is a derivative of resveratrol and is known to have antioxidant, anti-inflammatory and vasorelaxing activities. Passion fruits seed also contains a dimer of Piceatannol, Scirpusin B. The aim of this study was to investigate the effect of Scirpusin B on the coronary circulation of the isolated rat heart. Methods: Hearts were isolated from male Fischer 344 rats (5 – 6 months old, and perfused with modified Krebs-Henseleit solution aerated with 95% O2 and 5% CO2 (37 °C at constant pressure (75 cmH2O by Langendorff’s method. Piceatannol or Scirpusin B (10, 30 and 100 μM was injected as a bolus into the aortic cannula and coronary flow (CF was continuously measured by the electromagnetic flow meter. In some experiments, rat hearts were pretreated with L-NAME (an inhibitor of nitric oxide synthase or Diclofenac (an inhibitor of cyclooxygenase to reveal the possible involvement of nitric oxide (NO and vasodilating prostanoids in the effect of Scirpusin B. Results: Scirpusin B increased CF up to 108.2 % of the initial value, while Piceatannol did not increase CF. In addition; Scirpusin B increased CF concentration-dependently. Pretreatment with L-NAME or Diclofenac significantly attenuated the Scirpusin B-induced coronary vasodilatation. Scirpusin B did not change the heart rate either left ventricular pressure. Conclusion: This study shows that Scirpusin B could increase CF via production of NO and vasodilating prostanoids.

  17. Arginine induces GH gene expression by activating NOS/NO signaling in rat isolated hemi-pituitaries

    Directory of Open Access Journals (Sweden)

    S.C.F. Olinto

    2012-11-01

    Full Text Available The amino acid arginine (Arg is a recognized secretagogue of growth hormone (GH, and has been shown to induce GH gene expression. Arg is the natural precursor of nitric oxide (NO, which is known to mediate many of the effects of Arg, such as GH secretion. Arg was also shown to increase calcium influx in pituitary cells, which might contribute to its effects on GH secretion. Although the mechanisms involved in the effects of Arg on GH secretion are well established, little is known about them regarding the control of GH gene expression. We investigated whether the NO pathway and/or calcium are involved in the effects of Arg on GH gene expression in rat isolated pituitaries. To this end, pituitaries from approximately 170 male Wistar rats (~250 g were removed, divided into two halves, pooled (three hemi-pituitaries and incubated or not with Arg, as well as with different pharmacological agents. Arg (71 mM, the NO donor sodium nitroprusside (SNP, 1 and 0.1 mM and a cyclic guanosine monophosphate (cGMP analogue (8-Br-cGMP, 1 mM increased GH mRNA expression 60 min later. The NO acceptor hemoglobin (0.3 µM blunted the effect of SNP, and the combined treatment with Arg and L-NAME (a NO synthase (NOS inhibitor, 55 mM abolished the stimulatory effect of Arg on GH gene expression. The calcium channel inhibitor nifedipine (3 µM also abolished Arg-induced GH gene expression. The present study shows that Arg directly induces GH gene expression in hemi-pituitaries isolated from rats, excluding interference from somatostatinergic neurons, which are supposed to be inhibited by Arg. Moreover, the data demonstrate that the NOS/NO signaling pathway and calcium mediate the Arg effects on GH gene expression.

  18. The role of K –ATP channel in the preconditioning effect of magnesium in the rat isolated heart

    Directory of Open Access Journals (Sweden)

    Bazargan M.

    2007-05-01

    Full Text Available There is growing interest for beneficial effect of Mg in the cardiovascular disorders. A number of cardiovascular disorders including myocardial infarction, arrhythmias and congestive heart failure have been associated with low extracellular or intracellular concentrations of Mg. The aim of present study was to investigate the preconditioning effects of magnesium (Mg on cardiac function and infarct size in the globally ischemic-reperfusion in isolated rat heart. Rat hearts were Langendorff-perfused, subjected to 30 minutes of global ischemia and 90 minutes of reperfusion, and assigned to one of the following treatment groups with 7 hearts in each group: (1 control, (2 ischemic- reperfusion, (IR, (3 ischemic preconditioning, (IPC of 5 minutes of global ischemia - reperfusion before lethal ischemia; or pretreatment with (4 30 µmol/L of Diazoxide (Dia, (5 8 mmol/L magnesium, (6 10 µmol/L glibenclamid (Gli, (7 magnesium and Dia and (8 magnesium and Gli. Infarct size was measured by the triphenyltetrazolium chloride method. Left ventricular function was assessed by left ventricular developed pressure (LVDP, heart rate and coronary flow (CF. Mg limited infarct size (9.76 % vs 44.47% in IR, P< 0.001 as did Dia (10.2 % vs 44.4 % in IR P< 0.001 and IPC (8.69 % vs 44.47% in IR, P< 0.001. The protective effect of magnesium was abolished by Gli. Administration of Mg had an anti-infarct effect in ischemic-reperfusion isolated rat hearts and improved cardiac function. Blockade of K-ATP channel abolished the protective effects of magnesium and suggest that K-ATP channel has an important role in this effects.

  19. Arginine induces GH gene expression by activating NOS/NO signaling in rat isolated hemi-pituitaries

    Energy Technology Data Exchange (ETDEWEB)

    Olinto, S.C.F. [Faculdade de Ciências Integradas do Pontal, Universidade Federal de Uberlândia, Ituiutaba, MG (Brazil); Adrião, M.G. [Departamento de Morfologia e Fisiologia, Universidade Federal Rural de Pernambuco, Recife, PE (Brazil); Castro-Barbosa, T.; Goulart-Silva, F.; Nunes, M.T. [Departamento de Fisiologia e Biofísica, Instituto de Ciências Biomédicas, Universidade de São Paulo, São Paulo, SP (Brazil)

    2012-06-01

    The amino acid arginine (Arg) is a recognized secretagogue of growth hormone (GH), and has been shown to induce GH gene expression. Arg is the natural precursor of nitric oxide (NO), which is known to mediate many of the effects of Arg, such as GH secretion. Arg was also shown to increase calcium influx in pituitary cells, which might contribute to its effects on GH secretion. Although the mechanisms involved in the effects of Arg on GH secretion are well established, little is known about them regarding the control of GH gene expression. We investigated whether the NO pathway and/or calcium are involved in the effects of Arg on GH gene expression in rat isolated pituitaries. To this end, pituitaries from approximately 170 male Wistar rats (∼250 g) were removed, divided into two halves, pooled (three hemi-pituitaries) and incubated or not with Arg, as well as with different pharmacological agents. Arg (71 mM), the NO donor sodium nitroprusside (SNP, 1 and 0.1 mM) and a cyclic guanosine monophosphate (cGMP) analogue (8-Br-cGMP, 1 mM) increased GH mRNA expression 60 min later. The NO acceptor hemoglobin (0.3 µM) blunted the effect of SNP, and the combined treatment with Arg and L-NAME (an NO synthase (NOS) inhibitor, 55 mM) abolished the stimulatory effect of Arg on GH gene expression. The calcium channel inhibitor nifedipine (3 µM) also abolished Arg-induced GH gene expression. The present study shows that Arg directly induces GH gene expression in hemi-pituitaries isolated from rats, excluding interference from somatostatinergic neurons, which are supposed to be inhibited by Arg. Moreover, the data demonstrate that the NOS/NO signaling pathway and calcium mediate the Arg effects on GH gene expression.

  20. Protectant activity of defibrotide in cardioplegia followed by ischemia/reperfusion injury in the isolated rat heart.

    Science.gov (United States)

    Rossoni, G; Pompilio, G; Biglioli, P; Alamanni, F; Tartara, P; Rona, P; Porqueddu, M; Berti, F

    1999-01-01

    Previous studies have shown that defibrotide, a polydeoxyribonucleotide obtained by depolymerization of DNA from porcine tissues, has important protective effects on myocardial ischemia, which may be associated with a prostacyclin-related mechanism. The purpose of this study was to investigate the direct effects of defibrotide (given in cardioplegia or after ischemia) on a model of rat heart recovery after cardioplegia followed by ischemia/reperfusion injury. Isolated rat hearts, undergoing 5 minutes of warm cardioplegic arrest followed by 20 minutes of global ischemia and 30 minutes of reperfusion, were studied using the modified Langendorff model. The cardioplegia consisted of St. Thomas' Hospital solution augmented with defibrotide (50, 100, and 200 microg/mL) or without defibrotide (controls). Left ventricular mechanical function and the levels of creatine kinase, lactate dehydrogenase, and 6-keto-prostaglandin F1alpha (6-keto-PGF1alpha; the stable metabolite of prostacyclin) were measured during preischemic and reperfusion periods. After global ischemia, hearts receiving defibrotide in the cardioplegic solution (n = 8) manifested in a concentration-dependent fashion lower left ventricular end-diastolic pressure (p defibrotide in the cardioplegic solution also had, in a dose-dependent way, lower levels of creatine-kinase (p defibrotide was given alone to the hearts at the beginning of reperfusion (n = 7), the recovery of postischemic left ventricular function was inferior (p defibrotide was given in cardioplegia. Defibrotide confers to conventional crystalloid cardioplegia a potent concentration-dependent protective effect on the recovery of isolated rat heart undergoing ischemia/reperfusion injury. The low cost and the absence of contraindications (cardiac toxicity and hemodynamic effects) make defibrotide a promising augmentation to cardioplegia.

  1. Arginine induces GH gene expression by activating NOS/NO signaling in rat isolated hemi-pituitaries

    International Nuclear Information System (INIS)

    Olinto, S.C.F.; Adrião, M.G.; Castro-Barbosa, T.; Goulart-Silva, F.; Nunes, M.T.

    2012-01-01

    The amino acid arginine (Arg) is a recognized secretagogue of growth hormone (GH), and has been shown to induce GH gene expression. Arg is the natural precursor of nitric oxide (NO), which is known to mediate many of the effects of Arg, such as GH secretion. Arg was also shown to increase calcium influx in pituitary cells, which might contribute to its effects on GH secretion. Although the mechanisms involved in the effects of Arg on GH secretion are well established, little is known about them regarding the control of GH gene expression. We investigated whether the NO pathway and/or calcium are involved in the effects of Arg on GH gene expression in rat isolated pituitaries. To this end, pituitaries from approximately 170 male Wistar rats (∼250 g) were removed, divided into two halves, pooled (three hemi-pituitaries) and incubated or not with Arg, as well as with different pharmacological agents. Arg (71 mM), the NO donor sodium nitroprusside (SNP, 1 and 0.1 mM) and a cyclic guanosine monophosphate (cGMP) analogue (8-Br-cGMP, 1 mM) increased GH mRNA expression 60 min later. The NO acceptor hemoglobin (0.3 µM) blunted the effect of SNP, and the combined treatment with Arg and L-NAME (an NO synthase (NOS) inhibitor, 55 mM) abolished the stimulatory effect of Arg on GH gene expression. The calcium channel inhibitor nifedipine (3 µM) also abolished Arg-induced GH gene expression. The present study shows that Arg directly induces GH gene expression in hemi-pituitaries isolated from rats, excluding interference from somatostatinergic neurons, which are supposed to be inhibited by Arg. Moreover, the data demonstrate that the NOS/NO signaling pathway and calcium mediate the Arg effects on GH gene expression

  2. Frequent combination of antimicrobial multiresistance and extraintestinal pathogenicity in Escherichia coli isolates from urban rats (Rattus norvegicus in Berlin, Germany.

    Directory of Open Access Journals (Sweden)

    Sebastian Guenther

    Full Text Available Urban rats present a global public health concern as they are considered a reservoir and vector of zoonotic pathogens, including Escherichia coli. In view of the increasing emergence of antimicrobial resistant E. coli strains and the on-going discussion about environmental reservoirs, we intended to analyse whether urban rats might be a potential source of putatively zoonotic E. coli combining resistance and virulence. For that, we took fecal samples from 87 brown rats (Rattus norvegicus and tested at least three E. coli colonies from each animal. Thirty two of these E. coli strains were pre-selected from a total of 211 non-duplicate isolates based on their phenotypic resistance to at least three antimicrobial classes, thus fulfilling the definition of multiresistance. As determined by multilocus sequence typing (MLST, these 32 strains belonged to 24 different sequence types (STs, indicating a high phylogenetic diversity. We identified STs, which frequently occur among extraintestinal pathogenic E. coli (ExPEC, such as STs 95, 131, 70, 428, and 127. Also, the detection of a number of typical virulence genes confirmed that the rats tested carried ExPEC-like strains. In particular, the finding of an Extended-spectrum beta-lactamase (ESBL-producing strain which belongs to a highly virulent, so far mainly human- and avian-restricted ExPEC lineage (ST95, which expresses a serogroup linked with invasive strains (O18:NM:K1, and finally, which produces an ESBL-type frequently identified among human strains (CTX-M-9, pointed towards the important role, urban rats might play in the transmission of multiresistant and virulent E. coli strains. Indeed, using a chicken infection model, this strain showed a high in vivo pathogenicity. Imagining the high numbers of urban rats living worldwide, the way to the transmission of putatively zoonotic, multiresistant, and virulent strains might not be far ahead. The unforeseeable consequences of such an emerging public

  3. [Investigation of antimicrobial resistance of Klebsiella pneumoniae and Pseudomonas aeruginosa isolates from rat-like animals around a hospital in Guangzhou].

    Science.gov (United States)

    Zhong, Xue-Shan; Ge, Jing; Chen, Shao-Wei; Xiong, Yi-Quan; Zheng, Xue-Yan; Qiu, Min; Huo, Shu-Ting; Chen, Qing

    2016-05-01

    To investigate antimicrobial resistance of Klebsiella pneumoniae and Pseudomonas aeruginosa isolates in fecal samples from rat-like animals. Rat-like animals were captured using cages around a hospital and the neighboring residential area between March and October, 2015. K. pneumoniae and P. aeruginosa were isolated from the fecal samples of the captured animals. Antimicrobial susceptibility test was performed according to the guidelines of Clinical and Laboratory Standards Institute (2014). A total of 329 rat-like animals were captured, including 205 Suncus murinus, 111 Rattus norvegicus, 5 Rattus flavipectus and 8 Mus musculus. The positivity rates of K. pneumoniae and P. aeruginosa were 78.4% and 34.7% in the fecal samples from the captured animals, respectively. K. pneumoniae isolates from Suncus murinus showed a high resistance to ampicillin, cephazolin, nitrofurantoin, piperacillin and cefotaxime (with resistance rates of 100%, 51.2%, 44.2%, 37.2%, and 23.3%, respectively), and K. pneumoniae isolates from Rattus spp. showed a similar drug-resistance profile. The prevalence rates of multidrug resistance and ESBLs were 40.9% and 10.7%, respectively. P. aeruginosa from both Suncus murinus and Rattus spp. exhibited the highest resistance rates to aztreonam (12.4% and 16.0%, respectively), followed by penicillins and fluoroquinolones. P. aeruginosa isolates were susceptible to cephems, aminoglycosides and carbapenems (with resistance rates below 5%). K. pneumoniae and P. aeruginosa isolated from rat-like animals showed drug-resistance profiles similar to those of the strains isolated from clinical patients, suggesting that the possible transmission of K. pneumoniae and P. aeruginosa between rat-like animals and human beings.

  4. Ethanolic Extract of Butea monosperma Leaves Elevate Blood Insulin Level in Type 2 Diabetic Rats, Stimulate Insulin Secretion in Isolated Rat Islets, and Enhance Hepatic Glycogen Formation

    Directory of Open Access Journals (Sweden)

    Mehdi Bin Samad

    2014-01-01

    Full Text Available We measured a vast range of parameters, in an attempt to further elucidate previously claimed antihyperglycemic activity of Butea monosperma. Our study clearly negates the possibility of antidiabetic activity by inhibited gastrointestinal enzyme action or by reduced glucose absorption. Reduction of fasting and postprandial glucose level was reconfirmed (P<0.05. Improved serum lipid profile via reduced low density lipoprotein (LDL, cholesterol, triglycerides (TG, and increased high density lipoprotein (HDL was also reestablished (P<0.05. Significant insulin secretagogue activity of B. monosperma was found in serum insulin assay of B. monosperma treated type 2 diabetic rats (P<0.01. This was further ascertained by our study on insulin secretion on isolated rat islets (P<0.05. Improved sensitivity of glucose was shown by the significant increase in hepatic glycogen deposition (P<0.05. Hence, we concluded that antihyperglycemic activity of B. monosperma was mediated by enhanced insulin secretion and enhanced glycogen formation in the liver.

  5. Unstable Expression of Commonly Used Reference Genes in Rat Pancreatic Islets Early after Isolation Affects Results of Gene Expression Studies.

    Directory of Open Access Journals (Sweden)

    Lucie Kosinová

    Full Text Available The use of RT-qPCR provides a powerful tool for gene expression studies; however, the proper interpretation of the obtained data is crucially dependent on accurate normalization based on stable reference genes. Recently, strong evidence has been shown indicating that the expression of many commonly used reference genes may vary significantly due to diverse experimental conditions. The isolation of pancreatic islets is a complicated procedure which creates severe mechanical and metabolic stress leading possibly to cellular damage and alteration of gene expression. Despite of this, freshly isolated islets frequently serve as a control in various gene expression and intervention studies. The aim of our study was to determine expression of 16 candidate reference genes and one gene of interest (F3 in isolated rat pancreatic islets during short-term cultivation in order to find a suitable endogenous control for gene expression studies. We compared the expression stability of the most commonly used reference genes and evaluated the reliability of relative and absolute quantification using RT-qPCR during 0-120 hrs after isolation. In freshly isolated islets, the expression of all tested genes was markedly depressed and it increased several times throughout the first 48 hrs of cultivation. We observed significant variability among samples at 0 and 24 hrs but substantial stabilization from 48 hrs onwards. During the first 48 hrs, relative quantification failed to reflect the real changes in respective mRNA concentrations while in the interval 48-120 hrs, the relative expression generally paralleled the results determined by absolute quantification. Thus, our data call into question the suitability of relative quantification for gene expression analysis in pancreatic islets during the first 48 hrs of cultivation, as the results may be significantly affected by unstable expression of reference genes. However, this method could provide reliable information

  6. Increased expression of mineralocorticoid receptor and 11beta-hydroxysteroid dehydrogenase type 2 in human atria during atrial fibrillation.

    Science.gov (United States)

    De-An, Pei; Li, Li; Zhi-Yun, Xu; Jin-Yu, Huang; Zheng-Ming, Xu; Min, Wang; Qiang, Yao; Shi-Eng, Huang

    2010-01-01

    Atrialfibrillation (AF) is associated with the activation of the renin-angiotensin-aldosterone system in the atria. It is not clear whether the expression of a mineralocorticoid receptor (MR), or 11beta-hydroxysteroid dehydrogenase type 2 (11betaHSD2), conferring aldosterone specificity to the MR, in patients with AF is altered. Patients with AF may be associated with increased expression of MR and 11betaHSD2 in the atria. Atrial tissue samples of 25 patients with rheumatic heart valve disease undergoing a valve replacement operation were examined. A total of 13 patients had chronic persistent AF (>6 mo) and 12 patients had no history of AF. The MR and 11betaHSD2 expression were analyzed at the mRNA and protein level. The localization of MR and 11betaHSD2 in atrial tissue was performed using specific immunohistochemistry staining. The results of real-time quantitative polymerase chain reaction (PCR) showed that AF groups, in comparison with sinus rhythm, had a higher mRNA expression level of MR or 11betaHSD2 (all P atrial tissue were also significantly increased in patients with AF compared with patients with sinus rhythm (P atrial interstitial fibrosis in patients with AF. These findings may have an important impact on the treatment of AF with aldosterone antagonists. Copyright 2010 Wiley Periodicals, Inc.

  7. Imaging evidence for endothelin ETA/ETB receptor heterodimers in isolated rat mesenteric resistance arteries

    DEFF Research Database (Denmark)

    Kapsokalyvas, Dimitrios; Schiffers, Paul M H; Maij, Nathan

    2014-01-01

    AIMS: In engineered cells, endothelin ETA and ETB receptors can heterodimerize. We tested whether this can also be observed in native tissue. MAIN METHODS: Rat mesenteric resistance arteries (rMRA) were maintained in organ culture for 24h to upregulate ETB-mediated contractions in addition to the...

  8. Effect of bicarbonate on potassium conductance of isolated perfused rat pancreatic ducts

    DEFF Research Database (Denmark)

    Novak, I; Greger, R

    1991-01-01

    dissected from rat pancreas. The basolateral membrane potential PDbl of unstimulated duct cells was between -60 mV and -70 mV, and the cells had a relatively large K+ conductance in the basolateral membrane as demonstrated by (a) 20-22 mV depolarization of PDbl in response to increase in bath K...

  9. Prolonged survival of isolated rat islet allografts pre-irradiated with X-rays

    Energy Technology Data Exchange (ETDEWEB)

    Kimura, Toshihisa; Note, Masayuki; Nakagawara, Gizo (Fukui Medical School, Matsuoka (Japan)); Kojima, Yasuhiko

    1994-04-01

    Prior to transplantation of islets, pre-incubation, or pre-irradiation may suppress the immunogenicity of islet cells without suppressing islet function. In the presently described experiments we investigated the use of X-ray irradiation prior to transplantation to reduce islet immunogenicity. To determine whether or not the islet function was reduced after irradiation, ACI rat islets were transplanted into the subrenal capsules of isogeneic rats which had been diabetic and examined the blood glucose level over a period of 40 days. The results indicated that irradiation injury was dose-dependent and that islets irradiated with over 80 Gy lost their function. Next, allogeneic transplantation was performed using the model of ACI rats to Lewis rats without the use of any immunosuppressive agent. Non-irradiated islets were rejected within 7 days. However 20 Gy or 40 Gy irradiated islets prolonged survival (18.7[+-]5.8 days (n=6) and 26.7[+-]10.0 days (n=6), respectively). To determine the basis for this effect, MHC expression of islets was examined by the immunoperoxidase technique. Immunohistologic studies showed that 40 Gy-irradiated islets were depleted of Class II antigen positive cells while Class I antigen expression was unchanged. These results suggest that the prolongation of islets survival by X-ray irradiation may possibly be due to, in part, the depletion of donor Class II antigen positive cells. (author).

  10. Fatty acid and amino acid modulation of glucose cycling in isolated rat hepatocytes

    NARCIS (Netherlands)

    Gustafson, LA; Neeft, M; Reijngoud, DJ; Kuipers, F; Sauerwein, HP; Romijn, JA; Herling, AW; Burger, HJ; Meijer, AJ

    2001-01-01

    We studied the influence of glucose/glucose 6-phosphate cycling on glycogen deposition from glucose in fasted-rat hepatocytes using S4048 and CP320626, specific inhibitors of glucose-6-phosphate translocase and glycogen phosphorylase respectively. The effect of amino acids and oleate was also

  11. Caspase 3 activity in isolated fetal rat lung fibroblasts and rat periodontal ligament fibroblasts: cigarette smoke-induced alterations

    Directory of Open Access Journals (Sweden)

    James Elliot Scott

    2016-03-01

    Full Text Available Background Cigarette smoking is the leading cause of preventable death in the world. It has been implicated in the pathogenesis of pulmonary, oral and systemic diseases. Smoking during pregnancy is clearly a risk factor for the developing fetus and may be a major cause of infant mortality. Moreover, the oral cavity is the first site of exposure to cigarette smoke and may be a possible source for the spread of toxins to other organs of the body. Fibroblasts in general are morphologically heterogeneous connective tissue cells with diverse functions. Apoptosis or programmed cell death is a crucial process during embryogenesis and for the maintenance of homeostasis throughout life. Deregulation of apoptosis has been implicated in abnormal lung development in the fetus and disease progression in adults. Caspases, are proteases which belong to the family of cysteine aspartic acid proteases and are the key components for the downstream amplification of intra-cellular apoptotic signals. Of the 14 caspases known, caspase-3 is the key executioner of apoptosis. Fetal rat lung fibroblasts but not PDL viability is reduced by exposure to CSE. In addition Caspase 3 activity is elevated after CSE exposure in fetal lung fibroblasts but not in PDLs. Expression of caspase 3 is induced in CSE exposed lung fibroblasts but not in PDLs. Caspase 3 was localized to the cytoplasm in both cell types.

  12. Effects of ketamine and its isomers on ischemic preconditioning in the isolated rat heart

    NARCIS (Netherlands)

    Molojavyi, A.; Preckel, B.; Comfère, T.; Müllenheim, J.; Thämer, V.; Schlack, W.

    2001-01-01

    BACKGROUND: Ischemic preconditioning protects the heart against subsequent ischemia. Opening of the adenosine triphosphate-sensitive potassium (KATP) channel is a key mechanism of preconditioning. Ketamine blocks KATP channels of isolated cardiomyocytes. The authors investigated the effects of

  13. Isolation of dendritic-cell-like S100β-positive cells in rat anterior pituitary gland.

    Science.gov (United States)

    Horiguchi, Kotaro; Fujiwara, Ken; Yoshida, Saishu; Higuchi, Masashi; Tsukada, Takehiro; Kanno, Naoko; Yashiro, Takashi; Tateno, Kozue; Osako, Shunji; Kato, Takako; Kato, Yukio

    2014-07-01

    S100β-protein-positive cells in the anterior pituitary gland appear to possess multifunctional properties. Because of their pleiotropic features, S100β-positive cells are assumed to be of a heterogeneous or even a non-pituitary origin. The observation of various markers has allowed these cells to be classified into populations such as stem/progenitor cells, epithelial cells, astrocytes and dendritic cells. The isolation and characterization of each heterogeneous population is a prerequisite for clarifying the functional character and origin of the cells. We attempt to isolate two of the subpopulations of S100β-positive cells from the anterior lobe. First, from transgenic rats that express green fluorescent protein (GFP) driven by the S100β protein promoter, we fractionate GFP-positive cells with a cell sorter and culture them so that they can interact with laminin, a component of the extracellular matrix. We observe that one morphological type of GFP-positive cells possesses extended cytoplasmic processes and shows high adhesiveness to laminin (process type), whereas the other is round in shape and exhibits low adherence to laminin (round type). We successfully isolate cells of the round type from the cultured GFP-positive cells by taking advantage of their low affinity to laminin and then measure mRNA levels of the two cell types by real-time polymerase chain reaction. The resultant data show that the process type expresses vimentin (mesenchymal cell marker) and glial fibrillary acidic protein (astrocyte marker). The round type expresses dendritic cell markers, CD11b and interleukin-6. Thus, we found a method for isolating dendritic-cell-like S100β-positive cells by means of their property of adhering to laminin.

  14. Correlation between Amitriptyline-Induced Cardiotoxic Effects and Cardiac S100b Protein in Isolated Rat Hearts

    Directory of Open Access Journals (Sweden)

    Nil Hocaoğlu

    2016-12-01

    Full Text Available Background: Amitriptyline is an important cause of mortality due to its cardiovascular toxicity. Aims: To investigate the changes in levels of cardiac S100b protein on amitriptyline-induced cardiotoxicity and also to examine the correlation between amitriptyline-induced cardiotoxic effects and cardiac S100b protein in an isolated rat heart model. Study Design: Animal experimentation, isolated heart model. Methods: After a stabilization period, isolated hearts were randomized to two groups (n=5 and n=7. In the control group, isolated hearts were subjected to an infusion of 5% dextrose for 60 minutes. In the amitriptyline group, 5.5×10-5 M amitriptyline was infused for 60 minutes to achieve amitriptyline toxicity. After the infusion period, heart tissues were removed for histological examination. Results: In comparison to control treatment, amitriptyline infusion decreased left ventricular developed pressure (LVDP, dp/dtmax and heart rate (HR and significantly prolonged QRS duration (p<0.05. The semiquantitative scores for S100b protein levels in amitriptyline-infused hearts were higher than in the control group (p<0.01. At the end of the experiment, in the amitriptyline-infused group, significant correlations were found between LVDP and S100b protein scores (r=-0.807, p=0.003 and between QRS duration and S100b protein scores (r=0.859, p=0.001. Conclusion: Our results indicate that the S100b protein may be a helpful indicator or biomarker in studying the cardiotoxic effects of amitriptyline.

  15. Insulin stimulation of phospholipid methylation in isolated rat adipocyte plasma membranes.

    OpenAIRE

    Kelly, K L; Kiechle, F L; Jarett, L

    1984-01-01

    Partially purified plasma membranes prepared from rat adipocytes contain N-methyltransferase(s) that utilize(s) S-adenosyl-L-methionine to synthesize phosphatidylcholine from phosphatidylethanolamine. The incorporation of [3H]methyl from S-adenosyl-L-[methyl-3H]methionine into plasma membrane phospholipids was linear with incubation time and plasma membrane protein concentration and was inhibited in a dose-dependent manner by both S-adenosyl-L-homocysteine and 3-deazadenosine. The addition of...

  16. Apixaban Enhances Vasodilatation Mediated by Protease-Activated Receptor 2 in Isolated Rat Arteries

    Directory of Open Access Journals (Sweden)

    Ambra Villari

    2017-07-01

    Full Text Available Apixaban (APX is a direct inhibitor of factor X (FXa approved for prophylaxis and treatment of deep venous thrombosis and atrial fibrillation. Because FXa activates protease-activated receptor 2 (PAR-2 in endothelium and vascular smooth muscle, inhibition of FXa by APX may affect vasomotor function. The effect of APX was assessed in vitro, by wire myography, in rat mesenteric resistance arteries (MRAs and basilar arteries challenged with vasoconstrictors [phenylephrine (PE; 5-hydroxytryptamine (5-HT], vasodilators [acetylcholine (ACh; sodium nitroprusside (SNP] or with the PAR-2 peptide agonist SLIGRL. APX (10 μM reduced the vasoconstriction to PE and 5-HT while did not change the vasodilatation to ACh or SNP. SLIGRL induced concentration-dependent vasodilation in pre-constricted arteries, that was reduced by incubation with the NO inhibitor NG-nitro-L-arginine (L-NNA and abolished by endothelium removal. APX enhanced vasodilation to SLIGRL either in the presence or in the absence of L-NNA, but was ineffective in endothelium-denuded vessels. In preparations from heparin-treated rats (to inhibit FXa APX did not change the vasodilation to SLIGRL. FXa enzymatic activity, detected in mesentery homogenates from controls, was inhibited by APX, whereas APX-sensitive enzymatic activity was undetectable in homogenates from heparin-treated rats. Immunoblot analysis showed that incubation of MRA or aorta with APX increased the abundance of PAR-2, an effect not seen in MRA from heparin-treated rats or in endothelium-denuded aortas. In conclusion, inhibition of FXa by APX increases vasodilatation mediated by PAR-2. APX may act by inhibiting PAR-2 desensitization induced by endogenous FXa. This effect could be useful in the context of endothelial dysfunction associated to cardiovascular diseases.

  17. Potassium-stimulated release of radiolabelled taurine and glycine from the isolated rat retina

    Energy Technology Data Exchange (ETDEWEB)

    Smith, L.F.; Pycock, C.J.

    1982-09-01

    The release of preloaded (/sup 3/H)glycine and (/sup 3/H)taurine in response to a depolarising stimulus (12.5-50 mM KCl) has been studied in the superfused rat retina. High external potassium concentration immediately increased the spontaneous efflux of (/sup 3/H)glycine, the effect of 50 mM K+ apparently being abolished by omitting calcium from the superfusing medium. In contrast, although high potassium concentrations increased the spontaneous efflux of (/sup 3/H)taurine from the superfused rat retina, this release was not evident until the depolarising stimulus was removed from the superfusing medium. The magnitude of this late release of (/sup 3/H)taurine was dependent on external K+ concentrations, and appeared immediately after cessation of the stimulus irrespective of whether it was applied for 4, 8, or 12 min. Potassium (50 mM)-induced release of taurine appeared partially calcium-dependent, being significantly reduced (p less than 0.01) but not abolished by replacing calcium with 1 mM EDTA in the superfusate. High-affinity uptake systems for both (/sup 3/H)glycine and (/sup 3/H)taurine were demonstrated in the rat retina in vitro (Km values, 1.67 microM and 2.97 microM; Vmax values, 19.3 and 23.1 nmol/g wet weight tissue/h, respectively). The results are discussed with respect to the possible neurotransmitter roles of both amino acids in the rat retina.

