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Sample records for cd1d-dependent antagonist inhibits

  1. CD1d-dependent NKT cells play a protective role in acute and chronic arthritis models by ameliorating antigen-specific Th1 responses

    DEFF Research Database (Denmark)

    Teige, Anna; Bockermann, Robert; Hasan, Maruf;

    2010-01-01

    A protective and anti-inflammatory role for CD1d-dependent NKT cells (NKTs) has been reported in experimental and human autoimmune diseases. However, their role in arthritis has been unclear, with conflicting reports of CD1d-dependent NKTs acting both as regulatory and disease-promoting cells...... in arthritis. These differing modes of action might be due to genetic differences of inbred mice and incomplete backcrossing of gene-modified mice. We therefore put special emphasis on controlling the genetic backgrounds of the mice used. Additionally, we used two different murine arthritis models, Ag......-induced arthritis (AIA) and collagen-induced arthritis (CIA), to evaluate acute and chronic arthritis in CD1d knockout mice and mice depleted of NK1.1(+) cells. CD1d-deficient mice developed more severe AIA compared with wild-type littermates, with a higher degree of inflammation and proteoglycan depletion. Chronic...

  2. A Selective TSH Receptor Antagonist Inhibits Stimulation of Thyroid Function in Female Mice

    OpenAIRE

    Neumann, Susanne; Nir, Eshel A; Eliseeva, Elena; Huang, Wenwei; Marugan, Juan; Xiao, Jingbo; Dulcey, Andrés E.; Gershengorn, Marvin C.

    2013-01-01

    Because the TSH receptor (TSHR) plays an important role in the pathogenesis of thyroid disease, a TSHR antagonist could be a novel treatment. We attempted to develop a small molecule, drug-like antagonist of TSHR signaling that is selective and active in vivo. We synthesized NCGC00242364 (ANTAG3) by chemical modification of a previously reported TSHR antagonist. We tested its potency, efficacy, and selectivity in a model cell system in vitro by measuring its activity to inhibit stimulation of...

  3. Inhibition of radiation-induced polyuria by histamine receptor antagonists

    International Nuclear Information System (INIS)

    In previous studies the authors have demonstrated that gamma radiation results in polyuria, which is preceded by polydypsia. This suggests that the increased thirst elicited by radiation causes increased urinary volume (UV). Histamine, which is released following radiation exposure, also elicits drinking by nonirradiated rats when administered exogenously. In this study the authors have investigated both the role of water deprivation and the effect of histamine receptor antagonists (HRA) on radiation-induced polyuria. Sprague-Dawley rats were housed individually in metabolic cages. Water was allowed ad libitum except in deprivation experiments where water was removed for 24 hr immediately following radiation. Cimetidine (CIM), an H2 HRA, and dexbromopheniramine (DXB), an H1 HRA, were administered i.p. (16 and 1 mg/kg, respectively) 30 min prior to irradiation (950 rads from a cobalt source). UV was determined at 24-hr intervals for 3 days preceding irradiation and 24 hr postirradiation. UV in DXB treated rats was significantly reduced 24 hr postirradiation (CON = 427 +/- 54%; DXB = 247 +/- 39% of preirradiated CON) compared to postirradiation control values. CIM did not affect postirradiation UV. These data suggest that radiation-induced polyuria is caused by polydypsia which is, in part, mediated by histamine induced by an H1 receptor

  4. Dual-function CXCR4 Antagonist Polyplexes to Deliver Gene Therapy and Inhibit Cancer Cell Invasion**

    OpenAIRE

    Li, Jing; Zhu, Yu; Hazeldine, Stuart T.; Li, Chunying; Oupický, David

    2012-01-01

    A bicyclam-based biodegradable polycation with CXCR4 antagonistic activity was developed with potential for combined drug/gene cancer therapies. The dual-function polycation prevents cancer cell invasion by inhibiting CXCL12 stimulated CXCR4 activation, while at the same time efficiently and safely delivers plasmid DNA into cancer cells.

  5. Inhibition of rabbit platelet activation in vitro by antagonists of platelet-activating factor (PAF)

    International Nuclear Information System (INIS)

    The authors used washed, [3H]serotonin-labeled rabbit platelets to study the in vitro aggregation and secretion responses induced by graded doses of PAF in the presence or absence of specific antagonists of PAF. These antagonists included CV-3988, L-652,731, triazolam and alprazolam. Platelets were pretreated with either an antagonist or the appropriate diluent for 60 sec prior to the addition of PAF (2 x 10-10 to 2 x 10-7 M). Aggregation was monitored continuously and recorded as the height of the aggregation tracing at 60 sec post-PAF. Secretion of [3H]-serotonin was measured in a sample of the platelets removed at 60 sec post-PAF. When 2 x 10-10 M PAF was used as the stimulus, the concentration of antagonist needed for 50% inhibition (IC50) of secretion was obtained at 0.05 μM, 0.15 μM, 0.6 μM and 2.5 μM, respectively, for L-652,731, CV-3988, triazolam and alprazolam. The corresponding IC50 for aggregation was obtained at 0.2 μM, 0.1 μM, 1.5 μM and 6.5 μM, respectively. The inhibitory effects of these antagonists could be overcome by increasing the dose of PAF used. Although all of the antagonists were capable of completely inhibiting platelet aggregation and secretion, L-652,731 was the most potent PAF antagonist on a molar basis

  6. A RNA antagonist of hypoxia-inducible factor-1alpha, EZN-2968, inhibits tumor cell growth

    DEFF Research Database (Denmark)

    Greenberger, Lee M; Horak, Ivan D; Filpula, David; Sapra, Puja; Westergaard, Majken; Frydenlund, Henrik F; Albaek, Charlotte; Schrøder, Henrik; Ørum, Henrik

    2008-01-01

    pathways, is associated with poor prognosis in many types of cancer. Therefore, down-regulation of HIF-1alpha protein by RNA antagonists may control cancer growth. EZN-2968 is a RNA antagonist composed of third-generation oligonucleotide, locked nucleic acid, technology that specifically binds and inhibits......-regulation of endogenous HIF-1alpha and vascular endothelial growth factor in the liver. The effect can last for days after administration of single dose of EZN-2968 and is associated with long residence time of locked nucleic acid in certain tissues. In efficacy studies, tumor reduction was found in nude mice...

  7. 5-HT2B Receptor Antagonists Inhibit Fibrosis and Protect from RV Heart Failure

    Directory of Open Access Journals (Sweden)

    Wiebke Janssen

    2015-01-01

    Full Text Available Objective. The serotonin (5-HT pathway was shown to play a role in pulmonary hypertension (PH, but its functions in right ventricular failure (RVF remain poorly understood. The aim of the current study was to investigate the effects of Terguride (5-HT2A and 2B receptor antagonist or SB204741 (5-HT2B receptor antagonist on right heart function and structure upon pulmonary artery banding (PAB in mice. Methods. Seven days after PAB, mice were treated for 14 days with Terguride (0.2 mg/kg bid or SB204741 (5 mg/kg day. Right heart function and remodeling were assessed by right heart catheterization, magnetic resonance imaging (MRI, and histomorphometric methods. Total secreted collagen content was determined in mouse cardiac fibroblasts isolated from RV tissues. Results. Chronic treatment with Terguride or SB204741 reduced right ventricular fibrosis and showed improved heart function in mice after PAB. Moreover, 5-HT2B receptor antagonists diminished TGF-beta1 induced collagen synthesis of RV cardiac fibroblasts in vitro. Conclusion. 5-HT2B receptor antagonists reduce collagen deposition, thereby inhibiting right ventricular fibrosis. Chronic treatment prevented the development and progression of pressure overload-induced RVF in mice. Thus, 5-HT2B receptor antagonists represent a valuable novel therapeutic approach for RVF.

  8. A selective TSH receptor antagonist inhibits stimulation of thyroid function in female mice.

    Science.gov (United States)

    Neumann, Susanne; Nir, Eshel A; Eliseeva, Elena; Huang, Wenwei; Marugan, Juan; Xiao, Jingbo; Dulcey, Andrés E; Gershengorn, Marvin C

    2014-01-01

    Because the TSH receptor (TSHR) plays an important role in the pathogenesis of thyroid disease, a TSHR antagonist could be a novel treatment. We attempted to develop a small molecule, drug-like antagonist of TSHR signaling that is selective and active in vivo. We synthesized NCGC00242364 (ANTAG3) by chemical modification of a previously reported TSHR antagonist. We tested its potency, efficacy, and selectivity in a model cell system in vitro by measuring its activity to inhibit stimulation of cAMP production stimulated by TSH, LH, or FSH. We tested the in vivo activity of ANTAG3 by measuring its effects to lower serum free T4 and thyroid gene expression in female BALB/c mice continuously treated with ANTAG3 for 3 days and given low doses of TRH continuously or stimulated by a single administration of a monoclonal thyroid-stimulating antibody M22. ANTAG3 was selective for TSHR inhibition; half-maximal inhibitory doses were 2.1 μM for TSHR and greater than 30 μM for LH and FSH receptors. In mice treated with TRH, ANTAG3 lowered serum free T4 by 44% and lowered mRNAs for sodium-iodide cotransporter and thyroperoxidase by 75% and 83%, respectively. In mice given M22, ANTAG3 lowered serum free T4 by 38% and lowered mRNAs for sodium-iodide cotransporter and thyroperoxidase by 73% and 40%, respectively. In conclusion, we developed a selective TSHR antagonist that is effective in vivo in mice. This is the first report of a small-molecule TSHR antagonist active in vivo and may lead to a drug to treat Graves' disease. PMID:24169564

  9. Inhibition of Acetylcholinesterase Modulates NMDA Receptor Antagonist Mediated Alterations in the Developing Brain

    Directory of Open Access Journals (Sweden)

    Ivo Bendix

    2014-03-01

    Full Text Available Exposure to N-methyl-d-aspartate (NMDA receptor antagonists has been demonstrated to induce neurodegeneration in newborn rats. However, in clinical practice the use of NMDA receptor antagonists as anesthetics and sedatives cannot always be avoided. The present study investigated the effect of the indirect cholinergic agonist physostigmine on neurotrophin expression and the extracellular matrix during NMDA receptor antagonist induced injury to the immature rat brain. The aim was to investigate matrix metalloproteinase (MMP-2 activity, as well as expression of tissue inhibitor of metalloproteinase (TIMP-2 and brain-derived neurotrophic factor (BDNF after co-administration of the non-competitive NMDA receptor antagonist MK801 (dizocilpine and the acetylcholinesterase (AChE inhibitor physostigmine. The AChE inhibitor physostigmine ameliorated the MK801-induced reduction of BDNF mRNA and protein levels, reduced MK801-triggered MMP-2 activity and prevented decreased TIMP-2 mRNA expression. Our results indicate that AChE inhibition may prevent newborn rats from MK801-mediated brain damage by enhancing neurotrophin-associated signaling pathways and by modulating the extracellular matrix.

  10. Cysteinyl Leukotriene Receptor Antagonists Inhibit Tumor Metastasis by Inhibiting Capillary Permeability

    OpenAIRE

    Nozaki, Masako; Yoshikawa, Masanobu; Ishitani, Kunihiko; Kobayashi, Hiroyuki; HOUKIN, KIYOHIRO; Imai, Kohzoh; Ito, Yoichiro; Muraki, Takamura

    2010-01-01

    We explored the possibility of the cysteinyl leukotriene receptor antagonists, pranlukast and montelukast, preventing tumor cell migration through both cerebral and peripheral capillaries. To study tumor cell migration through brain capillaries, male Fisher rats were cannulated via the cisterna magna under pentobarbital anesthesia. RCN9 cells labeled with a fluorescent marker PKH67 were intravenously administered following arachidonic acid administration into the subarachnoid space, and speci...

  11. Inhibition of the superantigenic activities of Staphylococcal enterotoxin A by an aptamer antagonist.

    Science.gov (United States)

    Wang, Kaiyu; Wu, Dong; Chen, Zhuang; Zhang, Xianhui; Yang, Xiangyue; Yang, Chaoyong James; Lan, Xiaopeng

    2016-09-01

    Staphylococcal enterotoxin A (SEA) is an important component of Staphylococcus aureus pathogenesis. SEA induces T lymphocytes activation and proliferation, resulting in the release of a large number of inflammatory cytokines. Blocking the toxic cascade triggered by SEA may be an effective strategy for the treatment of SEA-induced diseases. Through a systematic evolution of ligands by exponential enrichment process, we obtained an aptamer (S3) that could bind SEA with both high affinity and specificity, with a Kd value 36.93 ± 7.29 nM (n = 3). This aptamer antagonist effectively inhibited SEA-mediated human peripheral blood mononuclear cells proliferation and inflammatory cytokines (IFN-γ, TNF-α, IL-2 and IL-6) secretion. Moreover, PEGylated S3 significantly reduced mortality in murine lethal toxic shock models established by lipopolysaccharide-potentiated SEA. Therefore, this novel aptamer antagonist has the potential to become a new strategy for treating S. aureus infections and SEA-induced diseases. PMID:27179422

  12. GABAB Receptor Antagonist CGP46381 Inhibits Form-Deprivation Myopia Development in Guinea Pigs

    Directory of Open Access Journals (Sweden)

    Zhen-Ying Cheng

    2015-01-01

    Full Text Available The aim was to investigate the effects of the GABAB receptor antagonist, CGP46381, on form-deprivation myopia (FDM in guinea pigs. Twenty-four guinea pigs had monocular visual deprivation induced using a diffuser for 11 days (day 14 to 25. The deprived eyes were treated with daily subconjunctival injections (100 μl of either 2% CGP46381, 0.2% CGP46381, or saline or received no injection. The fellow eyes were left untreated. Another six animals received no treatment. At the start and end of the treatment period, ocular refractions were measured using retinoscopy and vitreous chamber depth (VCD and axial length (AL using A-scan ultrasound. All of the deprived eyes developed relative myopia (treated versus untreated eyes, P0.05. Subconjunctival injections of CGP46381 inhibit FDM development in guinea pigs in a dose-dependent manner.

  13. Dopamine receptor antagonist thioridazine inhibits tumor growth in a murine breast cancer model.

    Science.gov (United States)

    Yin, Tao; He, Sisi; Shen, Guobo; Ye, Tinghong; Guo, Fuchun; Wang, Yongsheng

    2015-09-01

    Neuropsychological factors have been shown to influence tumor progression and therapeutic response. The present study investigated the effect of the dopamine receptor antagonist thioridazine on murine breast cancer. The anti‑tumor efficacy of thioridazine was assessed using a murine breast cancer model. Cell apoptosis and proliferation were analyzed in vitro using flow cytometry (FCM) and the MTT assay, respectively. Western blot analysis was performed to assess Akt, phosphorylated (p)‑Akt, signal transducer and activator of transcription (STAT) 3, p‑STAT3 and p‑p65 in tumor cells following treatment with thioridazine. The Ki67 index and the number of terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL)‑positive apoptotic cells were assessed in the tumor sections. Thioridazine was found to reduce tumor growth, inhibit tumor cell proliferation and induce apoptosis in a dose‑ and time‑dependent manner in vitro. Thioridazine was also found to markedly inhibit tumor proliferation and induce tumor cell apoptosis in vivo as shown by the lower Ki67 index and increase in TUNEL‑positive cells. In addition, thioridazine was observed to inhibit the activation of the canonical nuclear factor κ‑light‑chain‑enhancer of activated B cells pathway and exert anti‑tumor effects by remodeling the tumor stroma, as well as inhibit angiogenesis in the tumor microenvironment. In conclusion, thioridazine was found to significantly inhibit breast tumor growth and the potential for thioridazine to be used in cancer therapy may be re‑evaluated and investigated in clinical settings. PMID:26095429

  14. ML-18 is a non-peptide bombesin receptor subtype-3 antagonist which inhibits lung cancer growth.

    Science.gov (United States)

    Moody, Terry W; Mantey, Samuel A; Moreno, Paola; Nakamura, Taichi; Lacivita, Enza; Leopoldo, Marcello; Jensen, Robert T

    2015-02-01

    Bombesin receptor subtype (BRS)-3 is a G protein coupled receptor (GPCR) for the bombesin (BB)-family of peptides. BRS-3 is an orphan GPCR and little is known of its physiological role due to the lack of specific agonists and antagonists. PD168368 is a nonpeptide antagonist for the neuromedin B (NMB) receptor (R) whereas PD176252 is a nonpeptide antagonist for the gastrin releasing peptide (GRP) R and NMBR but not BRS-3. Here nonpeptide analogs of PD176252 e.g. the S-enantiomer ML-18, and the R-enantiomer, EMY-98, were investigated as BRS-3 antagonists using lung cancer cells. ML-18 and EMY-98 inhibited specific (125)I-BA1 (DTyr-Gln-Trp-Ala-Val-βAla-His-Phe-Nle-NH2)BB(6-14) binding to NCI-H1299 lung cancer cells stably transfected with BRS-3 with IC50 values of 4.8 and >100μM, respectively. In contrast, ML-18 bound with lower affinity to the GRPR and NMBR with IC50 values of 16 and >100μM, respectively. ML-18 (16μM), but not its enantiomer EMY-98, inhibited the ability of 10nM BA1 to elevate cytosolic Ca(2+) in a reversible manner using lung cancer cells loaded with FURA2-AM. ML-18 (16μM), but not EMY-98, inhibited the ability of 100nM BA1 to cause tyrosine phosphorylation of the EGFR and ERK in lung cancer cells. ML-18 but not EMY-98 inhibited the proliferation of lung cancer cells. The results indicate that ML-18 is a nonpeptide BRS-3 antagonist that should serve as a template to improve potency and selectivity. PMID:25554218

  15. The Wnt antagonist Wif-1 interacts with CTGF and inhibits CTGF activity.

    Science.gov (United States)

    Surmann-Schmitt, Cordula; Sasaki, Takako; Hattori, Takako; Eitzinger, Nicole; Schett, Georg; von der Mark, Klaus; Stock, Michael

    2012-05-01

    Wnt inhibitory factor 1 (Wif-1) is a secreted antagonist of Wnt signalling. We recently demonstrated that this molecule is expressed predominantly in superficial layers of epiphyseal cartilage but also in bone and tendon. Moreover, we showed that Wif-1 is capable of binding to several cartilage-related Wnt ligands and interferes with Wnt3a-dependent Wnt signalling in chondrogenic cells. Here we provide evidence that the biological function of Wif-1 may not be confined to the modulation of Wnt signalling but appears to include the regulation of other signalling pathways. Thus, we show that Wif-1 physically binds to connective tissue growth factor (CTGF/CCN2) in vitro, predominantly by interaction with the C-terminal cysteine knot domain of CTGF. In vivo such an interaction appears also likely since the expression patterns of these two secreted proteins overlap in peripheral zones of epiphyseal cartilage. In chondrocytes CTGF has been shown to induce the expression of cartilage matrix genes such as aggrecan (Acan) and collagen2a1 (Col2a1). In this study we demonstrate that Wif-1 is capable to interfere with CTGF-dependent induction of Acan and Col2a1 gene expression in primary murine chondrocytes. Conversely, CTGF does not interfere with Wif-1-dependent inhibition of Wnt signalling. These results indicate that Wif-1 may be a multifunctional modulator of signalling pathways in the cartilage compartment. PMID:21928342

  16. Purinergic receptor antagonists inhibit odorant-mediated CREB phosphorylation in sustentacular cells of mouse olfactory epithelium.

    LENUS (Irish Health Repository)

    Dooley, Ruth

    2012-02-01

    BACKGROUND: Extracellular nucleotides have long been known to play neuromodulatory roles and to be involved in intercellular signalling. In the olfactory system, ATP is released by olfactory neurons, and exogenous ATP can evoke an increase in intracellular calcium concentration in sustentacular cells, the nonneuronal supporting cells of the olfactory epithelium. Here we investigate the hypothesis that olfactory neurons communicate with sustentacular cells via extracellular ATP and purinergic receptor activation. RESULTS: Here we show that exposure of mice to a mixture of odorants induced a significant increase in the levels of the transcription factor CREB phosphorylated at Ser-133 in the nuclei of both olfactory sensory neurons and sustentacular cells. This activation was dependent on adenylyl cyclase III-mediated olfactory signaling and on activation of P2Y purinergic receptors on sustentacular cells. Purinergic receptor antagonists inhibited odorant-dependent CREB phosphorylation specifically in the nuclei of the sustentacular cells. CONCLUSION: Our results point to a possible role for extracellular nucleotides in mediating intercellular communication between the neurons and sustentacular cells of the olfactory epithelium in response to odorant exposure. Maintenance of extracellular ionic gradients and metabolism of noxious chemicals by sustentacular cells may therefore be regulated in an odorant-dependent manner by olfactory sensory neurons.

  17. Purinergic receptor antagonists inhibit odorant-mediated CREB phosphorylation in sustentacular cells of mouse olfactory epithelium

    LENUS (Irish Health Repository)

    Dooley, Ruth

    2011-08-22

    Abstract Background Extracellular nucleotides have long been known to play neuromodulatory roles and to be involved in intercellular signalling. In the olfactory system, ATP is released by olfactory neurons, and exogenous ATP can evoke an increase in intracellular calcium concentration in sustentacular cells, the nonneuronal supporting cells of the olfactory epithelium. Here we investigate the hypothesis that olfactory neurons communicate with sustentacular cells via extracellular ATP and purinergic receptor activation. Results Here we show that exposure of mice to a mixture of odorants induced a significant increase in the levels of the transcription factor CREB phosphorylated at Ser-133 in the nuclei of both olfactory sensory neurons and sustentacular cells. This activation was dependent on adenylyl cyclase III-mediated olfactory signaling and on activation of P2Y purinergic receptors on sustentacular cells. Purinergic receptor antagonists inhibited odorant-dependent CREB phosphorylation specifically in the nuclei of the sustentacular cells. Conclusion Our results point to a possible role for extracellular nucleotides in mediating intercellular communication between the neurons and sustentacular cells of the olfactory epithelium in response to odorant exposure. Maintenance of extracellular ionic gradients and metabolism of noxious chemicals by sustentacular cells may therefore be regulated in an odorant-dependent manner by olfactory sensory neurons.

  18. Antagonists of IGF:Vitronectin Interactions Inhibit IGF-I-Induced Breast Cancer Cell Functions.

    Science.gov (United States)

    Kashyap, Abhishek S; Shooter, Gary K; Shokoohmand, Ali; McGovern, Jacqui; Sivaramakrishnan, Manaswini; Croll, Tristan I; Cane, Gaëlle; Leavesley, David I; Söderberg, Ola; Upton, Zee; Hollier, Brett G

    2016-07-01

    We provide proof-of-concept evidence for a new class of therapeutics that target growth factor:extracellular matrix (GF:ECM) interactions for the management of breast cancer. Insulin-like growth factor-I (IGF-I) forms multiprotein complexes with IGF-binding proteins (IGFBP) and the ECM protein vitronectin (VN), and stimulates the survival, migration and invasion of breast cancer cells. For the first time we provide physical evidence for IGFBP-3:VN interactions in breast cancer patient tissues; these interactions were predominantly localized to tumor cell clusters and in stroma surrounding tumor cells. We show that disruption of IGF-I:IGFBP:VN complexes with L(27)-IGF-II inhibits IGF-I:IGFBP:VN-stimulated breast cancer cell migration and proliferation in two- and three-dimensional assay systems. Peptide arrays screened to identify regions critical for the IGFBP-3/-5:VN and IGF-II:VN interactions demonstrated IGFBP-3/-5 and IGF-II binds VN through the hemopexin-2 domain, and VN binds IGFBP-3 at residues not involved in the binding of IGF-I to IGFBP-3. IGFBP-interacting VN peptides identified from these peptide arrays disrupted the IGF-I:IGFBP:VN complex, impeded the growth of primary tumor-like spheroids and, more importantly, inhibited the invasion of metastatic breast cancer cells in 3D assay systems. These studies provide first-in-field evidence for the utility of small peptides in antagonizing GF:ECM-mediated biologic functions and present data demonstrating the potential of these peptide antagonists as novel therapeutics. Mol Cancer Ther; 15(7); 1602-13. ©2016 AACR. PMID:27196774

  19. Inhibition by Isoptin (a calcium antagonist) of the mitogenic stimulation of lymphocytes prior to the S-phase

    International Nuclear Information System (INIS)

    Isoptin (α-isopropyl-α-(N-methyl-N-homoveratryl) -γ-amino-propyl-3,4-dimethoxyphenylacetonitril-hydrochloride) - a calcium antagonist - inhibited mitogenic stimulation of lymphocytes. Isoptin acted prior to the S-phase of the cell cycle but did not prevent the early events involved in triggering of cell mitosis. The drug seems to be a good tool for studying the relevance of the 'early events' assumed to be involved in lymphocyte stimulation. (author)

  20. Nitric oxide regulates antagonistically phagocytic and neurite outgrowth inhibiting capacities of microglia.

    Science.gov (United States)

    Scheiblich, Hannah; Bicker, Gerd

    2016-05-01

    Traumatic injury or the pathogenesis of some neurological disorders is accompanied by inflammatory cellular mechanisms, mainly resulting from the activation of central nervous system (CNS) resident microglia. Under inflammatory conditions, microglia up-regulate the inducible isoform of NOS (iNOS), leading to the production of high concentrations of the radical molecule nitric oxide (NO). At the onset of inflammation, high levels of microglial-derived NO may serve as a cellular defense mechanism helping to clear the damaged tissue and combat infection of the CNS by invading pathogens. However, the excessive overproduction of NO by activated microglia has been suggested to govern the inflammation-mediated neuronal loss causing eventually complete neurodegeneration. Here, we investigated how NO influences phagocytosis of neuronal debris by BV-2 microglia, and how neurite outgrowth of human NT2 model neurons is affected by microglial-derived NO. The presence of NO greatly increased microglial phagocytic capacity in a model of acute inflammation comprising lipopolysaccharide (LPS)-activated microglia and apoptotic neurons. Chemical manipulations suggested that NO up-regulates phagocytosis independently of the sGC/cGMP pathway. Using a transwell system, we showed that reactive microglia inhibit neurite outgrowth of human neurons via the generation of large amounts of NO over effective distances in the millimeter range. Application of a NOS blocker prevented the LPS-induced NO production, totally reversed the inhibitory effect of microglia on neurite outgrowth, but reduced the engulfment of neuronal debris. Our results indicate that a rather simple notion of treating excessive inflammation in the CNS by NO synthesis blocking agents has to consider functionally antagonistic microglial cell responses during pharmaceutic therapy. © 2015 Wiley Periodicals, Inc. Develop Neurobiol 76: 566-584, 2016. PMID:26264566

  1. Inhibition of Flavobacterium psychrophilum biofilm formation using a biofilm of the antagonist Pseudomonas fluorescens FF48

    OpenAIRE

    De la Fuente, Mery; Vidal, José M; Miranda, Claudio D; González, Gerardo; Urrutia, Homero

    2013-01-01

    The most important bacterial pathology currently occurring in Chilean freshwater salmon farming is the cold-water disease produced by the psychrotrophic bacteria Flavobacterium psychrophilum. The main aim of this study was to characterize the inhibitory activity of an antagonist strain on the formation of biofilms of a F. psychrophilum strain. The antagonistic strain Pseudomonas fluorescens FF48 was isolated from the sediment beneath the salmon cages of a freshwater Chilean salmon farm and wa...

  2. Inhibition of Luminescence and Virulence in the Black Tiger Prawn (Penaeus monodon) Pathogen Vibrio harveyi by Intercellular Signal Antagonists

    Science.gov (United States)

    Manefield, Michael; Harris, Lachlan; Rice, Scott A.; de Nys, Rocky; Kjelleberg, Staffan

    2000-01-01

    Expression of luminescence in the Penaeus monodon pathogen Vibrio harveyi is regulated by an intercellular quorum sensing mechanism involving the synthesis and detection of two signaling molecules, one of which is N-hydroxy butanoyl-l-homoserine lactone and the other of which is uncharacterized. Indirect evidence has suggested that virulence, associated with a toxic extracellular protein, and luminescence in V. harveyi are coregulated. In this study the effects of an acylated homoserine lactone antagonist produced by the marine alga Delisea pulchra on luminescence and toxin production in a virulent strain of V. harveyi were analyzed. Luminescence and toxin production were both inhibited by the signal antagonist at concentrations that had no impact on growth. Toxin production was found to be prematurely induced in V. harveyi cultures incubated in a 10% conditioned medium. Additionally, a significant reduction in the toxicity of concentrated supernatant extracts from V. harveyi cultures incubated in the presence of the signal antagonist, as measured by in vivo toxicity assays in mice and prawns, was observed. These results suggest that intercellular signaling antagonists have potential utility in the control of V. harveyi prawn infections. PMID:10788385

  3. Bicyclams, selective antagonists of the human chemokine receptor CXCR4, potently inhibit feline immunodeficiency virus replication

    NARCIS (Netherlands)

    Horzinek, M.C.; Egberink, H.F.; Clercq, E. de; Vliet, A.L.W. van; Balzarini, J.; Bridger, G.J.; Henson, G.; Schols, D.

    1999-01-01

    Bicyclams are low-molecular-weight anti-human immunodeficiency virus (HIV) agents that have been shown to act as potent and selective CXC chemokine receptor 4 (CXCR4) antagonists. Here, we demonstrate that bicyclams are potent inhibitors of feline immunodeficiency virus (FIV) replication when evalua

  4. CysLT1 leukotriene receptor antagonists inhibit the effects of nucleotides acting at P2Y receptors

    Science.gov (United States)

    Mamedova, Liaman; Capra, Valérie; Accomazzo, Maria Rosa; Gao, Zhan-Guo; Ferrario, Silvia; Fumagalli, Marta; Abbracchio, Maria P.; Rovati, G. Enrico; Jacobson, Kenneth A.