  18. Cyclic-AMP mediated drugs: differential or global reduction of eicosanoid synthesis in the isolated rat lung?

    Directory of Open Access Journals (Sweden)

    Mark J. Post

    1992-01-01

    Full Text Available In this study the question was addressed whether cAMP mediated drugs induce a differential reduction of branches of the arachidonic acid metabolism rather than a global reduction of eicosanoid synthesis. The isolated lungs of actively sensitized rats were employed to study prostaglandin and leukotriene release in the presence and absence of the cAMP mediated drugs theophylline, milrinone, sulmazole, isobutyl-methylxanthine and salbutamol. The release of eicosanoids as measured by RIA was predominantly basal and continuous, with a mild antigen induced stimulation only for TXB2 and the leukotrienes. All drugs reduced eicosanoid release globally. It is concluded that cAMP mediated drugs interfere with arachidonic acid metabolism at a site proximal to the branching into lipoxygenase and cyclo-oxygenase pathways.

  19. Effect of Alkaloids Isolated from Phyllodium pulchellum on Monoamine Levels and Monoamine Oxidase Activity in Rat Brain.

    Science.gov (United States)

    Cai, Lu; Wang, Chao; Huo, Xiao-Kui; Dong, Pei-Pei; Zhang, Bao-Jing; Zhang, Hou-Li; Huang, Shan-Shan; Zhang, Bo; Yu, Sheng-Ming; Zhong, Ming; Ma, Xiao-Chi

    2016-01-01

    Phyllodium pulchellum (P. pulchellum) is a folk medicine with a significant number of bioactivities. The aim of this study was to investigate the effects displayed by alkaloids fractions, isolated from the roots of P. pulchellum, on neurotransmitters monoamine levels and on monoamine oxidase (MAO) activity. Six alkaloids, which had indolealkylamine or β-carboline skeleton, were obtained by chromatographic technologies and identified by spectroscopic methods such as NMR and MS. After treatment with alkaloids of P. pulchellum, the reduction of DA levels (54.55%) and 5-HT levels (35.01%) in rat brain was observed by HPLC-FLD. The effect of alkaloids on the monoamines metabolism was mainly related to MAO inhibition, characterized by IC50 values of 37.35 ± 6.41 and 126.53 ± 5.39 μg/mL for MAO-A and MAO-B, respectively. The acute toxicity indicated that P. pulchellum extract was nontoxic.

  20. Effects of SH-reagents of different molecular size upon glucose metabolism in isolated rat fat cells

    International Nuclear Information System (INIS)

    Kather, H.; Simon, B.

    1975-01-01

    To study the role of membrane SH-groups in glucose transport of isolated rat fat cells we compared the effects of a small organic mercurial reagent p-CMB with those of a large p-CMB-derivative - p-CMB-Dextran, MW approximately 10,000 -. It could be shown that both compounds were of almost identical reactivity on fat cell homogenate metabolism. When applied to intact fat cells uncoupled p-CMB showed an 1) insulin-like enhancement of 14 C incorporation from (U- 14 C) glucose into CO 2 and triglyceride, 2) inhibition of the insulin-stimulatory effect on these parameters and 3) inhibition of basal glucose uptake dependent on the concentrations used. Identical concentrations of p-CMB-Dextran, however, failed to influence basal glucose uptake as well as the insulin mediated increase in glucose metabolism. (orig.) [de

  1. Effects of SH-reagents of different molecular size upon glucose metabolism in isolated rat fat cells

    Energy Technology Data Exchange (ETDEWEB)

    Kather, H; Simon, B [Heidelberg Univ. (F.R. Germany). Klinisches Inst. fuer Herzinfarktforschung

    1975-09-01

    To study the role of membrane SH-groups in glucose transport of isolated rat fat cells we compared the effects of a small organic mercurial reagent p-CMB with those of a large p-CMB-derivative - p-CMB-Dextran, MW approximately 10,000 -. It could be shown that both compounds were of almost identical reactivity on fat cell homogenate metabolism. When applied to intact fat cells uncoupled p-CMB showed an 1) insulin-like enhancement of /sup 14/C incorporation from (U-/sup 14/C) glucose into CO/sub 2/ and triglyceride, 2) inhibition of the insulin-stimulatory effect on these parameters and 3) inhibition of basal glucose uptake dependent on the concentrations used. Identical concentrations of p-CMB-Dextran, however, failed to influence basal glucose uptake as well as the insulin mediated increase in glucose metabolism.

  2. Oral toxicity evaluation of kefir-isolated Lactobacillus kefiranofaciens M1 in Sprague-Dawley rats.

    Science.gov (United States)

    Owaga, E E; Chen, M J; Chen, W Y; Chen, C W; Hsieh, R H

    2014-08-01

    Lactobacilli kefiranofaciens M1 has shown novel immunomodulation and anti-allergy probiotic attributes in cell and animal models. An acute oral toxicity assessment of L. kefiranofaciens M1 was evaluated in Sprague-Dawley rats. The rats were randomly assigned to four groups (12 rats/sex/group): the low dose group was orally gavaged with L. kefiranofaciens M1 at 3.0×10(8)cfu/kg bw while the medium dose and high dose groups received 9.0×10(9)cfu/kg bw and 1.8×10(10)cfu/kg bw, respectively, for 28days. The control group received phosphate buffer saline. The body weights were measured weekly while blood samples were collected for haematology and serum biochemistry tests. Histopathology of the organs (heart, liver, kidney, adrenal glands, spleen, ovary, testis), and urinalysis were conducted on study termination. The body weight gain of the L. kefiranofaciens M1 and control groups were comparable during the administration period. Overall, L. kefiranofaciens M1 did not induce adverse effects on haematology, serum biochemistry, and urinalysis parameters. Gross and microscopic histopathology of the organs revealed no toxicity effect of L. kefiranofaciens M1. In conclusion, 1.8×10(10)cfu/kg bw of L. kefiranofaciens M1 was considered as the no-observed-adverse-effect-level (NOAEL), which was the highest dose tested in the present study. Copyright © 2014 Elsevier Ltd. All rights reserved.

  3. Tributyltin contributes in reducing the vascular reactivity to phenylephrine in isolated aortic rings from female rats.

    Science.gov (United States)

    Rodrigues, Samya Mere L; Ximenes, Carolina F; de Batista, Priscila R; Simões, Fabiana V; Coser, Pedro Henrique P; Sena, Gabriela C; Podratz, Priscila L; de Souza, Leticia N G; Vassallo, Dalton V; Graceli, Jones B; Stefanon, Ivanita

    2014-03-21

    Organotin compounds such as tributyltin (TBT) are used as antifouling paints by shipping companies. TBT inhibits the aromatase responsible for the transformation of testosterone into estrogen. Our hypothesis is that TBT modulates the vascular reactivity of female rats. Female Wistar rats were treated daily (Control; CONT) or TBT (100 ng/kg) for 15 days. Rings from thoracic aortas were incubated with phenylephrine (PHE, 10(-10)-10(-4) M) in the presence and absence of endothelium, and in the presence of N(G)-Nitro-L-Arginine Methyl Ester (L-NAME), tetraethylammonium (TEA) and apocynin. TBT decreased plasma levels of estrogen and the vascular response to PHE. In the TBT group, the vascular reactivity was increased in the absence of endothelium, L-NAME and TEA. The decrease in PHE reactivity during incubation with apocynin was more evident in the TBT group. The sensitivity to acetylcholine (ACh) and sodium nitroprusside (SNP) was reduced in the TBT group. TBT increased collagen, reduced α1-smooth muscle actin. Female rats treated with TBT for 15 days showed morphology alteration of the aorta and decreased their vascular reactivity, probably due to mechanisms dependent on nitric oxide (NO) bioavailability, K(+) channels and an increase in oxidative stress. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

  4. Effects of tri-n-butyltin chloride on energy metabolism, macromolecular synthesis, precursor uptake and cyclic AMP production in isolated rat thymocytes

    NARCIS (Netherlands)

    Snoeij, N.J.; Punt, P.M.; Penninks, A.H.; Seinen, W.

    1986-01-01

    The inhibitor of oxidative phosphorylation tri-n-butyltin chloride (TBTC) causes membrane damage and disintegration of isolated rat thymocytes at concentrations higher than 1 μM. From a concentration of 0.1 μM, TBTC disturbs energy metabolism as indicated by an increase in methylglucose uptake,

  5. Intracellular [Ca2+] and Vo2 after manipulation of the free-energy of the Na+/Ca(2+)-exchanger in isolated rat ventricular myocytes

    NARCIS (Netherlands)

    Fiolet, J. W.; Baartscheer, A.; Schumacher, C. A.

    1995-01-01

    We have investigated whether the Na+/Ca(2+)-exchanger has a functional regulatory role in the control of oxidative metabolism in suspensions of isolated rat ventricular myocytes. Therefore we simultaneously measured intracellular [Ca2+] ([Ca2+]i) with Indo-1 and respiratory rate (Vo2) after abrupt

  6. DNA damage in isolated rat hepatocytes exposed to C.I. pigment orange 5 and C.I. pigment yellow 12 by the alkaline comet assay

    DEFF Research Database (Denmark)

    Møller, P; Wallin, Håkan; Grunnet, N

    1998-01-01

    The induction of DNA damage by commonly used printing ink pigments, C.I. pigment orange 5 (C.I. 12075) and C.I. pigment yellow 12 (C.I. 21090), was investigated in freshly isolated rat hepatocytes with the comet assay. C.I. pigment yellow 12 is a 3,3'-dichlorobenzidine-based diarylide pigment...

  7. Persistent changes in the initial rate of pyruvate transport by isolated rat liver mitochondria after preincubation with adenine nucleotides and calcium ions

    NARCIS (Netherlands)

    Vaartjes, W.J.; Breejen, J.N. den; Geelen, M.J.H.; Bergh, S.G. van den

    1980-01-01

    1. Preincubation of isolated rat-liver mitochondria in the presence of adenine nucleotides or Ca2+ results in definite and persistent changes in the initial rate of pyruvate transport. 2. These changes in the rate of pyruvate transport are accompanied by equally persistent changes in the opposite

  8. Uptake and metabolism of fructose by rat neocortical cells in vivo and by isolated nerve terminals in vitro.

    Science.gov (United States)

    Hassel, Bjørnar; Elsais, Ahmed; Frøland, Anne-Sofie; Taubøll, Erik; Gjerstad, Leif; Quan, Yi; Dingledine, Raymond; Rise, Frode

    2015-05-01

    Fructose reacts spontaneously with proteins in the brain to form advanced glycation end products (AGE) that may elicit neuroinflammation and cause brain pathology, including Alzheimer's disease. We investigated whether fructose is eliminated by oxidative metabolism in neocortex. Injection of [(14) C]fructose or its AGE-prone metabolite [(14) C]glyceraldehyde into rat neocortex in vivo led to formation of (14) C-labeled alanine, glutamate, aspartate, GABA, and glutamine. In isolated neocortical nerve terminals, [(14) C]fructose-labeled glutamate, GABA, and aspartate, indicating uptake of fructose into nerve terminals and oxidative fructose metabolism in these structures. This was supported by high expression of hexokinase 1, which channels fructose into glycolysis, and whose activity was similar with fructose or glucose as substrates. By contrast, the fructose-specific ketohexokinase was weakly expressed. The fructose transporter Glut5 was expressed at only 4% of the level of neuronal glucose transporter Glut3, suggesting transport across plasma membranes of brain cells as the limiting factor in removal of extracellular fructose. The genes encoding aldose reductase and sorbitol dehydrogenase, enzymes of the polyol pathway that forms glucose from fructose, were expressed in rat neocortex. These results point to fructose being transported into neocortical cells, including nerve terminals, and that it is metabolized and thereby detoxified primarily through hexokinase activity. We asked how the brain handles fructose, which may react spontaneously with proteins to form 'advanced glycation end products' and trigger inflammation. Neocortical cells took up and metabolized extracellular fructose oxidatively in vivo, and isolated nerve terminals did so in vitro. The low expression of fructose transporter Glut5 limited uptake of extracellular fructose. Hexokinase was a main pathway for fructose metabolism, but ketohexokinase (which leads to glyceraldehyde formation) was

  9. Anti-apoptosis effect of polysaccharide isolated from the seeds of Cuscuta chinensis Lam on cardiomyocytes in aging rats.

    Science.gov (United States)

    Sun, Shou-Li; Guo, Li; Ren, Ya-Chao; Wang, Bing; Li, Rong-Hui; Qi, Yu-Shan; Yu, Hui; Chang, Nai-Dan; Li, Ming-Hui; Peng, Hai-Sheng

    2014-09-01

    To investigate the mechanism of apoptosis in myocardial cells of aging rats induced by D-galactose and to study the effect of the Polysaccharide isolated from the seeds of Cuscuta chinensis Lam (PCCL) on apoptosis of cardiomyocytes and its corresponding machinasim in aging rat model. Fifty male SD rats were randomly divided into 5 groups. Normal control group (NC). D-galactose (100 mg · kg(-1)d(-1) for 56 day) indued aging group (MC), D-galactose plus 100 mg kg(-1) d(-1) PCCL group (ML), D-galactose plus 200 mg kg(-1) d(-1) PCCL group (MM), and D-galactose plus 400 mg kg(-1) d(-1) PCCL group (MH). Same volume of solution (water, or PCCL aqueous solution) was given by gavage for 56 days. Then the hearts were collected and apoptosis parameters were evaluated. Caspase-3 and Cyt c were determined by fluorescence spectrometer, the apoptosis rate was assessed by AnnexinV-FITC method by Flow-Cytometry, [Ca(2+)]i and [Ca(2+)]i overloaded by KCL were observed by laser scanning confocal microscopy (LSCM); Bcl-2 and Bax were examined by immunohistochemistry. The content of Cyt C, [Ca(2+)]i of cardiomyocytes, the activity of Caspase-3, Bax expression level in D-galactose induced aging group were higher than NC (p < 0.05). The ratio of Bcl-2/Bax was decreased in D-galactose induced aging group compared to NC. On the other hand, the content of Cyt C, [Ca(2+)]i of cardiomyocytes, the activity of Caspase-3 and apoptosis rate, as well as Bax expression level in all three PCCL groups were decreased compared to galactose induced group (p < 0.05). Bcl-2/Bax ratio was increased in all PCCL groups compared to galactose induced aging group. PCCL could decrease the apoptosis of cardiomyocytes by the mitochondria apoptosis pathway.

  10. MCT1 and MCT4 Expression During Myocardial Ischemic-Reperfusion Injury in the Isolated Rat Heart

    Directory of Open Access Journals (Sweden)

    Yi Zhu

    2013-09-01

    Full Text Available Background/Aims: Myocardium ischemia-reperfusion (I/R injury can be caused by imbalances in cellular metabolism. Lactate, transported by monocarboxylate transporters (MCTs, has been implicated as a mechanism in this process. The present study was designed to investigate the expression and functional role of MCTs in rat hearts during ischemia and reperfusion. Methods: Langendorff-perfused rat hearts were subjected to 20 minutes stabilization, 30 minutes of global ischemia and 60 minutes reperfusion. Hearts were collected serially for detecting expression changes in MCT1, MCT4 during myocardial I/R injury and lactate concentration was measured. Post-ischemic left ventricular function and infract size were determined at end-point, followed by the pretreatment of D-lactate, a competitive inhibitor of MCTs. Results: MCT4 was significantly increased following global ischemia and MCT1 expression was increased during the early stages of reperfusion in isolated rat hearts, while the expression of the ancillary protein CD147 was increased during I/R injury. We determined increases in AMPK phosphorylation status, which was significantly elevated following ischemia and early reperfusion. Blocking monocarboxylate transport by competitive inhibition with D-lactate caused decreased left ventricular performance and increased infarct size. Conclusion: Increased MCT4 expression facilitates lactate extrusion during the ischemic period, while increased MCT1 may facilitate lactate transport into and out of cells simultaneously during early reperfusion, with increases in AMPK phosphorylation status during the myocardial I/R period. Lactate transport by MCTs has a profound protective effect during myocardial ischemia reperfusion injury.

  11. Enhanced preservation of the isolated rat heart after hypothermic storage by pinacidil pretreatment and storage in lazaroid U74500A

    International Nuclear Information System (INIS)

    Hicks, M.; Du, Z.Y.; Spratt, P.; Macdonald, P.

    1998-01-01

    The aim of the present study was to compare 3 protocols incorporating these approaches on the preservation of haemodynamic function in the isolated working rat heart after hypothermic storage. These protocols were: 1) pretreatment of the heart with 200 μM pinacidil, an ATP-sensitive potassium channel opener; 2) storage in cardioplegic solution containing the lipid soluble lazaroid antioxidant U74500A (30 μM); 3) A combination of protocols 1 and 2. Methods: Hearts from Wistar rats (250 to 330g body weight) were perfused on a Langendorff apparatus. Each heart was ligated to an aortic cannula and perfused retrogradely, with oxygenated Krebs solution at a hydrostatic pressure of 100 cm H 2 O. The system was then converted to 'working mode' by switching the perfusate from aorta to a left atrial cannula (filling pressure 15 cm H 2 O). After stabilisation, the following pre-arrest indices of cardiac function were recorded: heart rate (HR), coronary flow (CF), aortic flow (AF) and cardiac output (CO). Hearts were then randomised to protocols 1-3, untreated controls or vehicle treated controls (n=6 animals/ group). Hearts were stored in an extracellular-based preservation solution for 12 hours at 2-3degC, remounted on the perfusion apparatus and stabilised as before. Haemodynamic measurements were then repeated. Conclusions: Combined pharmacological activation of ATP-sensitive potassium channels before cardioplegia and the addition of U74500A to the preservation solution is associated with a significantly enhanced haemodynamic function in the rat heart after 12 hours of hypothermic storage. These data suggest a novel use for these agents in the transplantation context

  12. Enhanced preservation of the isolated rat heart after hypothermic storage by pinacidil pretreatment and storage in lazaroid U74500A

    Energy Technology Data Exchange (ETDEWEB)

    Hicks, M. [St Vincent`s Hospital, Darlinghurst, NSW (Australia). Division of Clinical Pharmacology and Toxicology; Du, Z.Y.; Spratt, P.; Macdonald, P. [St Vincent`s Hospital, Darlinghurst, NSW (Australia). Cardiopulmonary Transplant Unit

    1998-12-31

    The aim of the present study was to compare 3 protocols incorporating these approaches on the preservation of haemodynamic function in the isolated working rat heart after hypothermic storage. These protocols were: 1) pretreatment of the heart with 200 {mu}M pinacidil, an ATP-sensitive potassium channel opener; 2) storage in cardioplegic solution containing the lipid soluble lazaroid antioxidant U74500A (30 {mu}M); 3) A combination of protocols 1 and 2. Methods: Hearts from Wistar rats (250 to 330g body weight) were perfused on a Langendorff apparatus. Each heart was ligated to an aortic cannula and perfused retrogradely, with oxygenated Krebs solution at a hydrostatic pressure of 100 cm H{sub 2}O. The system was then converted to `working mode` by switching the perfusate from aorta to a left atrial cannula (filling pressure 15 cm H{sub 2}O). After stabilisation, the following pre-arrest indices of cardiac function were recorded: heart rate (HR), coronary flow (CF), aortic flow (AF) and cardiac output (CO). Hearts were then randomised to protocols 1-3, untreated controls or vehicle treated controls (n=6 animals/ group). Hearts were stored in an extracellular-based preservation solution for 12 hours at 2-3degC, remounted on the perfusion apparatus and stabilised as before. Haemodynamic measurements were then repeated. Conclusions: Combined pharmacological activation of ATP-sensitive potassium channels before cardioplegia and the addition of U74500A to the preservation solution is associated with a significantly enhanced haemodynamic function in the rat heart after 12 hours of hypothermic storage. These data suggest a novel use for these agents in the transplantation context Truncated abstract. 1 tab.

  13. Activity-dependent intracellular Ca2+ transients in unmyelinated nerve fibres of the isolated adult rat vagus nerve.

    Science.gov (United States)

    Wächtler, J; Mayer, C; Grafe, P

    1998-04-01

    Confocal laser scanning microscopy was used to follow changes in the free intracellular calcium concentration ([Ca2+]i) in nerve fibres and adjacent Schwann cells in isolated rat vagus nerves. [Ca2+]i was monitored by the Ca2+-sensitive fluorescent dyes Calcium Green-1 and Fura Red. Intracellular Ca2+ transients were observed during repetitive (1-50 Hz) supramaximal electrical stimulation or by bath application of ATP. Trains of action potentials were more effective at elongated, fibre-like structures of the vagus nerves, whereas ATP-induced Ca2+ transients were found predominantly in regions of Schwann cell bodies. Activity-induced Ca2+ signals were unaffected by pharmacological manipulation of intracellular Ca2+ stores, during long-lasting application of purinergic receptor agonists, or by substitution of extracellular Na+ with Li+. However, they were abolished in the presence of Ca2+-free bathing solution or after the blocking of Ca2+ channels with Cd2+. Ca2+ transients were also observed during Ca2+ action potentials. Such "Ca2+ spikes" were elicited by electrical stimulation in the presence of a combination of tetrodotoxin and K+ channel blockers. These data suggest that voltage-dependent Ca2+ channels, activated during short trains of Na+ action potentials, produce an increase in intra-axonal [Ca2+] of rat vagus nerves. We did not find evidence for activity-dependent Ca2+ transients in the Schwann cells surrounding the unmyelinated axons.

  14. Activation of muscarinic M-1 cholinoceptors by curcumin to increase contractility in urinary bladder isolated from Wistar rats.

    Science.gov (United States)

    Cheng, Tse-Chou; Lu, Chih-Cheng; Chung, Hsien-Hui; Hsu, Chih-Chieh; Kakizawa, Nozomi; Yamada, Shizuo; Cheng, Juei-Tang

    2010-04-05

    Curcumin is an active principle contained in rhizome of Curcuma longa, and it has been recently mentioned to show affinity to muscarinic M-1 cholinoceptors (M(1)-mAChR). In the present study, we found that curcumin caused a concentration-dependent increase of muscle tone in urinary bladder isolated from Wistar rats. This action was inhibited by pirenzepine at concentration enough to block M(1)-mAChR. In radioligand-binding assay, specific binding of [(3)H]-oxotremorine (OXO-M) in the rat bladder homogenates was also displaced by curcumin in a concentration-dependent manner. In the presence of inhibitors for PLC-PKC pathway, either U73122 (phospholipase C inhibitor) or chelerythrine (protein kinase C inhibitor), curcumin-stimulated contraction in urinary bladder was markedly reduced. In conclusion, the obtained results suggest that curcumin can activate M(1)-mAChR at concentrations lower than to scavenge free radicals to increase of muscle tone in urinary bladder through PLC-PKC pathway.

  15. Mitochondria As the Target for the Modulatory Effect of Curcumin in Oxaliplatin-induced Toxicity in Isolated Rat Liver Mitochondria.

    Science.gov (United States)

    Waseem, Mohammad; Parvez, Suhel; Tabassum, Heena

    2017-01-01

    To explore hepatoprotective action of curcumin (CMN, a bioflavonoid) on oxaliplatin (Oxa)-triggered mitochondrial oxidative stress and respiratory chain complexes in liver of rats. Oxa is a ubiquitously utilized platinum-based chemotherapeutic agent commonly used for the treatment of colorectal cancer. Mitochondria have recently emerged as targets for anticancer drugs in several kinds of toxicity including hepatotoxicity that can lead to neoplastic disease. There is a dearth of evidence involving the role of mitochondria in mediating Oxa-evoked hepatotoxicity and its underlying mechanism is still debatable. The study was performed in mitochondria isolated from liver of Wistar rats. Oxa (200 μg/mL) and CMN (5 μmol) were incubated under in vitro conditions. Oxa evoked a significant increase in the membrane lipid peroxidation (LPO) levels, protein carbonyl (PC) contents, decrease in reduced glutathione (GSH) and nonprotein thiol (NP-SH) levels. Oxa also caused a marked decline in the activities of enzymatic antioxidants and respiratory chain enzymes (I, II, III and V) in liver mitochondria. CMN pre-treatment significantly prevented the activities of enzymatic antioxidants and mitochondrial respiratory chain enzymes. CMN also restored the LPO and PC contents, GSH and NP-SH levels in liver mitochondria. CMN intake might be effective in regulation of Oxa-evoked mitotoxicity during chemotherapy. Moreover, it is included in the armamentarium for anticancer agent-induced oxidative stress. Copyright © 2017 IMSS. Published by Elsevier Inc. All rights reserved.

  16. Palmitate activates autophagy in INS-1E β-cells and in isolated rat and human pancreatic islets.

    Directory of Open Access Journals (Sweden)

    Luisa Martino

    Full Text Available We have investigated the in vitro effects of increased levels of glucose and free fatty acids on autophagy activation in pancreatic beta cells. INS-1E cells and isolated rat and human pancreatic islets were incubated for various times (from 2 to 24 h at different concentrations of glucose and/or palmitic acid. Then, cell survival was evaluated and autophagy activation was explored by using various biochemical and morphological techniques. In INS-1E cells as well as in rat and human islets, 0.5 and 1.0 mM palmitate markedly increased autophagic vacuole formation, whereas high glucose was ineffective alone and caused little additional change when combined with palmitate. Furthermore, LC3-II immunofluorescence co-localized with that of cathepsin D, a lysosomal marker, showing that the autophagic flux was not hampered in PA-treated cells. These effects were maintained up to 18-24 h incubation and were associated with a significant decline of cell survival correlated with both palmitate concentration and incubation time. Ultrastructural analysis showed that autophagy activation, as evidenced by the occurrence of many autophagic vacuoles in the cytoplasm of beta cells, was associated with a diffuse and remarkable swelling of the endoplasmic reticulum. Our results indicate that among the metabolic alterations typically associated with type 2 diabetes, high free fatty acids levels could play a role in the activation of autophagy in beta cells, through a mechanism that might involve the induction of endoplasmic reticulum stress.

  17. ECoG sleep-waking rhythms and bodily activity in the cerveau isolé rat.

    Science.gov (United States)

    Nakata, K; Kawamura, H

    1986-01-01

    In rats with a high mesencephalic transection, isolating both the locus coeruleus and raphe nuclei from the forebrain, Electrocorticogram (ECoG) and Electromyogram (EMG) of the neck muscles were continuously recorded. Normal sleep-waking ECoG changes with a significant circadian rhythm reappeared in 4 to 9 days after transection. Neck muscle EMG and bodily movements were independent of the ECoG changes and did not show any significant circadian rhythm. In these high mesencephalic rats with sleep-waking ECoG changes, large bilateral hypothalamic lesions were made by passing DC current either in the preoptic area or in the posterior hypothalamus. After the preoptic area lesions the amount of low voltage fast ECoG per day markedly increased, whereas after the posterior hypothalamic lesions, the total amount of low voltate fast wave per day decreased showing long-lasting slow wave sleep pattern. These results support an idea that the forebrain, especially in the hypothalamus including the preoptic area, a mechanism inducing sleep-waking ECoG changes is localized.

  18. The production of (14C) oxalate during the metabolism of (14C) carbohydrates in isolated rat hepatocytes.

    Science.gov (United States)

    Rofe, A M; James, H M; Bais, R; Edwards, J B; Conyers, R A

    1980-04-01

    Oxalate (14C) was produced during the metabolism of (U-14C) carbohydrates in hepatocytes isolated from normal rats. At 10 mM, the order of oxalate production was fructose > glycerol > xylitol > sorbitol greater than or equal to glucose in the ratio 10 : 4 : 3 : 1 : 1. This difference between oxalate production from fructose and glucose was reflected in their rates of utilisation, glucose being poorly metabolised in hepatocytes from fasted rats. Fructose was rapidly metabolised, producing glucose, lactate and pyruvate as the major metabolites. Glycerol, xylitol and sorbitol were metabolised at half the rate of fructose, the major metabolites being glucose, lactate and glycerophosphate. The marked similarity in the pattern of intermediary metabolites produced by these polyols was not, however, reflected in the rates of oxalate production. Hepatic polyol metabolism resulted in high levels of cytosolic NADH, as indicated by elevated lactate : pyruvate and glycerophosphate : dihydroxyacetone phosphate ratios. The artificial electron acceptor, phenazine methosulphate (PMS) stimulated oxalate production from the polyols, particularly xylitol. In the presence of PMS, the order of oxalate production was fructose greater than or equal to xylitol > glycerol > sorbitol in the ratio 10 : 10 : 6 : 2. The production of glucose, lactate and pyruvate from the polyols was also stimulated by PMS, whereas the general metabolism of fructose, including oxalate production, was little affected. Oxalate (14C) was produced from (1-14C), (2-14C) and (6-14C) but not (3,4-14C) glucose in hepatocytes isolated from non-fasted, pyridoxine-deficient rats. Whilst this labelling pattern is consistent with oxalate being produced by a number of pathways, it is suggested that metabolism via hydroxypyruvate is a major route for oxalate production from various carbohydrates, with perhaps the exception of xylitol, which appears to have an alternative mechanism for oxalate production. The observation that

  19. Effects of Constant Flow vs. Constant Pressure Perfusion on Fluid Filtration in Severe Hypothermic Isolated Blood-Perfused Rat Lungs.

    Science.gov (United States)

    Halsøy, Kathrine; Kondratiev, Timofey; Tveita, Torkjel; Bjertnaes, Lars J

    2016-01-01

    Victims of severe accidental hypothermia are prone to fluid extravasation but rarely develop lung edema. We hypothesize that combined hypothermia-induced increase in pulmonary vascular resistance (PVR) and a concomitant fall in cardiac output protect the lungs against edema development. Our aim was to explore in hypothermic-isolated blood-perfused rat lungs whether perfusion at constant pressure influences fluid filtration differently from perfusion at constant flow. Isolated blood-perfused rat lungs were hanging freely in a weight transducer for measuring weight changes (ΔW). Fluid filtration coefficient (Kfc), was determined by transiently elevating left atrial pressure (Pla) by 5.8 mmHg two times each during normothermia (37°C) and during hypothermia (15°C). The lung preparations were randomized to two groups. One group was perfused with constant flow (Constant flow group) and the other group with constant pulmonary artery pressure (Constant PPA group). Microvascular pressure (Pmv) was determined before and during elevation of Pla (ΔPmv) by means of the double occlusion technique. Kfc was calculated with the formula Kfc = ΔW/ΔPmv/min. All Kfc values were normalized to predicted lung weight (P LW ), which was based on body weight (BW) according to the formula: P LW  = 0.0053 BW - 0.48 and presented as Kfc PLW in mg/min/mmHg/g. At cessation, bronchoalveolar lavage (BAL) fluid/perfusate protein concentration (B/P) ratio was determined photometrically. Data were analyzed with parametric or non-parametric tests as appropriate. p  Kfc PLW and B/P ratio increased significantly by more than 10-fold during hypothermia concerted by visible signs of edema in the trachea. Hemoglobin and hematocrit increased within the Constant flow group and between the groups at cessation of the experiments. In hypothermic rat lungs perfused at constant flow, fluid filtration coefficient per gram P LW and B/P ratio increased more than 10-fold concerted by increased

  20. Toxicity and Kinetics of (3H)Microcystin-LR in Isolated Perfused Rat Livers

    Science.gov (United States)

    1990-03-20

    with a Waters 490 multiwavelength detector, as described by Robinson et al. (1989). A C-18 column (Adsorbosphere HS, 4.6 x 250 mm, 5 Am, Alltech ...1988). The isolated perfused liver has several advantages over other model systems for the study of hepatotoxins. Unlike the in-vitro cell systems

  1. Supravital dithizone staining in the isolation of human and rat pancreatic islets

    DEFF Research Database (Denmark)

    Hansen, W A; Christie, M R; Kahn, R

    1989-01-01

    Dithizone, a zinc chelating agent, is known to selectively stain the islets of Langerhans in the pancreas. In the present study, we have used this stain to aid the identification of islets in material obtained by collagenase digestion of human pancreas. Islets were shown to rapidly and reversibly...... techniques for the large scale isolation of functionally intact human islets....

  2. Rapid and reversible impairments of short- and long-term social recognition memory are caused by acute isolation of adult rats via distinct mechanisms.

    Science.gov (United States)

    Shahar-Gold, Hadar; Gur, Rotem; Wagner, Shlomo

    2013-01-01

    Mammalian social organizations require the ability to recognize and remember individual conspecifics. This social recognition memory (SRM) can be examined in rodents using their innate tendency to investigate novel conspecifics more persistently than familiar ones. Here we used the SRM paradigm to examine the influence of housing conditions on the social memory of adult rats. We found that acute social isolation caused within few days a significant impairment in acquisition of short-term SRM of male and female rats. Moreover, SRM consolidation into long-term memory was blocked following only one day of social isolation. Both impairments were reversible, but with different time courses. Furthermore, only the impairment in SRM consolidation was reversed by systemic administration of arginine-vasopressin (AVP). In contrast to SRM, object recognition memory was not affected by social isolation. We conclude that acute social isolation rapidly induces reversible changes in the brain neuronal and molecular mechanisms underlying SRM, which hamper its acquisition and completely block its consolidation. These changes occur via distinct, AVP sensitive and insensitive mechanisms. Thus, acute social isolation of rats swiftly causes changes in their brain and interferes with their normal social behavior.