    2016-01-01

    Montelukast and pranlukast are orally active leukotriene receptor antagonists selective for the CysLT1 receptor. Conversely, the hP2Y1,2,4,6,11,12,13,14 receptors represent a large family of GPCRs responding to either adenine or uracil nucleotides, or to sugar-nucleotides. Montelukast and pranlukast were found to inhibit nucleotide-induced calcium mobilization in a human monocyte-macrophage like cell line, DMSO-differentiated U937 (dU937). Montelukast and pranlukast inhibited the effects of UTP with IC50 values of 7.7 and 4.3 μM, respectively, and inhibited the effects of UDP with IC50 values of 4.5 and 1.6 μM, respectively, in an insurmountable manner. Furthermore, ligand binding studies using [3H]LTD4 excluded the possibility of orthosteric nucleotide binding to the CysLT1 receptor. dU937 cells were shown to express P2Y2, P2Y4, P2Y6, P2Y11, P2Y13 and P2Y14 receptors. Therefore, these antagonists were studied functionally in a heterologous expression system for the human P2Y receptors. In 1321N1 astrocytoma cells stably expressing human P2Y1,2,4,6 receptors, CysLT1 antagonists inhibited both the P2Y agonist-induced activation of phospholipase C and intracellular Ca2+ mobilization. IC50 values at P2Y1 and P2Y6 receptors were astrocytoma cells expressing an endogenous M3 muscarinic receptor, 10 μM montelukast had no effect on the carbachol-induced rise in intracellular Ca2+. These data demonstrated that CysLT1 receptor antagonists interact functionally with signaling pathways of P2Y receptors, and this should foster the study of possible implications for the clinical use of these compounds in asthma or in other inflammatory conditions. PMID:16280122

  5. The antidepressant 5-HT2A receptor antagonists pizotifen and cyproheptadine inhibit serotonin-enhanced platelet function.

    Directory of Open Access Journals (Sweden)

    Olivia A Lin

    Full Text Available There is considerable interest in defining new agents or targets for antithrombotic purposes. The 5-HT2A receptor is a G-protein coupled receptor (GPCR expressed on many cell types, and a known therapeutic target for many disease states. This serotonin receptor is also known to regulate platelet function. Thus, in our FDA-approved drug repurposing efforts, we investigated the antiplatelet activity of cyproheptadine and pizotifen, two antidepressant 5-HT2A Receptor antagonists. Our results revealed that cyproheptadine and pizotifen reversed serotonin-enhanced ADP-induced platelet aggregation in vitro and ex vivo. And the inhibitory effects of these two agents were found to be similar to that of EMD 281014, a 5-HT2A Receptor antagonist under development. In separate experiments, our studies revealed that these 5-HT2A receptor antagonists have the capacity to reduce serotonin-enhanced ADP-induced elevation in intracellular calcium levels and tyrosine phosphorylation. Using flow cytometry, we also observed that cyproheptadine, pizotifen, and EMD 281014 inhibited serotonin-enhanced ADP-induced phosphatidylserine (PS exposure, P-selectin expression, and glycoprotein IIb-IIIa activation. Furthermore, using a carotid artery thrombosis model, these agents prolonged the time for thrombotic occlusion in mice in vivo. Finally, the tail-bleeding time was investigated to assess the effect of cyproheptadine and pizotifen on hemostasis. Our findings indicated prolonged bleeding time in both cyproheptadine- and pizotifen-treated mice. Notably, the increases in occlusion and bleeding times associated with these two agents were comparable to that of EMD 281014, and to clopidogrel, a commonly used antiplatelet drug, again, in a fashion comparable to clopidogrel and EMD 281014. Collectively, our data indicate that the antidepressant 5-HT2A antagonists, cyproheptadine and pizotifen do exert antiplatelet and thromboprotective effects, but similar to clopidogrel and

  6. Scorpion venom-induced neutrophilia is inhibited by a PAF receptor antagonist in the rat.

    Science.gov (United States)

    Borges, C M; Silveira, M R; Aparecida, M; Beker, C L; Freire-Maia, L; Teixeira, M M

    2000-04-01

    A dramatic blood neutrophilia is an important feature of the severe envenoming caused by the Brazilian scorpion Tityus serrulatus and may contribute to the development of lung injury in children. We examined the effects of an intravenous injection of T. serrulatus scorpion venom (TsV) on the total number of leukocytes and neutrophils in the blood of anesthetized rats. Injection of TsV (250 microg/kg) induces a significant leukocytosis 2 and 3 h after its injection, explained by an increase in the number of neutrophils. The release of catecholamines and action on adrenoceptors is responsible for most of the systemic manifestations of TsV. However, pretreatment with the beta-adrenoceptor antagonists metoprolol and propranolol or the alpha1-adrenoceptor antagonist prazosin (0.25 mg/kg) did not prevent TsV-induced neutrophilia. Blood neutrophilia induced by TsV occurred simultaneously with a significant reduction of mature neutrophils in bone marrow. Pretreatment with the platelet-activating factor (PAF) receptor antagonists UK-74505 or WEB-2086 prevented TsV-induced increase in blood neutrophils and reduction in the number of neutrophils in the bone marrow. It is concluded that scorpion venom induces blood neutrophilia in rats, explained by a PAF receptor-dependent mobilization of neutrophils from the bone marrow. PMID:10770284

  7. The 5-HT3 receptor antagonist alosetron inhibits the colorectal distention induced depressor response and spinal c-fos expression in the anaesthetised rat

    OpenAIRE

    Kozlowski, C; Green, A.; Grundy, D; Boissonade, F; Bountra, C

    2000-01-01

    BACKGROUND—Noxious intestinal distention elicits a reflex depressor response in the sodium pentobarbitone anaesthetised rat, which can be used as an index of visceral nociception. 5-HT3 receptor antagonists inhibit this reflex. Repeated colorectal distention (CRD) induces Fos like immunoreactivity (Fos-LI) in the rat spinal cord.
AIMS—To examine the effect of the 5-HT3 receptor antagonist alosetron on the depressor response to CRD, and on Fos expression in the lumbosacral spinal cord.
METHODS...

  8. Blocking S1P interaction with S1P1 receptor by a novel competitive S1P1-selective antagonist inhibits angiogenesis

    International Nuclear Information System (INIS)

    Highlights: ► The effect of a newly developed S1P1-selective antagonist on angiogenic responses. ► S1P1 is a critical component of VEGF-related angiogenic responses. ► S1P1-selective antagonist showed in vitro activity to inhibit angiogenesis. ► S1P1-selective antagonist showed in vivo activity to inhibit angiogenesis. ► The efficacy of S1P1-selective antagonist for anti-cancer therapies. -- Abstract: Sphingosine 1-phosphate receptor type 1 (S1P1) was shown to be essential for vascular maturation during embryonic development and it has been demonstrated that substantial crosstalk exists between S1P1 and other pro-angiogenic growth factors, such as vascular endothelial growth factor (VEGF) and basic fibroblast growth factor. We developed a novel S1P1-selective antagonist, TASP0277308, which is structurally unrelated to S1P as well as previously described S1P1 antagonists. TASP0277308 inhibited S1P- as well as VEGF-induced cellular responses, including migration and proliferation of human umbilical vein endothelial cells. Furthermore, TASP0277308 effectively blocked a VEGF-induced tube formation in vitro and significantly suppressed tumor cell-induced angiogenesis in vivo. These findings revealed that S1P1 is a critical component of VEGF-related angiogenic responses and also provide evidence for the efficacy of TASP0277308 for anti-cancer therapies.

  9. GABAB Receptor Antagonist CGP46381 Inhibits Form-Deprivation Myopia Development in Guinea Pigs

    OpenAIRE

    Zhen-Ying Cheng; Xu-Ping Wang; Schmid, Katrina L.; Yu-Fei Han; Xu-Guang Han; Hong-Wei Tang; Xin Tang

    2015-01-01

    The aim was to investigate the effects of the GABAB receptor antagonist, CGP46381, on form-deprivation myopia (FDM) in guinea pigs. Twenty-four guinea pigs had monocular visual deprivation induced using a diffuser for 11 days (day 14 to 25). The deprived eyes were treated with daily subconjunctival injections (100 μl) of either 2% CGP46381, 0.2% CGP46381, or saline or received no injection. The fellow eyes were left untreated. Another six animals received no treatment. At the start and end of...

  10. Inhibition of in vivo [(3)H]MK-801 binding by NMDA receptor open channel blockers and GluN2B antagonists in rats and mice.

    Science.gov (United States)

    Fernandes, Alda; Wojcik, Trevor; Baireddy, Praveena; Pieschl, Rick; Newton, Amy; Tian, Yuan; Hong, Yang; Bristow, Linda; Li, Yu-Wen

    2015-11-01

    N-methyl-D-aspartate (NMDA) receptor antagonists, including open channel blockers and GluN2B receptor subtype selective antagonists, have been developed for the treatment of depression. The current study investigated effects of systemically administered NMDA channel blockers and GluN2B receptor antagonists on NMDA receptor activity in rodents using in vivo [(3)H]MK-801 binding. The receptor occupancy of GluN2B antagonists was measured using ex vivo [(3)H]Ro 25-6981 binding. Ketamine, a NMDA receptor channel blocker, produced a dose/exposure- and time-dependent inhibition of in vivo [(3)H]MK-801 binding that was maximal at ~100%. The complete inhibition of in vivo [(3)H]MK-801 binding was also observed with NMDA receptor channel blockers, AZD6765 (Lanicemine) and MK-801 (Dizocilpine). CP-101,606 (Traxoprodil), a GluN2B antagonist, produced a dose/exposure- and time-dependent inhibition of in vivo [(3)H]MK-801 binding that was maximal at ~60%. Partial inhibition was also observed with other GluN2B antagonists including MK-0657 (CERC-301), EVT-101, Ro 25-6981 and radiprodil. For all GluN2B antagonists tested, partial [(3)H]MK-801 binding inhibition was achieved at doses saturating GluN2B receptor occupancy. Combined treatment with ketamine (10mg/kg, i.p.) and Ro 25-6981(10mg/kg, i.p.) produced a level of inhibition of in vivo [(3)H]MK-801 binding that was similar to treatment with either agent alone. In conclusion, this in vivo [(3)H]MK-801 binding study shows that NMDA receptor activity in the rodent forebrain can be inhibited completely by channel blockers, but only partially (~60%) by GluN2B receptor antagonists. At doses effective in preclinical models of depression, ketamine may preferentially inhibit the same population of NMDA receptors as Ro 25-6981, namely those containing the GluN2B subunit. PMID:26325093

  11. Structural basis of Nav1.7 inhibition by an isoform-selective small-molecule antagonist.

    Science.gov (United States)

    Ahuja, Shivani; Mukund, Susmith; Deng, Lunbin; Khakh, Kuldip; Chang, Elaine; Ho, Hoangdung; Shriver, Stephanie; Young, Clint; Lin, Sophia; Johnson, J P; Wu, Ping; Li, Jun; Coons, Mary; Tam, Christine; Brillantes, Bobby; Sampang, Honorio; Mortara, Kyle; Bowman, Krista K; Clark, Kevin R; Estevez, Alberto; Xie, Zhiwei; Verschoof, Henry; Grimwood, Michael; Dehnhardt, Christoph; Andrez, Jean-Christophe; Focken, Thilo; Sutherlin, Daniel P; Safina, Brian S; Starovasnik, Melissa A; Ortwine, Daniel F; Franke, Yvonne; Cohen, Charles J; Hackos, David H; Koth, Christopher M; Payandeh, Jian

    2015-12-18

    Voltage-gated sodium (Nav) channels propagate action potentials in excitable cells. Accordingly, Nav channels are therapeutic targets for many cardiovascular and neurological disorders. Selective inhibitors have been challenging to design because the nine mammalian Nav channel isoforms share high sequence identity and remain recalcitrant to high-resolution structural studies. Targeting the human Nav1.7 channel involved in pain perception, we present a protein-engineering strategy that has allowed us to determine crystal structures of a novel receptor site in complex with isoform-selective antagonists. GX-936 and related inhibitors bind to the activated state of voltage-sensor domain IV (VSD4), where their anionic aryl sulfonamide warhead engages the fourth arginine gating charge on the S4 helix. By opposing VSD4 deactivation, these compounds inhibit Nav1.7 through a voltage-sensor trapping mechanism, likely by stabilizing inactivated states of the channel. Residues from the S2 and S3 helices are key determinants of isoform selectivity, and bound phospholipids implicate the membrane as a modulator of channel function and pharmacology. Our results help to elucidate the molecular basis of voltage sensing and establish structural blueprints to design selective Nav channel antagonists. PMID:26680203

  12. Calcineurin antagonists inhibit interferon-gamma production by downregulation of interleukin-18 in human mixed lymphocyte reactions.

    Directory of Open Access Journals (Sweden)

    Kuinose M

    2000-10-01

    Full Text Available Tacrolimus (FK-506 and cyclosporin A (CsA are calcineurin antagonists used widely as T-cell immunosuppressants; however, their relative efficacy on the production of interleukin-18 (IL-18 remains undefined. We have examined the effects of FK-506 and CsA on the cytokine generation of human peripheral blood mononuclear cells (PBMCs in mixed lymphocyte reaction (MLR with lipopolysaccharide (LPS. We studied the levels of interleukin-18 (IL-18, IL-12, IL-10, IL-6, IL-2 and interferon-gamma (IFN-gamma in the supernatant in allo-MLR by ELISA assay. Supernatant levels of IFN-gamma, IL-2, IL-6, IL-10 and IL-12 were detected 12 h after MLR and markedly increased thereafter. In contrast, production of IL-18 was detected at 12 h, reached a near maximum level at 24 h and decreased at 72 h. These results suggested that IFN-gamma production depended on IL-18, IL-12 and IL-2 in the early phase of MLR and depended mainly on IL-12 and IL-2 in the late phase. Both calcineurin antagonists inhibit the generation of IL-18, which plays a large role in allogeneic cell interactions, in macrophages and they also promote an equivalent down-regulation of T helper 1 (Th1 and Th2 responses in a concentration-dependent manner. About 90% of IFN-gamma production induced by MLR was inhibited by an anti-IL-18 antibody, showing that IL-18 can trigger IFN-gamma production in MLR. These results suggest that dual signaling consisting of antigen-driven nuclear factor of activated T cells (NFAT activation and LPS-mediated NF-kappaB activation is crucial for IL-18 production in macrophages, and that IL-18 can trigger IFN-gamma production in T-cells by MLR.

  13. Interleukin-1 receptor antagonist inhibits neuronal damage caused by fluid percussion injury in the rat.

    Science.gov (United States)

    Toulmond, S; Rothwell, N J

    1995-02-13

    Increased expression of the cytokine interleukin-1 (IL-1) has been observed in rodent and human brain after injury, and IL-1 has been implicated in ischaemic and excitotoxic brain damage in the rat. These data suggest that neurodegeneration caused by brain injury may be mediated by local IL-1 production and action. This hypothesis was tested by studying the effects of central injection of recombinant human interleukin-1 receptor antagonist (rhIL-1ra) on brain damage (assessed histologically, H and E stain) induced by fluid percussion trauma in the rat. Injection of rhIL-1ra (10 micrograms, i.c.v.) 15 min and 2, 4, 6, 8, 24 and 48 h after injury significantly reduced, by 44%, the extent of damage measured 3 days later. Similar protection was observed in animals killed 7 days after injury. Delayed administration of rhIL-1ra (4, 6, 8, 24 and 48 h) after injury also significantly reduced (by 28%) neuronal damage. These data indicate that endogenous IL-1 mediates damage caused by traumatic brain injury and that rhIL-1ra offers significant protection even when treatment is delayed. PMID:7743213

  14. Inhibition of platelet aggregation by AZD6140, a reversible oral P2Y12 receptor antagonist, compared with clopidogrel in patients with acute coronary syndromes

    DEFF Research Database (Denmark)

    Storey, Robert F; Husted, Steen; Harrington, Robert A;

    2007-01-01

    -pretreated patients. BACKGROUND: Clopidogrel, in combination with aspirin, reduces cardiovascular events in patients with acute coronary syndromes (ACS). However, patients with poor inhibition of platelet aggregation with clopidogrel may be less well protected. AZD6140 is a reversible oral P2Y(12) receptor antagonist...

  15. Clopidogrel (Plavix®), a P2Y(12) receptor antagonist, inhibits bone cell function in vitro and decreases trabecular bone in vivo

    DEFF Research Database (Denmark)

    Syberg, Susanne; Brandao-Burch, Andrea; Patel, Jessal J;

    2012-01-01

    Clopidogrel (Plavix®), a selective P2Y(12) receptor antagonist, is widely prescribed to reduce the risk of heart attack and stroke and acts via the inhibition of platelet aggregation. Accumulating evidence now suggests that extracellular nucleotides, signalling through P2 receptors, play a...

  16. Cinnamamides, Novel Liver X Receptor Antagonists that Inhibit Ligand-Induced Lipogenesis and Fatty Liver.

    Science.gov (United States)

    Sim, Woo-Cheol; Kim, Dong Gwang; Lee, Kyeong Jin; Choi, You-Jin; Choi, Yeon Jae; Shin, Kye Jung; Jun, Dae Won; Park, So-Jung; Park, Hyun-Ju; Kim, Jiwon; Oh, Won Keun; Lee, Byung-Hoon

    2015-12-01

    Liver X receptor (LXR) is a member of the nuclear receptor superfamily, and it regulates various biologic processes, including de novo lipogenesis, cholesterol metabolism, and inflammation. Selective inhibition of LXR may aid the treatment of nonalcoholic fatty liver diseases. In the present study, we evaluated the effects of three cinnamamide derivatives on ligand-induced LXRα activation and explored whether these derivatives could attenuate steatosis in mice. N-(4-trifluoromethylphenyl) 3,4-dimethoxycinnamamide (TFCA) decreased the luciferase activity in LXRE-tk-Luc-transfected cells and also suppressed ligand-induced lipid accumulation and expression of the lipogenic genes in murine hepatocytes. Furthermore, it significantly attenuated hepatic neutral lipid accumulation in a ligand-induced fatty liver mouse system. Modeling study indicated that TFCA inhibited activation of the LXRα ligand-binding domain by hydrogen bonding to Arg305 in the H5 region of that domain. It regulated the transcriptional control exerted by LXRα by influencing coregulator exchange; this process involves dissociation of the thyroid hormone receptor-associated proteins (TRAP)/DRIP coactivator and recruitment of the nuclear receptor corepressor. These results show that TFCA has the potential to attenuate ligand-induced lipogenesis and fatty liver by selectively inhibiting LXRα in the liver. PMID:26384859

  17. Transplacental delivery of the Wnt antagonist Frzb1 inhibits development of caudal paraxial mesoderm and skeletal myogenesis in mouse embryos.

    Science.gov (United States)

    Borello, U; Coletta, M; Tajbakhsh, S; Leyns, L; De Robertis, E M; Buckingham, M; Cossu, G

    1999-10-01

    Axial structures (neural tube/notochord) and surface ectoderm activate myogenesis in the mouse embryo; their action can be reproduced, at least in part, by several molecules such as Sonic hedgehog and Wnts. Recently, soluble Wnt antagonists have been identified. Among those examined only Frzb1 was found to be expressed in the presomitic mesoderm and newly formed somites and thus its possible role in regulating myogenesis was investigated in detail. When presomitic mesoderm or newly formed somites were cultured with axial structures and surface ectoderm on a feeder layer of C3H10T1/2 cells expressing Frzb1, myogenesis was abolished or severely reduced in presomitic mesoderm and the three most recently formed somites. In contrast, no effect was observed on more mature somites. Inhibition of myogenesis did not appear to be associated with increased cell death since the final number of cells in the explants grown in the presence of Frzb1 was only slightly reduced in comparison with controls. In order to examine the possible function of Frzb1 in vivo, we developed a method based on the overexpression of the soluble antagonist by transient transfection of WOP cells with a Frzb1 expression vector and injection of transfected cells into the placenta of pregnant females before the onset of maternofoetal circulation. Frzb1, secreted by WOP cells, accumulated in the embryo and caused a marked reduction in size of caudal structures. Myogenesis was strongly reduced and, in the most severe cases, abolished. This was not due to a generalized toxic effect since only several genes downstream of the Wnt signaling pathway such as En1, Noggin and Myf5 were downregulated; in contrast, Pax3 and Mox1 expression levels were not affected even in embryos exhibiting the most severe phenotypes. Taken together, these results suggest that Wnt signals may act by regulating both myogenic commitment and expansion of committed cells in the mouse mesoderm. PMID:10477293

  18. Blocking S1P interaction with S1P{sub 1} receptor by a novel competitive S1P{sub 1}-selective antagonist inhibits angiogenesis

    Energy Technology Data Exchange (ETDEWEB)

    Fujii, Yasuyuki, E-mail: y.fujii@po.rd.taisho.co.jp [Department of Molecular Function and Pharmacology Laboratories, Taisho Pharmaceutical Co. Ltd., 1-403 Saitama, Saitama 331-9530 (Japan); Ueda, Yasuji; Ohtake, Hidenori; Ono, Naoya; Takayama, Tetsuo; Nakazawa, Kiyoshi [Department of Molecular Function and Pharmacology Laboratories, Taisho Pharmaceutical Co. Ltd., 1-403 Saitama, Saitama 331-9530 (Japan); Igarashi, Yasuyuki [Laboratory of Biomembrane and Biofunctional Chemistry, Hokkaido University, Sapporo, Hokkaido 060-0812 (Japan); Goitsuka, Ryo [Division of Development and Aging, Research Institute for Biological Sciences, Tokyo University of Science, Noda, Chiba 278-0022 (Japan)

    2012-03-23

    Highlights: Black-Right-Pointing-Pointer The effect of a newly developed S1P{sub 1}-selective antagonist on angiogenic responses. Black-Right-Pointing-Pointer S1P{sub 1} is a critical component of VEGF-related angiogenic responses. Black-Right-Pointing-Pointer S1P{sub 1}-selective antagonist showed in vitro activity to inhibit angiogenesis. Black-Right-Pointing-Pointer S1P{sub 1}-selective antagonist showed in vivo activity to inhibit angiogenesis. Black-Right-Pointing-Pointer The efficacy of S1P{sub 1}-selective antagonist for anti-cancer therapies. -- Abstract: Sphingosine 1-phosphate receptor type 1 (S1P{sub 1}) was shown to be essential for vascular maturation during embryonic development and it has been demonstrated that substantial crosstalk exists between S1P{sub 1} and other pro-angiogenic growth factors, such as vascular endothelial growth factor (VEGF) and basic fibroblast growth factor. We developed a novel S1P{sub 1}-selective antagonist, TASP0277308, which is structurally unrelated to S1P as well as previously described S1P{sub 1} antagonists. TASP0277308 inhibited S1P- as well as VEGF-induced cellular responses, including migration and proliferation of human umbilical vein endothelial cells. Furthermore, TASP0277308 effectively blocked a VEGF-induced tube formation in vitro and significantly suppressed tumor cell-induced angiogenesis in vivo. These findings revealed that S1P{sub 1} is a critical component of VEGF-related angiogenic responses and also provide evidence for the efficacy of TASP0277308 for anti-cancer therapies.

  19. Fully human antagonistic antibodies against CCR4 potently inhibit cell signaling and chemotaxis.

    Directory of Open Access Journals (Sweden)

    Urs B Hagemann

    Full Text Available CC chemokine receptor 4 (CCR4 represents a potentially important target for cancer immunotherapy due to its expression on tumor infiltrating immune cells including regulatory T cells (Tregs and on tumor cells in several cancer types and its role in metastasis.Using phage display, human antibody library, affinity maturation and a cell-based antibody selection strategy, the antibody variants against human CCR4 were generated. These antibodies effectively competed with ligand binding, were able to block ligand-induced signaling and cell migration, and demonstrated efficient killing of CCR4-positive tumor cells via ADCC and phagocytosis. In a mouse model of human T-cell lymphoma, significant survival benefit was demonstrated for animals treated with the newly selected anti-CCR4 antibodies.For the first time, successful generation of anti- G-protein coupled chemokine receptor (GPCR antibodies using human non-immune library and phage display on GPCR-expressing cells was demonstrated. The generated anti-CCR4 antibodies possess a dual mode of action (inhibition of ligand-induced signaling and antibody-directed tumor cell killing. The data demonstrate that the anti-tumor activity in vivo is mediated, at least in part, through Fc-receptor dependent effector mechanisms, such as ADCC and phagocytosis. Anti-CC chemokine receptor 4 antibodies inhibiting receptor signaling have potential as immunomodulatory antibodies for cancer.

  20. Stereoselective inhibition of thromboxane-induced coronary vasoconstriction by 1,4-dihydropyridine calcium channel antagonists

    International Nuclear Information System (INIS)

    The biological activity of the (+)-S- and (-)-R-enantiomers of niguldipine, of the (-)-S- and (+)-R-enantiomers of felodipine and nitrendipine, and of rac-nisoldipine and rac-nimodipine was investigated in vitro and in vivo. Inhibition of coronary vasoconstriction due to the thromboxane A2 (TxA2)-mimetic U-46619 in guinea pig Langendorff hearts, displacement of (+)-[3H]isradipine from calcium channel binding sites of guinea pig skeletal muscle T-tubule membranes, and blood pressure reduction in spontaneously hypertensive rats were determined. The enantiomers were obtained by stereoselective synthesis. Cross-contamination was less than 0.5% for both S- and R-enantiomers of niguldipine and nitrendipine and less than 1% for those of felodipine. From the doses necessary for a 50% inhibition of coronary vasoconstriction, stereoselectivity ratios for (+)-(S)-/(-)-(R)-niguldipine, (-)-(S)-/(+)-(R)-felodipine, and (-)-(S)-/(+)-(R)-nitrendipine of 28, 13, and 7, respectively, were calculated. The potency ratio rac-nisoldipine/rac-nimodipine was 3.5. Ratios obtained from binding experiments and antihypertensive activity were (+)-(S)-/(-)-(R)-niguldipine = 45 and 35, (-)-(S)-/(+)-(R)-felodipine = 12 and 13, (-)-(S)-/(+)-(R)-nitrendipine = 8 and 8, and rac-nisoldipine/rac-nimodipine = 8 and 7, respectively. Highly significant correlations were found between the in vitro potency of the substances to prevent U-46619-induced coronary vasoconstriction and their affinity for calcium channel binding sites as well as their antihypertensive activity

  1. Inhibition of human immunodeficiency virus replication by a dual CCR5/CXCR4 antagonist

    DEFF Research Database (Denmark)

    Princen, Katrien; Hatse, Sigrid; Vermeire, Kurt;

    2004-01-01

    Here we report that the N-pyridinylmethyl cyclam analog AMD3451 has antiviral activity against a wide variety of R5, R5/X4, and X4 strains of human immunodeficiency virus type 1 (HIV-1) and HIV-2 (50% inhibitory concentration [IC(50)] ranging from 1.2 to 26.5 microM) in various T-cell lines, CCR5......- or CXCR4-transfected cells, peripheral blood mononuclear cells (PBMCs), and monocytes/macrophages. AMD3451 also inhibited R5, R5/X4, and X4 HIV-1 primary clinical isolates in PBMCs (IC(50), 1.8 to 7.3 microM). A PCR-based viral entry assay revealed that AMD3451 blocks R5 and X4 HIV-1 infection at the...... inhibit but enhanced the binding of several anti-CXCR4 monoclonal antibodies (such as clone 12G5) at the cell surface, pointing to a different interaction with CXCR4. AMD3451 is the first low-molecular-weight anti-HIV agent with selective HIV coreceptor, CCR5 and CXCR4, interaction....

  2. Mycoparasitic and Antagonistic Inhibition on Phytophthora cinnamomi Rands by Microbial Agents Isolated from Manure Composts

    Directory of Open Access Journals (Sweden)

    I. Nyoman Pugeg Aryantha

    2006-01-01

    Full Text Available We isolated bacteria and fungi from composted chicken, sheep, cow and horse manure and screened each isolate for their ability to suppress P. cinnamomi in dual-culture in vitro assays. Of the 180 isolates, including 31 actinomycetes, 64 fungi, 44 fluorescent pseudomonads and 41 endospore-forming bacteria, 45 isolates significantly inhibited the growth of P. cinnamomi on plates. The inhibitory microbes included 24 fungi (including Trichoderma sp., Gliocladium penicillioides and Fusarium sp., 0 actinomycetes (all Streptomyces sp., 7 fluorescent pseudomonads (Pseudomonas sp. and 4 endospore-forming bacteria (Bacillus sp.. The most common mode of action observed was antibiosis, although mycoparasitism, indicated by parallel hyphal growth, hyphal coiling, appressorium formation and direct penetration, was also observed with one isolate of Trichoderma. These results help to explain the role of microbes in the suppression and biological control of P. cinnamomi by composted manures.