  3. Rapid and reversible impairments of short- and long-term social recognition memory are caused by acute isolation of adult rats via distinct mechanisms.

    Directory of Open Access Journals (Sweden)

    Hadar Shahar-Gold

    Full Text Available Mammalian social organizations require the ability to recognize and remember individual conspecifics. This social recognition memory (SRM can be examined in rodents using their innate tendency to investigate novel conspecifics more persistently than familiar ones. Here we used the SRM paradigm to examine the influence of housing conditions on the social memory of adult rats. We found that acute social isolation caused within few days a significant impairment in acquisition of short-term SRM of male and female rats. Moreover, SRM consolidation into long-term memory was blocked following only one day of social isolation. Both impairments were reversible, but with different time courses. Furthermore, only the impairment in SRM consolidation was reversed by systemic administration of arginine-vasopressin (AVP. In contrast to SRM, object recognition memory was not affected by social isolation. We conclude that acute social isolation rapidly induces reversible changes in the brain neuronal and molecular mechanisms underlying SRM, which hamper its acquisition and completely block its consolidation. These changes occur via distinct, AVP sensitive and insensitive mechanisms. Thus, acute social isolation of rats swiftly causes changes in their brain and interferes with their normal social behavior.

  4. Cytoplasmic binding and disposition kinetics of diclofenac in the isolated perfused rat liver

    Science.gov (United States)

    Weiss, Michael; Kuhlmann, Olaf; Hung, Daniel Y; Roberts, Michael S

    2000-01-01

    The binding kinetics of diclofenac to hepatocellular structures were evaluated in the perfused rat liver using the multiple indicator dilution technique and a stochastic model of organ transit time density.The single-pass, in situ rat liver preparation was perfused with buffer solution (containing 2% albumin) at 30 ml min−1. Diclofenac and [14C]-sucrose (extracellular reference) were injected simultaneously as a bolus dose into the portal vein (six experiments in three rats). An analogous series of experiments was performed with [14C]-diclofenac and [3H]-sucrose.The diclofenac outflow data were analysed using three models of intracellular distribution kinetics, assuming (1) instantaneous distribution and binding (well-mixed model), (2) ‘slow' binding at specific intracellular sites after instantaneous distribution throughout the cytosol (slow binding model), and (3) ‘slowing' of cytoplasmic diffusion due to instantaneous binding (slow diffusion model).The slow binding model provided the best description of the data. The rate constants for cellular influx and sequestration were 0.126±0.026 and 0.013±0.009 s−1, respectively. The estimated ratio of cellular initial distribution volume to extracellular volume of 2.82 indicates an almost instantaneous distribution in the cellular water space, while the corresponding ratio of 5.54 estimated for the apparent tissue distribution volume suggests a relatively high hepatocellular binding. The non-instantaneous intracellular equilibration process was characterized by time constants of the binding and unbinding process of 53.8 and 49.5 s, respectively. The single-pass availability of diclofenac was 86%. The results obtained with [14C]-diclofenac and [3H]-sucrose were not statistically different. PMID:10903973

  5. Use of scintillometric quantitation of unscheduled DNA synthesis in isolated rat hepatocytes for the screening of genotoxic agents

    International Nuclear Information System (INIS)

    Hsia, M.T.

    1987-01-01

    The induction of unscheduled DNA synthesis has been considered as a suitable endpoint for the screening of genotoxic agents. Experimentally, unscheduled DNA synthesis is most frequently measured by autoradiography. The purpose of this report was to examine the usefulness of the liquid scintillation counting technique in measuring unscheduled DNA synthesis response in isolated rat hepatocytes. The various liquid scintillation counting-based unscheduled DNA synthesis assay procedures were examined according to the following groupings: (1) procedures based on the acid precipitation of cellular macromolecules, (2) procedures based on isopycnic gradient centrifugation of solubilized cells, (3) procedures based on nuclei isolation in conjunction with other DNA purification methods, and (4) procedures based on the selective retention of hepatocellular DNA. Limited cases in which test chemicals gave positive unscheduled DNA synthesis response in liquid scintillation counting-based assays and negative unscheduled DNA synthesis response in autoradiography-based assays are presented. It is concluded that liquid scintillation counting-based unscheduled DNA synthesis assays represent an appropriate system for inclusion in carcinogenicity and mutagenicity testing programs

  6. Phenylalanine metabolism in isolated rat liver cells. Effects of glucagon and diabetes.

    OpenAIRE

    Carr, F P; Pogson, C I

    1981-01-01

    1. Methods are described for monitoring the metabolic flux through phenylalanine hydroxylase, the tyrosine catabolic pathway and phenylalanine: pyruvate transaminase in isolated liver cell incubations. 2. The relationship between hydroxylase flux and phenylalanine concentration is sigmoidal. 3. Glucagon increases hydroxylase activity at low, near-physiological, substrate concentrations only. The hormone does not affect the rate of formation of phenylpyruvate. 4. Experimental diabetes (for 10 ...

  7. [Relaxant activity of aqueous and ethanol extracts of parsley (Petroselinum crispum (Mill) Nym. ex A. W Hill, Apiaceae) on isolated ileum of rat].

    Science.gov (United States)

    Branković, Suzana; Kitić, Dusanka; Radenković, Mirjana; Ivetić, Vesna; Veljković, Slavimir; Nesić, Milkica

    2010-01-01

    Parsley (Petroselinum crispum) is used in the traditional herbal medicine to treat intestinal disorders. The aim of this study was to examine the effect of aqueous and ethanol extracts of parsley on spontaneous and acetylcholine induced contractions on isolated rat ileum. Wistar albino rats (250-300 g) were used in this study. The ileum portions were isolated out and cleaned off mesenteries. Preparations 2 cm long were mounted in 20 ml tissue baths containing Tyrode's solution maintained at 37 degrees C and aerated with a mixture of 5% carbon dioxide in oxygen. In the first part of experiments, contractile responses to the aqueous (ethanol) extracts of parsley were recorded. In the second part, increasing concentrations of acetylcholine were added to the organ bath for a full concentration response curve and then concentration response curves were obtained after adding the aqueous (ethanol) extracts of parsley. Our results showed that aqueous (62.22 +/- 7.15%) and ethanol (79.16 +/- 9.34%) extracts of parsley in dose dependent manner decreased the tonus of spontaneous contractions of isolated rat ileum. The aqueous (32.16 +/- 2.75%) and ethanol (53.96 +/- 4.86%) extracts of parsley reduced the acetylcholine induced contraction, the reduction was greater with ethanol extract than with the aqueous one. It can be concluded that the aqueous and ethanol extracts of parsley exert antispasmodic activity on rat ileum. The relaxant effect of ethanol extract was better comparing to aqueous extract of parsley.

  8. TRPC1 expression and distribution in rat hearts

    Directory of Open Access Journals (Sweden)

    W. Niu

    2009-12-01

    Full Text Available Transient receptor potential canonical (TRPC proteins have been identified as a family of plasma membrane calcium-permeable channels. TRPC proteins can be activated by various stimuli and act as cellular sensors in mammals. Stretch-activated ion channels (SACs have been proposed to underlie cardiac mechano-electric feedback (MEF, although the molecular entity of SAC remains unknown. There is evidence suggesting that transient receptor potential canonical 1 (TRPC1 is a stretch-activated ion channel. As a non-selective cation channel, TRPC1 may cause stretch-induced depolarization and arrhythmia and thus may contribute to the MEF of the heart. In this study, we examined the expression patterns of TRPC1 in detail at both the mRNA and protein levels in rat hearts.We isolated total RNA from the left and right atria, and the left and right ventricles, and detected TRPC1 mRNA in these tissues using reverse-transcriptase polymerase chain reaction (RT-PCR. To study the protein localization and targeting, we performed immunohistochemistry and immunofluorescence labeling with the antibody against TRPC1. TRPC1 was detected in the cardiomyocytes of the ventricle and atrium at both the mRNA and protein levels. The cell membrane and Ttubule showed strong fluorescence labeling in the ventricular myocytes. Purkinje cells, the endothelial cells and smooth muscle cells of the coronary arterioles also displayed TRPC1 labeling. No TRPC1 was detected in fibroblasts. In conclusion, TRPC1 is widely expressed in the rat heart, including in working cells, Purkinje cells and vascular cells, suggesting that it plays an important role in the heart. The specific distribution pattern offered a useful insight into its function in adult rat ventricular cells. Further investigations are needed to clarify the role of TRPC1 in regulating cardiac activity, including cardiac MEF.

  9. INTERACTION OF VERAPAMIL AND LITHIUM AT THE NEUROMUSCULAR JUNCTION ON RAT ISOLATED MUSCLE-HEMIDIAPHRAGM

    Directory of Open Access Journals (Sweden)

    H. R. Sadeghipour

    1998-08-01

    Full Text Available It has been reported that cither lithium or verapamil can potentiate the neuromuscular blocking activity of certain neuromuscular blockers. In the present investigation, possible interaction of verapamil with lithium has been described. The dose ■ response effects of verapamil and lithium on diaphragmatic contractility were assessed in vitro. Mechanical responses of the muscle to indirect (nerve and direct (muscle electrical stimulation were recorded. Verapamil depressed rat diaphragm twitch tensions induced by nerve stimulation in a dose - dependent manner with the 50 percent depression of the original twitch tensions (ICSQ by 5.6 xlO^mmol/l."nThe IC50 of verapamil for direct stimulation of the muscle was LI x W'5 mmol II. Partial replacement of sodium chloride by lithium chloride (0.5, 1.5 and 5 mmol /1 in the medium did not change the depressant effect of verapamil on muscle twitches induced by direct (muscle or indirect (nerve electrical stimulation.

  10. Gamma irradiation of isolated rat islets pretransplantation produces indefinite allograft survival in cyclosporine-treated recipients

    International Nuclear Information System (INIS)

    James, R.F.; Lake, S.P.; Chamberlain, J.; Thirdborough, S.; Bassett, P.D.; Mistry, N.; Bell, P.R.

    1989-01-01

    In this study we have examined the use of low-dose gamma-irradiation for the reduction of islet immunogenicity in the strong allogeneic combination of WAG rat islets transplanted into diabetic AUG recipients. First, we determined that gamma-irradiation reduced immunogenicity in vitro by use of a modified MLR with WAG islets as stimulators and AUG splenocytes as responders. We then determined the maximum dose of gamma-irradiation that could be used (250 rads) before islet function was affected. As 250 rads islet pretreatment alone was ineffective in prolonging allograft survival, we combined the pretreatment with a short course (days 0, 1, 2; 30 mg/kg) of cyclosporine. We found that CsA was only effective in significantly prolonging allograft survival when given subcutaneously in olive oil. The CsA treatment alone gave a significantly prolonged survival time for the islet allografts (median, 37 days vs. 6 days for controls), but when combined with the 250 rads islet pretreatment a synergistic effect was seen with 100% becoming long-term survivors (greater than 100 days). The long-term surviving AUG rats from both the CsA alone group and the CsA plus 250 rads pretreated islets group were challenged with WAG dendritic cells (DC). The islets from the 250 rads pretreated group were subsequently rejected (day 6) while the CsA alone group were not affected. The role of low dose gamma-irradiation when combined with CsA treatment of islet graft recipients in inducing specific unresponsiveness will be discussed

  11. Gamma irradiation of isolated rat islets pretransplantation produces indefinite allograft survival in cyclosporine-treated recipients

    Energy Technology Data Exchange (ETDEWEB)

    James, R.F.; Lake, S.P.; Chamberlain, J.; Thirdborough, S.; Bassett, P.D.; Mistry, N.; Bell, P.R.

    1989-06-01

    In this study we have examined the use of low-dose gamma-irradiation for the reduction of islet immunogenicity in the strong allogeneic combination of WAG rat islets transplanted into diabetic AUG recipients. First, we determined that gamma-irradiation reduced immunogenicity in vitro by use of a modified MLR with WAG islets as stimulators and AUG splenocytes as responders. We then determined the maximum dose of gamma-irradiation that could be used (250 rads) before islet function was affected. As 250 rads islet pretreatment alone was ineffective in prolonging allograft survival, we combined the pretreatment with a short course (days 0, 1, 2; 30 mg/kg) of cyclosporine. We found that CsA was only effective in significantly prolonging allograft survival when given subcutaneously in olive oil. The CsA treatment alone gave a significantly prolonged survival time for the islet allografts (median, 37 days vs. 6 days for controls), but when combined with the 250 rads islet pretreatment a synergistic effect was seen with 100% becoming long-term survivors (greater than 100 days). The long-term surviving AUG rats from both the CsA alone group and the CsA plus 250 rads pretreated islets group were challenged with WAG dendritic cells (DC). The islets from the 250 rads pretreated group were subsequently rejected (day 6) while the CsA alone group were not affected. The role of low dose gamma-irradiation when combined with CsA treatment of islet graft recipients in inducing specific unresponsiveness will be discussed.

  12. RNA-sequencing data analysis of uterus in ovariectomized rats fed with soy protein isolate, 17β-estradiol and casein

    Directory of Open Access Journals (Sweden)

    Martin J. Ronis

    2016-06-01

    Full Text Available This data file describes the bioinformatics analysis of uterine RNA-seq data comparing genome wide effects of feeding soy protein isolate compared to casein to ovariectomized female rats age 64 days relative to treatment of casein fed rats with 5 μg/kg/d estradiol and relative to rats treated with estradiol and also fed soy protein isolate. Complete raw data files were deposited in the gene Expression Omnibus (GEO at NCBI (http:/www.ncbi.nlm.nih.gov.geo/ under the GEO accession number GEO: GSE69819. Data presented here incudes a summary of the differential expression analysis with top 30 genes up- and down-regulated by soy protein isolate (SPI, estradiol (E2 and SPI+E2. Additional functional annotation analysis of KEGG pathways is also presented for each treatment, together with networks of interaction between those pathways. Further interpretation and discussion of this data can be found in the article “Uterine responses to feeding soy protein isolate and treatment with 17β-estradiol differ in ovariectomized female rats” Ronis et al. (2016 [1].

  13. Gastroprotective effect of diligustilide isolated from roots of Ligusticum porteri coulter & rose (Apiaceae) on ethanol-induced lesions in rats.

    Science.gov (United States)

    Velázquez-Moyado, Josué A; Martínez-González, Alejandro; Linares, Edelmira; Bye, Robert; Mata, Rachel; Navarrete, Andrés

    2015-11-04

    The rhizome of Ligusticum porteri Coulter& Rose (LP) has been traditionally used by the ethnic group Raramuri in the North of México for treatment of diabetes, tuberculosis, stomachaches, diarrhea and ritual healing ceremonies. It is use as antiulcer remedy has been extended to all Mexico. To evaluate the gastroprotective activity of LP organic extracts and the major natural product diligustilide (DLG),using as experimental model the inhibition of the ethanol-induced lesions in rats. Gastric ulcers were induced by intragastric instillation of absolute ethanol (1 mL). We tested the gastroprotective activity of the organic extracts of LP and the pure compound DLG. The ulcer index (UI) was determined to measure the activity. In order to elucidate the action mechanism of DLG the animals were treated with L-NAME, N-ethylmalemide, Forskolin, 2',5'-dideoxyadenosine, Indomethacin, Glibenclameide, Diazoxide, NaHS and DL-Propargylglycine. The pylorus-ligated rat model was used to measure gastric secretion. The oral administration of organic extracts of Ligusticum porteri showed gastroprotective effect at 30 mg/Kg on ethanol induced gastric lesions; hexane and dichloromethane extracts were the most active. DLG was the major compound in the hexane extract. This compound at 10 mg/kg prevented significantly the gastric injuries induced by ethanol. The alkylation of endogenous non-protein-SH groups with N-ethylmaleimide abolished the gastroprotective effect of DLG and blocking the formation of endogenous prostaglandins by the pretreatment with indomethacin attenuated the gastroprotective effect of DLG. The gastroprotective activity demonstrated in this study tends to support the ethnomedical use of Ligusticum porteri roots. DLG, isolated as major compound of this medicinal plant has a clear gastroprotective effect on the ethanol-induced gastric lesions. The results suggest that the antiulcer activity of DLG depends on the participation of the endogenous non-protein -SH groups

  14. Effects of dihydropyridines on tension and calcium-45 influx in isolated mesenteric resistance vessels from spontaneously hypertensive and normotensive rats

    International Nuclear Information System (INIS)

    Cauvin, C.; Hwang, O.; Yamamoto, M.; van Breemen, C.

    1987-01-01

    Contractile tension responses to norepinephrine and depolarizing potassium (80 mM K+), as well as calcium-45 influx stimulated by these agents, were studied in isolated mesenteric resistance vessels (each 100 microM internal diameter) from spontaneously hypertensive rats (SHRs) and from normotensive Wistar Kyoto rats (WKYs). Inhibitory effects of 2 dihydropyridine Ca++ antagonists, PN 200-110 (isradipine) and nisoldipine, on these parameters were also determined. Contractile responses to 80 mM K+ were inhibited by both Ca++ antagonists with the same potency and efficacy in SHR compared with WKY vessels (PN 200-110 IC50 = 2.8 +/- 1.3 X 10(-8) M in SHRs and 2.5 +/- 1.5 X 10(-8) M in WKYs; nisoldipine IC50 = 1.1 +/- 0.4 X 10(-8) M in SHRs and 1.2 +/- 0.9 X 10(-8) M in WKYs). However, contractile responses to norepinephrine (10(-4) M) were inhibited less potently by nisoldipine in SHR vessels (IC50 = 2.2 +/- 0.3 X 10(-9) M) compared with WKY vessels (IC50 = 1.6 +/- 0.6 X 10(-10) M). Similarly, PN 200-110 tended to be less (but not significantly less) potent in SHR vessels (IC50 = 3.3 +/- 1.8 X 10(-8) M) than in WKY vessels (IC50 = 3.4 +/- 0.9 X 10(-9) M); its efficacy was significantly depressed in the SHR vessels (by approximately 20%). When norepinephrine-stimulated calcium-45 influx was determined in the presence of these Ca++ antagonists, a similar profile emerged with respect to a comparison of SHR and WKY vessels. These results support a previously hypothesized alteration in receptor-activated Ca++ influx pathways in SHR mesenteric resistance vessels

  15. Effects of high-protein diet containing isolated whey protein in rats submitted to resistance training of aquatic jumps.

    Science.gov (United States)

    Avila, Eudes Thiago Pereira; da Rosa Lima, Thiago; Tibana, Ramires Alsamir; de Almeida, Paula Caroline; Fraga, Géssica Alves; de Souza Sena, Mariana; Corona, Luiz Felipe Petusk; Navalta, James Wilfred; Rezaei, Sajjad; Ghayomzadeh, Morteza; Damazo, Amílcar Sabino; Prestes, Jonato; Voltarelli, Fabrício Azevedo

    2018-02-13

    Isolated whey protein (IWP) can decrease body fat compared with other protein sources. The present study verified the effects of high protein diet (HD) containing IWP on several parameters of rats subjected to resistance training (RT). Thirty-two male Wistar rats (60 days of age) were separated into four groups (n = 8/group): sedentary normoproteic (IWP 14%; SN); sedentary hyperproteic (IWP 35%; SH); trained normoproteic (IWP 14%; TN), and trained hyperproteic (WPI 35%; TH). Relative tissue/organ weight (g): perirenal and retroperitoneal adipose tissues were lower in SH and TH compared with SN (no difference to TN); omental and subcutaneous adipose tissues were higher in SN compared with SH. Epididymal adipose tissue was higher in SN compared with other groups. Heart weight was higher in TH compared with TN and SN, but not SH; kidney and liver higher in TH and SH compared with SN and TN; gastrocnemius lower in SN compared with other groups; soleus higher in SH in relation to other groups. The triglycerides levels (mg/dL) was reduced in the TH groups compared with SH, TN, and SN. There were no changes both in the concentrations of adiponectin and leptin and in the protein expression of GLUT-4 and p70 s6k . HD containing WPI improved body composition, increased the weight of the heart, kidneys, liver and gastrocnemius and soleus muscles; however, this diet maintained the normal histomorphology of muscle and liver and, when associated with RT, reduced the serum levels of triglycerides. Copyright © 2018 Elsevier Inc. All rights reserved.

  16. The detection of the non-M2 muscarinic receptor subtype in the rat heart atria and ventricles

    Czech Academy of Sciences Publication Activity Database

    Mysliveček, J.; Klein, M.; Nováková, M.; Říčný, Jan

    2008-01-01

    Roč. 378, č. 1 (2008), s. 103-116 ISSN 0028-1298 R&D Projects: GA MŠk(CZ) LC554; GA ČR(CZ) GA304/08/0256 Institutional research plan: CEZ:AV0Z50110509 Keywords : heart * muscarinic receptors * PLC activity Subject RIV: FH - Neuro logy Impact factor: 2.830, year: 2008

  17. Secretion of 35SO4-labeled proteins from isolated rat hepatocytes

    International Nuclear Information System (INIS)

    von Wuertemberg, M.M.F.; Fries, E.

    1989-01-01

    Sulfation is a Golgi-specific modification of secretory proteins. We have characterized the proteins that are labeled with 35 SO 4 in cultures of rat hepatocytes and studied their transport to the medium. Analysis by polyacrylamide gel electrophoresis showed that of the five most heavily labeled proteins, four had well-defined mobilities--apparent molecular masses of 188, 142, 125, and 82 kDa--whereas one was electrophoretically heterogeneous--apparent molecular mass of 35-45 kDa. Judging by their relatively high resistance to acid treatment, the sulfate residues in the 125- and 35-45-kDa proteins were linked to carbohydrate. Some of the secreted proteins were sialylated. In samples of pulse-labeled cells, there appeared to be no unsialylated forms, indicating that sulfation occurred after sialylation, presumably in the trans Golgi. Kinetic experiments showed that the cellular half-life was the same for all the sulfated proteins--about 8 min--consistent with the idea that transport from the Golgi complex to the cell surface occurs by liquid bulk flow

  18. Genetic regulation by amino acids of specific membrane protein biosynthesis in isolated rat hepatocytes

    International Nuclear Information System (INIS)

    Chiles, T.C.; Handlogten, M.E.; Kilberg, M.S.

    1986-01-01

    Rat Hepatocytes in primary culture were incubated in amino acid-free (AAF) medium or amino acid-supplemented (AAS) medium for 2-6 hr. The effect of amino acid starvation on the synthesis of specific membrane proteins was monitored by including 3 H-leucine during the incubation. A crude plasma membrane fraction was prepared and then analyzed by 2-D gel electrophoresis followed by fluorography. Amino acid deprivation caused an induction of the synthesis of 5 of the 30 proteins studied. The ratio (AAF/-AAS) of cpm incorporated into the remaining 25 proteins was 0.8 +/- 0.2, whereas the ratio for the 5 proteins that showed amino acid-dependent synthesis ranged from 1.5 to 2.5. The presence of 4 μM actinomycin in the AAF medium completely blocked the starvation-induced synthesis of the 5 proteins tested, but did not alter significantly the ratio of cpm incorporated into the other 25 proteins. Binding studies involving ConA suggested a plasma membrane location for the 5 proteins. The molecular weight values of the starvation-induced proteins are 70, 66, 66, 67, and 45kD. Surface-labelling of intact cells and preparation of antibodies against the 5 proteins will be used to establish the subcellular location and to describe the amino acid-dependent synthesis of each in more detail

  19. Hemidesmus indicus and Hibiscus rosa-sinensis Affect Ischemia Reperfusion Injury in Isolated Rat Hearts

    Directory of Open Access Journals (Sweden)

    Vinoth Kumar Megraj Khandelwal

    2011-01-01

    Full Text Available Hemidesmus indicus (L. R. Br. (HI and Hibiscus rosa-sinensis L. (HRS are widely used traditional medicine. We investigated cardioprotective effects of these plants applied for 15 min at concentrations of 90, 180, and 360 μg/mL in Langendorff-perfused rat hearts prior to 25-min global ischemia/120-min reperfusion (I/R. Functional recovery (left ventricular developed pressure—LVDP, and rate of development of pressure, reperfusion arrhythmias, and infarct size (TTC staining served as the endpoints. A transient increase in LVDP (32%–75% occurred at all concentrations of HI, while coronary flow (CF was significantly increased after HI 180 and 360. Only a moderate increase in LVDP (21% and 55% and a tendency to increase CF was observed at HRS 180 and 360. HI and HRS at 180 and 360 significantly improved postischemic recovery of LVDP. Both the drugs dose-dependently reduced the numbers of ectopic beats and duration of ventricular tachycardia. The size of infarction was significantly decreased by HI 360, while HRS significantly reduced the infarct size at all concentrations in a dose-dependent manner. Thus, it can be concluded that HI might cause vasodilation, positive inotropic effect, and cardioprotection, while HRS might cause these effects at higher concentrations. However, further study is needed to elucidate the exact mechanism of their actions.

  20. G protein in stimulation of PI hydrolysis by CCK [cholecystokinin] in isolated rat pancreatic acinar cells

    International Nuclear Information System (INIS)

    Matozaki, Takashi; Sakamoto, Choitsu; Nagao, Munehiko; Nishizaki, Hogara; Baba, Shigeaki

    1988-01-01

    To clarify the possible role of a guanine nucleotide-binding protein (G protein) in the signal transducing system activated by cholecystokinin (CCK), actions of CCK on rat pancreatic acini were compared with those of fluoride, a well-known activator of stimulatory (G s ) or inhibitory (G i ) G protein. When acini were incubated with increasing concentrations of either CCK-octapeptide (CCK8) or NaF, a maximal stimulation of amylase release from acini occurred at 100 pM CCK8 or 10 mM NaF, respectively; this secretory rate decreased as CCK8 or NaF concentration was increased. NaF caused an increase in cytoplasmic Ca 2+ concentration from the internal Ca 2+ store and stimulated accumulation of inositol phosphates in acini, as observed with CCK. Guanylimidodiphosphate activated the generation of inositol phosphates in the [ 3 H]inositol-labeled pancreatic acinar cell membrane preparation, with half-maximal and maximal stimulation at 1 and 10 μM, respectively. Furthermore, the effects of submaximal CCK concentrations on inositol phosphate accumulation in membranes were markedly potentiated in the presence of 100 μM GTP, which alone was ineffective. Combined findings of the present study strongly suggest that pancreatic CCK receptors are probably coupled to the activation of polyphosphoinositide (PI) breakdown by a G protein, which appears to be fluoride sensitive but is other than G s - or G i -like protein

  1. Agonist of inward rectifier K+ channels enhances the protection of ischemic postconditioning in isolated rat hearts.

    Science.gov (United States)

    Liao, Z; Feng, Z; Long, C

    2014-07-01

    Selective inhibition of inward rectifier K + channels could abolish the protection mediated by ischemic preconditioning, but the roles of these channels in ischemic postconditioning have not been well characterized. Our study aims to evaluate the effect of inward rectifier K + channels on the protection induced by ischemic postconditioning. Langendorff-perfused rat hearts (n=8 per group) were split into four groups: postconditioning hearts (IPO group); ischemic postconditioning with BaCl 2 hearts (PB group); ischemic postconditioning with zacopride hearts (PZ group); and without ischemic postconditioning (CON group). After suffering 30 minutes of global ischemia, groups IPO, PB and PZ went through 10 seconds of ischemic postconditioning with three different perfusates: respectively, Krebs-Henseleit buffer (IPO group); 20 μmol/L BaCl 2 (antagonist of the channel, PB group); 1 μmol/L zacopride (agonist of the channel, PZ group). At the end of reperfusion, the myocardial performance was better preserved in the PZ group than the other three groups. The PB group showed no significant differences from the CON group. Our study has shown that the I K1 channel agonist zacopride is associated with the enhancement of ischemic postconditioning. © The Author(s) 2014.

  2. Transport of cefodizime, a novel third generation cephalosporin antibiotic, in isolated rat choroid plexus

    International Nuclear Information System (INIS)

    Nohjoh, T.; Suzuki, H.; Sawada, Y.; Sugiyama, Y.; Iga, T.; Hanano, M.

    1989-01-01

    To characterize the transport system by which cephalosporin antibiotics are accumulated by the choroid plexus, kinetic analysis of cefodizime transport was performed. Accumulation of cefodizime was against an electrochemical potential gradient via a saturable process (Km = 470 microM, Vmax = 174 nmol/ml of tissue per min) that was inhibited by metabolic inhibitors (KCN and 2,4-dinitrophenol), hypothermia, a sulfhydryl reagent (p-hydroxymer-curibenzoic acid) and anion transport inhibitors (probenecid and 4,4'-diisothiocyanostilbene -2,2'-disulfonic acid). Accumulation of cefodizime was inhibited competitively by benzylpenicillin with an inhibition constant of aproximately 100 microM. Cefodizime inhibited competitively the accumulation of benzylpenicillin with an inhibition constant of approximately 500 microM. Kinetic analysis using 16 kinds of beta-lactam antibiotics also supported the view (1) that the transport system of cefodizime is shared by benzylpenicillin and (2) that these beta-lactam antibiotics are transported via a common transport system. These findings indicate that the major transport system of cephalosporin antibiotics in the rat choroid plexus is via a carrier-mediated active anion transport process. The affinity of beta-lactam antibiotics for this transport system in the choroid plexus may be a major factor in determining their pharmacokinetics in the cerebrospinal fluid

  3. Immobilization of Na,K-ATPase isolated from rat brain synaptic plasma membranes

    Directory of Open Access Journals (Sweden)

    ANICA HROVAT

    2002-12-01

    Full Text Available Rat brain Na,K-ATPase partially purified by SDS from synaptic plasma membranes (SPM was immobilized by adsorption on nitrocellulose (NC, polyvinylidene fluoride (PVDF and glass fiber (GF membranes. Partial SDS solubilization increased the enzyme activity by 40 %. With regard to the preservation of the enzyme activity, nitrocellulose was shown to be the optimal support for the immobilization. The enzyme showed the highest percentage activity (14 % after 30 min of SPM adsorption, at 20°C under the vaccum, with 25 mg of proteins per NC disc filter. In addition, adsorption on NC stabilizes the Na,K-ATPase, since the activity was substantial 72 h after adsorption at 20°C. After adsorption, the sensitivity of the enzyme to HgCl2and CdCll2 inhibition was higher. The results show that immobilized Na,K-ATPase SPM can be used as a practical model for the detection of metal ions in different samples.

  4. Extraction of long-chain fatty acids in isolated rat heart during acute low-flow ischemia.

    Science.gov (United States)

    Richter, W S; Fischer, S; Ernst, N; Munz, D L

    2001-07-01

    Although beta-oxidation of fatty acids is suppressed rapidly during ischemia, the behavior of fatty acid extraction at different flow rates is incompletely understood. This study assessed the relationship between flow and extraction of (123)I-iodophenylpentadecanoic acid (IPPA) in the isolated heart model, especially at low flow. Isolated hearts from male Wistar rats (n = 15) were subjected to retrograde perfusion with constant flow (Krebs Henseleit solution containing 10 mmol/L glucose). A latex balloon in the left ventricle allowed isovolumetric contractions and ventricular pressure measurements. The extraction of (123)I-IPPA was assessed with the indicator dilution technique and (99m)Tc-albumin as the intravascular reference. The flow was either increased from the control flow (8 mL/min) until 300% or reduced until 10%. (123)I-IPPA extraction was measured three times before and 10 min after flow alteration. The tracer uptake was estimated from the product of net extraction and flow. The mean (123)I-IPPA extraction at the control flow (third measurement) was 51.6% +/- 2.8%. Between flow rates of approximately 25% and 300%, (123)I-IPPA extraction increased exponentially at decreasing flow rates. At flow rates < or =25% of the control flow, (123)I-IPPA extraction was exponentially higher than predicted. (123)I-IPPA uptake and flow changed largely in parallel. During low flow, the rate-pressure product showed the expected decline (perfusion-contraction matching). The extraction of (123)I-IPPA is preserved and slightly increased (relative to flow) during acute low-flow ischemia.