  3. Inhibition of Peripheral Nerve Scarring by Calcium Antagonists, Also Known as Calcium Channel Blockers.

    Science.gov (United States)

    Xue, Jin-Wei; Jiao, Jian-Bao; Liu, Xiao-Feng; Jiang, Yuan-Tao; Yang, Guang; Li, Chun-Yu; Yin, Wei-Tian; Ling, Li

    2016-05-01

    The aim of this research was to investigate the impact of calcium channel blockers (verapamil) on the formation of scars in the sciatic nerve anastomosis after peripheral nerve injury. One hundred twenty healthy, male Sprague-Dawley rats were selected and prepared with right sciatic nerve injury for this study. Samples were selected at the fourth and 12th weeks, respectively, after treatment and observations were made on the nerve anastomosis healing and diameter. Image analysis and statistical processing were carried out relating to the results of the study. The diameter of the anastomosis of the treatment group at weeks 4 and 12 was noticeably smaller than the control group (P regeneration. It can effectively inhibit the formation of scarring from nerve injury. It also provided an excellent microenvironment for the regeneration of nerve fibers. PMID:26488333

  4. Selective and rapid monitoring of dual platelet inhibition by aspirin and P2Y12 antagonists by using multiple electrode aggregometry

    Directory of Open Access Journals (Sweden)

    Lorenz Reinhard

    2010-05-01

    Full Text Available Abstract Background Poor platelet inhibition by aspirin or clopidogrel has been associated with adverse outcomes in patients with cardiovascular diseases. A reliable and facile assay to measure platelet inhibition after treatment with aspirin and a P2Y12 antagonist is lacking. Multiple electrode aggregometry (MEA, which is being increasingly used in clinical studies, is sensitive to platelet inhibition by aspirin and clopidogrel, but a critical evaluation of MEA monitoring of dual anti-platelet therapy with aspirin and P2Y12 antagonists is missing. Design and Methods By performing in vitro and ex vivo experiments, we evaluated in healthy subjects the feasibility of using MEA to monitor platelet inhibition of P2Y12 antagonists (clopidogrel in vivo, cangrelor in vitro and aspirin (100 mg per day in vivo, and 1 mM or 5.4 mM in vitro alone, and in combination. Statistical analyses were performed by the Mann-Whitney rank sum test, student' t-test, analysis of variance followed by the Holm-Sidak test, where appropriate. Results ADP-induced platelet aggregation in hirudin-anticoagulated blood was inhibited by 99.3 ± 1.4% by in vitro addition of cangrelor (100 nM; p 95% and 100 ± 3.2%, respectively (p in vitro or ex vivo. Oral intake of clopidogrel did not significantly reduce AA-induced aggregation, but P2Y12 blockade by cangrelor (100 nM in vitro diminished AA-stimulated aggregation by 53 ± 26% (p Conclusions Selective platelet inhibition by aspirin and P2Y12 antagonists alone and in combination can be rapidly measured by MEA. We suggest that dual anti-platelet therapy with these two types of anti-platelet drugs can be optimized individually by measuring platelet responsiveness to ADP and AA with MEA before and after drug intake.

  5. Plant extracts inhibit ADP-induced platelet activation in humans: their potential therapeutic role as ADP antagonists.

    Science.gov (United States)

    Jagroop, Indera Anita

    2014-01-01

    Adenosine diphosphate (ADP) plays a pivotal role in platelet activation. Platelet hyperactivity is associated with vascular disease and also has a key role in haemostasis and thrombosis. ADP activates platelets through three purinoceptor subtypes, the G(q)-coupled P2Y(1) receptor, G(i)-coupled P2Y(12) receptor and P2X(1) ligand-gated cation channel. Platelet ADP purinergic receptors are therefore suitable targets for antiplatelet drugs. Thienopyridines such as clopidogrel and ticlopidine, as well as other ADP receptor antagonists like prasugrel, ticagrelor, cangrelor and elinogrel have demonstrated clinical benefits via the inhibition of the selective purinergic ADP receptor, P2Y(12). However, they still have limitations in their mode of action and efficacy, like increased risk of bleeding. Thus, the ongoing pursuit to develop newer and more effective antiplatelet agents continues. There is a growing interest in the purinergic antiplatelet properties exhibited by plant extracts. This article considers the following: pomolic acid isolated from Licania pittieri, brazilin isolated from the heartwood of Caesalpinia sappan L, phylligenin isolated from the twigs of Muraltia vulpina, bark oil of Gonystylus velutinus, seed and bark extracts from Aesculus hippocastanum L. and red wine phenolics and catechins isolated from green tea. Moreover, the method used to investigate platelet purinergic receptors should be considered, since using a more sensitive, high-resolution platelet sizer can sometimes detect platelet variations when the light transmission method was not able to do so. The exact mechanisms by which these plant extracts work need further investigation. They all however inhibit ADP-induced activation in human platelets. This could explain, at least in part, the protective effect of plant extracts as antiplatelet agents. PMID:24190032

  6. A novel muscarinic antagonist R2HBJJ inhibits non-small cell lung cancer cell growth and arrests the cell cycle in G0/G1.

    Directory of Open Access Journals (Sweden)

    Nan Hua

    Full Text Available Lung cancers express the cholinergic autocrine loop, which facilitates the progression of cancer cells. The antagonists of mAChRs have been demonstrated to depress the growth of small cell lung cancers (SCLCs. In this study we intended to investigate the growth inhibitory effect of R2HBJJ, a novel muscarinic antagonist, on non-small cell lung cancer (NSCLC cells and the possible mechanisms. The competitive binding assay revealed that R2HBJJ had a high affinity to M3 and M1 AChRs. R2HBJJ presented a strong anticholinergic activity on carbachol-induced contraction of guinea-pig trachea. R2HBJJ markedly suppressed the growth of NSCLC cells, such as H1299, H460 and H157. In H1299 cells, both R2HBJJ and its leading compound R2-PHC displayed significant anti-proliferative activity as M3 receptor antagonist darifenacin. Exogenous replenish of ACh could attenuate R2HBJJ-induced growth inhibition. Silencing M3 receptor or ChAT by specific-siRNAs resulted in a growth inhibition of 55.5% and 37.9% on H1299 cells 96 h post transfection, respectively. Further studies revealed that treatment with R2HBJJ arrested the cell cycle in G0/G1 by down-regulation of cyclin D1-CDK4/6-Rb. Therefore, the current study reveals that NSCLC cells express an autocrine and paracrine cholinergic system which stimulates the growth of NSCLC cells. R2HBJJ, as a novel mAChRs antagonist, can block the local cholinergic loop by antagonizing predominantly M3 receptors and inhibit NSCLC cell growth, which suggest that M3 receptor antagonist might be a potential chemotherapeutic regimen for NSCLC.

  7. A novel muscarinic antagonist R2HBJJ inhibits non-small cell lung cancer cell growth and arrests the cell cycle in G0/G1.

    Science.gov (United States)

    Hua, Nan; Wei, Xiaoli; Liu, Xiaoyan; Ma, Xiaoyun; He, Xinhua; Zhuo, Rengong; Zhao, Zhe; Wang, Liyun; Yan, Haitao; Zhong, Bohua; Zheng, Jianquan

    2012-01-01

    Lung cancers express the cholinergic autocrine loop, which facilitates the progression of cancer cells. The antagonists of mAChRs have been demonstrated to depress the growth of small cell lung cancers (SCLCs). In this study we intended to investigate the growth inhibitory effect of R2HBJJ, a novel muscarinic antagonist, on non-small cell lung cancer (NSCLC) cells and the possible mechanisms. The competitive binding assay revealed that R2HBJJ had a high affinity to M3 and M1 AChRs. R2HBJJ presented a strong anticholinergic activity on carbachol-induced contraction of guinea-pig trachea. R2HBJJ markedly suppressed the growth of NSCLC cells, such as H1299, H460 and H157. In H1299 cells, both R2HBJJ and its leading compound R2-PHC displayed significant anti-proliferative activity as M3 receptor antagonist darifenacin. Exogenous replenish of ACh could attenuate R2HBJJ-induced growth inhibition. Silencing M3 receptor or ChAT by specific-siRNAs resulted in a growth inhibition of 55.5% and 37.9% on H1299 cells 96 h post transfection, respectively. Further studies revealed that treatment with R2HBJJ arrested the cell cycle in G0/G1 by down-regulation of cyclin D1-CDK4/6-Rb. Therefore, the current study reveals that NSCLC cells express an autocrine and paracrine cholinergic system which stimulates the growth of NSCLC cells. R2HBJJ, as a novel mAChRs antagonist, can block the local cholinergic loop by antagonizing predominantly M3 receptors and inhibit NSCLC cell growth, which suggest that M3 receptor antagonist might be a potential chemotherapeutic regimen for NSCLC. PMID:23285263

  8. Role of 5-hydroxytryptamine in platelet thrombus formation and mechanisms of inhibition of thrombus formation by 5-hydroxytryptamine2A antagonists in rabbits.

    Science.gov (United States)

    Takano, S

    1995-01-01

    The role of 5-hydroxytryptamine (5-HT) in platelet thrombus formation and in the mechanisms of inhibition of thrombus formation by 5-HT2A antagonists was investigated using a turbidimetric method. Collagen-induced platelet aggregation occurred simultaneously with a release of 5-HT from the platelets. The supernatant of collagen-aggregated platelets induced a further aggregation volume-dependently. This supernatant-induced aggregation was inhibited by either 5-HT2A antagonists or adenosine-diphosphate (ADP) scavenging. 5-Hydroxytryptamine and a small amount of the supernatant shifted the dose-response curves of collagen to the left. The aggregation velocity and the onset of aggregation by collagen were significantly increased by the supernatant, but not by 5-HT. The 5-HT2A antagonists, ketanserin and MCI-9042, returned the dose-response curves of the maximum aggregation and of the aggregation velocity of collagen, which were already amplified by the supernatant, to the original values. The onset of aggregation was delayed by the antagonists, but was not completely returned to the original points. There were distinct differences between the effects of endogenous 5-HT, derived from platelets which were stimulated by collagen, and those of exogenous 5-HT on both extensive platelet activation and amplification of the collagen-induced aggregation. These findings suggest that endogenous 5-HT activates platelets in synergism with ADP. The 5-HT2A antagonists used, block the synergism via 5-HT2A receptors and lead to inhibition of a positive feedback loop of thrombus formation. PMID:8836449

  9. Novel, isoform-selective, cholecystokinin A receptor antagonist inhibits colon and pancreatic cancers in preclinical models through novel mechanism of action.

    Science.gov (United States)

    Ponnusamy, Suriyan; Lattmann, Eric; Lattmann, Pornthip; Thiyagarajan, Thirumagal; Padinjarethalakal, Balaram N; Narayanan, Ramesh

    2016-04-01

    Colon and pancreatic cancers contribute to 90,000 deaths each year in the USA. These cancers lack targeted therapeutics due to heterogeneity of the disease and multiple causative factors. One important factor that contributes to increased colon and pancreatic cancer risk is gastrin. Gastrin mediates its actions through two G-protein coupled receptors (GPCRs): cholecystokinin receptor A (CCK-A) and CCK-B/gastrin receptor. Previous studies have indicated that colon cancer predominantly expresses CCK-A and responds to CCK-A isoform antagonists. However, many CCK-A antagonists have failed in the clinic due to poor pharmacokinetic properties or lack of efficacy. In the present study, we synthesized a library of CCK-A isoform-selective antagonists and tested them in various colon and pancreatic cancer preclinical models. The lead CCK-A isoform, selective antagonist PNB-028, bound to CCK-A at 12 nM with a 60-fold selectivity towards CCK-A over CCK-B. Furthermore, it inhibited the proliferation of CCK-A-expressing colon and pancreatic cancer cells without affecting the proliferation of non-cancerous cells. PNB-028 was also extremely effective in inhibiting the growth of MAC-16 and LoVo colon cancer and MIA PaCa pancreatic cancer xenografts in immune-compromised mice. Genome‑wide microarray and kinase-array studies indicate that PNB-028 inhibited oncogenic kinases and angiogenic factors to inhibit the growth of colon cancer xenografts. Safety pharmacology and toxicology studies have indicated that PNB-028 is extremely safe and has a wide safety margin. These studies suggest that targeting CCK-A selectively renders promise to treat colon and pancreatic cancers and that PNB-028 could become the next-generation treatment option. PMID:26820391

  10. The T-type calcium channel antagonist Z944 disrupts prepulse inhibition in both epileptic and non-epileptic rats.

    Science.gov (United States)

    Marks, Wendie N; Greba, Quentin; Cain, Stuart M; Snutch, Terrance P; Howland, John G

    2016-09-22

    The role of T-type calcium channels in brain diseases such as absence epilepsy and neuropathic pain has been studied extensively. However, less is known regarding the involvement of T-type channels in cognition and behavior. Prepulse inhibition (PPI) is a measure of sensorimotor gating which is a basic process whereby the brain filters incoming stimuli to enable appropriate responding in sensory rich environments. The regulation of PPI involves a network of limbic, cortical, striatal, pallidal and pontine brain areas, many of which show high levels of T-type calcium channel expression. Therefore, we tested the effects of blocking T-type calcium channels on PPI with the potent and selective T-type antagonist Z944 (0.3, 1, 3, 10mg/kg; i.p.) in adult Wistar rats and two related strains, the Genetic Absence Epilepsy Rats from Strasbourg (GAERS) and Non-Epileptic Control (NEC). PPI was tested using a protocol that varied prepulse intensity (3, 6, and 12dB above background) and prepulse-pulse interval (30, 50, 80, 140ms). Z944 decreased startle in the Wistar strain at the highest dose relative to lower doses. Z944 dose-dependently disrupted PPI in the Wistar and GAERS strains with the most potent effect observed with the higher doses. These findings suggest that T-type calcium channels contribute to normal patterns of brain activity that regulate PPI. Given that PPI is disrupted in psychiatric disorders, future experiments that test the specific brain regions involved in the regulation of PPI by T-type calcium channels may help inform therapeutic development for those suffering from sensorimotor gating impairments. PMID:27365170

  11. Skin-targeted inhibition of PPAR β/δ by selective antagonists to treat PPAR β/δ-mediated psoriasis-like skin disease in vivo.

    Directory of Open Access Journals (Sweden)

    Katrin Hack

    Full Text Available We have previously shown that peroxisome proliferator activating receptor ß/δ (PPAR β/δ is overexpressed in psoriasis. PPAR β/δ is not present in adult epidermis of mice. Targeted expression of PPAR β/δ and activation by a selective synthetic agonist is sufficient to induce an inflammatory skin disease resembling psoriasis. Several signalling pathways dysregulated in psoriasis are replicated in this model, suggesting that PPAR β/δ activation contributes to psoriasis pathogenesis. Thus, inhibition of PPAR β/δ might harbour therapeutical potential. Since PPAR β/δ has pleiotropic functions in metabolism, skin-targeted inhibition offer the potential of reducing systemic adverse effects. Here, we report that three selective PPAR β/δ antagonists, GSK0660, compound 3 h, and GSK3787 can be formulated for topical application to the skin and that their skin concentration can be accurately quantified using ultra-high performance liquid chromatography (UPLC/mass spectrometry. These antagonists show efficacy in our transgenic mouse model in reducing psoriasis-like changes triggered by activation of PPAR β/δ. PPAR β/δ antagonists GSK0660 and compound 3 do not exhibit systemic drug accumulation after prolonged application to the skin, nor do they induce inflammatory or irritant changes. Significantly, the irreversible PPAR β/δ antagonist (GSK3787 retains efficacy when applied topically only three times per week which could be of practical clinical usefulness. Our data suggest that topical inhibition of PPAR β/δ to treat psoriasis may warrant further exploration.

  12. A Novel Nociceptin Receptor Antagonist LY2940094 Inhibits Excessive Feeding Behavior in Rodents: A Possible Mechanism for the Treatment of Binge Eating Disorder.

    Science.gov (United States)

    Statnick, Michael A; Chen, Yanyun; Ansonoff, Michael; Witkin, Jeffrey M; Rorick-Kehn, Linda; Suter, Todd M; Song, Min; Hu, Charlie; Lafuente, Celia; Jiménez, Alma; Benito, Ana; Diaz, Nuria; Martínez-Grau, Maria Angeles; Toledo, Miguel A; Pintar, John E

    2016-02-01

    Nociceptin/orphanin FQ (N/OFQ), a 17 amino acid peptide, is the endogenous ligand of the ORL1/nociceptin-opioid-peptide (NOP) receptor. N/OFQ appears to regulate a variety of physiologic functions including stimulating feeding behavior. Recently, a new class of thienospiro-piperidine-based NOP antagonists was described. One of these molecules, LY2940094 has been identified as a potent and selective NOP antagonist that exhibited activity in the central nervous system. Herein, we examined the effects of LY2940094 on feeding in a variety of behavioral models. Fasting-induced feeding was inhibited by LY2940094 in mice, an effect that was absent in NOP receptor knockout mice. Moreover, NOP receptor knockout mice exhibited a baseline phenotype of reduced fasting-induced feeding, relative to wild-type littermate controls. In lean rats, LY2940094 inhibited the overconsumption of a palatable high-energy diet, reducing caloric intake to control chow levels. In dietary-induced obese rats, LY2940094 inhibited feeding and body weight regain induced by a 30% daily caloric restriction. Last, in dietary-induced obese mice, LY2940094 decreased 24-hour intake of a high-energy diet made freely available. These are the first data demonstrating that a systemically administered NOP receptor antagonist can reduce feeding behavior and body weight in rodents. Moreover, the hypophagic effect of LY2940094 is NOP receptor dependent and not due to off-target or aversive effects. Thus, LY2940094 may be useful in treating disorders of appetitive behavior such as binge eating disorder, food choice, and overeating, which lead to obesity and its associated medical complications and morbidity. PMID:26659925

  13. ANG II type 1 receptor antagonist irbesartan inhibits coronary angiogenesis stimulated by chronic intermittent hypoxia in neonatal rats

    Czech Academy of Sciences Publication Activity Database

    Rakusan, K.; Chvojková, Zuzana; Oliviero, P.; Ošťádalová, Ivana; Kolář, František; Chassagne, C.; Samuel, J. L.; Ošťádal, Bohuslav

    2007-01-01

    Roč. 292, č. 3 (2007), H1237-H1244. ISSN 0363-6135 R&D Projects: GA MŠk 1M0510 Institutional research plan: CEZ:AV0Z50110509 Keywords : angiogenesis neonatal rat * ANG II type 1 receptor antagonist heart * ischemic tolerance Subject RIV: ED - Physiology Impact factor: 3.973, year: 2007

  14. In vivo inhibition of plasma protein leakage and Salmonella enteritidis-induced mortality in the rat by a specific paf-acether antagonist: BN 52021.

    Science.gov (United States)

    Etienne, A; Hecquet, F; Soulard, C; Spinnewyn, B; Clostre, F; Braquet, P

    1986-01-01

    The effects of BN 52021, a new specific paf-acether receptor antagonist and the total Ginkgo Biloba extract (GBE 761) from which this product was isolated, were studied in the rat on paf-acether-induced permeability and cell number changes and on endotoxin-induced lethality. Their activities were compared to those of cyclooxygenase, 5-lipoxygenase and phospholipase A2 inhibitors. BN 52021 given s.c. or orally exerted a dose-related inhibition of paf-acether deleterious effects as well as of endotoxin lethality whereas the other drugs tested were poorly effective. These results strongly suggest paf-acether involvement in endotoxic and septic shock. PMID:3515870

  15. An anti-CCR5 monoclonal antibody and small molecule CCR5 antagonists synergize by inhibiting different stages of human immunodeficiency virus type 1 entry

    International Nuclear Information System (INIS)

    HIV-1 coreceptors are attractive targets for novel antivirals. Here, inhibition of entry by two classes of CCR5 antagonists was investigated. We confirmed previous findings that HIV-1 isolates vary greatly in their sensitivity to small molecule inhibitors of CCR5-mediated entry, SCH-C and TAK-779. In contrast, an anti-CCR5 monoclonal antibody (PA14) similarly inhibited entry of diverse viral isolates. Sensitivity to small molecules was V3 loop-dependent and inversely proportional to the level of gp120 binding to CCR5. Moreover, combinations of the MAb and small molecules were highly synergistic in blocking HIV-1 entry, suggesting different mechanisms of action. This was confirmed by time course of inhibition experiments wherein the PA14 MAb and small molecules were shown to inhibit temporally distinct stages of CCR5 usage. We propose that small molecules inhibit V3 binding to the second extracellular loop of CCR5, whereas PA14 preferentially inhibits subsequent events such as CCR5 recruitment into the fusion complex or conformational changes in the gp120-CCR5 complex that trigger fusion. Importantly, our findings suggest that combinations of CCR5 inhibitors with different mechanisms of action will be central to controlling HIV-1 infection and slowing the emergence of resistant strains

  16. GABAB antagonists

    DEFF Research Database (Denmark)

    Frydenvang, Karla Andrea; Hansen, J J; Krogsgaard-Larsen, P;

    1994-01-01

    Phaclofen, which is the phosphonic acid analogue of the GABAB agonist (RS)-3-(4-chlorophenyl)-4-aminobutyric acid (baclofen), is a GABAB antagonist. As part of our studies on the structural requirements for activation and blockade of GABAB receptors, we have resolved phaclofen using chiral...... chromatographic techniques. The absolute stereochemistry of (-)-(R)-phaclofen was established by X-ray crystallographic analysis. (-)-(R)-Phaclofen was shown to inhibit the binding of [3H]-(R)-baclofen to GABAB receptor sites on rat cerebellar membranes (IC50 = 76 +/- 13 microM), whereas (+)-(S)-phaclofen was...... inactive in this binding assay (IC50 > 1000 microM). (-)-(R)-Phaclofen (200 microM) was equipotent with (RS)-phaclofen (400 microM) in antagonizing the action of baclofen in rat cerebral cortical slices, while (+)-(S)-phaclofen (200 microM) was inactive. The structural similarity of the agonist (R)-baclofen...

  17. The GABAА receptors agonists and antagonists influence on formation of a latent inhibition at rats with different levels of anxiety

    OpenAIRE

    A. V. Redkina; L. V. Loskutova; Т. A. Zamoshchina

    2012-01-01

    Latent inhibition phenomenon indexes the ability to ignore irrelevant stimuli. Disturbance of latent inhibition is registered in different psychiatric populations with pathology in the emotional and cognitive spheres. In our experiments latent inhibition was measured in a conditioned passive avoidance reaction in rats that previously received 0 or 20 conditioned stimuli exposures followed by foot shock. Latent inhibition was disrupted in high-anxiety rats and pathologically enhanced in low-an...

  18. Oxytocin stimulated release of PGF2α and its inhibition by a cyclooxygenase inhibitor and an oxytocin receptor antagonist from equine endometrial cultures.

    Science.gov (United States)

    Penrod, Leah V; Allen, Ronald E; Rhoads, Michelle L; Limesand, Sean W; Arns, Mark J

    2013-06-01

    Uterine inflammation results in a poor uterine environment and early embryonic loss in the mare due to an inhibition of maternal recognition of pregnancy caused from increased prostaglandin F2α (PGF2α). Oxytocin binds to endometrial cell receptors to activate prostaglandin synthesis. An oxytocin receptor antagonist (Atosiban) and a cyclooxygenase inhibitor (indomethacin) both decrease PGF2α production. The aim of this study was to evaluate the in vitro effects of Atosiban and indomethacin on equine uterine prostaglandin secretion. Equine endometrial explants were harvested on day two of behavioral estrus. Endometrial explant cultures were challenged with oxytocin (250nM) and PGF2α concentrations were measured over time. Explants were also cultured with Atosiban and indomethacin for 6h to determine the influence on PGF2α secretion. When endometrial explants were challenged with oxytocin, PGF2α concentrations were greater (PAtosiban or indomethacin. These findings show equine endometrial explants can be stimulated with oxytocin to increase secretion of PGF2α and this secretion can be inhibited through an oxytocin receptor antagonist and a Cox inhibitor, suggesting that this response to oxytocin involves an oxytocin receptor mediated event that activates the prostaglandin synthesis cascade through cyclooxygenase. Furthermore, this data suggests a role for the use of these inhibitors in vivo to decrease uterine PGF2α secretion and prevent early luteal regression and embryonic loss. PMID:23664650

  19. The P2Y(12 antagonists, 2MeSAMP and cangrelor, inhibit platelet activation through P2Y(12/G(i-dependent mechanism.

    Directory of Open Access Journals (Sweden)

    Binggang Xiang

    Full Text Available BACKGROUND: ADP is an important physiological agonist that induces integrin activation and platelet aggregation through its receptors P2Y(1 (Gα(q-coupled and P2Y(12 (Gα(i-coupled. P2Y(12 plays a critical role in platelet activation and thrombosis. Adenosine-based P2Y(12 antagonists, 2-methylthioadenosine 5'-monophosphate triethylammonium salt hydrate (2MeSAMP and Cangrelor (AR-C69931MX have been widely used to demonstrate the role of P2Y(12 in platelet function. Cangrelor is being evaluated in clinical trials of thrombotic diseases. However, a recent study reported that both 2MeSAMP and Cangrelor raise intra-platelet cAMP levels and inhibit platelet aggregation through a P2Y(12-independent mechanism. METHODOLOGY/PRINCIPAL FINDINGS: The present work, using P2Y(12 deficient mice, sought to clarify previous conflicting reports and to elucidate the mechanisms by which 2MeSAMP and Cangrelor inhibit platelet activation and thrombosis. 2MeSAMP and Cangrelor inhibited aggregation and ATP release of wild-type but not P2Y(12 deficient platelets. 2MeSAMP and Cangrelor neither raised intracellular cAMP concentrations nor induced phosphorylation of vasodilator-stimulated phosphoprotein (VASP in washed human or mouse platelets. Furthermore, unlike the activators (PGI(2 and forskolin of the cAMP pathway, 2MeSAMP and Cangrelor failed to inhibit Ca(2+ mobilization, Akt phosphorylation, and Rap1b activation in P2Y(12 deficient platelets. Importantly, while injection of Cangrelor inhibited thrombus formation in a FeCl(3-induced thrombosis model in wild-type mice, it failed to affect thrombus formation in P2Y(12 deficient mice. CONCLUSIONS: These data together demonstrate that 2MeSAMP and Cangrelor inhibit platelet function through the P2Y(12-dependent mechanism both in vitro and in vivo.

  20. Adenosine AA Receptor Antagonists Do Not Disrupt Rodent Prepulse Inhibition: An Improved Side Effect Profile in the Treatment of Parkinson's Disease

    Directory of Open Access Journals (Sweden)

    Carina J. Bleickardt

    2012-01-01

    Full Text Available Parkinson's disease (PD is characterized by loss of dopaminergic neurons in the substantia nigra. Current treatments for PD focus on dopaminergic therapies, including L-dopa and dopamine receptor agonists. However, these treatments induce neuropsychiatric side effects. Psychosis, characterized by delusions and hallucinations, is one of the most serious such side effects. Adenosine A2A receptor antagonism is a nondopaminergic treatment for PD with clinical and preclinical efficacy. The present studies assessed A2A antagonists SCH 412348 and istradefylline in rodent prepulse inhibition (PPI, a model of psychosis. Dopamine receptor agonists pramipexole (0.3–3 mg/kg, pergolide (0.3–3 mg/kg, and apomorphine (0.3–3 mg/kg significantly disrupted PPI; ropinirole (1–30 mg/kg had no effect; L-dopa (100–300 mg/kg disrupted rat but not mouse PPI. SCH 412348 (0.3–3 mg/kg did not disrupt rodent PPI; istradefylline (0.1–1 mg/kg marginally disrupted mouse but not rat PPI. These results suggest that A2A antagonists, unlike dopamine agonists, have an improved neuropsychiatric side effect profile.

  1. The papain inhibitor (SPI) of Streptomyces mobaraensis inhibits bacterial cysteine proteases and is an antagonist of bacterial growth

    OpenAIRE

    Zindel, S.; Kaman, W.E.; Frols, S.; Pfeifer, F; Peters, A.; Hays, J.P.; Fuchsbauer, H.-L.

    2013-01-01

    A novel papain inhibitory protein (SPI) from Streptomyces mobaraensis was studied to measure its inhibitory effect on bacterial cysteine protease activity (Staphylococcus aureus SspB) and culture supernatants (Porphyromonas gingivalis, Bacillus anthracis). Further, growth of Bacillus anthracis, Staphylococcus aureus, Pseudomonas aeruginosa, and Vibrio cholerae was completely inhibited by 10 μM SPI. At this concentration of SPI, no cytotoxicity was observed. We conclude that SPI inhibits bacte...

  2. Levo-tetrahydropalmatine, a natural, mixed dopamine receptor antagonist, inhibits methamphetamine self-administration and methamphetamine-induced reinstatement.

    Science.gov (United States)

    Gong, Xiaokang; Yue, Kai; Ma, Baomiao; Xing, Junqiao; Gan, Yongping; Wang, Daisong; Jin, Guozhang; Li, Chaoying

    2016-05-01

    Despite the high prevalence of methamphetamine (METH) use, no FDA-approved pharmacological treatment is currently available for individuals with a METH addiction. Levo-tetrahydropalmatine (l-THP) is an alkaloid substance derived from corydalis and stephania that has been used in traditional Asian medicine for its analgesic, sedative and hypnotic properties. Previous pharmacological studies of l-THP indicated that it not only binds to D1 and D2 receptors but also has a low affinity for D3 receptors and may function as an antagonist. The unique pharmacological profile of l-THP suggests that it may have potential therapeutic effects on drug addiction; however, the effects of l-THP in individuals with METH addictions are largely unknown. In this study, we investigated the effects of l-THP on METH self-administration and METH-induced reinstatement. In our experiments, l-THP (1.25, 2.50 and 5.00 mg/kg, i.p.) decreased METH self-administration under the fixed-ratio 1 schedule. l-THP (2.50 and 5.00 mg/kg, i.p) also prevented the METH-induced reinstatement of METH-seeking behaviors. Interestingly, l-THP (1.25 and 2.50mg/kg, i.p) did not affect locomotor activity following METH injection (1mg/kg) suggesting that the observed effects of l-THP (2.50mg/kg) on METH-induced reinstatement were not due to motor impairments. Thus, l-THP (a natural, mixed dopamine (DA) receptor antagonist) attenuates METH self-administration and METH-induced reinstatement. PMID:26806555

  3. A substance P antagonist, [D-Pro2, D-Trp7,9]SP, inhibits inflammatory responses in the rabbit eye

    International Nuclear Information System (INIS)

    Neurogenic factors released by antidromic nerve stimulation are thought to be in part responsible for the vasodilation and breakdown of the blood-aqueous barrier that follows trauma to the eye. Substance P is one candidate for the mediation of the inflammatory response since it is thought to be a neurotransmitter in sensory afferents and since exogenous substance P is capable of eliciting a response characteristic of inflammation. In rabbits, intravitreal or topical application onto the eye of a specific substance P antagonist, [d-Pro2, D-Trp7,9]SP, inhibited not only the irritant effects of exogenous substance P but also the inflammatory response to a standardized trauma (infrared irradiation of the iris). These observations suggest that substance P, or a related peptide, is a neurogenic mediator of the inflammatory response in the eye

  4. Gastrin-releasing peptide receptor antagonist or N-acetylcysteine combined with omeprazol protect against mitochondrial complex II inhibition in a rat model of gastritis.