  5. Cardiovascular Activity of Labdane Diterpenes from Andrographis paniculata in Isolated Rat Hearts

    Directory of Open Access Journals (Sweden)

    Khalijah Awang

    2012-01-01

    Full Text Available The dichloromethane (DCM extract of Andrographis paniculata Nees was tested for cardiovascular activity. The extract significantly reduced coronary perfusion pressure by up to 24.5±3.0 mm Hg at a 3 mg dose and also reduced heart rate by up to 49.5±11.4 beats/minute at this dose. Five labdane diterpenes, 14-deoxy-12-hydroxyandrographolide (1, 14-deoxy-11,12-didehydroandrographolide (2, 14-deoxyandrographolide (3, andrographolide (4, and neoandrographolide (5, were isolated from the aerial parts of this medicinal plant. Bioassay-guided studies using animal model showed that compounds, (2 and (3 were responsible for the coronary vasodilatation. This study also showed that andrographolide (4, the major labdane diterpene in this plant, has minimal effects on the heart.

  6. Cardiovascular Activity of Labdane Diterpenes from Andrographis paniculata in Isolated Rat Hearts

    Science.gov (United States)

    Awang, Khalijah; Abdullah, Nor Hayati; Hadi, A. Hamid A.; Su Fong, Yew

    2012-01-01

    The dichloromethane (DCM) extract of Andrographis paniculata Nees was tested for cardiovascular activity. The extract significantly reduced coronary perfusion pressure by up to 24.5 ± 3.0 mm Hg at a 3 mg dose and also reduced heart rate by up to 49.5 ± 11.4 beats/minute at this dose. Five labdane diterpenes, 14-deoxy-12-hydroxyandrographolide (1), 14-deoxy-11,12-didehydroandrographolide (2), 14-deoxyandrographolide (3), andrographolide (4), and neoandrographolide (5), were isolated from the aerial parts of this medicinal plant. Bioassay-guided studies using animal model showed that compounds, (2) and (3) were responsible for the coronary vasodilatation. This study also showed that andrographolide (4), the major labdane diterpene in this plant, has minimal effects on the heart. PMID:22536026

  7. NMR study of damage on isolated perfused rat heart exposed to ischemia and hypoxia

    International Nuclear Information System (INIS)

    Luo Xuechun; Yan Yongbin; Zhang Riqing; Fan Lili

    2001-01-01

    Myocardial ischemia is the most common and primary cause of myocardium damage. Numerous conventional techniques and methods have been developed for ischemia and reperfusion studies. However, because of damage to the heart sample, most of these techniques can not be used to continuously monitor the full dynamic course of the myocardial metabolic pathway. The nuclear magnetic resonance (NMR) surface coil technique, which overcomes the limitations of conventional instrumentation, can be used to quantitatively study every stage of the perfused heart (especially after perfusion stoppage) continuously, dynamically, and without damage under normal or designed physiological conditions at the molecular level. In this paper, 31 P-NMR was used to study the effects of ischemia and hypoxia on isolated perfused hearts. The results show that complete hypoxia caused more severe functional damage to the myocardial cells than complete ischemia

  8. Characterisation of a novel enterobacteria phage, CAjan, isolated from rat faeces.

    Science.gov (United States)

    Carstens, Alexander B; Kot, Witold; Lametsch, Rene; Neve, Horst; Hansen, Lars H

    2016-08-01

    In this study, we describe the isolation and characterisation of the novel enterobacteria phage CAjan. This phage belongs to the order Caudovirales and the family Siphoviridae. The phage possesses a linear, double-stranded DNA genome consisting of 59,670 bp with a G+C content of 44.7 % and 91 predicted open reading frames (ORFs). Putative functions were assigned to 39 of the ORFs (37.4 %). The phage structural genes were furthermore functionally characterised by LC MS/MS. CAjan, together with Escherichia phage Seurat and Escherichia phage slur01, represent a novel and genetically distinct clade of Siphoviridae phages that could be considered to constitute a new phage genus. Despite limited sequence similarity, the phages in this group share a number of other common features, including genome structure and the presence of queuosine biosynthesis genes.

  9. Auditory sensory processing deficits in sensory gating and mismatch negativity-like responses in the social isolation rat model of schizophrenia

    DEFF Research Database (Denmark)

    Witten, Louise; Oranje, Bob; Mørk, Arne

    2014-01-01

    Patients with schizophrenia exhibit disturbances in information processing. These disturbances can be investigated with different paradigms of auditory event related potentials (ERP), such as sensory gating in a double click paradigm (P50 suppression) and the mismatch negativity (MMN) component...... in an auditory oddball paradigm. The aim of the current study was to test if rats subjected to social isolation, which is believed to induce some changes that mimic features of schizophrenia, displays alterations in sensory gating and MMN-like response. Male Lister-Hooded rats were separated into two groups; one...... group socially isolated (SI) for 8 weeks and one group housed (GH). Both groups were then tested in a double click sensory gating paradigm and an auditory oddball paradigm (MMN-like) paradigm. It was observed that the SI animals showed reduced sensory gating of the cortical N1 amplitude. Furthermore...

  10. Ultrastructural analysis of bone nodules formed in vitro by isolated fetal rat calvaria cells

    International Nuclear Information System (INIS)

    Bhargava, U.; Bar-Lev, M.; Bellows, C.G.; Aubin, J.E.

    1988-01-01

    When cells enzymatically digested from 21 d fetal rat calvaria are grown in ascorbic acid and Na beta-glycerophosphate, they form discrete three-dimensional nodular structures with the histological and immunohistochemical appearance of woven bone. The present investigation was undertaken to verify that bone-like features were identifiable at the ultrastructural level. The nodules formed on top of a fibroblast-like multilayer of cells. The upper surface of the nodules was lined by a continuous layer of cuboidal osteoblastic cells often seen to be joined by adherens junctions. Numerous microvilli, membrane protrusions, and coated pits could be seen on the upper surface of these cells, their cytoplasm contained prominent RER and Golgi membranes, and processes extended from their lower surfaces into a dense, highly organized collagenous matrix. Some osteocyte-like cells were completely embedded within this matrix; they also displayed RER and prominent processes which extended through the matrix and often made both adherens and gap junctional contacts with the processes of other cells. The fibroblastic cells not participating in nodule formation were surrounded by a less dense collagenous matrix and, in contrast to the matrix of the nodules, it did not mineralize. An unmineralized osteoid-like layer was seen directly below the cuboidal top layer of cells. A mineralization front was detectable below this in which small, discrete structures resembling matrix vesicles and feathery mineral crystals were evident and frequently associated with the collagen fibrils. More heavily mineralized areas were seen further into the nodule. Electron microprobe and electron and X-ray diffraction analysis confirmed the mineral to be hydroxyapatite

  11. The Hepatoprotective Effects of Corn Silk against Dose-induced Injury of Ecstasy (MDMA Using Isolated Rat Liver Perfusion System

    Directory of Open Access Journals (Sweden)

    Mohammad Karami

    2016-07-01

    Full Text Available Background: Corn silk (CS is widely used in Iranian traditional medicine. The aim of this study was to investigate hepatoprotective activity of CS by Isolated Rat Liver Perfusion System (IRLP. Methods: Hydro-alcoholic extract of corn silk (10, 20, 40, and 100 mg kg-1 was evaluated for its hepatoprotective activity by IRLP. Phenol and flavonoid contents of the extract were determined as gallic acid and quercetin equivalents from a calibration curve, respectively. IRLP system is ideal for studying biochemical alterations of chemicals with minimum neuro-hormonal effects. In this study, the liver was perfused with Kerbs-Henseleit buffer, containing different concentration of hydro-alcoholic extract of corn silk (10, 20, 40, 50,100mg/kg, added to the buffer, and perfused for 2 hours. During the perfusion, many factors, including amino-transferees activities and the level of GSH, were assessed as indicators of liver viability. Consequently, sections of liver tissues were examined for any histopathological changes. Results: Histopathological changes in liver tissues were related to hydro-alcoholic extract of corn silk concentrations in a dose-dependent manner. Also, 50 and 100mg/kg doses caused significant (P<0.05 histopathological changes. Level of GSH in samples perfused with hydro-alcoholic extract increased compared to the control group. Conclusion: Hepatoprotective effect of CS is due to decreased lipid peroxidation, although other mechanisms might also be involved.

  12. The effect of streptomycin on stretch-induced electrophysiological changes of isolated acute myocardial infarcted hearts in rats.

    Science.gov (United States)

    Fu, Lu; Cao, Jun-xian; Xie, Rong-sheng; Li, Jia; Han, Ying; Zhu, Li-qun; Dai, Ying-nan

    2007-08-01

    To explore whether the stretch of ischaemic myocardium could modulate the electrophysiological characteristics, especially repolarization via mechanoelectric feedback (MEF), as well as the effect of streptomycin (SM) on these changes. Methods Thirty-six wistar rats were randomly divided into four groups: control group (n = 9), SM group (n = 9), myocardial infarction (MI) group (n = 9), and MI + SM group (n = 9). After perfused on Langendorff, the isolated hearts were stretched for 5s by a ballon inflation of 0.2mL. After being stretched, the effect of the stretch was observed for 30s, including the 20, 20-70, 70, and 90% monophasic action potential duration (MAPD), i.e. MAPD(20), MAPD(20-70), MAPD(70), and MAPD(90), respectively, premature ventricular beats (PVB), and ventricular tachycardia (VT). Results The stretch caused a decrease in MAPD(20-70) (both P 0.05, except MAPD(20-70) between the control and SM groups, P maintenance of malignant arrhythmias. SM could significantly inhibit the occurrence of arrhythmias, which may correlate with the effect on blocking stretch-activated ion channels.

  13. Characterization of the effects of erythromycin estolate and erythromycin base on the excretory function of the isolated rat liver

    International Nuclear Information System (INIS)

    Gaeta, G.B.; Utili, R.; Adinolfi, L.E.; Abernathy, C.O.; Giusti, G.

    1985-01-01

    To investigate the mechanisms of erythromycin cholestasis, the effects of erythromycin estolate (EE) on the excretory function of the isolated perfused rat liver and on liver plasma membrane (LM) preparations were studied and compared to those of erythromycin base (EB) and lauryl sulfate (LS), added alone or in combination. EE (at 125 to 200 microM) caused dose-dependent reductions of bile and perfusate flows, bile acid (BA) excretion, and biliary BA concentration. The alterations of the excretory function were only in part due to the decreased perfusate flow. In contrast, both 200 and 300 microM concentrations of EB elicited similar choleretic responses, which were presumably related to the osmotic activity of the drug excreted in the bile. LS did not affect hepatic excretory functions. However, the simultaneous addition of EB and LS resulted in a rate of bile flow lower than that observed with EB alone. EE, but not EB, increased canalicular permeability to [ 14 C]sucrose as measured by bile to plasma (B:P) ratio. Neither drugs altered [ 14 C]erythritol B:P ratio. In LM preparations both Na+,K+- and Mg2+-ATPase activities were inhibited in a dose-dependent manner by EE, but not by EB. The data suggest that EE could affect bile flow by inhibiting cotransport of Na+ and BA and by altering LM permeability and support the view that the effect of erythromycins on the liver may be related to their surface activity

  14. Wound healing effect of flavonoid rich fraction and luteolin isolated from Martynia annua Linn. on streptozotocin induced diabetic rats

    Institute of Scientific and Technical Information of China (English)

    Santram Lodhi; Abhay K Singhai

    2013-01-01

    Objective: To evaluate wound healing potential of flavonoid fractions of Martynia annua (M. annua) Linn. leaves in diabetic rats on the basis of folkloric information and preliminary study. Methods: The flavonoid compound luteolin and apigenin were isolated from dried leaves of plant by column chromatography. The two concentrations (0.2% and 0.5% w/w) of luteolin and flavonoid fraction were selected for topically applied as ointment on diabetic wound. The Povidone Iodine Ointment USP was used as a reference. On 18th days, protein content, hydroxyproline and antioxidants (SOD, CAT and GSH) level in granuloma tissues were determined.Results:The results showed that, percent wound contraction were observed significantly (P<0.01) greater in MAF fraction and 0.5% w/w of luteolin treatment groups. Presence of matured collagen fibres and fibroblasts with better angiogenesis were observed in histopathological studies.Conclusions:In conclusion, our findings suggest that flavonoid fraction (MAF) and luteolin (0.5%w/w) may have potential benefit in enhancing wound healing in diabetic condition, possibly due to free-radical scavenging activity of plant.

  15. Experimental testing of Mackay's model for functional antagonism in the isolated costo-uterus of the rat.

    Science.gov (United States)

    Henry, P. J.; Lulich, K. M.; Paterson, J. W.

    1985-01-01

    Several key predictions of a recently developed model for functional antagonism (Mackay, 1981) were experimentally tested using the rat isolated costo-uterine preparation. In the presence of the functional antagonist fenoterol (Fen), the functional constants (KAF) for carbachol and oxotremorine (Oxo) were respectively 9.9 and 3.4 fold greater than their corresponding affinity constants (KA). According to Mackay's model for functional antagonism, the higher KAF/KA ratio for carbachol indicates that this cholinoceptor agonist has a greater efficacy than Oxo. This was confirmed by using conventional pharmacological methods. As predicted from the model of functional antagonism, the plot of KAF/KA-1 against the fraction of cholinoceptors not irreversibly blocked by phenoxybenzamine (Pbz) was linear for both carbachol and Oxo and the lines of best fit crossed the axes at a point not significantly different from the origin. The value of 4.6 for the relative efficacy of carbachol to Oxo estimated from functional antagonism studies was comparable to the value of 5.6 calculated using the method of irreversible antagonism proposed by Furchgott (1966). PMID:3840396

  16. Influence of some mononucleotides and their corresponding nucleosides on the metabolism of carbohydrates in the isolated rat diaphragm muscle

    Science.gov (United States)

    Beloff-Chain, Anne; Betto, P.; Bleszynski, W.; Catanzaro, Raffaella; Chain, E. B.; Dmitrovskii, A. A.; Longinotti, L.; Pocchiari, F.

    1965-01-01

    1. The influence of ATP on glucose metabolism was studied in the isolated rat diaphragm; it was shown that ATP increases the oxidation of glucose and the aerobic conversion of glucose into lactate, whereas it decreases glycogen synthesis. There was no influence of ATP on the anaerobic formation of lactate from glucose. 2. A maximum effect of ATP on the oxidation of glucose (about 160% increase) was obtained in the presence of 10mm-ATP; in the presence of 2mm-ATP the effect was about 65%, and was approximately constant from 10 to 90min. incubation period. 3. In a phosphate-free tris-buffered medium the oxidation of glucose was considerably decreased, but the percentage stimulation by ATP was about the same as in a phosphate-buffered medium. 4. ATP was shown to increase the oxidation of fructose, glucose 6-phosphate, glucose 1-phosphate, fructose 1,6-diphosphate and, to a much smaller extent, pyruvate. 5. ADP stimulated the oxidation of glucose to the same extent as ATP at a concentration of 2mm and the effect with AMP was only slightly less; IMP and adenosine had only a small stimulatory effect at this concentration, whereas inosine had no effect. PMID:16749165

  17. Activation of muscarinic M-1 cholinoceptors by curcumin to increase glucose uptake into skeletal muscle isolated from Wistar rats.

    Science.gov (United States)

    Cheng, Tse-Chou; Lin, Chian-Shiung; Hsu, Chih-Chieh; Chen, Li-Jen; Cheng, Kai-Chun; Cheng, Juei-Tang

    2009-11-20

    Curcumin, an active principle contained in rhizome of Curcuma longa, has been mentioned to show merit for diabetes through its anti-oxidative and anti-inflammatory properties. In the present study, we found that curcumin caused a concentration-dependent increase of glucose uptake into skeletal muscle isolated from Wistar rats. This action was inhibited by pirenzepine at concentration enough to block muscarinic M-1 cholinoceptor (M(1)-mAChR). In radioligand binding assay, the binding of [(3)H]-pirenzepine was also displaced by curcumin in a concentration-dependent manner. In the presence of inhibitors for PLC-PI3K pathway, either U73122 (phospholipase C inhibitor) or LY294002 (phosphoinositide 3-kinase inhibitor), curcumin-stimulated glucose uptake into skeletal muscle was markedly reduced. In Western blotting analysis, the membrane protein level of glucose transporter 4 (GLUT4) increased by curcumin was also reversed by blockade of M(1)-mAChR or PLC-PI3K pathway in a same manner. In conclusion, the obtained results suggest that curcumin can activate M(1)-mAChR at concentrations lower than to scavenge free radicals for increase of glucose uptake into skeletal muscle through PLC-PI3-kinase pathway.

  18. Influence of Bovine Whey Protein Concentrate and Hydrolysate Preparation Methods on Motility in the Isolated Rat Distal Colon

    Science.gov (United States)

    Dalziel, Julie E.; Anderson, Rachel C.; Bassett, Shalome A.; Lloyd-West, Catherine M.; Haggarty, Neill W.; Roy, Nicole C.

    2016-01-01

    Whey protein concentrate (WPC) and hydrolysate (WPH) are protein ingredients used in sports, medical and pediatric formulations. Concentration and hydrolysis methods vary for whey sourced from cheese and casein co-products. The purpose of this research was to investigate the influence of whey processing methods on in vitro gastrointestinal (GI) health indicators for colonic motility, epithelial barrier integrity and immune modulation. WPCs from casein or cheese processing and WPH (11% or 19% degree of hydrolysis, DH) were compared for their effects on motility in a 1 cm section of isolated rat distal colon in an oxygenated tissue bath. Results showed that WPC decreased motility irrespective of whether it was a by-product of lactic acid or mineral acid casein production, or from cheese production. This indicated that regardless of the preparation methodology, the whey protein contained components that modulate aspects of motility within the distal colon. WPH (11% DH) increased contractile frequency by 27% in a delayed manner and WPH (19% DH) had an immediate effect on contractile properties, increasing tension by 65% and frequency by 131%. Increased motility was associated with increased hydrolysis that may be attributed to the abundance of bioactive peptides. Increased frequency of contractions by WPH (19% DH) was inhibited (by 44%) by naloxone, implicating a potential involvement of opioid receptors in modulation of motility. Trans-epithelial electrical resistance and cytokine expression assays revealed that the WPC proteins studied did not alter intestinal barrier integrity or elicit any discernible immune response. PMID:27983629

  19. Brain regional differences in social encounter-induced Fos expression in male and female rats after post-weaning social isolation.

    Science.gov (United States)

    Ahern, Megan; Goodell, Dayton J; Adams, Jessica; Bland, Sondra T

    2016-01-01

    Early life adversity has been related to a number of psychological disorders including mood and other disorders that can manifest as inappropriate or aggressive responses to social challenges. The present study used post-weaning social isolation (PSI) in rats, a model of early life adversity, to examine its effects on Fos protein expression produced by exposure to a novel social encounter. We have previously reported that the social encounter-induced increase in Fos expression in the medial prefrontal cortex observed in group-housed controls (GRP) was attenuated in rats that had experienced PSI. Here we assessed Fos expression in other brain regions thought to be involved in emotion regulation and social behavior. Male and female rats were housed in same-sex groups or in isolation (ISO) for 4 weeks beginning on postnatal day (P) 21 and were exposed to a single 15 min social encounter with a novel same-sex conspecific on P49. Fos positive cells were assessed using immunohistochemistry in 16 regions within the forebrain. Exposure to a novel conspecific increased Fos expression in the forebrain of GRP rats in a region- and sex-specific fashion. This increase was blunted or absent in ISO rats within many regions including cortical regions, thalamus, habenula, dentate gyrus, lateral septum, and basolateral amygdala. In several regions, the increase in Fos was greater in male than in female group housed rats. Negative relationships were observed between social interactions and Fos in some regions. Forebrain hypofunction produced by early-life adversity may be involved in socially inappropriate behavior. Copyright © 2015 Elsevier B.V. All rights reserved.

  20. Antioxidative effects of pumpkin seed (Cucurbita pepo) protein isolate in CCl4-induced liver injury in low-protein fed rats.

    Science.gov (United States)

    Nkosi, C Z; Opoku, A R; Terblanche, S E

    2006-11-01

    The effects of pumpkin seed (Cucurbita pepo) protein isolate on the plasma activity levels of catalase (CA), superoxide dismutase (SOD), glutathione peroxidase (GSHpx) and total antioxidant capacity (TAC) as well as glucose-6-phosphatase (G6Pase) in liver homogenates and lipid peroxidation (LPO-malondialdehyde-MDA) levels in liver homogenates and liver microsomal fractions against carbon tetrachloride (CCl(4))-induced acute liver injury in low-protein fed Sprague-Dawley rats (Rattus norvegicus) were investigated. A group of male Sprague-Dawley rats maintained on a low-protein diet for 5 days were divided into three subgroups. Two subgroups were injected with carbon tetrachloride and the other group with an equivalent amount of olive oil. Two hours after CCl(4) intoxication one of the two subgroups was administered with pumpkin seed protein isolate and thereafter switched onto a 20% pumpkin seed protein isolate diet. The other two groups of rats were maintained on the low-protein diet for the duration of the investigation. Groups of rats from the different subgroups were killed at 24, 48 and 72 h after their respective treatments. After 5 days on the low-protein diet the activity levels of all the enzymes as well as antioxidant levels were significantly lower than their counterparts on a normal balanced diet. However, a low-protein diet resulted in significantly increased levels of lipid peroxidation. The CCl(4) intoxicated rats responded in a similar way, regarding all the variables investigated, to their counterparts on a low-protein diet. The administration of pumpkin seed protein isolate after CCl(4) intoxication resulted in significantly increased levels of all the variables investigated, with the exception of the lipid peroxidation levels which were significantly decreased. From the results of the present study it is concluded that pumpkin seed protein isolate administration was effective in alleviating the detrimental effects associated with protein

  1. Reversed-phase high-performance liquid chromatographic analyses of insulin biosynthesis in isolated rat and mouse islets

    DEFF Research Database (Denmark)

    Linde, S; Hansen, Bruno A.; Welinder, B S

    1989-01-01

    deletion compared to rat C-peptide I. A marked species difference in the ratio between insulin I and II was observed, i.e., 2:1 in the rat and 1:2 in the mouse. Pulse-chase experiments in rat islets have demonstrated that the ratio between insulin I and II in newly synthesized insulin is higher than...

  2. Vasorelaxation induced by common edible tropical plant extracts in isolated rat aorta and mesenteric vascular bed.

    Science.gov (United States)

    Runnie, I; Salleh, M N; Mohamed, S; Head, R J; Abeywardena, M Y

    2004-06-01

    In this study, the vasodilatory actions of nine edible tropical plant extracts were investigated. Ipomoea batatas (sweet potato leaf), Piper betle (betel leaf), Anacardium occidentale (cashew leaf), Gynandropsis gynandra (maman leaf), Carica papaya (papaya leaf), and Mentha arvensis (mint leaf) extracts exhibited more than 50% relaxing effect on aortic ring preparations, while Piper betle and Cymbopogon citratus (lemongrass stalk) showed comparable vasorelaxation on isolated perfused mesenteric artery preparation. The vascular effect on the aortic ring preparations were mainly endothelium-dependent, and mediated by nitric oxide (NO) as supported by the inhibition of action in the presence of N(omega)-nitro-L-arginine (NOLA), an nitric oxide synthase (NOS) inhibitor, or by the removal of endothelium. In contrast, vasodilatory actions in resistance vessels (perfused mesenteric vascular beds) appear to involve several biochemical mediators, including NO, prostanoids, and endothelium-dependent hyperpolarizing factors (EDHFs). Total phenolic contents and antioxidant capacities varied among different extracts and found to be independent of vascular relaxation effects. This study demonstrates that many edible plants common in Asian diets to possess potential health benefits, affording protection at the vascular endothelium level.

  3. The cardioprotective and inotropic components of the postconditioning effects of GLP-1 and GLP-1(9-36)a in an isolated rat heart

    DEFF Research Database (Denmark)

    Ossum, Alvilde; van Deurs, Ulla; Engstrøm, Thomas

    2009-01-01

    GLP-1 and its metabolite GLP-1(9-36)a have been shown to exert cardiotropic effects, and were demonstrated to be cardioprotective agents in isolated, postischemic rat or mouse hearts. An agent's total effect on myocardial performance in a postconditioning paradigm is a sum of its myocyte-preservi......GLP-1 and its metabolite GLP-1(9-36)a have been shown to exert cardiotropic effects, and were demonstrated to be cardioprotective agents in isolated, postischemic rat or mouse hearts. An agent's total effect on myocardial performance in a postconditioning paradigm is a sum of its myocyte...... protocol, as exemplified by use of GLP-1 and GLP-1(9-36)a following a global ischemia in isolated rat hearts. Peptides were administered during the first 15min of 120min reperfusion. GLP-1 0.3nM reduced infarct size from 23.2+/-2.4% to 14.1+/-2.3% of area-at-risk (n=15, P=0.0223), an effect abolished......, rather than any true inotropic effect. In contrast, GLP-1(9-36)a did not reduce infarct size significantly, but acted as a strong negative inotrope in postischemic hearts, causing a contractility deficit (LVDP 58.8%, P=0.0004; RPP 58.2%, P=0.0007; dP/dt(max)=58.2%, P=0.0012), quantifiable by an analysis...

  4. Hepatic bilirubin uptake in the isolated perfused rat liver is not facilitated by albumin binding

    International Nuclear Information System (INIS)

    Stollman, Y.R.; Gaertner, U.; Theilmann, L.; Ohmi, N.; Wolkoff, A.W.

    1983-01-01

    Bilirubin uptake by the liver has kinetic characteristics which suggest carrier-mediation. Bilirubin is readily bound to albumin. A liver cell surface receptor for albumin has been postulated. The present study was designed to examine directly whether albumin facilitates the hepatic uptake of bilirubin and whether uptake of bilirubin depends on binding to albumin. Rat liver was perfused with a protein-free fluorocarbon medium, and single-pass uptake of 1, 10, or 200 nmol of [ 3 H]bilirubin was determined after injection as an equimolar complex with 125 I-albumin, with 125 I-ligandin, or free with only a [ 14 C]sucrose reference. Uptake of 10 nmol of [ 3 H]bilirubin was 67.5 +/- 3.7% of the dose when injected with 125 I-albumin, 67.4 +/- 6.5% when injected with 125 I-ligandin, and 74.9 +/- 2.4% when injected with [ 14 C]sucrose (P greater than 0.1). At 200 nmol, uptake fell to 46.4 +/- 3.1% ( 125 I-albumin) and 63.3 +/- 3.4% [( 14 C]sucrose) of injected [ 3 H]bilirubin (P less than 0.01), which suggests saturation of the uptake mechanism. When influx was quantitated by the model of Goresky, similar results were obtained. When [ 3 H]bilirubin was injected simultaneously with equimolar 125 I-albumin and a [ 14 C]sucrose reference, there was no delay in 125 I-albumin transit as compared with that of [ 14 C]sucrose. This suggested that the off-rate of albumin from a putative hepatocyte receptor would have to be very rapid, which is unusual for high affinity receptor-ligand interaction. There was no evidence for facilitation of bilirubin uptake by binding to albumin or for interaction of albumin with a liver cell surface receptor. These results suggest that the hepatic bilirubin uptake mechanism is one of high affinity which can extract bilirubin from circulating carriers such as albumin, ligandin, or fluorocarbon

  5. Acute effects of ethanol in the control of protein synthesis in isolated rat liver cells

    International Nuclear Information System (INIS)

    Girbes, T.; Susin, A.; Ayuso, M.S.; Parrilla, R.

    1983-01-01

    The acute effect of ethanol on hepatic protein synthesis is a rather controversial issue. In view of the conflicting reports on this subject, the effect of ethanol on protein labeling from L-[ 3 H]valine in isolated liver cells was studied under a variety of experimental conditions. When tracer doses of the isotope were utilized, ethanol consistently decreased the rate of protein labeling, regardless of the metabolic conditions of the cells. This inhibition was not prevented by doses of 4-methylpyrazole large enough to abolish all the characteristic metabolic effects of ethanol, and it was not related to perturbations on the rates of L-valine transport and/or proteolysis. When ethanol was tested in the presence of saturating doses of L-[ 3 H]valine no effect on protein labeling was observed. These observations suggest that the ethanol effect in decreasing protein labeling from tracer doses of the radioactive precursor does not reflect variations in the rate of protein synthesis but reflects changes in the specific activity of the precursor. These changes probably are secondary to variations in the dimensions of the amino acid pool utilized for protein synthesis. Even though it showed a lack of effect when tested alone, in the presence of saturating doses of the radioactive precursor ethanol inhibited the stimulatory effects on protein synthesis mediated by glucose and several gluconeogenic substrates. This effect of ethanol was not prevented by inhibitors of alcohol dehydrogenase, indicating that a shift of the NAD system to a more reduced state is not the mediator of its action. It is suggested that ethanol probably acted by changing the steady-state levels of some common effector(s) generated from the metabolism of all these fuels or else by preventing the inactivation of a translational repressor

  6. Early Life Stress Increases Metabolic Risk, HPA Axis Reactivity, and Depressive-Like Behavior When Combined with Postweaning Social Isolation in Rats.

    Science.gov (United States)

    Vargas, Javier; Junco, Mariana; Gomez, Carlos; Lajud, Naima

    2016-01-01

    Early-life stress is associated with depression and metabolic abnormalities that increase the risk of cardiovascular disease and diabetes. Such associations could be due to increased glucocorticoid levels. Periodic maternal separation in the neonate and rearing in social isolation are potent stressors that increase hypothalamus-pituitary-adrenal axis activity. Moreover, social isolation promotes feed intake and body weight gain in rats subjected to periodic maternal separation; however, its effects on metabolic risks have not been described. In the present study, we evaluated whether periodic maternal separation, social isolation rearing, and a combination of these two stressors (periodic maternal separation + social isolation rearing) impair glucose homeostasis and its relation to the hypothalamus-pituitary-adrenal axis and depressive-like behavior. Periodic maternal separation increased basal corticosterone levels, induced a passive coping strategy in the forced swimming test, and was associated with a mild (24%) increase in fasting glucose, insulin resistance, and dyslipidemia. Rearing in social isolation increased stress reactivity in comparison to both controls and in combination with periodic maternal separation, without affecting the coping strategy associated with the forced swimming test. However, social isolation also increased body weight gain, fasting glucose (120%), and insulin levels in rats subjected to periodic maternal separation. Correlation analyses showed that stress-induced effects on coping strategy on the forced swimming test (but not on metabolic risk markers) are associated with basal corticosterone levels. These findings suggest that maternal separation and postweaning social isolation affect stress and metabolic vulnerability differentially and that early-life stress-related effects on metabolism are not directly dependent on glucocorticoid levels. In conclusion, our study supports the cumulative stress hypothesis, which suggests that

  7. A novel escapable social interaction test reveals that social behavior and mPFC activation during an escapable social encounter are altered by post-weaning social isolation and are dependent on the aggressiveness of the stimulus rat.

    Science.gov (United States)

    Goodell, Dayton J; Ahern, Megan A; Baynard, Jessica; Wall, Vanessa L; Bland, Sondra T

    2017-01-15

    Post-weaning social isolation (PSI) has been shown to increase aggressive behavior and alter medial prefrontal cortex (mPFC) function in social species such as rats. Here we developed a novel escapable social interaction test (ESIT) allowing for the quantification of escape and social behaviors in addition to mPFC activation in response to an aggressive or nonaggressive stimulus rat. Male rats were exposed to 3 weeks of PSI (ISO) or group (GRP) housing, and exposed to 3 trials, with either no trial, all trials, or the last trial only with a stimulus rat. Analysis of social behaviors indicated that ISO rats spent less time in the escape chamber and more time engaged in social interaction, aggressive grooming, and boxing than did GRP rats. Interestingly, during the third trial all rats engaged in more of the quantified social behaviors and spent less time escaping in response to aggressive but not nonaggressive stimulus rats. Rats exposed to nonaggressive stimulus rats on the third trial had greater c-fos and ARC immunoreactivity in the mPFC than those exposed to an aggressive stimulus rat. Conversely, a social encounter produced an increase in large PSD-95 punctae in the mPFC independently of trial number, but only in ISO rats exposed to an aggressive stimulus rat. The results presented here demonstrate that PSI increases interaction time and aggressive behaviors during escapable social interaction, and that the aggressiveness of the stimulus rat in a social encounter is an important component of behavioral and neural outcomes for both isolation and group-reared rats. Copyright © 2016 Elsevier B.V. All rights reserved.

  8. A novel escapable social interaction test reveals that social behavior and mPFC activation during an escapable social encounter are altered by post-weaning social isolation and are dependent on the aggressiveness of the stimulus rat

    Science.gov (United States)

    Goodell, Dayton J.; Ahern, Megan A.; Baynard, Jessica; Wall, Vanessa L.; Bland, Sondra T.

    2016-01-01

    Post-weaning social isolation (PSI) has been shown to increase aggressive behavior and alter medial prefrontal cortex (mPFC) function in social species such as rats. Here we developed a novel escapable social interaction test (ESIT) allowing for the quantification of escape and social behaviors in addition to mPFC activation in response to an aggressive or nonaggressive stimulus rat. Male rats were exposed to 3 weeks of PSI (ISO) or group (GRP) housing, and exposed to 3 trials, with either no trial, all trials, or the last trial only with a stimulus rat. Analysis of social behaviors indicated that ISO rats spent less time in the escape chamber and more time engaged in social interaction, aggressive grooming, and boxing than did GRP rats. Interestingly, during the third trial all rats engaged in more of the quantified social behaviors and spent less time escaping in response to aggressive but not nonaggressive stimulus rats. Rats exposed to nonaggressive stimulus rats on the third trial had greater c-fos and ARC immunoreactivity in the mPFC than those exposed to an aggressive stimulus rat. Conversely, a social encounter produced an increase in large PSD-95 punctae in the mPFC independently of trial number, but only in ISO rats exposed to an aggressive stimulus rat. The results presented here demonstrate that PSI increases interaction time and aggressive behaviors during escapable social interaction, and that the aggressiveness of the stimulus rat in a social encounter is an important component of behavioral and neural outcomes for both isolation and group-reared rats. PMID:27633556

  9. Myocardial 99mTc-sestamibi extraction and washout in hypertensive heart failure using an isolated rat heart

    International Nuclear Information System (INIS)

    Fukushima, Kenji; Momose, Mitsuru; Kondo, Chisato; Higuchi, Takahiro; Kusakabe, Kiyoko; Hagiwara, Nobuhisa

    2010-01-01

    Purpose: Myocardial mitochondria are the primary part of energy production for healthy cardiac contraction. And mitochondrial dysfunction would play an important role in progressive heart failure. In the recent years, myocardial washout of 99m Tc-sestamibi [( 99m Tc-hexakis-2-methoxy-2-methylpropyl isonitrile (MIBI)] has been introduced to be a potential marker in patients with heart failure. The objective of this study was to clarify MIBI extraction and washout kinetics using isolated perfusion system in hypertension induced model of myocardial dysfunction. Methods: Six-week-old Dahl-salt sensitive rats, allotted to 4 groups; a 5-week high-salt group (5wk-HS), 12-week high-salt group (12wk-HS) and two age-matched, low-salt diet control groups (5wk-LS and 12wk-LS). The rats in 5wk-HS and 12wk-HS groups were fed a high-salt diet (containing 8% NaCl). Cardiac function was examined by echocardiography before removing heart. Hearts were perfused according to the Langendorff method at a constant flow rate, in which 20-min MIBI washin was conducted followed by 25-min MIBI washout. Whole heart radioactivity was collected every sec by an external gamma detector. The myocardial extraction, K 1 (ml/min) and washout rate, k 2 (min -1 ) were generated. Results: High-salt diet groups showed significant high-blood pressure. Echocardiography revealed thickened LV walls in 5wk-HS, and reduced cardiac function in 12wk-HS, compared to each age-matched control group. K 1 showed no significant difference among all groups (5wk-HS: 2.36±1.07, 5wk-control: 2.59±0.28, 12wk-HS: 1.91±0.90, and 12wk-control: 2.84±0.57). k 2 in 5wk-HS was comparable to that in the age matched control group (0.00030±0.00039 vs -0.000010±0.00044), but it was increased remarkably in 18wk-HS compared to the age matched control group (0.0025±0.0011 vs 0.000025±0.000041, P<.01), and 5wk-HS (P<.01). Conclusion: In the course of hypertensive heart disease, MIBI washout was increased in the transitional state

  10. Myocardial {sup 99m}Tc-sestamibi extraction and washout in hypertensive heart failure using an isolated rat heart

    Energy Technology Data Exchange (ETDEWEB)

    Fukushima, Kenji [Department of Cardiology, Tokyo Women' s Medical University, Tokyo 162-8666 (Japan); Department of Radiology, Johns Hopkins University, Baltimore, MD (United States); Momose, Mitsuru, E-mail: mmomose@rad.twmu.ac.j [Department of Diagnostic Imaging and Nuclear Medicine, Tokyo Women' s Medical University, Tokyo 162-8666 (Japan); Kondo, Chisato [Department of Diagnostic Imaging and Nuclear Medicine, Tokyo Women' s Medical University, Tokyo 162-8666 (Japan); Higuchi, Takahiro [Department of Radiology, Johns Hopkins University, Baltimore, MD (United States); Kusakabe, Kiyoko [Department of Diagnostic Imaging and Nuclear Medicine, Tokyo Women' s Medical University, Tokyo 162-8666 (Japan); Hagiwara, Nobuhisa [Department of Cardiology, Tokyo Women' s Medical University, Tokyo 162-8666 (Japan)

    2010-11-15

    Purpose: Myocardial mitochondria are the primary part of energy production for healthy cardiac contraction. And mitochondrial dysfunction would play an important role in progressive heart failure. In the recent years, myocardial washout of {sup 99m}Tc-sestamibi [({sup 99m}Tc-hexakis-2-methoxy-2-methylpropyl isonitrile (MIBI)] has been introduced to be a potential marker in patients with heart failure. The objective of this study was to clarify MIBI extraction and washout kinetics using isolated perfusion system in hypertension induced model of myocardial dysfunction. Methods: Six-week-old Dahl-salt sensitive rats, allotted to 4 groups; a 5-week high-salt group (5wk-HS), 12-week high-salt group (12wk-HS) and two age-matched, low-salt diet control groups (5wk-LS and 12wk-LS). The rats in 5wk-HS and 12wk-HS groups were fed a high-salt diet (containing 8% NaCl). Cardiac function was examined by echocardiography before removing heart. Hearts were perfused according to the Langendorff method at a constant flow rate, in which 20-min MIBI washin was conducted followed by 25-min MIBI washout. Whole heart radioactivity was collected every sec by an external gamma detector. The myocardial extraction, K{sub 1} (ml/min) and washout rate, k{sub 2} (min{sup -1}) were generated. Results: High-salt diet groups showed significant high-blood pressure. Echocardiography revealed thickened LV walls in 5wk-HS, and reduced cardiac function in 12wk-HS, compared to each age-matched control group. K{sub 1} showed no significant difference among all groups (5wk-HS: 2.36{+-}1.07, 5wk-control: 2.59{+-}0.28, 12wk-HS: 1.91{+-}0.90, and 12wk-control: 2.84{+-}0.57). k{sub 2} in 5wk-HS was comparable to that in the age matched control group (0.00030{+-}0.00039 vs -0.000010{+-}0.00044), but it was increased remarkably in 18wk-HS compared to the age matched control group (0.0025{+-}0.0011 vs 0.000025{+-}0.000041, P<.01), and 5wk-HS (P<.01). Conclusion: In the course of hypertensive heart disease, MIBI

  11. Intermittent losartan administration triggers cardiac post-conditioning in isolated rat hearts: role of BK2 receptors.

    Directory of Open Access Journals (Sweden)

    Luca Sgarra

    Full Text Available The angiotensin (Ang and bradykinin (BK tissue-system plays a pivotal role in post-conditioning, but the efficacy of angiotensin type 1 receptor (AT1R blockers (ARBs in post-ischemic strategies is still under investigation. We evaluated functional and morphological outcomes, together with activation of cytosolic RISK pathway kinases, in rat hearts subjected to losartan (LOS or irbesartan (IRB post-ischemic administration.Isolated rat hearts underwent 30 min ischemia and 120 min reperfusion. Post-conditioning was obtained by intermittent (10 s/each or continuous drug infusion during the first 3 min of reperfusion. Left ventricular end-diastolic pressure (LVEDP, left ventricular developed pressure (dLVP, coronary flow (CF, and left ventricular infarct mass (IM were measured together with the activation status of RISK kinases Akt, p42/44 MAPK and GSK3β.When compared to hearts subjected to ischemia/reperfusion (iI/R alone, continuous IRB or LOS administration did not significantly reduce total infarct mass (cIRB or cLOS vs. iI/R, p = 0.2. Similarly, intermittent IRB (iIRB was not able to enhance cardioprotection. Conversely, intermittent LOS administration (iLOS significantly ameliorated cardiac recovery (iLOS vs iI/R, p<0.01. Differences between iLOS and iIRB persisted under continuous blockade of AT2R (iLOS+cPD vs. iIRB+cPD, p<0.05. Interestingly, iLOS cardioprotection was lost when BK2R was simultaneously blocked (iLOS+cHOE vs. iI/R, p = 0.6, whereas concurrent administration of iBK and iIRB replicated iLOS effects (iIRB+iBK vs. iLOS, p = 0.7. At the molecular level, iIRB treatment did not significantly activate RISK kinases, whereas both iLOS and iBK treatments were associated with activation of the Akt/GSK3β branch of the RISK pathways (p<0.05 vs. iI/R, for both.Our results suggest that intermittent losartan is effective in mediating post-conditioning cardioprotection, whereas irbesartan is not. The infarct mass reduction by intermittent

  12. Biosynthesis of agmatine in isolated mitochondria and perfused rat liver: studies with 15N-labelled arginine

    Science.gov (United States)

    2005-01-01

    An important but unresolved question is whether mammalian mitochondria metabolize arginine to agmatine by the ADC (arginine decarboxylase) reaction. 15N-labelled arginine was used as a precursor to address this question and to determine the flux through the ADC reaction in isolated mitochondria obtained from rat liver. In addition, liver perfusion system was used to examine a possible action of insulin, glucagon or cAMP on a flux through the ADC reaction. In mitochondria and liver perfusion, 15N-labelled agmatine was generated from external 15N-labelled arginine. The production of 15N-labelled agmatine was time- and dose-dependent. The time-course of [U-15N4]agmatine formation from 2 mM [U-15N4]arginine was best fitted to a one-phase exponential curve with a production rate of approx. 29 pmol·min−1·(mg of protein)−1. Experiments with an increasing concentration (0– 40 mM) of [guanidino-15N2]arginine showed a Michaelis constant Km for arginine of 46 mM and a Vmax of 3.7 nmol·min−1·(mg of protein)−1 for flux through the ADC reaction. Experiments with broken mitochondria showed little changes in Vmax or Km values, suggesting that mitochondrial arginine uptake had little effect on the observed Vmax or Km values. Experiments with liver perfusion demonstrated that over 95% of the effluent agmatine was derived from perfusate [guanidino-15N2]arginine regardless of the experimental condition. However, the output of 15N-labelled agmatine (nmol·min−1·g−1) increased by approx. 2-fold (P<0.05) in perfusions with cAMP. The findings of the present study provide compelling evidence that mitochondrial ADC is present in the rat liver, and suggest that cAMP may stimulate flux through this pathway. PMID:15656789

  13. Effects of cocaine combined with a social cue on conditioned place preference and nucleus accumbens monoamines after isolation rearing in rats

    Science.gov (United States)

    Grotewold, Susan K.; Wall, Vanessa L.; Goodell, Dayton J.; Hayter, Cassandra

    2015-01-01

    Rationale Social interaction during drug exposure can potentiate cocaine reward. Isolation rearing (ISO) during adolescence increases social interaction and may amplify this potentiation. Objectives The objectives of this study are to determine whether ISO alters conditioned place preference (CPP) for cocaine when combined with a social cue and to determine whether ISO alters the effects of cocaine when combined with social cue on nucleus accumbens shell (NAcS) dopamine (DA) and serotonin (5-HT). Methods Male and female rats were either ISO or group (GRP) reared for 4 weeks during adolescence. CPP was performed using a low dose of cocaine (2 mg/kg or saline) with or without exposure to a novel same-sex conspecific during conditioning. In vivo microdialysis was performed using the same parameters. Results ISO rats engaged in more social and aggressive behaviors during conditioning relative to GRP. Cocaine reduced social and aggressive behaviors in all rats. CPP was not influenced by rearing condition. Cocaine produced significant CPP, and a social cue produced CPP only in males. In contrast, the interaction of cocaine and a social cue on NAcS DA and 5-HT differed depending upon rearing condition. In isolates, cocaine-induced DA was attenuated, while cocaine plus a social cue produced potentiated DA and 5-HT. Conclusions Exposure to a low dose of cocaine in the presence of a social cue produced additive effects on CPP while producing synergistic effects on DA and 5-HT in the NAcS of ISO rats. The aversive effects of this compound stimulus may negate the rewarding effects in isolates. PMID:24553577

  14. Possible involvements of glutamate and adrenergic receptors on acute toxicity of methylphenidate in isolated hippocampus and cerebral cortex of adult rats.

    Science.gov (United States)

    Motaghinejad, Majid; Motevalian, Manijeh; Shabab, Behnaz

    2017-04-01

    Neurodegeneration induced by methylphenidate (MPH), as a central stimulant with unknown long-term consequences, in adult rats' brain and the possible mechanisms involved were studied. Rats were acutely treated with MPH in the presence and absence of some receptor antagonists such as ketamine, topiramate, yohimbine, and haloperidol. Motor activity and anxiety level in rats were monitored. Antioxidant and inflammatory parameters were also measured in isolated hippocampus and cerebral cortex. MPH-treated groups (10 and 20 mg/kg) demonstrated anxiety-like behavior and increased motor activity. MPH significantly increased lipid peroxidation, GSSG content, IL-1β and TNF-α levels in isolated tissues, and also significantly reduced GSH content, superoxide dismutase (SOD), glutathione peroxidase (GPx), and glutathione reductase (GR) activities in hippocampus and cerebral cortex. Pretreatment of animals by receptor antagonists caused inhibition of MPH-induced motor activity disturbances and anxiety-like behavior. Pretreatment of animals by ketamine, topiramate, and yohimbine inhibited the MPH-induced oxidative stress and inflammation; it significantly decreased lipid peroxidation, GSSG level, IL-1β and TNF-α levels and increased GSH content, SOD, GPx, and GR activities in hippocampus and cerebral cortex of acutely MPH-treated rats. Pretreatment with haloperidol did not cause any change in MPH-induced oxidative stress and inflammation. In conclusion, acute administration of high doses of MPH can cause oxidative and inflammatory changes in brain cells and induce neurodegeneration in hippocampus and cerebral cortex of adult rats and these changes might probably be mediated by glutamate (NMDA or AMPA) and/or α 2 -adrenergic receptors. © 2016 Société Française de Pharmacologie et de Thérapeutique.

  15. Uterine responses to feeding soy protein isolate and treatment with 17β-estradiol differ in ovariectomized female rats

    Energy Technology Data Exchange (ETDEWEB)

    Ronis, Martin J., E-mail: mronis@lsuhsc.edu [Department of Pharmacology & Experimental Therapeutics, Louisiana State University Health Sciences Center, New Orleans, LA 70112 (United States); Gomez-Acevedo, Horacio; Blackburn, Michael L. [Arkansas Children' s Nutrition Center, University of Arkansas for Medical Sciences, Little Rock, AR 72202 (United States); Cleves, Mario A. [Arkansas Children' s Nutrition Center, University of Arkansas for Medical Sciences, Little Rock, AR 72202 (United States); Department of Pediatrics, University of Arkansas for Medical Sciences, Little Rock, AR 72202 (United States); Singhal, Rohit [Department of Pharmacology & Toxicology, University of Arkansas for Medical Sciences, Little Rock, AR 72202 (United States); Badger, Thomas M. [Arkansas Children' s Nutrition Center, University of Arkansas for Medical Sciences, Little Rock, AR 72202 (United States); Department of Pediatrics, University of Arkansas for Medical Sciences, Little Rock, AR 72202 (United States)

    2016-04-15

    There are concerns regarding reproductive toxicity from consumption of soy foods, including an increased risk of endometriosis and endometrial cancer, as a result of phytoestrogen consumption. In this study, female rats were fed AIN-93G diets made with casein (CAS) or soy protein isolate (SPI) from postnatal day (PND) 30, ovariectomized on PND 50 and infused with 5 μg/kg/d 17β-estradiol (E2) or vehicle. E2 increased uterine wet weight (P < 0.05). RNAseq analysis revealed that E2 significantly altered expression of 1991 uterine genes (P < 0.05). SPI feeding had no effect on uterine weight and altered expression of far fewer genes than E2 at 152 genes (P < 0.05). Overlap between E2 and SPI genes was limited to 67 genes. Functional annotation analysis indicated significant differences in uterine biological processes affected by E2 and SPI and little evidence for recruitment of estrogen receptor (ER)α to the promoters of ER-responsive genes after SPI feeding. The major E2 up-regulated uterine pathways were carcinogenesis and extracellular matrix organization, whereas SPI feeding up-regulated uterine peroxisome proliferator activated receptor (PPAR) signaling and fatty acid metabolism. The combination of E2 and SPI resulted in significant regulation of 504 fewer genes relative to E2 alone. The ability of E2 to induce uterine proliferation in response to the carcinogen dimethybenz(a)anthracene (DMBA) as measured by expression of PCNA and Ki67 mRNA was suppressed by feeding SPI (P < 0.05). These data suggest that SPI is a selective estrogen receptor modulator (SERM) interacting with a small sub-set of E2-regulated genes and is anti-estrogenic in the presence of endogenous estrogens. - Highlights: • Concerns exist regarding risk of uterine cancer from consumption of soy products. • These concerns are related to potential estrogenicity. • Estradiol and soy protein isolate effects on uterine gene expression were compared. • Soy acts as a selective estrogen

  16. Uterine responses to feeding soy protein isolate and treatment with 17β-estradiol differ in ovariectomized female rats

    International Nuclear Information System (INIS)

    Ronis, Martin J.; Gomez-Acevedo, Horacio; Blackburn, Michael L.; Cleves, Mario A.; Singhal, Rohit; Badger, Thomas M.

    2016-01-01

    There are concerns regarding reproductive toxicity from consumption of soy foods, including an increased risk of endometriosis and endometrial cancer, as a result of phytoestrogen consumption. In this study, female rats were fed AIN-93G diets made with casein (CAS) or soy protein isolate (SPI) from postnatal day (PND) 30, ovariectomized on PND 50 and infused with 5 μg/kg/d 17β-estradiol (E2) or vehicle. E2 increased uterine wet weight (P < 0.05). RNAseq analysis revealed that E2 significantly altered expression of 1991 uterine genes (P < 0.05). SPI feeding had no effect on uterine weight and altered expression of far fewer genes than E2 at 152 genes (P < 0.05). Overlap between E2 and SPI genes was limited to 67 genes. Functional annotation analysis indicated significant differences in uterine biological processes affected by E2 and SPI and little evidence for recruitment of estrogen receptor (ER)α to the promoters of ER-responsive genes after SPI feeding. The major E2 up-regulated uterine pathways were carcinogenesis and extracellular matrix organization, whereas SPI feeding up-regulated uterine peroxisome proliferator activated receptor (PPAR) signaling and fatty acid metabolism. The combination of E2 and SPI resulted in significant regulation of 504 fewer genes relative to E2 alone. The ability of E2 to induce uterine proliferation in response to the carcinogen dimethybenz(a)anthracene (DMBA) as measured by expression of PCNA and Ki67 mRNA was suppressed by feeding SPI (P < 0.05). These data suggest that SPI is a selective estrogen receptor modulator (SERM) interacting with a small sub-set of E2-regulated genes and is anti-estrogenic in the presence of endogenous estrogens. - Highlights: • Concerns exist regarding risk of uterine cancer from consumption of soy products. • These concerns are related to potential estrogenicity. • Estradiol and soy protein isolate effects on uterine gene expression were compared. • Soy acts as a selective estrogen

  17. Association of nicotinic acetylcholine receptors with central respiratory control in isolated brainstem-spinal cord preparation of neonatal rats

    Directory of Open Access Journals (Sweden)

    EIKI HATORI

    2006-01-01

    Full Text Available Nicotine exposure is a risk factor in several breathing disorders Nicotinic acetylcholine receptors (nAChRs exist in the ventrolateral medulla, an important site for respiratory control. We examined the effects of nicotinic acetylcholine neurotransmission on central respiratory control by addition of a nAChR agonist or one of various antagonists into superfusion medium in the isolated brainstem-spinal cord from neonatal rats. Ventral C4 neuronal activity was monitored as central respiratory output, and activities of respiratory neurons in the ventrolateral medulla were recorded in whole-cell configuration. RJR-2403 (0.1-10mM, alpha4beta2 nAChR agonist induced dose-dependent increases in respiratory frequency. Non-selective nAChR antagonist mecamylamine (0.1-100mM, alpha4beta2 antagonist dihydro-beta-erythroidine (0.1-100mM, alpha7 antagonist methyllycaconitine (0.1-100mM, and a-bungarotoxin (0.01-10mM all induced dose-dependent reductions in C4 respiratory rate. We next examined effects of 20mM dihydro-beta-erythroidine and 20mM methyllycaconitine on respiratory neurons. Dihydro-beta-erythroidine induces hyperpolarization and decreases intraburst firing frequency of inspiratory and preinspiratory neurons. In contrast, methyllycaconitine has no effect on the membrane potential of inspiratory neurons, but does decrease their intraburst firing frequency while inducing hyperpolarization and decreasing intraburst firing frequency in preinspiratory neurons. These findings indicate that alpha4beta2 nAChR is involved in both inspiratory and preinspiratory neurons, whereas alpha7 nAChR functions only in preinspiratory neurons to modulate C4 respiratory rate

  18. Anti-diabetic properties of flavonoid compounds isolated from Hyphaene thebaica epicarp on alloxan induced diabetic rats

    Science.gov (United States)

    Salib, Josline Y.; Michael, Helana N.; Eskande, Emad Fawzy

    2013-01-01

    Background: Diabetes mellitus, becoming the third killer of mankind after cancer and cardiovascular diseases, is one of the most challenging diseases facing health care professionals today. That is why; there has been a growing interest in the therapeutic use of natural products for diabetes, especially those derived from plants. Aim: To evaluate the anti-diabetic activity together with the accompanying biological effects of the fractions and the new natural compounds of Hyphaene thebaica (HT) epicarp. Materials and Methods: 500 g of coarsely powdered of (HT) fruits epicarp were extracted by acetone. The acetone crude extract was fractionated with methanol and ethyl acetate leaving a residual water-soluble fraction WF. The anti-diabetic effects of the WF and one of its compounds of the acetone extract of the (HT) epicarp were investigated in this study using 40 adult male rats. Results: Phytochemical investigation of active WF revealed the presence of ten different flavonoids, among which two new natural compounds luteolin 7-O-[6”-O-α-Lrhamnopyranosyl]-β-D-galactopyranoside 3 and chrysoeriol 7-O-β-D-galactopyranosyl(1→2)-α-L-arabinofuranoside 5 were isolated. Supplementation of the WF improved glucose and insulin tolerance and significantly lowered blood glycosylated hemoglobin levels. On the other hand, compound 5 significantly reduced AST and ALT levels of liver, respectively. Likewise, the kidney functions were improved for both WF and compound 5, whereby both urea and creatinine levels in serum were highly significant Conclusion: The results justify the use of WF and compound 5 of the (HT) epicarp as anti-diabetic agent, taking into consideration that the contents of WF were mainly flavonoids PMID:23598921

  19. Further Identification of the Effect of Bradykinin Potentiating Factor Isolated From Scorpion Venom on Irradiated White Rat

    International Nuclear Information System (INIS)

    Hasan, H.F.

    2011-01-01

    Scorpion venom of Androctonus amoreuxi contains a strong bradykinin potentiating factor (BPF) that augments bradykinin effect through enhancing its release and acts as an angiotensin converting enzyme inhibitor (ACEI). Both irradiation and stimulation of renin-angiotensin system (RAS) induce oxidative stress. Possible interruption of the RAS with an ACEI induced by BPF isolated from the scorpion, Androctonus amoreuxi venom or the presence of angiotensin II receptor blocker (ARB) losartan and/or γ- radiation were evaluated. The examined parameters included blood erythrocytes count (RBC), total leucocytic count (WBC), haemoglobin content (Hb) and hematocrit value (Hct) as well as, glutathione content (GSH), malondialdehyde (MDA) and advanced oxidative protein product (AOPP) of kidney homogenate besides aldosterone, sodium, potassium, chloride, calcium, urea, creatinine and uric acid levels of serum. A group of rats (70 - 80 gm each) were received i.p. injection of BPIF (1μg / g body wt) twice per week for three weeks, while the other group received i.p. injection of losartan (5μg / g body wt) twice per week for three weeks. γ-Irradiation was performed at a dose level of 4Gy. All animals were examined after an investigation period of 21 days from γ- irradiation. Either BPF or losartan was performed together with irradiation. The results pointed out that irradiation discerned a significant elevation in the level of MDA, AOPP, aldosterone, sodium, urea and creatinine, and a significant drop in the haematological values (RBCs, WBCs, Hb and Hct), GSH, calcium and uric acid. Repeated injections of BPF or losartan had a beneficial result against the deleterious effect of γ- irradiation. The present investigation clarifies comparable effects for treatment of radiation damage to the kidney through RAS by BPF as (ACEI) and losartan as (ARB). The present work adds further identification to the properties of BPF in controlling of radiation damage. Therapeutic agents from

  20. Mechanism of norepinephrine release elicited by renal nerve stimulation, veratridine and potassium chloride in the isolated rat kidney

    International Nuclear Information System (INIS)

    el-Din, M.M.; Malik, K.U.

    1987-01-01

    We have investigated the mechanism by which renal nerve stimulation (RNS), veratridine (Vt) and KCl promote release of norepinephrine in the isolated rat kidney perfused with Tyrode's solution and prelabeled with [ 3 H]norepinephrine by examining the overflow of tritium elicited by these stimuli during 1) extracellular Ca++ depletion, 2) alterations in extracellular Na+ concentration and 3) administration of tetrodotoxin, amiloride, LiCl and calcium channel blockers. RNS (1-4 Hz), Vt (15-90 nmol) and KCl (150-500 mumol) produced renal vasoconstriction and enhanced the tritium overflow in a frequency- and concentration-dependent manner, respectively. Omission of Ca++ (1.8 mM) from the perfusion fluid abolished the renal vasoconstriction and the increase in tritium overflow elicited by RNA and KCl and substantially reduced that caused by Vt. Lowering the Na+ concentration in the perfusion medium (from 150 to 25 mM) reduced the overflow of tritium and the renal vasoconstriction caused by RNS (2 Hz) or Vt (45 nmol); the increase in tritium overflow in response to these stimuli was positively correlated with extracellular Na+ (25-150 mM). In contrast, KCl-induced tritium overflow was negatively correlated with extracellular Na+ concentration. Tetrodotoxin (0.3 microM) abolished the effect of RNS and Vt, but not that of KCl, to increase overflow of tritium and to produce renal vasoconstriction. Administration of amiloride (180 microM) enhanced the overflow of tritium but attenuated the associated renal vasoconstriction produced by RNS, Vt and KCl. Replacement of NaCl (75 mM) with equimolar concentration of LiCl enhanced the overflow of tritium elicited by RNS, Vt and KCl; the associated renal vasoconstriction remained unaltered

  1. Insulin Preconditioning Elevates p-Akt and Cardiac Contractility after Reperfusion in the Isolated Ischemic Rat Heart

    Directory of Open Access Journals (Sweden)

    Tamaki Sato

    2014-01-01

    Full Text Available Insulin induces cardioprotection partly via an antiapoptotic effect. However, the optimal timing of insulin administration for the best quality cardioprotection remains unclear. We tested the hypothesis that insulin administered prior to ischemia provides better cardioprotection than insulin administration after ischemia. Isolated rat hearts were prepared using Langendorff method and divided into three groups. The Pre-Ins group (Pre-Ins received 0.5 U/L insulin prior to 15 min no-flow ischemia for 20 min followed by 20 min of reperfusion. The Post-Ins group (Post-Ins received 0.5 U/L insulin during the reperfusion period only. The control group (Control was perfused with KH buffer throughout. The maximum of left ventricular derivative of pressure development (dP/dt(max was recorded continuously. Measurements of TNF-α and p-Akt in each time point were assayed by ELISA. After reperfusion, dP/dt(max in Pre-Ins was elevated, compared with Post-Ins at 10 minutes after reperfusion and Control at all-time points. TNF-α levels at 5 minutes after reperfusion in the Pre-Ins were lower than the others. After 5 minutes of reperfusion, p-Akt was elevated in Pre-Ins compared with the other groups. Insulin administration prior to ischemia provides better cardioprotection than insulin administration only at reperfusion. TNF-α suppression is possibly mediated via p-Akt leading to a reduction in contractile myocardial dysfunction.

  2. Electrical stimulation of the isolated rat intestine in the presence of nutrient stimulus enhances glucagon-like peptide-1 release

    International Nuclear Information System (INIS)

    Schwartz, Ann; Ort, Tatiana; Kajekar, Radhika; Hornby, Pamela J; Wade, Paul R

    2010-01-01

    The release of small intestinal hormones by constituents of ingested food, such as fatty acids, is integral to post-prandial responses that reduce food intake. Recent evidence suggests that small intestinal electrical stimulation reduces food intake, although the mechanism of action is debated. To test the hypothesis that intestinal stimulation directly alters hormone release locally we used isolated rat distal ileum and measured glucagon-like peptide-1 (GLP-1) released in the presence or absence of linoleic acid (LA) and electrical field stimulation (EFS). Intact segments were oriented longitudinally between bipolar stimulating electrodes in organ bath chambers containing modified Krebs–Ringers bicarbonate (KRB) buffer including protease inhibitors. Incubation in LA (3 mg ml −1 ) for 45 min increased GLP-1 concentration (21.9 ± 2.6 pM versus KRB buffer alone 3.6 ± 0.1 pM). Eleven electrical stimulation conditions were tested. In the presence of LA none of the stimulation conditions inhibited LA-evoked GLP-1 release, whereas two high frequency short pulse widths (14 V, 20 Hz, 5 ms and 14 V, 40 Hz, 5 ms) and one low frequency long pulse width (14 V, 0.4 Hz, 300 ms) EFS conditions enhanced LA-evoked GLP-1 release by >250%. These results are consistent with a local effect of intestinal electrical stimulation to enhance GLP-1 release in response to luminal nutrients in the intestines. Enhancing hormone release could improve the efficacy of intestinal electrical stimulation and provide a potential treatment for obesity and metabolic conditions

  3. Role of glycolysis in maintenance of the action potential duration and contractile activity in isolated perfused rat heart.

    Science.gov (United States)

    Opie, L H; Tuschmidt, R; Bricknell, O; Girardier, L

    1980-01-01

    1. Changing substrates from glucose to pyruvate in paced isolated rat hearts, perfused by the Langendorff technique at 65 cm H2O with a Krebs-Henseleit bicarbonate buffer, produced effects which are opposite to those of ouabain treatment: negative inotropy, decreased work efficiency, hyperpolarization, increased maximum rate of rise and amplitude of the action potential, increased conduction velocity. 2. All the effects resulting from perfusion with pyruvate can be reversed by adding ouabain at a concentration of 100 microM. 3. The correlation between various tissue metabolises and change in contractile force (delta F), rate of tension development [maximum + (dF/dt)] and rate of relaxation [maximum -(dF/dt)] was studied by multiple linear regression. No significant correlation was found with either glycogen content and tissue lactate or with cAMP and cGMP. A weak negative correlation was found with ATP and phosphocreatine. The strongest correlation was found 76 to 807 nM/g in passing from glucose- to pyruvate-containing perfusion solution. 4. In vitro tests performed with a solution containing high energy phosphates and magnesium at concentrations equal to their calculated values in the cytosol (pH 7.0) showed that a significant negative correlation exists between citrate concentration (range: 1 and 1500 M) and free calcium concentration in the micromole range. 5. It is concluded that the effects of pyruvate (non glucose substrate) perfusion could be mediated by a decrease in cytosolic-free calcium resulting from an increase in intracellular citrate. The observation that all these effects can be reversed by ouabain is taken as a circumstantial evidence of a common mechanism.

  4. [Differences in dynamics of insulin and insulin-like growth I (IGF-I) receptors internalization in isolated rat hepatocytes].