    Science.gov (United States)

    Rezin, Gislaine T; Petronilho, Fabricia C; Araújo, João H; Gonçalves, Cinara L; Daufenbach, Juliana F; Cardoso, Mariane R; Roesler, Rafael; Schwartsmann, Gilberto; Dal-Pizzol, Felipe; Streck, Emilio L

    2011-03-01

    The pathophysiology of gastritis involves an imbalance between gastric acid attack and mucosal defence. In addition, the gastric mucosal injury results in adenosine triphosphate (ATP) depletion leading to mitochondrial dysfunction. Several studies have shown the association of mitochondrial disorders with gastrointestinal dysfunction. In the present study, we investigated the activity of mitochondrial respiratory chain complexes activity in the stomach of rats with gastritis induced by indomethacin (IDM) and treated with omeprazole (OM), N-acetylcysteine (NAC) and the gastrin-releasing peptide receptor (GRPR) antagonist RC-3095. Adult male Wistar rats were pre-treated for 7 days with OM, NAC, RC-3095, combination of OM plus RC-3095, OM plus NAC and water (control). The animals were then submitted to fasting for 24 hr; IDM was administered. The rats were killed 6 hr later, and the stomachs were used for evaluation of macroscopic damage and respiratory chain activity. Our results showed that complex I and IV activities were not affected by administration of IDM. On the other hand, complex II and III activities were inhibited. In addition, OM plus RC-3095 and OM plus NAC did not reverse complex II activity inhibition. However, the complex III activity inhibition was reversed only with the combined use of OM plus RC-3095 and OM plus NAC. Our results are in agreement with previous studies indicating mitochondrial dysfunction in the pathophysiology of gastrointestinal tract disease and we suggest that GRPR antagonism might be a novel therapeutic strategy in gastritis. PMID:21138529

  5. NK4, an antagonist of hepatocyte growth factor (HGF), inhibits growth of multiple myeloma cells: molecular targeting of angiogenic growth factor.

    Science.gov (United States)

    Du, Wenlin; Hattori, Yutaka; Yamada, Taketo; Matsumoto, Kunio; Nakamura, Toshikazu; Sagawa, Morihiko; Otsuki, Takemi; Niikura, Takako; Nukiwa, Toshihiro; Ikeda, Yasuo

    2007-04-01

    Hepatocyte growth factor (HGF) promotes cell growth and motility and also increases neovascularization. Multiple myeloma (MM) cells produce HGF, and the plasma concentration of HGF is significantly elevated in patients with clinically active MM, suggesting that HGF might play a role in the pathogenesis of MM. NK4, an antagonist of HGF, is structurally homologous to angiostatin, and our previous report showed that NK4 inhibited the proliferation of vascular endothelial cells induced by HGF stimulation. The purposes of this study were to elucidate the contribution of HGF to the growth of MM cells as well as to investigate the possibility of the therapeutic use of NK4. In vitro study showed that NK4 protein stabilized the growth of MM cell lines and regulated the activation of c-MET, ERK1/2, STAT3, and AKT-1. Recombinant adenovirus containing NK4 cDNA (AdCMV.NK4) was injected intramuscularly into Icr/scid mice bearing tumors derived from HGF-producing MM cells. AdCMV.NK4 significantly inhibited the growth of these tumors in vivo. Histologic examination revealed that AdCMV.NK4 induced apoptosis of MM cells, accompanied by a reduction in neovascularization in the tumors. Thus, NK4 inhibited the growth of MM cells via antiangiogenic as well as direct antitumor mechanisms. The molecular targeting of HGF by NK4 could be applied as a novel therapeutic approach to MM. PMID:17179234

  6. The small-molecule IAP antagonist AT406 inhibits pancreatic cancer cells in vitro and in vivo.

    Science.gov (United States)

    Jiang, Yongsheng; Meng, Qinghua; Chen, Bo; Shen, Haiyu; Yan, Bing; Sun, Baoyou

    2016-09-01

    In the present study, we tested the anti-pancreatic cancer activity by AT406, a small-molecule antagonist of IAP (inhibitor of apoptosis proteins). In established (Panc-1 and Mia-PaCa-2 lines) and primary human pancreatic cancer cells, treatment of AT406 significantly inhibited cell survival and proliferation. Yet, same AT406 treatment was non-cytotoxic to pancreatic epithelial HPDE6c7 cells. AT406 increased caspase-3/-9 activity and provoked apoptosis in the pancreatic cancer cells. Reversely, AT406' cytotoxicity in these cells was largely attenuated with pre-treatment of caspase inhibitors. AT406 treatment caused degradation of IAP family proteins (cIAP1 and XIAP) and release of cytochrome C, leaving Bcl-2 unaffected in pancreatic cancer cells. Bcl-2 inhibition (by ABT-737) or shRNA knockdown dramatically sensitized Panc-1 cells to AT406. In vivo, oral administration of AT406 at well-tolerated doses downregulated IAPs (cIAP1/XIAP) and inhibited Panc-1 xenograft tumor growth in severe combined immunodeficient (SCID) nude mice. Together, our preclinical results suggest that AT406 could be further evaluated as a promising anti-pancreatic cancer agent. PMID:27387230

  7. ISO-1, a macrophage migration inhibitory factor antagonist, inhibits airway remodeling in a murine model of chronic asthma.

    Science.gov (United States)

    Chen, Pei-Fen; Luo, Ya-ling; Wang, Wei; Wang, Jiang-xin; Lai, Wen-yan; Hu, Si-ming; Cheng, Kai Fan; Al-Abed, Yousef

    2010-01-01

    Airway remodeling is the process of airway structural change that occurs in patients with asthma in response to persistent inflammation and leads to increasing disease severity. Drugs that decrease this persistent inflammation play a crucial role in managing asthma episodes. Mice sensitized (by intraperitoneal administration) and then challenged (by inhalation) with ovalbumin (OVA) develop an extensive eosinophilic inflammatory response, goblet cell hyperplasia, collagen deposition, airway smooth muscle thickening, and airway wall area increase, similar to pathologies observed in human asthma. We used OVA-sensitized/challenged mice as a murine model of chronic allergic airway inflammation with subepithelial fibrosis (i.e., asthma). In this OVA mouse model, mRNA and protein of macrophage migration inhibitory factor (MIF) are upregulated, a response similar to what has been observed in the pathogenesis of acute inflammation in human asthma. We hypothesized that MIF induces transforming growth factor-β1 (TGF-β1) synthesis, which has been shown to play an important role in asthma and airway remodeling. To explore the role of MIF in the development of airway remodeling, we evaluated the effects of an MIF small-molecule antagonist, (S,R)3-(4-hy-droxyphenyl)-4,5-dihydro-5-isoxazole acetic acid methyl ester (ISO-1), on pathologies associated with the airway-remodeling process in the OVA mouse model. We found that administration of ISO-1 significantly mitigated all symptoms caused by OVA treatment. In addition, the treatment of OVA-sensitized mice with the MIF antagonist ISO-1 significantly reduced TGF-β1 mRNA levels in pulmonary tissue and its protein level in bronchial alveolar lavage fluid supernatants. We believe the repression of MIF in the ISO-1 treatment group led to the significant suppression observed in the inflammatory responses associated with the allergen-induced lung inflammation and fibrosis in our murine asthma (OVA) model. Our results implicate a

  8. Identification of a novel antagonist of the ErbB1 receptor capable of inhibiting migration of human glioblastoma cells

    DEFF Research Database (Denmark)

    Staberg, Mikkel; Riemer, Christian; Xu, Ruodan;

    2013-01-01

    BACKGROUND: Receptors of the ErbB family are involved in the development of various cancers, and the inhibition of these receptors represents an attractive therapeutic concept. Upon ligand binding, ErbB receptors become activated as homo- or heterodimers, leading to the activation of downstream s...

  9. Inhibition of Aspergillus flavus in soil by antagonistic Pseudomonas strains reduces the potential for airborne spore dispersal

    Science.gov (United States)

    Pseudomonas chlororaphis strain JP1015 and Pseudomonas fluorescens strain JP2175 were previously isolated from Mississippi cornfield soil samples and selected for their growth inhibition of Aspergillus flavus in laboratory culture. In this study, the antifungal activity of these bacterial strains a...

  10. Salvianolic acid B inhibits platelets as a P2Y12 antagonist and PDE inhibitor: evidence from clinic to laboratory.

    Science.gov (United States)

    Liu, Lei; Li, Jian; Zhang, Yan; Zhang, Shenghui; Ye, Jianqin; Wen, Zhichao; Ding, Jianping; Kunapuli, Satya P; Luo, Xinping; Ding, Zhongren

    2014-10-01

    Salviae miltiorrhiza (Danshen) has been used for thousands of years in China and some other Asian countries to treat atherothrombotic diseases. Salvianolate which consists of three water-soluble ingredients purified from Salviae miltiorrhiza, has been approved by Chinese SFDA to treat coronary artery disease. So far, there is no evidence clearly showing the clinical efficiency of salvianolate and the underlying mechanism. This study is to evaluate the effects of salvianolate on platelets in patients with acute coronary syndrome and explore the underlying mechanism. We evaluated the effects of salvianolate on platelets in patients with acute coronary syndrome by measuring ADP-induced PAC-1 binding and P-selectin expression on platelets. Salvianolate significantly potentiated the antiplatelet effects of standard dual antiplatelet therapy. We also investigated the antiplatelet effects of salvianolatic acid B (Sal-B), the major component which composes 85% of salvianolate. Sal-B inhibits human platelet activation induced by multiple agonists in vitro by inhibiting phosphodiesterase (PDE) and antagonizing P2Y12 receptor. For the first time, we show the antiplatelet efficiency of salvianolate in ACS patients undergoing treatment with clopidogrel plus aspirin, and demonstrate that Sal-B, the major component of salvianolate inhibits human platelet activation via PDE inhibition and P2Y12 antagonism which may account for the clinical antiplatelet effects of salvianolate. Our results suggest that Sal-B may substitute salvianolate for clinical use. PMID:25077998

  11. Highly specific inhibition of leukaemia virus membrane fusion by interaction of peptide antagonists with a conserved region of the coiled coil of envelope

    Directory of Open Access Journals (Sweden)

    van Aalten Daan MF

    2008-08-01

    Full Text Available Abstract Background Human T-cell leukaemia virus (HTLV-1 and bovine leukaemia virus (BLV entry into cells is mediated by envelope glycoprotein catalyzed membrane fusion and is achieved by folding of the transmembrane glycoprotein (TM from a rod-like pre-hairpin intermediate to a trimer-of-hairpins. For HTLV-1 and for several virus groups this process is sensitive to inhibition by peptides that mimic the C-terminal α-helical region of the trimer-of-hairpins. Results We now show that amino acids that are conserved between BLV and HTLV-1 TM tend to map to the hydrophobic groove of the central triple-stranded coiled coil and to the leash and C-terminal α-helical region (LHR of the trimer-of-hairpins. Remarkably, despite this conservation, BLV envelope was profoundly resistant to inhibition by HTLV-1-derived LHR-mimetics. Conversely, a BLV LHR-mimetic peptide antagonized BLV envelope-mediated membrane fusion but failed to inhibit HTLV-1-induced fusion. Notably, conserved leucine residues are critical to the inhibitory activity of the BLV LHR-based peptides. Homology modeling indicated that hydrophobic residues in the BLV LHR likely make direct contact with a pocket at the membrane-proximal end of the core coiled-coil and disruption of these interactions severely impaired the activity of the BLV inhibitor. Finally, the structural predictions assisted the design of a more potent antagonist of BLV membrane fusion. Conclusion A conserved region of the HTLV-1 and BLV coiled coil is a target for peptide inhibitors of envelope-mediated membrane fusion and HTLV-1 entry. Nevertheless, the LHR-based inhibitors are highly specific to the virus from which the peptide was derived. We provide a model structure for the BLV LHR and coiled coil, which will facilitate comparative analysis of leukaemia virus TM function and may provide information of value in the development of improved, therapeutically relevant, antagonists of HTLV-1 entry into cells.

  12. Chikusetsusaponin IVa Butyl Ester (CS-IVa-Be), a Novel IL6R Antagonist, Inhibits IL6/STAT3 Signaling Pathway and Induces Cancer Cell Apoptosis.

    Science.gov (United States)

    Yang, Jie; Qian, Shihui; Cai, Xueting; Lu, Wuguang; Hu, Chunping; Sun, Xiaoyan; Yang, Yang; Yu, Qiang; Gao, S Paul; Cao, Peng

    2016-06-01

    The activation of IL6/STAT3 signaling is associated with the pathogenesis of many cancers. Agents that suppress IL6/STAT3 signaling have cancer-therapeutic potential. In this study, we found that chikusetsusaponin IVa butyl ester (CS-IVa-Be), a triterpenoid saponin extracted from Acanthopanas gracilistylus W.W.Smith, induced cancer cell apoptosis. CS-IVa-Be inhibited constitutive and IL6-induced STAT3 activation, repressed STAT3 DNA-binding activity, STAT3 nuclear translocation, IL6-induced STAT3 luciferase reporter activity, IL6-induced STAT3-regulated antiapoptosis gene expression in MDA-MB-231 cells, and IL6-induced TF-1 cell proliferation. Surprisingly, CS-IVa-Be inhibited IL6 family cytokines rather than other cytokines induced STAT3 activation. Further studies indicated that CS-IVa-Be is an antagonist of IL6 receptor via directly binding to the IL6Rα with a Kd of 663 ± 74 nmol/L and the GP130 (IL6Rβ) with a Kd of 1,660 ± 243 nmol/L, interfering with the binding of IL6 to IL6R (IL6Rα and GP130) in vitro and in cancer cells. The inhibitory effect of CS-IVa-Be on the IL6-IL6Rα-GP130 interaction was relatively specific as CS-IVa-Be showed higher affinity to IL6Rα than to LIFR (Kd: 4,910 ± 1,240 nmol/L) and LeptinR (Kd: 4,990 ± 915 nmol/L). We next demonstrated that CS-IVa-Be not only directly induced cancer cell apoptosis but also sensitized MDA-MB-231 cells to TRAIL-induced apoptosis via upregulating DR5. Our findings suggest that CS-IVa-Be as a novel IL6R antagonist inhibits IL6/STAT3 signaling pathway and sensitizes the MDA-MB-231 cells to TRAIL-induced cell death. Mol Cancer Ther; 15(6); 1190-200. ©2016 AACR. PMID:26929249

  13. Dopamine D2 receptor radiotracers [11C](+)-PHNO and [3H]raclopride are indistinguishably inhibited by D2 agonists and antagonists ex vivo

    International Nuclear Information System (INIS)