    Science.gov (United States)

    Kolychev, A P; Ternovskaya, E E; Arsenieva, A V; Shapkina, E V

    2013-01-01

    Insulin and IGF-I are two related peptides performing in the mammalian body functionally different roles of the metabolic and growth hormones, respectively. Internalization of the insulin-receptor complex (IRC) is the most important chain of mechanism of the action of hormone. To elucidate differences in the main stages of internalization of the two related hormones, the internalization dynamics of 125I-insulin and 125I-IGF-I was traced in isolated rat hepatocytes at 37 and 12 degrees C. There were established marked differences in the process of internalization of labeled hormones, which is stimulated by insulin and IGF-I. At 37 degrees C the insulin-stimulated internalization, unlike the process initiated by IGF-I, did not reach the maximal level for 1 h of incubation. However, essential differences in the internalization course of these two related peptide were obvious at the temperature of 12 degrees C. The internalization level of insulin receptors at 12 degrees C decreased by one third in spite of a significant increase of the insulin receptor binding on the hepatocytes plasma membrane. At 12 degrees C a slight decrease of the proportion of intracellular 125I-IGF-I correlated with a decrease in the 125I-IGF-I binding to receptors on the cell membrane. Internalization of IGF-I receptors was not affected by low temperature, as neither its level, nor the rate changed at 12 degrees C. The paradoxical decrease of the insulin-stimulated internalization at low temperature seems to represent a peculiar "inhibition mechanism" of immersion of IRC into the cell, which leads to accumulation of the complexes on the cell surface and possibly to a readjustment of the insulin biological activity. The resistance of internalization of the IGF-I receptor to cold seems to be related to the more ancient origin of this mechanism in the poikilothermal vertebrates.

  5. Magnesium deficiency improves glucose homeostasis in the rat: studies in vivo and in isolated islets in vitro.

    Science.gov (United States)

    Reis, M A; Latorraca, M Q; Carneiro, E M; Boschero, A C; Saad, M J; Velloso, L A; Reyes, F G

    2001-05-01

    The serum mineral levels, glucose disappearance rate (kg), total area under the glucose (DeltaG) and insulin (DeltaI) curves, and static insulin secretion were compared among rats fed a Mg-deficient diet for 6 (DF-6) or 11 (DF-11) weeks, and rats fed a control diet for the same periods (CO-6 and CO-11 groups). No change in glucose homeostasis was observed among DF-6, CO-6 and CO-11 rats. DF-11 rats showed an elevated kg and a reduced DeltaG and DeltaI. For evaluating the effect of supplementation, rats fed a control or Mg-deficient diet for 6 weeks were then fed a Mg- supplemented diet for 5 weeks (SCO and SDF groups respectively). The serum Mg levels in SDF rats were similar to those in CO-11 and SCO rats, but higher than in the DF-11 group. SDF rats showed similar kg, DeltaG and DeltaI compared with the CO-11 and SCO groups. However, a significantly lower kg and higher DeltaG and DeltaI were observed in SDF compared with DF-11 rats. Basal and 8.3 mmol glucose/l-stimulated insulin secretion by islets from DF-11 rats were higher than by islets from CO-11 rats. These results indicate that moderate Mg depletion for a long period may increase the secretion and sensitivity to insulin, while Mg supplementation in formerly Mg-deficient rats may prevent the increase in sensitivity and secretion of insulin.

  6. Cardamonin (2',4'-dihydroxy-6'-methoxychalcone) isolated from Boesenbergia rotunda (L.) Mansf. inhibits CFA-induced rheumatoid arthritis in rats.

    Science.gov (United States)

    Voon, Fui-Ling; Sulaiman, Mohd Roslan; Akhtar, Muhammad Nadeem; Idris, Mohamad Fauzi; Akira, Ahmad; Perimal, Enoch Kumar; Israf, Daud Ahmad; Ming-Tatt, Lee

    2017-01-05

    Boesenbergia rotunda (L.) Mansf. had been traditionally used as herbs to treat pain and rheumatism. Cardamonin (2',4'-dihydroxy-6'-methoxychalcone) is a compound isolated from Boesenbergia rotunda (L.) Mansf.. Previous study had shown the potential of cardamonin in inhibiting the release of pro-inflammatory cytokines such as tumour necrosis factor-α (TNF-α), interleukin-1β (IL-1β), and interleukin-6 (IL-6) in vitro. Thus, the possible therapeutic effect of cardamonin in the rheumatoid arthritis (RA) joints is postulated. This study was performed to investigate the anti-arthritic properties of cardamonin in rat model of induced RA, particularly on the inflammatory and pain response of RA. Rheumatoid arthritis paw inflammation was induced by intraplantar (i.pl.) injection of complete Freund's adjuvant (CFA) in Sprague Dawley rats. Using four doses of cardamonin (0.625, 1.25, 2.5, and 5.0mg/kg), anti-arthritic activity was evaluated through the paw edema, mechanical allodynia and thermal hyperalgesia responses. Enzyme-linked immunosorbent assay (ELISA) was carried out to evaluate the plasma level of TNF-α, IL-1β, and IL-6. Histological slides were prepared from the harvested rat paws to observe the arthritic changes in the joints. Behavioral, biochemical, and histological studies showed that cardamonin demonstrated significant inhibition on RA-induced inflammatory and pain responses as well as progression of joint destruction in rats. ELISA results showed that there was significant inhibition in TNF-α, IL-1β, and IL-6 levels in plasma of the cardamonin-treated RA rats. Overall, cardamonin possesses potential anti-arthritic properties in CFA-induced RA rat model. Copyright © 2016 Elsevier B.V. All rights reserved.

  7. The metabolism of L-phenylalanine and L-tyrosine by liver cells isolated from adrenalectomized rats and from streptozotocin-diabetic rats.

    OpenAIRE

    Stanley, J C; Fisher, M J; Pogson, C I

    1985-01-01

    Flux through, and maximal activities of, key enzymes of phenylalanine and tyrosine degradation were measured in liver cells prepared from adrenalectomized rats and from streptozotocin-diabetic rats. Adrenalectomy decreased the phenylalanine hydroxylase flux/activity ratio; this was restored by steroid treatment in vivo. Changes in the phosphorylation state of the hydroxylase may mediate these effects; there was no significant change in the maximal activity of the hydroxylase. Tyrosine metabol...

  8. Isolation stress and chronic mild stress induced immobility in the defensive burying behavior and a transient increased ethanol intake in Wistar rats.

    Science.gov (United States)

    Vázquez-León, Priscila; Martínez-Mota, Lucía; Quevedo-Corona, Lucía; Miranda-Páez, Abraham

    2017-09-01

    Stress can be experienced with or without adverse effects, of which anxiety and depression are two of the most important due to the frequent comorbidity with alcohol abuse in humans. Historically, stress has been considered a cause of drug use, particularly alcohol abuse due to its anxiolytic effects. In the present work we exposed male Wistar rats to two different stress conditions: single housing (social isolation, SI), and chronic mild stress (CMS). We compared both stressed groups to group-housed rats and rats without CMS (GH) to allow the determination of a clear behavioral response profile related to their respective endocrine stress response and alcohol intake pattern. We found that SI and CMS, to a greater extent, induced short-lasting increased sucrose consumption, a transient increase in serum corticosterone level, high latency/immobility, and low burying behavior in the defensive burying behavior (DBB) test, and a transient increase in alcohol intake. Thus, the main conclusion was that stress caused by both SI and CMS induced immobility in the DBB test and, subsequently, induced a transient increased voluntary ethanol intake in Wistar rats with a free-choice home-cage drinking paradigm. Copyright © 2017 Elsevier Inc. All rights reserved.

  9. In vitro effects of diethylstilbestrol, genistein, 4-tert-butylphenol, and 4-tert-octylphenol on steroidogenic activity of isolated immature rat ovarian follicles

    International Nuclear Information System (INIS)

    Myllymaeki, Sari; Haavisto, Tapio; Vainio, Minna; Toppari, Jorma; Paranko, Jorma

    2005-01-01

    Isolated rat ovarian follicles grow and produce steroid hormones in vitro and so provide a good model for studying the effects of hormonally active compounds on follicular steroidogenesis. We have evaluated the effects of diethylstilbestrol (DES), genistein (GEN) and two alkylphenols, 4-tert-butylphenol (BP) and 4-tert-octylphenol (OP) on the growth, survival, and steroid hormone and cAMP production by isolated 14-day-old rat (Sprague-Dawley) ovarian follicles. During a 5-day culture, FSH was obligatory for follicle growth and increased estradiol and testosterone secretion in a dose-dependent manner. DES (10 -6 M) caused the strongest decline in estradiol and testosterone levels but did not have detectable effects on either cAMP production or aromatase enzyme activity. GEN caused a prominent decrease in cAMP and testosterone levels without significant changes in secreted estradiol. The latter, apparently, was due to a dose-dependent stimulation of aromatase enzyme activity in the presence of genistein. Both BP and OP decreased estradiol and testosterone secretion in a dose-dependent manner while no effect on aromatase activity was observed. OP, unlike BP, decreased forskolin-induced cAMP levels. Xenoestrogens at the used concentrations did not interfere with the growth and survival of the follicles. The results indicate that isolated ovarian follicles representing intact morphological and functional units offer a sensitive model system for elucidating the female-specific reproductive effects of environmental chemicals

  10. Immediate and delayed anxiety- and depression-like profiles in the adolescent Wistar-Kyoto rat model of endogenous depression following postweaning social isolation.

    Science.gov (United States)

    Shetty, Reshma A; Sadananda, Monika

    2017-03-01

    In order to understand links that exist between inherited risk or predisposition, brain and behavioural development, endocrine regulation and social/environmental stimuli, animal models are crucial. The Wistar-Kyoto (WKY) rat has been shown to have validity as a model of adult and adolescent depression. While sex- and age-specific differences in some of the face, predictive and construct validities of the model such as depression-like behaviours have been established, anhedonia and anxiety using other induced anxiety paradigms such as elevated plus maze remain equivocal. First, post-weaning social isolation effects on inherent and induced anxiety behaviours were tested during two critical time periods, early- and mid-adolescence. Isolation induced immediate effects on novel environment-induced hyperactivity and anxiety-related behaviours. Adolescent WKYs demonstrated reduced 50-kHz ultrasonic vocalizations suggesting agoraphobia-like behaviours. Second, isolated rats, despite being subsequently social-/group-housed demonstrated longer lasting effects on social interaction measures and anhedonia. This establishes that the depression-like profile observed during early- and mid-adolescence persists into late adolescence and early adulthood in WKY. Further, that interventions at a later stage during adolescence may not be able to reverse early adolescent effects in the context of pre-disposition, thus highlighting the irreversibility of being double-hit during critical time periods of brain and behavioural development and maturation. Copyright © 2016 Elsevier B.V. All rights reserved.

  11. Identification of THY1 as a novel thyrotrope marker and THY1 antibody-mediated thyrotrope isolation in the rat anterior pituitary gland.

    Science.gov (United States)

    Horiguchi, Kotaro; Nakakura, Takashi; Yoshida, Saishu; Tsukada, Takehiro; Kanno, Naoko; Hasegawa, Rumi; Takigami, Shu; Ohsako, Shunji; Kato, Takako; Kato, Yukio

    2016-11-11

    Contact-dependent (juxtacrine) signaling is important for local cell-to-cell interaction and has received attention in recent years regarding its role in pituitary function, differentiation, and development. This study investigated one of the juxtacrine-related molecules, thymocyte differentiation antigen 1 (THY1), in the anterior lobe of the rat pituitary gland. Western blot analysis revealed expression of the THY1 protein in the adult rat anterior lobe. We also found that the THY1 ligand, integrin-β2 (ITGB2), is also expressed in the pituitary gland. In situ hybridization and immunohistochemical analyses showed that both THY1 mRNA and protein were present in almost, if not all, thyroid-stimulating hormone (TSH)-immunopositive cells (thyrotropes) and that ITGB2 was co-expressed in these cells. As THY1 appeared to represent a novel marker for thyrotropes, we then attempted to isolate these cells from various anterior lobe cells by the use of a THY1 antibody and a pluriBead-cascade cell isolation system. This technology allowed the isolation of thyrotropes with 83% purity at about 17-fold enrichment. Furthermore, the isolated THY1-immunopositive cells had higher Tsh mRNA levels compared with THY1-immunonegative cells and released TSH in response to thyrotropin-releasing hormone. These findings indicated that THY1 represents a potent thyrotrope marker and that the thyrotrope isolation method using the THY1 antibody may serve as a powerful tool to analyze their function including juxtacrine regulation through THY1/ITGB2 interaction. Copyright © 2016 Elsevier Inc. All rights reserved.

  12. Direct comparison of cardioprotective effects of necroptosis inhibitors against global ischemia-reperfusion in the isolated rat heart

    Directory of Open Access Journals (Sweden)

    Yu. V. Dmitriev

    2017-01-01

    Full Text Available The study was aimed at comparative assessment of cardioprotective properties of various necroptosis inhibitors in the isolated perfused rat heart subjected to global ischemia-reperfusion.Materials and Methods. The study was performed on 38 male Wistar rats weighting 250–300 g. The following necroptosis inhibitors were tested: necrostatin-1 (Nec-1, necrostatin-5 (Nec-5, necrostatin-1s (Nec1s, and necrosulfonamide (NSA. All tested substances were administered intraperitoneally (i.p. 1 hour prior to heart perfusion. Control animals were treated either with the vehicle (dimethyl sulfoxide, DMSO or with 0,9% sodium chloride solution (Controls. The dose of necroptosis inhibitors was calculated on the basis of effective concentration (EC50 data. One hour after i.p. injection, the animals were anesthetized, the hearts were rapidly excised, the aorta was cannulated and retrogradely perfused according to Langendorff. After stabilization, the perfusion was stopped for 35 minutes, which was followed by 2 hours of reperfusion. Prior to stabilization, fluid-filled polyethylene balloon was placed into the left ventricle for left ventricular pressure registration. Coronary flow was measured at baseline and during reperfusion by means of perfusate collection. The volume of necrotic myocardium was expressed as a percentage of triphenyltetrazolium chloride-negative tissue relative to the entire heart volume.Results. The volume of myocardial necrosis and functional heart parameters were not different between Controls and DMSO group. All tested necroptosis inhibitors demonstrated infarct-limiting effect. However, there were no differences between the groups. The volume of necrotic myocardium was (50,5 ± 7,82%, (29,9 ± 3,42%, (27,7 ± 3,42%, (30,6 ± 3,82%, and (34,7 ± 5,82% in DMSO, Nec-1, Nec-5, Nec-1s, and NSA groups, respectively (p < 0,01 vs. DMSO group.Nec-1s and NSA were shown to improve functional recovery of the heart after ischemia. In particular, left

  13. Isolated secretion granules from parotid glands of chronically stimulated rats possess an alkaline internal pH and inward-directed H+ pump activity

    International Nuclear Information System (INIS)

    Arvan, P.; Castle, J.D.

    1986-01-01

    Secretion granules have been isolated from the parotid glands of rats that have been chronically stimulated with the β-adrenergic agonist, isoproterenol. These granules are of interest because they package a quantitatively different set of secretory proteins in comparison with granules from the normal gland. Polypeptides enriched in proline, glycine, and glutamine, which are known to have pI's >10, replace α-amylase (pI's = 6.8) as the principal content species. The internal pH of granules from the treated rats changes from 7.8 in a potassium sulfate medium to 6.9 in a choline chloride medium. The increased pH over that of normal parotid granules (∼6.8) appears to protect the change in composition of the secretory contents. Whereas normal mature parotide granules have practically negligible levels of H + pumping ATPase activity, the isolated granules from isoproterenol-treated rats undergo a time-dependent internal acidification that requires the presence of ATP and is abolished by an H + ionophore. Additionally, an inside-positive granule transmembrane potential develops after ATP addition that depends upon ATP hydrolysis. Two independent methods have been used that exclude the possibility that contaminating organelles are the source of the H + -ATPase activity. Together these data provide clear evidence for the presence of an H + pump in the membranes of parotid granules from chronically stimulated rats. However, despite the presence of H + -pump activity, fluorescence microscopy with the weak base, acridine orange, reveals that the intragranular pH in live cells is greater than that of the cytoplasm

  14. Hydrogen sulfide postconditioning protects isolated rat hearts against ischemia and reperfusion injury mediated by the JAK2/STAT3 survival pathway

    Directory of Open Access Journals (Sweden)

    Heng-Fei Luan

    2012-10-01

    Full Text Available The JAK2/STAT3 signal pathway is an important component of survivor activating factor enhancement (SAFE pathway. The objective of the present study was to determine whether the JAK2/STAT3 signaling pathway participates in hydrogen sulfide (H2S postconditioning, protecting isolated rat hearts from ischemic-reperfusion injury. Male Sprague-Dawley rats (230-270 g were divided into 6 groups (N = 14 per group: time-matched perfusion (Sham group, ischemia/reperfusion (I/R group, NaHS postconditioning group, NaHS with AG-490 group, AG-490 (5 µM group, and dimethyl sulfoxide (DMSO; <0.2% group. Langendorff-perfused rat hearts, with the exception of the Sham group, were subjected to 30 min of ischemia followed by 90 min of reperfusion after 20 min of equilibrium. Heart rate, left ventricular developed pressure (LVDP, left ventricular end-diastolic pressure (LVEDP, and the maximum rate of increase or decrease of left ventricular pressure (± dp/dt max were recorded. Infarct size was determined using triphenyltetrazolium chloride (TTC staining. Myocardial TUNEL staining was used as the in situ cell death detection method and the percentage of TUNEL-positive nuclei to all nuclei counted was used as the apoptotic index. The expression of STAT3, bcl-2 and bax was determined by Western blotting. After reperfusion, compared to the I/R group, H2S significantly improved functional recovery and decreased infarct size (23.3 ± 3.8 vs 41.2 ± 4.7%, P < 0.05 and apoptotic index (22.1 ± 3.6 vs 43.0 ± 4.8%, P < 0.05. However, H2S-mediated protection was abolished by AG-490, the JAK2 inhibitor. In conclusion, H2S postconditioning effectively protects isolated I/R rat hearts via activation of the JAK2/STAT3 signaling pathway.

  15. Citalopram Ameliorates Synaptic Plasticity Deficits in Different Cognition-Associated Brain Regions Induced by Social Isolation in Middle-Aged Rats.

    Science.gov (United States)

    Gong, Wei-Gang; Wang, Yan-Juan; Zhou, Hong; Li, Xiao-Li; Bai, Feng; Ren, Qing-Guo; Zhang, Zhi-Jun

    2017-04-01

    Our previous experiments demonstrated that social isolation (SI) caused AD-like tau hyperphosphorylation and spatial memory deficits in middle-aged rats. However, the underlying mechanisms of SI-induced spatial memory deficits remain elusive. Middle-aged rats (10 months) were group or isolation reared for 8 weeks. Following the initial 4-week period of rearing, citalopram (10 mg/kg i.p.) was administered for 28 days. Then, pathophysiological changes were assessed by performing behavioral, biochemical, and pathological analyses. We found that SI could cause cognitive dysfunction and decrease synaptic protein (synaptophysin or PSD93) expression in different brain regions associated with cognition, such as the prefrontal cortex, dorsal hippocampus, ventral hippocampus, amygdala, and caudal putamen, but not in the entorhinal cortex or posterior cingulate. Citalopram could significantly improve learning and memory and partially restore synaptophysin or PSD93 expression in the prefrontal cortex, hippocampus, and amygdala in SI rats. Moreover, SI decreased the number of dendritic spines in the prefrontal cortex, dorsal hippocampus, and ventral hippocampus, which could be reversed by citalopram. Furthermore, SI reduced the levels of BDNF, serine-473-phosphorylated Akt (active form), and serine-9-phosphorylated GSK-3β (inactive form) with no significant changes in the levels of total GSK-3β and Akt in the dorsal hippocampus, but not in the posterior cingulate. Our results suggest that decreased synaptic plasticity in cognition-associated regions might contribute to SI-induced cognitive deficits, and citalopram could ameliorate these deficits by promoting synaptic plasticity mainly in the prefrontal cortex, dorsal hippocampus, and ventral hippocampus. The BDNF/Akt/GSK-3β pathway plays an important role in regulating synaptic plasticity in SI rats.

  16. Remodeling of Kv1.5 channel in right atria from Han Chinese patients with atrial fibrillation.

    Science.gov (United States)

    Ou, Xian-hong; Li, Miao-ling; Liu, Rui; Fan, Xin-rong; Mao, Liang; Fan, Xue-hui; Yang, Yan; Zeng, Xiao-rong

    2015-04-28

    The incidence of atrial fibrillation (AF) in rheumatic heart diseases (RHD) is very high and increases with age. Occurrence and maintenance of AF are very complicated process accompanied by many different mechanisms. Ion-channel remodeling, including the voltage-gated potassium channel Kv1.5, plays an important role in the pathophysiology of AF. However, the changes of Kv1.5 channel expression in Han Chinese patients with RHD and AF remain poorly understood. The aim of the present study was to investigate whether the Kv1.5 channels of the right atria may be altered with RHD, age, and sex to contribute to AF. Right atrial appendages were obtained from 20 patients with normal cardiac functions who had undergone surgery, and 26 patients with AF. Subjects were picked from 4 groups: adult and aged patients in normal sinus rhythm (SR) and AF. Patients were divided into non-RHD and RHD groups or men and women groups in normal SR and AF, respectively. The expression of Kv1.5 protein and messenger RNA (mRNA) were measured using Western blotting and polymerase chain reaction (PCR) method, respectively. Compared with the SR group, the expression of Kv1.5 protein decreased significantly in the AF group. However, neither Kv1.5 protein nor KCNA5 mRNA had significant differences in adult and aged groups, non-RHD and RHD group, and men and women group of AF. The expression of Kv1.5 channel protein changes with AF but not with age, RHD, and sex in AF.

  17. VLDL from Metabolic Syndrome Individuals Enhanced Lipid Accumulation in Atria with Association of Susceptibility to Atrial Fibrillation.

    Science.gov (United States)

    Lee, Hsiang-Chun; Lin, Hsin-Ting; Ke, Liang-Yin; Wei, Chi; Hsiao, Yi-Lin; Chu, Chih-Sheng; Lai, Wen-Ter; Shin, Shyi-Jang; Chen, Chu-Huang; Sheu, Sheng-Hsiung; Wu, Bin-Nan

    2016-01-20

    Metabolic syndrome (MetS) represents a cluster of metabolic derangements. Dyslipidemia is an important factor in MetS and is related to atrial fibrillation (AF). We hypothesized that very low density lipoproteins (VLDL) in MetS (MetS-VLDL) may induce atrial dilatation and vulnerability to AF. VLDL was therefore separated from normal (normal-VLDL) and MetS individuals. Wild type C57BL/6 male mice were divided into control, normal-VLDL (nVLDL), and MetS-VLDL (msVLDL) groups. VLDL (15 µg/g) and equivalent volumes of saline were injected via tail vein three times a week for six consecutive weeks. Cardiac chamber size and function were measured by echocardiography. MetS-VLDL significantly caused left atrial dilation (control, n = 10, 1.64 ± 0.23 mm; nVLDL, n = 7, 1.84 ± 0.13 mm; msVLDL, n = 10, 2.18 ± 0.24 mm; p < 0.0001) at week 6, associated with decreased ejection fraction (control, n = 10, 62.5% ± 7.7%, vs. msVLDL, n = 10, 52.9% ± 9.6%; p < 0.05). Isoproterenol-challenge experiment resulted in AF in young msVLDL mice. Unprovoked AF occurred only in elderly msVLDL mice. Immunohistochemistry showed excess lipid accumulation and apoptosis in msVLDL mice atria. These findings suggest a pivotal role of VLDL in AF pathogenesis for MetS individuals.

  18. Verapamil eliminates the hierarchical nature of activation frequencies from the pulmonary veins to the atria during paroxysmal atrial fibrillation.

    Science.gov (United States)

    Kushiyama, Yasunori; Osaka, Toshiyuki; Yokoyama, Eriko; Hasebe, Hideyuki; Kuroda, Yusuke; Kamiya, Kaichiro; Kodama, Itsuo

    2010-05-01

    There is evidence that verapamil promotes the persistence of paroxysmal atrial fibrillation (AF). Little is known about the underlying mechanisms. The purpose of this study was to determine the effect of verapamil on dominant frequencies (DFs) in the pulmonary veins (PVs) and atria during paroxysmal AF with reference to its potential arrhythmogenicity. Forty-three patients with paroxysmal AF were studied. Bipolar electrograms were recorded simultaneously during AF from the right atrial free wall (RAFW), coronary sinus (CS) and three PVs, or two PVs and the left atrial appendage (LAA). The DFs were obtained by fast Fourier transform analysis before and after infusion of verapamil (0.1 mg/kg, intravenously). At baseline, the maximum DF among the PVs (6.9 +/- 0.9 Hz) was significantly higher than the DF in the RAFW (6.2 +/- 0.7 Hz), CS (5.7 +/- 0.5 Hz), or LAA (5.9 +/- 0.7 Hz) (Patrial DF gradient (RAFW 0.7 +/- 0.9, CS 1.1 +/- 0.7, LAA 0.7 +/- 0.9 Hz). Verapamil increased the atrial DF to 6.9 +/- 0.8, 6.6 +/- 0.7, and 7.2 +/- 1.0 Hz in the RAFW, CS, and LAA, respectively (Patrial DF gradient was eliminated after verapamil (RAFW 0.2 +/- 0.8, CS 0.5 +/- 0.6, LAA -0.4 +/- 0.8 Hz; Patrial DF gradient during paroxysmal AF. Copyright 2010 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.

  19. Adolescent social isolation does not lead to persistent increases in anxiety- like behavior or ethanol intake in female long-evans rats.

    Science.gov (United States)

    Butler, Tracy R; Carter, Eugenia; Weiner, Jeffrey L

    2014-08-01

    Clinically, early life stress and anxiety disorders are associated with increased vulnerability for alcohol use disorders. In male rats, early life stress, imparted by adolescent social isolation, results in long-lasting increases in a number of behavioral risk factors for alcoholism, including greater anxiety-like behaviors and ethanol (EtOH) intake. Several recent studies have begun to use this model to gain insight into the relationships among anxiety measures, stress, EtOH intake, and neurobiological correlates driving these behaviors. As prior research has noted significant sex differences in the impact of adolescent stress on anxiety measures and EtOH drinking, the current study was conducted to determine if this same model produces an "addiction vulnerable" phenotype in female rodents. Female Long Evans rats were socially isolated (SI; 1/cage) or group housed (GH; 4/cage) for 6 weeks during adolescence. After this housing manipulation, behavioral assessment was conducted using the elevated plus maze, response to novelty in an open field environment, and the light/dark box. After behavioral testing, home cage EtOH drinking was assessed across an 8-week period. No group differences were detected in any of the behavioral measures of unconditioned anxiety-like behavior. Greater EtOH intake and preference were observed in SI females but these differences did not persist. The SI/GH model, which results in robust and enduring increases in anxiety measures and EtOH self-administration in male Long Evans rats, did not result in similar behavioral changes in female rats. These data, and that of others, suggest that adolescent social isolation is not a useful model with which to study neurobiological substrates linking antecedent anxiety and addiction vulnerability in female rats. Given the compelling epidemiological evidence that the relationship between chronic adolescent stress and alcohol addiction is particularly strong in women, there is clearly an urgent need

  20. Influence of β-adrenoceptor stimulation on the metabolism of C 18 unsaturated fatty acids in isolated heart of rat

    International Nuclear Information System (INIS)

    Makdissi, Samar

    1993-02-01

    The influence of stimulating β receptors on the metabolism of 18:1 n-9, 18:2 n-6 and 18:3 n-3 acids in an isolated perfused heart of a rat was studied. Experiments were carried out in two stages. In the first stage, each fatty acid was entered solely in Krebs liquid labelled with C 14 and complexed with albumin. In the second stage, isoproterenol (10 -4 M) was added to the previous mixture in order to stimulate the cardiac β-receptors. It appeared that the heart extracts each of 18:1 and 18:3 in a rate that exceeds the rate of extracting 18:2 and that the oxidation rate of 18:1 was the highest among the three studied acids which were alike in their esterification so they were all entered mainly in the triglycerid group (65-66%) and to less extend in the phospholipids (16-18%). While, the diglycerid and the free fatty acids did only form secondary compounds that would soon convert to the other groups that are more stable the reactions of double bond breakage for the 18:1 acid that converts to triple bond derivatives and 18:3 that converts to tetra, penta and hexa derivatives in the triglycerid were noticed. The 18:3 acid was the least influenced by the stimulation of β. The uptake rate of 18:2 acid was increased slightly while the 18:1 was decreased would indicate a competition between this acid ant the stored one in the cell. Also, the oxidation rate of 18:1 acid as well as the rate of entering it in the triglycerid and the phospholipids increased. In the same way, the oxidation rate of 18:2 acid increased, but its esterification turned in a way that the rate of entering it among the phospholipids increased, while the rate of entering it in the triglycerid decreased. According to what has been mentioned above, it can be said that the 18:1 plays an essential role in the production of direct power besides its role as a component of phospholipids that are deposited in the cellular membranes, while the metabolism of 18:2 acid turns-largely towards the phospholipids

  1. pKI values of prazosin and idazoxan for receptors stimulated by neuronally released transmitter in the epididymal portion of rat isolated vas deferens.

    OpenAIRE

    Mackay, D.; Kengatharan, M.

    1994-01-01

    1. A new method has been used to measure pKI values of prazosin and idazoxan against neuronally-released transmitter in the epididymal portion of the rat isolated vas deferens. The most reproducible results were obtained with a prolonged antagonist equilibration time (1 h). 2. Under these conditions the pKI of prazosin was practically unaffected by addition of alpha, beta-methylene-adenosine-5'-triphosphate (10 microM) to desensitize purinoceptors. Addition of desmethylimipramine (DMI) (0.3 m...

  2. The effects of beta-adrenoceptor activation on contraction in isolated fast- and slow-twitch skeletal muscle fibres of the rat.

    OpenAIRE

    Cairns, S. P.; Dulhunty, A. F.

    1993-01-01

    1. The aim of the experiments was to examined the effects of beta-adrenoceptor activation on twitch and tetanic contractions in fast- and slow-twitch mammalian skeletal muscle fibres. Isometric force was recorded from bundles of intact fibres isolated from the normal and denervated slow-twitch soleus and normal fast-twitch sternomastoid muscles of the rat. 2. Terbutaline (10 microM), a beta 2-adrenoceptor agonist, induced an average 15% potentiation of peak twitch and peak tetanic force in no...

  3. Persistent changes in the initial rate of pyruvate transport by isolated rat liver mitochondria after preincubation with adenine nucleotides and calcium ions

    OpenAIRE

    Vaartjes, W.J.; Breejen, J.N. den; Geelen, M.J.H.; Bergh, S.G. van den

    1980-01-01

    1. Preincubation of isolated rat-liver mitochondria in the presence of adenine nucleotides or Ca2+ results in definite and persistent changes in the initial rate of pyruvate transport. 2. These changes in the rate of pyruvate transport are accompanied by equally persistent changes in the opposite direction of the activity of pyruvate dehydrogenase (EC. 1.2.4.1). 3. Changes of the transmembrane pH gradient and of the membrane potential, brought about by the pretreatments of the mitochondria, c...

  4. Release of immunoreactive and radioactively prelabelled endogenous (pro-)insulin from isolated islets of rat pancreas in the presence of exogenous insulin

    Energy Technology Data Exchange (ETDEWEB)

    Schatz, H [Giessen Univ. (Germany, F.R.). Zentrum fuer Innere Medizin; Pfeiffer, E F

    1977-01-01

    To study the influence of insulin on its secretion, collagenase-isolated islets of rat pancreas were prelabelled with (/sup 3/H)leucine for 2 h. After washing the islets, (pro-)insulin release was stimulated by glucose in the presence or absence of exogenous insulin (up to 2.5 mu./ml. Hormone release was unchanged by the presence of exogenous insulin as judged by determination of both immunoreactive insulin and radioactivity incorporated into the proinsulin and insulin fractions of the medium. No direct feedback mechanism for insulin secretion was apparent from this study.

  5. Rats

    Directory of Open Access Journals (Sweden)

    Alexey Kondrashov

    2012-01-01

    Full Text Available We aimed to perform a chemical analysis of both Alibernet red wine and an alcohol-free Alibernet red wine extract (AWE and to investigate the effects of AWE on nitric oxide and reactive oxygen species production as well as blood pressure development in normotensive Wistar Kyoto (WKY and spontaneously hypertensive rats (SHRs. Total antioxidant capacity together with total phenolic and selected mineral content was measured in wine and AWE. Young 6-week-old male WKY and SHR were treated with AWE (24,2 mg/kg/day for 3 weeks. Total NOS and SOD activities, eNOS and SOD1 protein expressions, and superoxide production were determined in the tissues. Both antioxidant capacity and phenolic content were significantly higher in AWE compared to wine. The AWE increased NOS activity in the left ventricle, aorta, and kidney of SHR, while it did not change NOS activity in WKY rats. Similarly, increased SOD activity in the plasma and left ventricle was observed in SHR only. There were no changes in eNOS and SOD1 expressions. In conclusion, phenolics and minerals included in AWE may contribute directly to increased NOS and SOD activities of SHR. Nevertheless, 3 weeks of AWE treatment failed to affect blood pressure of SHR.

  6. Influence of physiologically active complex isolated from human amnion on lipid peroxide oxidation state and antioxidant activity of blood in rats after irradiation in different doses

    International Nuclear Information System (INIS)

    Borshchevs'ka, M.Yi.; Popov, V.V.; Abramova, L.P.; Kuz'myinova, Yi.A.

    1995-01-01

    The authors have studied the influence of physiologically active complex isolated from human amnion on the state of lipid peroxide oxidation according to diene conjugate and malonic dialdehyde amount and antioxidant enzyme activity (catalase and glutationperoxidase) in the blood of the rats exposed to single total irradiation in different doses (4 and 6 Gy) was studied. Definite changes of peroxide process intensity and reduction of the enzymes activity were shown to be observed in the blood of experimental animals even at long terms after the radiation exposure. Under the background of radiation exposure, administration of physiologically active complex isolated from human amnion produced protective effect on antioxidant enzyme activity which promoted normalization of peroxidation processes within the post-radiation period

  7. Isolation of an Angiotensin I-Converting Enzyme Inhibitory Protein with Antihypertensive Effect in Spontaneously Hypertensive Rats from the Edible Wild Mushroom Leucopaxillus tricolor

    Directory of Open Access Journals (Sweden)

    Xueran Geng

    2015-06-01

    Full Text Available An 86-kDa homodimeric angiotensin I-converting enzyme (ACE inhibitory protein designated as LTP was isolated from fruit bodies of the mushroom Leucopaxillus tricolor. The isolation procedure involved ultrafiltration through a membrane with a molecular weight cutoff of 10-kDa, ion exchange chromatography on Q-Sepharose, and finally fast protein liquid chromatography-gel filtration on Superdex 75. LTP exhibited an IC50 value of 1.64 mg∙mL−1 for its ACE inhibitory activity. The unique N-terminal amino acid sequence of LTP was disclosed by Edman degradation to be DGPTMHRQAVADFKQ. In addition, seven internal sequences of LTP were elucidated by liquid chromatography-tandem mass spectrometry (LC-MS/MS analysis. Results of the Lineweaver-Burk plot suggested that LTP competitively inhibited ACE. Both LTP and the water extract of L. tricolor exhibited a clear antihypertensive effect on spontaneously hypertensive rats.

  8. Pro-social 50-kHz ultrasonic communication in rats: post-weaning but not post-adolescent social isolation leads to social impairments—phenotypic rescue by re-socialization

    Science.gov (United States)

    Seffer, Dominik; Rippberger, Henrike; Schwarting, Rainer K. W.; Wöhr, Markus

    2015-01-01

    Rats are highly social animals and social play during adolescence has an important role for social development, hence post-weaning social isolation is widely used to study the adverse effects of juvenile social deprivation and to induce behavioral phenotypes relevant to neuropsychiatric disorders, like schizophrenia. Communication is an important component of the rat's social behavior repertoire, with ultrasonic vocalizations (USV) serving as situation-dependent affective signals. High-frequency 50-kHz USV occur in appetitive situations and induce approach behavior, supporting the notion that they serve as social contact calls; however, post-weaning isolation effects on the behavioral changes displayed by the receiver in response to USV have yet to be studied. We therefore investigated the impact of post-weaning isolation on socio-affective information processing as assessed by means of our established 50-kHz USV radial maze playback paradigm. We showed that post-weaning social isolation specifically affected the behavioral response to playback of pro-social 50-kHz but not alarm 22-kHz USV. While group-housed rats showed the expected preference, i.e., approach, toward 50-kHz USV, the response was even stronger in short-term isolated rats (i.e., 1 day), possibly due to a higher level of social motivation. In contrast, no approach was observed in long-term isolated rats (i.e., 4 weeks). Importantly, deficits in approach were reversed by peer-mediated re-socialization and could not be observed after post-adolescent social isolation, indicating a critical period for social development during adolescence. Together, these results highlight the importance of social experience for affiliative behavior, suggesting a critical involvement of play behavior on socio-affective information processing in rats. PMID:25983681

  9. Regulation of collagen production in freshly isolated cell populations from normal and cirrhotic rat liver: Effect of lactate

    International Nuclear Information System (INIS)

    Cerbon-Ambriz, J.; Cerbon-Solorzano, J.; Rojkind, M.

    1991-01-01

    Previous work has shown that lactic acid, and to a lesser extent pyruvic acid, is able to increase collagen synthesis significantly in liver slices of CCl4-treated rats but not normal rats. The purpose of this report is to document which cells in the cirrhotic liver are responsible for the lactate-stimulated increase in collagen synthesis. It was found that (a) incorporation of 3H-proline into protein-bound 3H-hydroxyproline is increased threefold to fourfold in hepatocytes from CCl4-treated rats as compared with normal rat hepatocytes; (b) neither the hepatocytes from normal nor those from CCl4-treated rats modify their collagen synthesizing capacity when 30 mmol/L lactic acid was added to the incubation medium; (c) nonparenchymal cells obtained from livers of CCl4-treated rats synthesize much less collagen than hepatocytes, but their synthesis is stimulated twofold by lactic acid; (d) from the different nonparenchymal cells, only fat-storing (Ito) cells increase collagen synthesis when lactic acid is present in the incubation medium. These results suggest that the increased lactic acid levels observed in patients with alcoholic hepatic cirrhosis may play an important role in the development of fibrosis by stimulating collagen production by fat-storing (Ito) cells

  10. Activation of neural cholecystokinin-1 receptors induces relaxation of the isolated rat duodenum which is reduced by nitric oxide synthase inhibitors

    Directory of Open Access Journals (Sweden)

    S.R. Martins

    2006-02-01

    Full Text Available Cholecystokinin (CCK influences gastrointestinal motility, by acting on central and peripheral receptors. The aim of the present study was to determine whether CCK has any effect on isolated duodenum longitudinal muscle activity and to characterize the mechanisms involved. Isolated segments of the rat proximal duodenum were mounted for the recording of isometric contractions of longitudinal muscle in the presence of atropine and guanethidine. CCK-8S (EC50: 39; 95% CI: 4.1-152 nM and cerulein (EC50: 58; 95% CI: 18-281 nM induced a concentration-dependent and tetrodotoxin-sensitive relaxation. Nomeganitro-L-arginine (L-NOARG reduced CCK-8S- and cerulein-induced relaxation (IC50: 5.2; 95% CI: 2.5-18 µM in a concentration-dependent manner. The magnitude of 300 nM CCK-8S-induced relaxation was reduced by 100 µM L-NOARG from 73 ± 5.1 to 19 ± 3.5% in an L-arginine but not D-arginine preventable manner. The CCK-1 receptor antagonists proglumide, lorglumide and devazepide, but not the CCK-2 receptor antagonist L-365,260, antagonized CCK-8S-induced relaxation in a concentration-dependent manner. These findings suggest that CCK-8S and cerulein activate intrinsic nitrergic nerves acting on CCK-1 receptors in order to cause relaxation of the rat duodenum longitudinal muscle.

  11. Evaluation of Chronic Physical and Psychological Stress Induction on Cardiac Ischemia / Reperfusion Injuries in Isolated Male Rat Heart: The Role of Sympathetic Nervous System

    Directory of Open Access Journals (Sweden)

    Kamran Rakhshan

    2015-10-01

    Full Text Available Exposure to stress leads to physiological changes called “stress response” which are the result ofthe changes in the adrenomedullary hormone system, hypothalamus-pituitary-adrenal (HPA and sympatheticnervous system (SNS activity. In the present study, the effects of chronic physical and psychological stressand also the role of sympathetic system effects in stress on ischemia/reperfusion (I/R injuries have beenstudied in isolated rat heart. Rat heart was isolated and subjected to 30 min regional ischemia and 120 minreperfusion. The daily stress was induced for one week prior to I/R induction. Sympathectomy was donechemically by injection of hydroxyl-dopamine prior to stress induction. There were no significant changes inheart rate and Coronary Flow between groups. Left ventricular developed pressure (LVDP and rate productpressure (RPP in both physical and psychological stress groups decreased significantly compared to those incontrol group (Pgroups. Infarct size significantly increased in both physical and psychological stress groups and control group(Pas compared with stress groups (Ppsychological stress prior to ischemia/reperfusion causes enhancement of myocardial injuries and it seemsthat increased sympathetic activity in response to stress is responsible for these adverse effects of stress onischemic/reperfused heart.

  12. Attenuation of ischemia-reperfusion injury by sevoflurane postconditioning involves protein kinase B and glycogen synthase kinase 3 beta activation in isolated rat hearts.

    Science.gov (United States)

    Fang, Neng-Xin; Yao, Yun-Tai; Shi, Chun-Xia; Li, Li-Huan

    2010-12-01

    Volatile anesthetic ischemic postconditioning reduces infarct size following ischemia/reperfusion. Whether phosphorylation of protein kinase B (PKB/Akt) and glycogen synthase kinase 3 beta (GSK3β) is causal for cardioprotection by postconditioning is controversial. We therefore investigated the impact of PKB/Akt and GSK3β in isolated perfused rat hearts subjected to 40 min of ischemia followed by 1 h of reperfusion. 2.0% sevoflurane (1.0 minimum alveolar concentration) was administered at the onset of reperfusion in 15 min as postconditioning. Western blot analysis was used to determine phosphorylation of PKB/Akt and its downstream target GSK3β after 1 h of reperfusion. Mitochondrial and cytosolic content of cytochrome C checked by western blot served as a marker for mitochondrial permeability transition pore opening. Sevoflurane postconditioning significantly improved functional cardiac recovery and decreased infarct size in isolated rat hearts. Compared with unprotected hearts, sevoflurane postconditioning-induced phosphorylation of PKB/Akt and GSK3β were significantly increased. Increase of cytochrome C in mitochondria and decrease of it in cytosol is significant when compared with unprotected ones which have reversal effects on cytochrome C. The current study presents evidence that sevoflurane-induced cardioprotection at the onset of reperfusion are partly through activation of PKB/Akt and GSK3β.

  13. Polyphenols isolated from virgin coconut oil attenuate cadmium-induced dyslipidemia and oxidative stress due to their antioxidant properties and potential benefits on cardiovascular risk ratios in rats.

    Science.gov (United States)

    Famurewa, Ademola Clement; Ejezie, Fidelis Ebele

    2018-01-01

    Literature has confirmed the pathogenic role of cadmium (Cd) and its exposure in the induction of dyslipidemia implicated in the development and increasing incidence of cardiovascular diseases. The current study explored whether polyphenolics isolated from virgin coconut oil (VCO) prevent Cd-induced dyslipidemia and investigate the underlying mechanism of action, in rats. Rats were pretreated with VCO polyphenols (10, 20 and 50 mg/kg body weight; orally) 2 weeks prior to concurrent Cd administration (5 mg/kg) for 5 weeks. Subsequently, serum concentrations of lipid and lipoprotein cholesterol and cardiovascular risk ratios were determined. Hepatic activities of superoxide dismutase (SOD) and catalase (CAT) as well as reduced glutathione (GSH) and malondialdehyde (MDA) contents were analyzed. Sub-chronic Cd administration significantly increased the serum levels of total cholesterol, triglycerides, low density lipoprotein cholesterol and very low density lipoprotein cholesterol while markedly reduced high density lipoprotein cholesterol. Hepatic activities of SOD and CAT as well as GSH content were suppressed by Cd, whereas MDA level was obviously increased. The co-administration of VCO polyphenol with Cd remarkably restored lipid profile and cardiovascular risk ratios and stabilized antioxidant defense systems comparable to control group. This is the first study presenting that polyphenols isolated from VCO prevent Cd-induced lipid abnormalities and cardiovascular risk ratios by improving antioxidant defense systems.

  14. Polyphenols isolated from virgin coconut oil attenuate cadmium-induced dyslipidemia and oxidative stress due to their antioxidant properties and potential benefits on cardiovascular risk ratios in rats

    Directory of Open Access Journals (Sweden)

    Ademola Clement Famurewa

    2017-12-01

    Full Text Available Objective: Literature has confirmed the pathogenic role of cadmium (Cd and its exposure in the induction of dyslipidemia implicated in the development and increasing incidence of cardiovascular diseases. The current study explored whether polyphenolics isolated from virgin coconut oil (VCO prevent Cd-induced dyslipidemia and investigate the underlying mechanism of action, in rats. Materials and Methods: Rats were pretreated with VCO polyphenols (10, 20 and 50 mg/kg body weight; orally 2 weeks prior to concurrent Cd administration (5 mg/kg for 5 weeks. Subsequently, serum concentrations of lipid and lipoprotein cholesterol and cardiovascular risk ratios were determined. Hepatic activities of superoxide dismutase (SOD and catalase (CAT as well as reduced glutathione (GSH and malondialdehyde (MDA contents were analyzed. Results: Sub-chronic Cd administration significantly increased the serum levels of total cholesterol, triglycerides, low density lipoprotein cholesterol and very low density lipoprotein cholesterol while markedly reduced high density lipoprotein cholesterol. Hepatic activities of SOD and CAT as well as GSH content were suppressed by Cd, whereas MDA level was obviously increased. The co-administration of VCO polyphenol with Cd remarkably restored lipid profile and cardiovascular risk ratios and stabilized antioxidant defense systems comparable to control group. Conclusion: This is the first study presenting that polyphenols isolated from VCO prevent Cd-induced lipid abnormalities and cardiovascular risk ratios by improving antioxidant defense systems.

  15. Antidepressant-Like Effects of Sanggenon G, Isolated from the Root Bark of Morus alba, in Rats: Involvement of the Serotonergic System.

    Science.gov (United States)

    Lim, Dong Wook; Jung, Jae-Woo; Park, Ji-Hae; Baek, Nam-In; Kim, Yun Tai; Kim, In-Ho; Han, Daeseok

    2015-01-01

    The root bark of Morus alba is commonly used as an alternative medicine due to its numerous health benefits in humans. However, the antidepressant effects of various active components from M. alba have not been fully elucidated. In this study, we aimed to determine whether sanggenon G, an active compound isolated from the root bark of M. alba, exhibited antidepressant-like activity in rats subjected to forced swim test (FST)-induced depression. Acute treatment of rats with sanggenon G (30 mg/kg, intraperitoneally (i.p.)) significantly reduced immobility time and increased swimming time without any significant change in climbing. Rats treated with sanggenon G also exhibited a decrease in the limbic hypothalamic-pituitary-adrenal (HPA) axis response to the FST, as indicated by attenuation of the corticosterone response and decreased c-Fos immunoreactivity in the hypothalamic paraventricular nucleus (PVN). In addition, the antidepressant-like effects of sanggenon G were significantly inhibited by WAY100635 (1 mg/kg, i.p.; a selective 5-hydroxytryptamine1A (5-HT1A) receptor antagonist), but not SCH23390 (0.05 mg/kg, i.p.; a dopamine D1 receptor antagonist). Our findings suggested that the antidepressant-like effects of sanggenon G were mediated by an interaction with the serotonergic system. Further studies are needed to evaluate the potential of sanggenon G as an alternative therapeutic approach for the treatment of depression.

  16. Stroke Status Evoked Adhesion Molecule Genetic Alterations in Astrocytes Isolated from Stroke-Prone Spontaneously Hypertensive Rats and the Apigenin Inhibition of Their Expression

    Directory of Open Access Journals (Sweden)

    Kazuo Yamagata

    2010-01-01

    Full Text Available We examined the possibility that the expression of adhesion molecules is regulated differently in cultured astrocytes from stroke-prone spontaneously hypertensive rats (SHRSP/IZM rats than in those from Wistar Kyoto rats (WKY/IZM by tumor necrosis factor-alpha (TNF- or hypoxia and reoxygenation (H/R and the inhibitory effects of apigenin. It was found that the expression of vascular cell adhesion molecule-1 (VCAM-1 by TNF- in astrocytes isolated from SHRSP/IZM was increased compared with that in WKY/IZM. The expression of monocyte chemotactic protein-1 (MCP-1 mRNA induced by H/R in SHRSP/IZM astrocytes was increased compared with that in normal oxygen concentrations. Apigenin strongly attenuated TNF--induced VCAM-1 mRNA and protein expression and suppressed the adhesion of U937 cells and SHRSP/IZM astrocytes. These results suggest that the expression levels of adhesion molecules during H/R affect disease outcome and can drive SHRSP/IZM to stroke. It is suggested that apigenin regulates adhesion molecule expression in reactive astrocytes during ischemia.

  17. Short post-weaning social isolation induces long-term changes in the dopaminergic system and increases susceptibility to psychostimulants in female rats.

    Science.gov (United States)

    Lampert, Carine; Arcego, Danusa Mar; de Sá Couto-Pereira, Natividade; Dos Santos Vieira, Aline; Toniazzo, Ana Paula; Krolow, Rachel; Garcia, Emily; Vendite, Deusa Aparecida; Calcagnotto, Maria Elisa; Dalmaz, Carla

    2017-10-01

    Childhood and adolescence are sensitive periods of development, marked by high brain maturation and plasticity. Exposure to early life stress, such as social isolation, is able to prompt changes in sensitive brain circuitries, essentially in the mesolimbic dopaminergic system and increase the risk for addictive behaviors later in life. Post-weaning social isolation can stimulate the consumption of rewarding substances, like drugs of abuse and palatable foods. However, most studies analyze long periods of social isolation and very little is known about the effects of a brief social isolation in a sensitive period of development and its association with palatable food on the reward system sensitization. Furthermore, females are more susceptible to the reinforcing effect of drugs than males. Therefore, the aim of this study was to analyze the effects of a short post-weaning social isolation combined with a free access to a chronic high sugar diet (HSD) on the dopaminergic system, oxidative status and behavioral response to an amphetamine-like drug in adulthood. We used female Wistar rats that were socially isolated from post-natal days (PD) 21 to 35 and received free access to a HSD until PD 60. On PD 65, animals were submitted to a challenge with diethylpropion (DEP), an amphetamine-like drug and different responses were analyzed: locomotor activity, immmunocontent of dopamine related proteins, and the oxidative status in the striatum, before and after the DEP challenge. We showed that a short post-weaning social isolation (SI) increased the locomotor response to DEP, when compared with previous saline administration. Social isolation also increased dopamine transporter, tyrosine hydroxylase, and decreased dopamine D2 receptor immunocontent. Additionally, SI increased the overall oxidative status parameters after the challenge with DEP. Interestingly, the exposure to a HSD prevented the SI effects on locomotor response, but did not interfere in the dopaminergic

  18. Antihyperglycemic effect ofJuniperus phoenicea L. on alloxan-induced diabetic rats and diterpenoids isolated from the fruits

    Institute of Scientific and Technical Information of China (English)

    Salma Ahmed El-Sawi; Hemaia Mohamed Motawae; Abdel-Rahman Omar El-Shabrawy; Mohamed Aboul-Fotouh Sleem; Amani Ameen Sleem; Maii Abdel Naby Ismail Maamoun

    2015-01-01

    Objective:To explore the traditional use ofJuniperus phoenicea L. (J. phoenicea) growing in Egypt as antidiabetic herb. Methods: The antihyperglycemic activities of the crude 80% ethanol and successive extracts of leaves and fruits of the plant were investigated in alloxan-induced diabetic rats after collecting blood samples through retro-orbital puncture technique. As a consequence of the biological results, phytochemical investigation of the chloroform fraction of fruits was carried out by column chromatography and thin layer chromatography. Results: Results revealed the reduction in blood glucose levels in rats, which were significantly different from control at 4 and 8 weeks (P Conclusions: It has become clear that leaves and fruits of the EgyptianJ. phoenicea provide effective antihyperglycemic action in diabetic rats as was reported in folk medicine. The high contents of terpenoids in the non-polar fractions may attribute to the antidiabetic effect of the plant.

  19. Aqueous ethanol extraction of dietary soy protein isolate improves 59Fe absorption by the rat from a casein-based test meal

    International Nuclear Information System (INIS)

    Thompson, D.B.

    1989-01-01

    A commercial soy protein isolate (SPI) was further processed in an attempt to understand how a diet based on SPI can cause decreased iron retention by the rat from a separately administered casein-based test meal. Groups of eight rats were fed either a casein-based diet or a diet based on SPI. The acid-precipitated SPI was incorporated into diets as such, after neutralization, after 60% (v/v) ethanol extraction and neutralization, or after 60% ethanol exposure and neutralization. All dietary SPI was heat-treated by exposure to steam at 108 degrees C for 30 min. Rats were fed their respective diets, each containing 25 mg Fe/kg, for 13 d, and then all rats were fed a 59 Fe-radiolabeled 2.5-g casein test meal containing 64 micrograms of iron. Ingested radioactivity was determined following the meal, and retained radioactivity over the subsequent 10-d period. Absorption was not distinguishable for groups fed the casein-based (78.3 ± 3.6%) and the ethanol-extracted, SPI-based diet (80.2 ± 5.4%). Absorption was lower (P less than 0.01) for groups fed each of the other SPI-based diets: SPI as such (68.3 ± 8.9%), neutralized SPI (69.8 ± 5.0%) and ethanol-exposed SPI (67.6 ± 4.8%). An ethanol-extractable component of SPI may be responsible for decreased iron absorption by animals fed SPI prior to a radiolabeled test meal

  20. Screening and characterization of purine nucleoside degrading lactic acid bacteria isolated from Chinese sauerkraut and evaluation of the serum uric acid lowering effect in hyperuricemic rats.

    Directory of Open Access Journals (Sweden)

    Ming Li

    Full Text Available Hyperuricemia is well known as the cause of gout. In recent years, it has also been recognized as a risk factor for arteriosclerosis, cerebrovascular and cardiovascular diseases, and nephropathy in diabetic patients. Foods high in purine compounds are more potent in exacerbating hyperuricemia. Therefore, the development of probiotics that efficiently degrade purine compounds is a promising potential therapy for the prevention of hyperuricemia. In this study, fifty-five lactic acid bacteria isolated from Chinese sauerkraut were evaluated for the ability to degrade inosine and guanosine, the two key intermediates in purine metabolism. After a preliminary screening based on HPLC, three candidate strains with the highest nucleoside degrading rates were selected for further characterization. The tested biological characteristics of candidate strains included acid tolerance, bile tolerance, anti-pathogenic bacteria activity, cell adhesion ability, resistance to antibiotics and the ability to produce hydrogen peroxide. Among the selected strains, DM9218 showed the best probiotic potential compared with other strains despite its poor bile resistance. Analysis of 16S rRNA sequences showed that DM9218 has the highest similarity (99% to Lactobacillus plantarum WCFS1. The acclimated strain DM9218-A showed better resistance to 0.3% bile salt, and its survival in gastrointestinal tract of rats was proven by PCR-DGGE. Furthermore, the effects of DM9218-A in a hyperuricemia rat model were evaluated. The level of serum uric acid in hyperuricemic rat can be efficiently reduced by the intragastric administration of DM9218-A (P<0.05. The preventive treatment of DM9218-A caused a greater reduction in serum uric acid concentration in hyperuricemic rats than the later treatment (P<0.05. Our results suggest that DM9218-A may be a promising candidate as an adjunctive treatment in patients with hyperuricemia during the onset period of disease. DM9218-A also has potential

  1. Deficiency of sex hormones does not affect 17-ß-estradiol-induced coronary vasodilation in the isolated rat heart.

    Science.gov (United States)

    Santos, R L; Lima, J T; Rouver, W N; Moysés, M R

    2016-01-01

    The relaxation of coronary arteries by estrogens in the coronary vascular beds of naive and hypertensive rats has been well described. However, little is known about this action in gonadectomized rats. We investigated the effect of 17-ß-estradiol (E2) in coronary arteries from gonadectomized rats, as well as the contributions of endothelium-derived factors and potassium channels. Eight-week-old female and male Wistar rats weighing 220-300 g were divided into sham-operated and gonadectomized groups (n=9-12 animals per group). The baseline coronary perfusion pressure (CPP) was determined, and the vasoactive effects of 10 μM E2 were assessed by bolus administration before and after endothelium denudation or by perfusion with NG-nitro-L-arginine methyl ester (L-NAME), indomethacin, clotrimazole, L-NAME plus indomethacin, L-NAME plus clotrimazole or tetraethylammonium (TEA). The CPP differed significantly between the female and sham-operated male animals. Gonadectomy reduced the CPP only in female rats. Differences in E2-induced relaxation were observed between the female and male animals, but male castration did not alter this response. For both sexes, the relaxation response to E2 was, at least partly, endothelium-dependent. The response to E2 was reduced only in the sham-operated female rats treated with L-NAME. However, in the presence of indomethacin, clotrimazole, L-NAME plus indomethacin or L-NAME plus clotrimazole, or TEA, the E2 response was significantly reduced in all groups. These results highlight the importance of prostacyclin, endothelium-derived hyperpolarizing factor, and potassium channels in the relaxation response of coronary arteries to E2 in all groups, whereas nitric oxide may have had an important role only in the sham-operated female group.

  2. Pro-social 50-kHz ultrasonic communication in rats: Post-weaning but not post-adolescent social isolation leads to social impairments – phenotypic rescue by re-socialization

    Directory of Open Access Journals (Sweden)

    Dominik eSeffer

    2015-05-01

    Full Text Available Rats are highly social animals and social play during adolescence has an important role for social development, hence post-weaning social isolation is widely used to study the adverse effects of juvenile social deprivation and to induce behavioral phenotypes relevant to neuropsychiatric disorders, like schizophrenia. Communication is an important component of the rat’s social behavior repertoire, with ultrasonic vocalizations (USV serving as situation-dependent affective signals. High-frequency 50-kHz USV occur in appetitive situations and induce approach behavior, supporting the notion that they serve as social contact calls; however, post-weaning isolation effects on the behavioral changes displayed by the receiver in response to USV have yet to be studied. We therefore investigated the impact of post-weaning isolation on socio-affective information processing as assessed by means of our established 50-kHz USV radial maze playback paradigm. We showed that post-weaning social isolation specifically affected the behavioral response to playback of pro-social 50-kHz but not alarm 22-kHz USV. While group-housed rats showed the expected preference, i.e. approach, towards 50-kHz USV, the response was even stronger in short-term isolated rats (i.e. 1 day, possibly due to a higher level of social motivation. In contrast, no approach was observed in long-term isolated rats (i.e. 4 weeks. Importantly, deficits in approach were reversed by peer-mediated re-socialization and could not be observed after post-adolescent social isolation, indicating a critical period for social development during adolescence. Together, these results highlight the importance of social experience for affiliative behavior, suggesting a critical involvement of play behavior on socio-affective information processing in rats.

  3. Properties of the luminal membrane of isolated perfused rat pancreatic ducts. Effect of cyclic AMP and blockers of chloride transport

    DEFF Research Database (Denmark)

    Novak, I; Greger, R

    1988-01-01

    - and interlobular ducts of rat pancreas was used. Responses of the epithelium to inhibitors and agonists were monitored by electrophysiological techniques. Addition of HCO-3/CO2 to the bath side of nonstimulated ducts depolarized the PD across the basolateral membrane (PDbl) by about 9 mV, as also observed...

  4. Physiology of spontaneous [Ca2+](i) oscillations in the isolated vasopressin and oxytocin neurones of the rat supraoptic nucleus

    Czech Academy of Sciences Publication Activity Database

    Kortus, Štěpán; Srinivasan, Ch.; Forostyak, O.; Ueta, Y.; Syková, E.; Chvátal, A.; Zápotocký, Martin; Verkhratsky, A.; Dayanithi, G.

    2016-01-01

    Roč. 59, č. 6 (2016), s. 280-288 ISSN 0143-4160 R&D Projects: GA ČR(CZ) GBP304/12/G069 Institutional support: RVO:67985823 Keywords : magnocellular neurosecretory cells * supraoptic nucleus * vasopressin * oxytocin * transgenic rats * Ca2+ oscillations Subject RIV: FH - Neurology Impact factor: 3.707, year: 2016

  5. Natural Ventilation in Atria

    DEFF Research Database (Denmark)

    Svidt, Kjeld; Heiselberg, Per; Hendriksen, Ole Juhl

    This case study comprises a monitoring programme as well as a Computational Fluid Dynamics (CFD) analysis of a natural ventilated atrium. The purpose has been to analyse the performance of a typical natural ventilation system in Denmark under both summer and winter conditions.......This case study comprises a monitoring programme as well as a Computational Fluid Dynamics (CFD) analysis of a natural ventilated atrium. The purpose has been to analyse the performance of a typical natural ventilation system in Denmark under both summer and winter conditions....

  6. Isolation of a Genomic Region Affecting Most Components of Metabolic Syndrome in a Chromosome-16 Congenic Rat Model.

    Directory of Open Access Journals (Sweden)

    Lucie Šedová

    Full Text Available Metabolic syndrome is a highly prevalent human disease with substantial genomic and environmental components. Previous studies indicate the presence of significant genetic determinants of several features of metabolic syndrome on rat chromosome 16 (RNO16 and the syntenic regions of human genome. We derived the SHR.BN16 congenic strain by introgression of a limited RNO16 region from the Brown Norway congenic strain (BN-Lx into the genomic background of the spontaneously hypertensive rat (SHR strain. We compared the morphometric, metabolic, and hemodynamic profiles of adult male SHR and SHR.BN16 rats. We also compared in silico the DNA sequences for the differential segment in the BN-Lx and SHR parental strains. SHR.BN16 congenic rats had significantly lower weight, decreased concentrations of total triglycerides and cholesterol, and improved glucose tolerance compared with SHR rats. The concentrations of insulin, free fatty acids, and adiponectin were comparable between the two strains. SHR.BN16 rats had significantly lower systolic (18-28 mmHg difference and diastolic (10-15 mmHg difference blood pressure throughout the experiment (repeated-measures ANOVA, P < 0.001. The differential segment spans approximately 22 Mb of the telomeric part of the short arm of RNO16. The in silico analyses revealed over 1200 DNA variants between the BN-Lx and SHR genomes in the SHR.BN16 differential segment, 44 of which lead to missense mutations, and only eight of which (in Asb14, Il17rd, Itih1, Syt15, Ercc6, RGD1564958, Tmem161a, and Gatad2a genes are predicted to be damaging to the protein product. Furthermore, a number of genes within the RNO16 differential segment associated with metabolic syndrome components in human studies showed polymorphisms between SHR and BN-Lx (including Lpl, Nrg3, Pbx4, Cilp2, and Stab1. Our novel congenic rat model demonstrates that a limited genomic region on RNO16 in the SHR significantly affects many of the features of metabolic

  7. In vitro model to study the effects of matrix stiffening on Ca2+ handling and myofilament function in isolated adult rat cardiomyocytes.

    Science.gov (United States)

    van Deel, Elza D; Najafi, Aref; Fontoura, Dulce; Valent, Erik; Goebel, Max; Kardux, Kim; Falcão-Pires, Inês; van der Velden, Jolanda

    2017-07-15

    This paper describes a novel model that allows exploration of matrix-induced cardiomyocyte adaptations independent of the passive effect of matrix rigidity on cardiomyocyte function. Detachment of adult cardiomyocytes from the matrix enables the study of matrix effects on cell shortening, Ca 2+ handling and myofilament function. Cell shortening and Ca 2+ handling are altered in cardiomyocytes cultured for 24 h on a stiff matrix. Matrix stiffness-impaired cardiomyocyte contractility is reversed upon normalization of extracellular stiffness. Matrix stiffness-induced reduction in unloaded shortening is more pronounced in cardiomyocytes isolated from obese ZSF1 rats with heart failure with preserved ejection fraction compared to lean ZSF1 rats. Extracellular matrix (ECM) stiffening is a key element of cardiac disease. Increased rigidity of the ECM passively inhibits cardiac contraction, but if and how matrix stiffening also actively alters cardiomyocyte contractility is incompletely understood. In vitro models designed to study cardiomyocyte-matrix interaction lack the possibility to separate passive inhibition by a stiff matrix from active matrix-induced alterations of cardiomyocyte properties. Here we introduce a novel experimental model that allows exploration of cardiomyocyte functional alterations in response to matrix stiffening. Adult rat cardiomyocytes were cultured for 24 h on matrices of tuneable stiffness representing the healthy and the diseased heart and detached from their matrix before functional measurements. We demonstrate that matrix stiffening, independent of passive inhibition, reduces cell shortening and Ca 2+ handling but does not alter myofilament-generated force. Additionally, detachment of adult cultured cardiomyocytes allowed the transfer of cells from one matrix to another. This revealed that stiffness-induced cardiomyocyte changes are reversed when matrix stiffness is normalized. These matrix stiffness-induced changes in cardiomyocyte

  8. Crude extract and purified components isolated from the stems of Tinospora crispa exhibit positive inotropic effects on the isolated left atrium of rats

    DEFF Research Database (Denmark)

    Praman, Siwaporn; Mulvany, Michael J.; Williams, David E.

    2013-01-01

    of 5 bioactive compounds: higenamine, salsolinol, tyramine, adenosine and uridine. Higenamine, salsolinol (at low concentration) and tyramine acted via the adrenergic receptors to increase the force of the atrial contraction, whereas a high concentration of salsolinol acted indirectly by stimulating...... an increase in the force of contraction of the electrical field stimulated left atrium. This effect was inhibited by propranolol, atenolol, ICI-118,551, phentolamine and atropine. The positive inotropic effect on the reserpenized isolated left atrium of the Tinospora crispa extract was significantly inhibited...... by propranolol, atenolol and ICI-118,551. Phentolamine, on the other hand, caused potentiation and the effect was inhibited when propranolol was also added. Higenamine caused an increase in the force of contraction of the electrical field stimulated left atrium and this effect was significantly inhibited by ICI...

  9. Effect of experimental diabetes on cholinergic, purinergic and peptidergic motor responses of the isolated rat bladder to electrical field stimulation or capsaicin.

    Science.gov (United States)

    Benkó, Rita; Lázár, Zsófia; Pórszász, Róbert; Somogyi, George T; Barthó, Loránd

    2003-09-30

    An attempt has been made to pharmacologically isolate cholinergic, P(2) purinoceptor-mediated and peptidergic (capsaicin-sensitive, tachykinin-mediated) contraction of the guanethidine-treated rat bladder detrusor preparation, in vitro. The effect of experimental diabetes was assessed on these types of contraction. Responses were evoked by electrical field stimulation (single shocks or 1 Hz for 30 s or 10 Hz for 40 s). Single shocks and 1-Hz stimulation were applied in the presence of (a). atropine (1 microM) or (b). P(2) purinoceptor antagonists (50 microM pyridoxalphosphate-6-azophenyl-2',4'-disulfonic acid) [PPADS] plus 100 microM suramin. Long-term electrical field stimulation (10 Hz for 40 s) (c). was applied with both atropine and the P(2) purinoceptor antagonists present in the organ bath. The effects of capsaicin (d). and ATP (e). were also studied. Three groups of experimental animals were used: streptozotocin-treated (50 mg.kg(-1) i.p., 8 weeks before the experiment), parallel solvent-treated and untreated rats. (a). Responses to electrical field stimulation in the presence of atropine were reduced by half by PPADS plus suramin, but were resistant to capsaicin tachyphylaxis. They were enhanced in preparations taken from diabetic rats. (b). Contractions to electrical field stimulation in the presence of PPADS plus suramin were reduced by 2/3 by atropine, but were left unchanged by capsaicin or diabetes. (c). Contractions to long-term stimulation had a quick and a sustained phase. Especially the latter was inhibited by capsaicin tachypyhlaxis; it was also strongly reduced in preparations taken from diabetic rats. (d). Contractions to capsaicin (30 nM and 1 microM) were resistant to tetrodotoxin, strongly reduced by a combination of tachykinin NK(1) and NK(2) receptor antagonists, and slightly reduced in preparations from diabetic animals. Capsaicin (1 microM) had no acute inhibitory action on cholinergic or purinergic responses, nor did it cause relaxation

  10. Comparison of atria and CHA2DS2-vasc risk stratification schemes for the prediction of stroke in the individual patient with atrial fibrillation and the impact on treatment decisions

    NARCIS (Netherlands)

    Van Den Ham, Hendrika A.; Klungel, Olaf H.; Singer, Daniel E.; Leufkens, Hubert G.M.; Van Staa, Tjeerd P.

    2014-01-01

    Background: Atrial fibrillation (AF) increases the risk of ischaemic stroke and treatment with anticoagulants should be prescribed according to stroke risk. Objectives: To compare the predictive ability of the currently recommended CHA2DS2-VASc ischaemic stroke risk score with the new ATRIA stroke

  11. Comparison of ATRIA and CHA2DS2-VASc risk stratification schemes for the prediction of stroke in the individual patient with atrial fibrillation and the impact on treatment decisions

    NARCIS (Netherlands)

    Van Den Ham, H.A.; Klungel, O.H.; Singer, D.E.; Leufkens, H.G.M.; Van Staa, T.P.

    2014-01-01

    Purpose: To compare the predictive ability of the currently recommended CHA2DS2-VASc ischaemic stroke risk score with the new ATRIA stroke risk score in patients with atrial fibrillation (AF). Methods: Patients with AF, not using warfarin, were assembled from the Clinical Practice Research Datalink

  12. The VGF-Derived Neuropeptide TLQP-21 Shows No Impact on Hormone Secretion in the Isolated Perfused Rat Pancreas

    DEFF Research Database (Denmark)

    Christiansen, Charlotte Bayer; Svendsen, B; Holst, Jens Juul

    2015-01-01

    investigated the impact of TLQP-21 on insulin, glucagon, and somatostatin secretion in the perfused rat pancreas. We found that administration of 5 and 50 nM TLQP-21 had no impact on pancreatic hormone secretion at 3.5 or 8 mM glucose levels. Increasing TLQP-21 (200 nM) and glucose concentration (3.5 and 16 m...

  13. Effect of insulin on albumin production and incorporation of 14C-leucine into proteins in isolated parenchymal liver cells from normal rats

    DEFF Research Database (Denmark)

    Dich, J; Gluud, C N

    1975-01-01

    the immunologically determined increment in the incubation medium was 1.7 +/- 0.2 mug albumin/min per g liver wet wt. This is about 30% of the rate of production in the perfused liver. Addition of insulin (10(-6)-10(-10) M) enhanced albumin production (50-17%), and incorporation of 14C-leucine both into albumin (50......Parenchymal rat liver cells were isolated by a modification of the collagenase method of Quistorff, Bondesen and Grunnet. The cells secreted albumin into the medium and incorporated 14C-leucine both into cell proteins and proteins secreted into the medium. Albumin production measured from......-8%), secreted proteins (40-9%) and cell proteins (20-8%). Insulin does not increase the production of albumin by depleting the cells. The effect of insulin on albumin production is compatible with an effect on the rate of synthesis as the specific activity of albumin is unaffected by addition of insulin....

  14. Amino acid transamination is crucial for ischaemic cardioprotection in normal and preconditioned isolated rat hearts--focus on L-glutamate

    DEFF Research Database (Denmark)

    Løfgren, Bo; Povlsen, Jonas Agerlund; Rasmussen, Lars Ege

    2010-01-01

    We have found that cardioprotection by l-glutamate mimics protection by classical ischaemic preconditioning (IPC). We investigated whether the effect of IPC involves amino acid transamination and whether IPC modulates myocardial glutamate metabolism. In a glucose-perfused, isolated rat heart model...... subjected to 40 min global no-flow ischaemia and 120 min reperfusion, the effects of IPC (2 cycles of 5 min ischaemia and 5 min reperfusion) and continuous glutamate (20 mm) administration during reperfusion on infarct size and haemodynamic recovery were studied. The effect of inhibiting amino acid...... transamination was evaluated by adding the amino acid transaminase inhibitor amino-oxyacetate (AOA; 0.025 mm) during reperfusion. Changes in coronary effluent, interstitial (microdialysis) and intracellular glutamate ([GLUT](i)) concentrations were measured. Ischaemic preconditioning and postischaemic glutamate...

  15. Hypercapnic vasodilatation in isolated rat basilar arteries is exerted via low pH and does not involve nitric oxide synthase stimulation or cyclic GMP production

    DEFF Research Database (Denmark)

    You, J P; Wang, Qian; Zhang, W

    1994-01-01

    this relaxation by 54% and 70%, respectively. The effect of L-NOARG was completely reversed by L-arginine. Blockade of nerve excitation with tetrodotoxin (TTX) had no affect on the 15% CO2 elicited vasodilatation. Measurements of cGMP in vessel segments showed no significant increase in cGMP content in response...... to hypercapnia. L-NOARG and MB, but not TTX, significantly reduced the basal cGMP content in cerebral vessels. Adding 1.5% halothane to the incubation medium did not result in a significant increase in cGMP content. Lowering the pH by cumulative application of 0.12 M HCl resulted in relaxation identical...... elicits vasodilatation of isolated rat basilar arteries by a mechanism independent of nitric oxide synthase (NOS) activity. The markedly reduced basal cGMP levels in cerebral vessels by L-NOARG and MB suggest that there exists a basal NO formation in the cerebral vessel wall....

  16. Isolation, purification, and partial characterization of a membrane-bound Cl-/HCO3--activated ATPase complex from rat brain with sensitivity to GABAAergic ligands.

    Science.gov (United States)

    Menzikov, Sergey A

    2017-02-07

    This study describes the isolation and purification of a protein complex with [Formula: see text]-ATPase activity and sensitivity to GABA A ergic ligands from rat brain plasma membranes. The ATPase complex was enriched using size-exclusion, affinity, and ion-exchange chromatography. The fractions obtained at each purification step were subjected to SDS-polyacrylamide gel electrophoresis (SDS-PAGE), which revealed four subunits with molecular mass ∼48, 52, 56, and 59 kDa; these were retained at all stages of the purification process. Autoradiography revealed that the ∼52 and 56 kDa subunits could bind [ 3 H]muscimol. The [Formula: see text]-ATPase activity of this enriched protein complex was regulated by GABA A ergic ligands but was not sensitive to blockers of the NKCC or KCC cotransporters.

  17. Conversion of p-tyrosine to p-tyramine in the isolated perfused rat kidney: Modulation by perfusate concentrations of p-tyrosine

    International Nuclear Information System (INIS)

    Brier, M.E.; Bowsher, R.R.; Henry, D.P.; Mayer, P.R.

    1991-01-01

    The authors used the isolated perfused rat kidney to evaluate the role of renal decarboxylation of p-tyrosine as the source of urinary p-tyramine. Kidneys were perfused with concentrations of p-tyrosine ranging from 0.02 mM to 2.0 mM. p-Tyramine was measured by a sensitive and specific radioenzymatic assay. An increase in the perfusate concentration of p-tyrosine resulted in a significant increase in p-tyramine production that was blocked by the addition of NSD-1015, an inhibitor of aromatic-1-amino decarboxylase (AADC). They conclude p-tyrosine is the precursor for the renal production of p-tyramine, renal AADC catalyzes the formation of urinary p-tyramine, synthesized p-tyramine is predominantly excreted in the urine, and p-tyramine synthesis is modulated by the arterial delivery of p-tyrosine to the kidney

  18. Polyphenolics isolated from virgin coconut oil inhibits adjuvant induced arthritis in rats through antioxidant and anti-inflammatory action.

    Science.gov (United States)

    Vysakh, A; Ratheesh, M; Rajmohanan, T P; Pramod, C; Premlal, S; Girish kumar, B; Sibi, P I

    2014-05-01

    We evaluated the protective efficacy of the polyphenolic fraction from virgin coconut oil (PV) against adjuvant induced arthritic rats. Arthritis was induced by intradermal injection of complete Freund's adjuvant. The activities of inflammatory, antioxidant enzymes and lipid peroxidation were estimated. PV showed high percentage of edema inhibition at a dose of 80mg/kg on 21st day of adjuvant arthritis and is non toxic. The expression of inflammatory genes such as COX-2, iNOS, TNF-α and IL-6 and the concentration of thiobarbituric acid reactive substance were decreased by treatment with PV. Antioxidant enzymes were increased and on treatment with PV. The increased level of total WBC count and C-reactive protein in the arthritic animals was reduced in PV treated rats. Synovial cytology showed that inflammatory cells and reactive mesothelial cells were suppressed by PV. Histopathology of paw tissue showed less edema formation and cellular infiltration on supplementation with PV. Thus the results demonstrated the potential beneficiary effect of PV on adjuvant induced arthritis in rats and the mechanism behind this action is due to its antioxidant and anti-inflammatory effects. Copyright © 2014 Elsevier B.V. All rights reserved.

  19. The analgesic agent tapentadol inhibits calcitonin gene-related peptide release from isolated rat brainstem via a serotonergic mechanism.

    Science.gov (United States)

    Greco, Maria Cristina; Navarra, Pierluigi; Tringali, Giuseppe

    2016-01-15

    In this study we tested the hypothesis that tapentadol inhibits GGRP release from the rat brainstem through a mechanism mediated by the inhibition of NA reuptake; as a second alternative hypothesis, we investigated whether tapentadol inhibits GGRP release via the inhibition of 5-HT reuptake. Rat brainstems were explanted and incubated in short-term experiments. CGRP released in the incubation medium was taken as a marker of CGRP release from the central terminals of trigeminal neurons within the brainstem. CGRP levels were measured by radioimmunoassay under basal conditions or in the presence of tapentadol; NA, 5-HT, clonidine, yohimbine and ondansetron were used as pharmacological tools to investigate the action mechanism of tapentadol. The α2-antagonist yohimbine failed to counteract the effects of tapentadol. Moreover, neither NA nor the α2-agonist clonidine per se inhibited K(+)-stimulated CGRP release, thereby indicating that the effects of tapentadol are nor mediated through the block of NA reuptake. Further experiments showed that 5-HT and tramadol, which inhibits both NA and 5-HT reuptake, significantly reduced K(+)-stimulated CGRP release. Moreover, the 5-HT3 antagonist ondansetron was able to counteract the effects of tapentadol in this system. This study provided pharmacological evidence that tapentadol inhibits stimulated CGRP release from the rat brainstem in vitro through a mechanism involving an increase in 5-HT levels in the system and the subsequent activation of 5-HT3 receptors. Copyright © 2015 Elsevier Inc. All rights reserved.

  20. Social Isolation During Postweaning Development Causes Hypoactivity of Neurons in the Medial Nucleus of the Male Rat Amygdala

    Science.gov (United States)

    Adams, Thomas; Rosenkranz, J Amiel

    2016-01-01

    Children exposed to neglect or social deprivation are at heightened risk for psychiatric disorders and abnormal social patterns as adults. There is also evidence that prepubertal neglect in children causes abnormal metabolic activity in several brain regions, including the amygdala area. The medial nucleus of the amygdala (MeA) is a key region for performance of social behaviors and still undergoes maturation during the periadolescent period. As such, the normal development of this region may be disrupted by social deprivation. In rodents, postweaning social isolation causes a range of deficits in sexual and agonistic behaviors that normally rely on the posterior MeA (MeAp). However, little is known about the effects of social isolation on the function of MeA neurons. In this study, we tested whether postweaning social isolation caused abnormal activity of MeA neurons. We found that postweaning social isolation caused a decrease of in vivo firing activity of MeAp neurons, and reduced drive from excitatory afferents. In vitro electrophysiological studies found that postweaning social isolation caused a presynaptic impairment of excitatory input to the dorsal MeAp, but a progressive postsynaptic reduction of membrane excitability in the ventral MeAp. These results demonstrate discrete, subnucleus-specific effects of social deprivation on the physiology of MeAp neurons. This pathophysiology may contribute to the disruption of social behavior after developmental social deprivation, and may be a novel target to facilitate the treatment of social disorders. PMID:26677945

  1. Social Isolation During Postweaning Development Causes Hypoactivity of Neurons in the Medial Nucleus of the Male Rat Amygdala.

    Science.gov (United States)

    Adams, Thomas; Rosenkranz, J Amiel

    2016-06-01

    Children exposed to neglect or social deprivation are at heightened risk for psychiatric disorders and abnormal social patterns as adults. There is also evidence that prepubertal neglect in children causes abnormal metabolic activity in several brain regions, including the amygdala area. The medial nucleus of the amygdala (MeA) is a key region for performance of social behaviors and still undergoes maturation during the periadolescent period. As such, the normal development of this region may be disrupted by social deprivation. In rodents, postweaning social isolation causes a range of deficits in sexual and agonistic behaviors that normally rely on the posterior MeA (MeAp). However, little is known about the effects of social isolation on the function of MeA neurons. In this study, we tested whether postweaning social isolation caused abnormal activity of MeA neurons. We found that postweaning social isolation caused a decrease of in vivo firing activity of MeAp neurons, and reduced drive from excitatory afferents. In vitro electrophysiological studies found that postweaning social isolation caused a presynaptic impairment of excitatory input to the dorsal MeAp, but a progressive postsynaptic reduction of membrane excitability in the ventral MeAp. These results demonstrate discrete, subnucleus-specific effects of social deprivation on the physiology of MeAp neurons. This pathophysiology may contribute to the disruption of social behavior after developmental social deprivation, and may be a novel target to facilitate the treatment of social disorders.

  2. Cardioprotective effect of magnetic hydrogel nanocomposite loaded N,α-L-rhamnopyranosyl vincosamide isolated from Moringa oleifera leaves against doxorubicin-induced cardiac toxicity in rats: in vitro and in vivo studies.

    Science.gov (United States)

    Cheraghi, Mostafa; Namdari, Mehrdad; Daraee, Hadis; Negahdari, Babak

    2017-06-01

    Cardioprotective effect of N, α-L-rhamnopyranosyl vincosamide (VR), isolated from the leaves of Moringa oleifera plant in doxorubicin (Dox)-induced cardiac toxicity rats was evaluated. Twelve (12) rats were randomly selected into three groups; two rats received distilled water in the control group, five rats in group I received varying concentration of VR treatment, and group II containing five rats received varying concentration of VR-loaded magnetic hydrogel nanocomposite. Malondialdehyde (MDA), glutathione peroxidase (GSH) and superoxide dismutase (SOD) enzymes activities level were analysed after two weeks. In addition, the expression of three heart failure markers; beta major histocompatibility complex (β-MHC), atrial natriuretic peptide (ANP), and B type natriuretic peptide (BNP) were also evaluated. It was observed that the level of these markers expression decreases with an increase in VR concentration (p < 0.05). The reduced GSH and SOD level were increased after VR administration, this extract also reduced the initially increased MDA level in cardiac tissue. Pharmacokinetic parameters evaluation showed that nanogel treated rats possesses a significantly increased VR plasma concentration, C max , K el , t ½(a), t ½(el), K a and AUC. The result of this study indicated that VR may help to lower the dosage level, and reduces the treatment course in cardiovascular diseases (CVD). Our conclusion proposes the cardio-protective ability of the isolated VR and its beneficial effect via free radical scavenging properties.

  3. The cardioprotective effect of vanillic acid on hemodynamic parameters, malondialdehyde, and infarct size in ischemia-reperfusion isolated rat heart exposed to PM10

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    Esmat Radmanesh

    2017-07-01

    Full Text Available Objective(s: Particulate matter (PM exposure can promote cardiac ischemia and myocardial damage. The effects of PM10 on hemodynamic parameters, lipid peroxidation, and infarct size induced by ischemia-reperfusion injury and the protective effects of vanillic acid (VA in isolated rat heart were investigated. Materials and Methods: Eighty male Wistar rats (250–300 g were divided into 8 groups (n=10: Control, Sham, VAc, VA, PMa (0.5 mg/kg PM, intratracheal instillation, PMb (2.5 mg/kg PM, intratracheal instillation, PMc (5 mg/kg PM, intratracheal instillation, and PMc + VA (5 mg/kg PM, intratracheal instillation; and 10 mg/kg vanillic acid, gavage for 10 days. PM10 was instilled into the trachea in two stages, within 48 hr. After isolating the hearts and transfer to a Langendorff apparatus, hearts were subjected to 30 min ischemia and 60 min reperfusion. Hemodynamic parameters (±dp/dt, LVSP, LVDP, and RPP, production of lipid peroxidation (MDA, and infarct size were assessed. Results: A significant decrease in ±dp/dt, LVSP, LVDP and RPP occurred in PM groups. A significant increase in MDA and myocardial infarct size occurred in PM groups. A significant increase in LVDP, LVSP, ±dp/dt, RPP and decrease in infarct size, MDA, and myocardial dysfunction was observed in groups that received vanillic acid after ischemia–reperfusion. Conclusion: It was demonstrated that PM10 increases MDA, as well as the percentage of cardiac infarct size, and has negative effects on hemodynamic parameters. This study suggests that vanillic acid may serve as an adjunctive treatment in delaying the progression of ischemic heart disease.

  4. Cytotoxic effects of psychotropic benzofuran derivatives, N-methyl-5-(2-aminopropyl)benzofuran and its N-demethylated derivative, on isolated rat hepatocytes.

    Science.gov (United States)

    Nakagawa, Yoshio; Suzuki, Toshinari; Tada, Yukie; Inomata, Akiko

    2017-03-01

    The novel psychoactive compounds derived from amphetamine have been illegally abused as recreational drugs, some of which are known to be hepatotoxic in humans and experimental animals. The cytotoxic effects and mechanisms of 5-(2-aminopropyl)benzofuran (5-APB) and N-methyl-5-(2-aminopropyl)benzofuran (5-MAPB), both of which are benzofuran analogues of amphetamine, and 3,4-methylenedioxy-N-methamphetamine (MDMA) were studied in freshly isolated rat hepatocytes. 5-MAPB caused not only concentration-dependent (0-4.0 mm) and time-dependent (0-3 h) cell death accompanied by the depletion of cellular ATP and reduced glutathione and protein thiol levels, but also accumulation of oxidized glutathione. Of the other analogues examined at a concentration of 4 mm, 5-MAPB/5-APB-induced cytotoxicity with the production of reactive oxygen species and loss of mitochondrial membrane potential was greater than that induced by MDMA. In isolated rat liver mitochondria, the benzofurans resulted in a greater increase in the rate of state 4 oxygen consumption than did MDMA, with a decrease in the rate of state 3 oxygen consumption. Furthermore, the benzofurans caused more of a rapid mitochondrial swelling dependent on the mitochondrial permeability transition than MDMA. 5-MAPB at a weakly toxic level (1 mm) was metabolized slowly: levels of 5-MAPB and 5-APB were approximately 0.9 mm and 50 μm, respectively, after 3 h incubation. Taken collectively, these results indicate that mitochondria are target organelles for the benzofuran analogues and MDMA, which elicit cytotoxicity through mitochondrial failure, and the onset of cytotoxicity may depend on the initial and/or residual concentrations of 5-MAPB rather than on those of its metabolite 5-APB. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

  5. Lipid Emulsion Inhibits Vasodilation Induced by a Toxic Dose of Bupivacaine via Attenuated Dephosphorylation of Myosin Phosphatase Target Subunit 1 in Isolated Rat Aorta

    Science.gov (United States)

    Ok, Seong-Ho; Byon, Hyo-Jin; Kwon, Seong-Chun; Park, Jungchul; Lee, Youngju; Hwang, Yeran; Baik, Jiseok; Choi, Mun-Jeoung; Sohn, Ju-Tae

    2015-01-01

    Lipid emulsions are widely used for the treatment of systemic toxicity that arises from local anesthetics. The goal of this in vitro study was to examine the cellular mechanism associated with the lipid emulsion-mediated attenuation of vasodilation induced by a toxic dose of bupivacaine in isolated endothelium-denuded rat aorta. The effects of lipid emulsion on vasodilation induced by bupivacaine, mepivacaine, and verapamil were assessed in isolated aorta precontracted with phenylephrine, the Rho kinase stimulant NaF, and the protein kinase C activator phorbol 12,13-dibutyrate (PDBu). The effects of Rho kinase inhibitor Y-27632 on contraction induced by phenylephrine or NaF were assessed. The effects of bupivacaine on intracellular calcium concentrations ([Ca2+]i) and tension induced by NaF were simultaneously measured. The effects of bupivacaine alone and lipid emulsion plus bupivacaine on myosin phosphatase target subunit 1 (MYPT1) phosphorylation induced by NaF were examined in rat aortic vascular smooth muscle cells. In precontracted aorta, the lipid emulsion attenuated bupivacaine-induced vasodilation but had no effect on mepivacaine-induced vasodilation. Y-27632 attenuated contraction induced by either phenylephrine or NaF. The lipid emulsion attenuated verapamil-induced vasodilation. Compared with phenylephrine-induced precontracted aorta, bupivacaine-induced vasodilation was slightly attenuated in NaF-induced precontracted aorta. The magnitude of the bupivacaine-induced vasodilation was higher than that of a bupivacaine-induced decrease in [Ca2+]i. Bupivacaine attenuated NaF-induced MYPT1 phosphorylation, whereas lipid emulsion pretreatment attenuated the bupivacaine-induced inhibition of MYPT1 phosphorylation induced by NaF. Taken together, these results suggest that lipid emulsions attenuate bupivacaine-induced vasodilation via the attenuation of inhibition of MYPT1 phosphorylation evoked by NaF. PMID:26664257

  6. The Relaxant Effect of Seed's Essential Oil and Oleo-Gum-Resin of Ferula Assa-Foetida on Isolated Rat's Ileum.

    Science.gov (United States)

    Bagheri, Sm; Hejazian, Sh; Dashti-R, Mh

    2014-03-01

    In Iranian folk medicine, several plants are used for treatment of gastrointestinal disorders, such as diarrhea and spasm. One of these herbal medications are the essential oil yielded from seeds of Ferula assa-foetida L. and an oleo-gum-resin known as asafetida, which is exudated from its root. F. assa-foetida grows wildly in south and central mountains of Iran. In this study, relaxant effect of asafoetida and seed's essential oil of F. assa-foetida was investigated in isolated rat's ileum in three doses. A total of 5 cm of ileum was removed and sets for recording its isotonic contractions. The amplitude of contractions induced by different doses of asafoetida and essential oil before and after exposing the specimens with cumulative logarithmic concentrations of acetylcholine (Ach) was evaluated. The relaxant effect of asafoetida and seed's essential oil of F. assa-foetida was investigated in isolated rat's ileum in three doses (0.1 0.2 and 0.3%). All statistical analysis was by GraphPad Prism 5 (San Diego, California) and comparisons were made by means of the analysis of variances followed by Tukey's test. The statistical significance was considered as P essential oil has significant antispasmodic action against cumulative concentrations of 10(-12) up to 10(-2) M Ach. In spasmolytic evaluation, our findings showed that the essential oil derived from F. assa-foetida seed in concentrations of 0.2% and 0.3% significantly reduced Ach (10(-4) M) induced contractions. Exposure to the 0.2% and 0.3% asafoetida, reduced the percentage of maximum contraction induced by 10(-4) M Ach to 43% and 12% respectively, which this reduction was statistically significant. The results of the present study, supports the traditional claim of asafoetida as an antispasmodic therapeutic.

  7. Morphological, molecular and functional differences of adult bone marrow- and adipose-derived stem cells isolated from rats of different ages

    Energy Technology Data Exchange (ETDEWEB)

    Mantovani, Cristina [Blond McIndoe Laboratories, School of Biomedicine, The University of Manchester, Room 3,106 Stopford Building, Oxford Road, Manchester M13 9PT, Academic Health Science Centre, Faculty of Medicine and Human Sciences (United Kingdom); Department of Integrative Medical Biology and Surgical and Perioperative Science, Umea University, Umea (Sweden); Department of Surgical and Perioperative Science, Umea University, Umea (Sweden); Raimondo, Stefania [Dipartimento di Scienze Cliniche e Biologiche, University of Turin (Italy); Haneef, Maryam S. [Blond McIndoe Laboratories, School of Biomedicine, The University of Manchester, Room 3,106 Stopford Building, Oxford Road, Manchester M13 9PT, Academic Health Science Centre, Faculty of Medicine and Human Sciences (United Kingdom); Geuna, Stefano [Dipartimento di Scienze Cliniche e Biologiche, University of Turin (Italy); Terenghi, Giorgio [Blond McIndoe Laboratories, School of Biomedicine, The University of Manchester, Room 3,106 Stopford Building, Oxford Road, Manchester M13 9PT, Academic Health Science Centre, Faculty of Medicine and Human Sciences (United Kingdom); Shawcross, Susan G., E-mail: sue.shawcross@manchester.ac.uk [Blond McIndoe Laboratories, School of Biomedicine, The University of Manchester, Room 3,106 Stopford Building, Oxford Road, Manchester M13 9PT, Academic Health Science Centre, Faculty of Medicine and Human Sciences (United Kingdom); Wiberg, Mikael [Department of Integrative Medical Biology and Surgical and Perioperative Science, Umea University, Umea (Sweden); Department of Surgical and Perioperative Science, Umea University, Umea (Sweden)

    2012-10-01

    Adult mesenchymal stem cells have self-renewal and multiple differentiation potentials, and play important roles in regenerative medicine. However, their use may be limited by senescence or age of the donor, leading to changes in stem cell functionality. We investigated morphological, molecular and functional differences between bone marrow-derived (MSC) and adipose-derived (ASC) stem cells isolated from neonatal, young and old rats compared to Schwann cells from the same animals. Immunocytochemistry, RT-PCR, proliferation assays, western blotting and transmission electron microscopy were used to investigate expression of senescence markers. Undifferentiated and differentiated ASC and MSC from animals of different ages expressed Notch-2 at similar levels; protein-38 and protein-53 were present in all groups of cells with a trend towards increased levels in cells from older animals compared to those from neonatal and young rats. Following co-culture with adult neuronal cells, dMSC and dASC from animals of all ages elicited robust neurite outgrowth. Mitotracker{sup Registered-Sign} staining was consistent with ultrastructural changes seen in the mitochondria of cells from old rats, indicative of senescence. In conclusion, this study showed that although the cells from aged animals expressed markers of senescence, aged MSC and ASC differentiated into SC-like cells still retain potential to support axon regeneration. -- Highlights: Black-Right-Pointing-Pointer Aged MSC and ASC differentiated into Schwann-like cells support axon regeneration. Black-Right-Pointing-Pointer p53 expression does not appreciably influence the biology of Schwann or stem cells. Black-Right-Pointing-Pointer Notch 2 expression was similar in cells derived from animals of different ages. Black-Right-Pointing-Pointer Proliferation rates of dMSC varied little over time or with animal age.

  8. Morphological, molecular and functional differences of adult bone marrow- and adipose-derived stem cells isolated from rats of different ages

    International Nuclear Information System (INIS)

    Mantovani, Cristina; Raimondo, Stefania; Haneef, Maryam S.; Geuna, Stefano; Terenghi, Giorgio; Shawcross, Susan G.; Wiberg, Mikael

    2012-01-01

    Adult mesenchymal stem cells have self-renewal and multiple differentiation potentials, and play important roles in regenerative medicine. However, their use may be limited by senescence or age of the donor, leading to changes in stem cell functionality. We investigated morphological, molecular and functional differences between bone marrow-derived (MSC) and adipose-derived (ASC) stem cells isolated from neonatal, young and old rats compared to Schwann cells from the same animals. Immunocytochemistry, RT-PCR, proliferation assays, western blotting and transmission electron microscopy were used to investigate expression of senescence markers. Undifferentiated and differentiated ASC and MSC from animals of different ages expressed Notch-2 at similar levels; protein-38 and protein-53 were present in all groups of cells with a trend towards increased levels in cells from older animals compared to those from neonatal and young rats. Following co-culture with adult neuronal cells, dMSC and dASC from animals of all ages elicited robust neurite outgrowth. Mitotracker ® staining was consistent with ultrastructural changes seen in the mitochondria of cells from old rats, indicative of senescence. In conclusion, this study showed that although the cells from aged animals expressed markers of senescence, aged MSC and ASC differentiated into SC-like cells still retain potential to support axon regeneration. -- Highlights: ► Aged MSC and ASC differentiated into Schwann-like cells support axon regeneration. ► p53 expression does not appreciably influence the biology of Schwann or stem cells. ► Notch 2 expression was similar in cells derived from animals of different ages. ► Proliferation rates of dMSC varied little over time or with animal age.

  9. Carbon-14 tracer studies in the metabolism of isolated rat-liver parenchymal cells under conditions of gluconeogenesis from lactate and pyruvate

    International Nuclear Information System (INIS)

    Muellhofer, G.; Mueller, C.; Stetten, C. von; Gruber, E.

    1977-01-01

    In rat liver perfusion experiments under conditions of gluconeogenesis from lactate and pyruvate, 14 C-labeling patterns of metabolites with (1- 14 C)-labeled and (2- 14 C)-labeled lactate or pyruvate. [ 14 C]bicarbonate and [1- 14 C]octanoate as tracers have been obtained which do not agree with generally assumed reaction schemes. The experiments have been repeated with incubations of isolated rat-liver parenchymal cells. The results demonstrate that the discrepancies between expected and analysed 14 C-labeling patterns of metabolites were still existent. From this observation, it may be concluded that 14 C-labelling patterns of metabolites are indicative for the existence of still unknown metabolic relationships in liver parenchymal cells. Furthermore, the results of o