    Introduction: In vitro, the dopamine D2 receptor exists in two states, with high and low affinity for agonists. The high-affinity state is the physiologically active state thought to be involved in dopaminergic illnesses such as schizophrenia. The positron emission tomography radiotracer [11C](+)-PHNO ([11C](+)-4-propyl-3,4,4a,5,6,10b-hexahydro-2H-naphtho[1,2-b][1,4] oxazin-9-o l), being a D2 agonist, should selectively label the high-affinity state at tracer dose and therefore be more susceptible to competition by agonist as compared to the antagonist [3H]raclopride, which binds to both affinity states. Methods: We tested this prediction using ex vivo dual-radiotracer experiments in conscious rats. D2 antagonists (haloperidol or clozapine), a partial agonist (aripiprazole), a full agonist [(-)-NPA] or the dopamine-releasing drug amphetamine (AMPH) were administered to rats prior to an intravenous coinjection of [11C](+)-PHNO and [3H]raclopride. Rats were sacrificed 60 min after radiotracer injection. Striatum, cerebellum and plasma samples were counted for 11C and 3H. The specific binding ratio {SBR, i.e., [%ID/g (striatum)-%ID/g (cerebellum)]/(%ID/g (cerebellum)} was used as the outcome measure. Results: In response to D2 antagonists, partial agonist or full agonist, [11C](+)-PHNO and [3H]raclopride SBRs responded indistinguishably in terms of both ED50 and Hill slope (e.g., (-)-NPA ED50 values are 0.027 and 0.023 mg/kg for [11C](+)-PHNO and [3H]raclopride, respectively). In response to AMPH challenge, [11C](+)-PHNO and [3H]raclopride SBRs were inhibited to the same degree. Conclusions: We have shown that the SBRs of [11C](+)-PHNO- and [3H]raclopride do not differ in their response to agonist challenge. These results do not support predictions of the in vivo binding behavior of a D2 agonist radiotracer and cast some doubt on the in vivo applicability of the D2 two-state model, as described by in vitro binding experiments

  14. Dopamine D2 receptor radiotracers [{sup 11}C](+)-PHNO and [{sup 3}H]raclopride are indistinguishably inhibited by D2 agonists and antagonists ex vivo

    Energy Technology Data Exchange (ETDEWEB)

    McCormick, Patrick N. [Institute of Medical Science, University of Toronto, Toronto, Ontario, M5S 1A8 (Canada)], E-mail: patrick.mccormick@camhpet.ca; Kapur, Shitij [Department of Psychiatry, University of Toronto, Toronto, Ontario, M5S 1A8 (Canada); PET Center, Center for Addiction and Mental Health, Toronto, Ontario, M5T 1R8 (Canada); Seeman, Philip [Department of Psychiatry, University of Toronto, Toronto, Ontario, M5S 1A8 (Canada); Department of Pharmacology, University of Toronto, Toronto, Ontario, M5S 1A8 (Canada); Wilson, Alan A. [Department of Psychiatry, University of Toronto, Toronto, Ontario, M5S 1A8 (Canada); PET Center, Center for Addiction and Mental Health, Toronto, Ontario, M5T 1R8 (Canada)

    2008-01-15

    Introduction: In vitro, the dopamine D2 receptor exists in two states, with high and low affinity for agonists. The high-affinity state is the physiologically active state thought to be involved in dopaminergic illnesses such as schizophrenia. The positron emission tomography radiotracer [{sup 11}C](+)-PHNO ([{sup 11}C](+)-4-propyl-3,4,4a,5,6,10b-hexahydro-2H-naphtho[1,2-b][1,4] oxazin-9-o l), being a D2 agonist, should selectively label the high-affinity state at tracer dose and therefore be more susceptible to competition by agonist as compared to the antagonist [{sup 3}H]raclopride, which binds to both affinity states. Methods: We tested this prediction using ex vivo dual-radiotracer experiments in conscious rats. D2 antagonists (haloperidol or clozapine), a partial agonist (aripiprazole), a full agonist [(-)-NPA] or the dopamine-releasing drug amphetamine (AMPH) were administered to rats prior to an intravenous coinjection of [{sup 11}C](+)-PHNO and [{sup 3}H]raclopride. Rats were sacrificed 60 min after radiotracer injection. Striatum, cerebellum and plasma samples were counted for {sup 11}C and {sup 3}H. The specific binding ratio {l_brace}SBR, i.e., [%ID/g (striatum)-%ID/g (cerebellum)]/(%ID/g (cerebellum){r_brace} was used as the outcome measure. Results: In response to D2 antagonists, partial agonist or full agonist, [{sup 11}C](+)-PHNO and [{sup 3}H]raclopride SBRs responded indistinguishably in terms of both ED{sub 50} and Hill slope (e.g., (-)-NPA ED{sub 50} values are 0.027 and 0.023 mg/kg for [{sup 11}C](+)-PHNO and [{sup 3}H]raclopride, respectively). In response to AMPH challenge, [{sup 11}C](+)-PHNO and [{sup 3}H]raclopride SBRs were inhibited to the same degree. Conclusions: We have shown that the SBRs of [{sup 11}C](+)-PHNO- and [{sup 3}H]raclopride do not differ in their response to agonist challenge. These results do not support predictions of the in vivo binding behavior of a D2 agonist radiotracer and cast some doubt on the in vivo

  15. Retrovirus-mediated delivery of an IL-4 receptor antagonist inhibits allergic responses in a murine model of asthma

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    This work reports the investigation of the effect of airway IL-4RA gene transfer by a recombinant retroviral vector on airway inflammation and airway responsiveness in asthmatic mice. The retrovirus-mediated delivery of IL-4RA to the airways of mice inhibited elevations of airway responsiveness and the development of allergic inflammation in asthmatic mice, and regulated the Th1/Th2 balance in OVA-sensitized and -challenged mouse models. This suggests that gene therapy is a therapeutic option for treating and controlling chronic airway inflammation and asthma symptoms.

  16. A PAF receptor antagonist inhibits acute airway inflammation and late-phase responses but not chronic airway inflammation and hyperresponsiveness in a primate model of asthma

    Directory of Open Access Journals (Sweden)

    R. H. Gundel

    1992-01-01

    Full Text Available We have examined the effects of a PAF receptor antagonist, WEB 2170, on several indices of acute and chronic airway inflammation and associated changes in lung function in a primate model of allergic asthma. A single oral administration WEB 2170 provided dose related inhibition of the release of leukotriene C4 (LTC4 and prostaglandin D2 (PGD2 recovered and quantified in bronchoalveolar lavage (BAL fluid obtained during the acute phase response to inhaled antigen. In addition, oral WEB 2170 treatment in dual responder primates blocked the acute influx of neutrophils into the airways as well as the associated late-phase airway obstruction occurring 6 h after antigen inhalation. In contrast, a multiple dosing regime with WEB 2170 (once a day for 7 consecutive days failed to reduce the chronic airway inflammation (eosinophilic and associated airway hyperresponsiveness to inhaled methacholine that is characteristic of dual responder monkeys. Thus, we conclude that the generation of PAF following antigen inhalation contributes to the development of lipid mediators, acute airway inflammation and associated late-phase airway obstruction in dual responder primates; however, PAF does not play a significant role in the maintenance of chronic airway inflammation and associated airway hyperresponsiveness in this primate model.

  17. The antagonistic regulation of abscisic acid-inhibited root growth by brassinosteroids is partially mediated via direct suppression of ABSCISIC ACID INSENSITIVE 5 expression by BRASSINAZOLE RESISTANT 1.

    Science.gov (United States)

    Yang, Xiaorui; Bai, Yang; Shang, Jianxiu; Xin, Ruijiao; Tang, Wenqiang

    2016-09-01

    Brassinosteroids (BRs) and abscisic acid (ABA) are plant hormones that antagonistically regulate many aspects of plant growth and development; however, the mechanisms that regulate the crosstalk of these two hormones are still not well understood. BRs regulate plant growth and development by activating BRASSINAZOLE RESISTANT 1 (BZR1) family transcription factors. Here we show that the crosstalk between BRs and ABA signalling is partially mediated by BZR1 regulated gene expression. bzr1-1D is a dominant mutant with enhanced BR signalling; our results showed that bzr1-1D mutant is less sensitive to ABA-inhibited primary root growth. By RNA sequencing, a subset of BZR1 regulated ABA-responsive root genes were identified. Of these genes, the expression of a major ABA signalling component ABA INSENSITIVE 5 (ABI5) was found to be suppressed by BR and by BZR1. Additional evidences showed that BZR1 could bind strongly with several G-box cis-elements in the promoter of ABI5, suppress the expression of ABI5 and make plants less sensitive to ABA. Our study demonstrated that ABI5 is a direct target gene of BZR1, and modulating the expression of ABI5 by BZR1 plays important roles in regulating the crosstalk between the BR and ABA signalling pathways. PMID:27149247

  18. ACH-806, an NS4A antagonist, inhibits hepatitis C virus replication by altering the composition of viral replication complexes.

    Science.gov (United States)

    Yang, Wengang; Sun, Yongnian; Hou, Xiaohong; Zhao, Yongsen; Fabrycki, Joanne; Chen, Dawei; Wang, Xiangzhu; Agarwal, Atul; Phadke, Avinash; Deshpande, Milind; Huang, Mingjun

    2013-07-01

    Treatment of hepatitis C patients with direct-acting antiviral drugs involves the combination of multiple small-molecule inhibitors of distinctive mechanisms of action. ACH-806 (or GS-9132) is a novel, small-molecule inhibitor specific for hepatitis C virus (HCV). It inhibits viral RNA replication in HCV replicon cells and was active in genotype 1 HCV-infected patients in a proof-of-concept clinical trial (1). Here, we describe a potential mechanism of action (MoA) wherein ACH-806 alters viral replication complex (RC) composition and function. We found that ACH-806 did not affect HCV polyprotein translation and processing, the early events of the formation of HCV RC. Instead, ACH-806 triggered the formation of a homodimeric form of NS4A with a size of 14 kDa (p14) both in replicon cells and in Huh-7 cells where NS4A was expressed alone. p14 production was negatively regulated by NS3, and its appearance in turn was associated with reductions in NS3 and, especially, NS4A content in RCs due to their accelerated degradation. A previously described resistance substitution near the N terminus of NS3, where NS3 interacts with NS4A, attenuated the reduction of NS3 and NS4A conferred by ACH-806 treatment. Taken together, we show that the compositional changes in viral RCs are associated with the antiviral activity of ACH-806. Small molecules, including ACH-806, with this novel MoA hold promise for further development and provide unique tools for clarifying the functions of NS4A in HCV replication. PMID:23629709

  19. TSH-Mediated TNFα Production in Human Fibrocytes Is Inhibited by Teprotumumab, an IGF-1R Antagonist

    Science.gov (United States)

    Mester, Tünde; Wei, Yi-Hsuan; Douglas, Raymond S.

    2015-01-01

    Purpose Fibrocytes (FC) are bone marrow-derived progenitor cells that are more abundant and infiltrate the thyroid and orbit in Graves orbitopathy (GO). FCs express high levels of thyrotropin receptor (TSHR) and insulin-like growth factor-1 receptor (IGF-1R). These receptors are physically and functionally associated, but their role in GO pathogenesis is not fully delineated. Treatment of FCs with thyroid stimulating hormone (TSH) or M22 (activating antibody to TSHR) induces the production of numerous cytokines, including tumor necrosis factor α (TNFα). Teprotumumab (TMB) is a human monoclonal IGF-1R blocking antibody currently in clinical trial for GO and inhibits TSHR-mediated actions in FCs. Aim To characterize the molecular mechanisms underlying TSH-induced TNFα production by FCs, and the role of IGF-1R blockade by TMB. Design FCs from healthy and GD patients were treated with combinations of TSH, M22, MG132 and AKTi (inhibitors of NF-κB and Akt, respectively), and TMB. TNFα protein production was measured by Luminex and flow cytometry. Messenger RNA expression was quantified by real time PCR. Results Treatment with TSH/M22 induced TNFα protein and mRNA production by FCs, both of which were reduced when FCs were pretreated with MG132 and AKTi (p<0.0001). TMB decreased TSH-induced TNFα protein production in circulating FCs from mean fluorescent index (MFI) value of 2.92 to 1.91, and mRNA expression in cultured FCs from 141- to 52-fold expression (p<0.0001). TMB also decreased M22-induced TNFα protein production from MFI of 1.67 to 1.12, and mRNA expression from 6- to 3-fold expression (p<0.0001). Conclusion TSH/M22 stimulates FC production of TNFα mRNA and protein. This process involves the transcription factor NF-κB and its regulator Akt. Blocking IGF-1R attenuates TSH/M22-induced TNFα production. This further delineates the interaction of TSHR and IGF1-R signaling pathways. By modulating the proinflammatory properties of FCs such as TNFα production

  20. TSH-Mediated TNFα Production in Human Fibrocytes Is Inhibited by Teprotumumab, an IGF-1R Antagonist.

    Directory of Open Access Journals (Sweden)

    Hong Chen

    Full Text Available Fibrocytes (FC are bone marrow-derived progenitor cells that are more abundant and infiltrate the thyroid and orbit in Graves orbitopathy (GO. FCs express high levels of thyrotropin receptor (TSHR and insulin-like growth factor-1 receptor (IGF-1R. These receptors are physically and functionally associated, but their role in GO pathogenesis is not fully delineated. Treatment of FCs with thyroid stimulating hormone (TSH or M22 (activating antibody to TSHR induces the production of numerous cytokines, including tumor necrosis factor α (TNFα. Teprotumumab (TMB is a human monoclonal IGF-1R blocking antibody currently in clinical trial for GO and inhibits TSHR-mediated actions in FCs.To characterize the molecular mechanisms underlying TSH-induced TNFα production by FCs, and the role of IGF-1R blockade by TMB.FCs from healthy and GD patients were treated with combinations of TSH, M22, MG132 and AKTi (inhibitors of NF-κB and Akt, respectively, and TMB. TNFα protein production was measured by Luminex and flow cytometry. Messenger RNA expression was quantified by real time PCR.Treatment with TSH/M22 induced TNFα protein and mRNA production by FCs, both of which were reduced when FCs were pretreated with MG132 and AKTi (p<0.0001. TMB decreased TSH-induced TNFα protein production in circulating FCs from mean fluorescent index (MFI value of 2.92 to 1.91, and mRNA expression in cultured FCs from 141- to 52-fold expression (p<0.0001. TMB also decreased M22-induced TNFα protein production from MFI of 1.67 to 1.12, and mRNA expression from 6- to 3-fold expression (p<0.0001.TSH/M22 stimulates FC production of TNFα mRNA and protein. This process involves the transcription factor NF-κB and its regulator Akt. Blocking IGF-1R attenuates TSH/M22-induced TNFα production. This further delineates the interaction of TSHR and IGF1-R signaling pathways. By modulating the proinflammatory properties of FCs such as TNFα production, TMB may be a promising

  1. Inhibition of human prostate cancer cells proliferation by a selective alpha1-adrenoceptor antagonist labedipinedilol-A involves cell cycle arrest and apoptosis

    International Nuclear Information System (INIS)

    In this research, we conducted an in vitro analysis to evaluate the prostate cancer cells response to labedipinedilol-A in order to determine the effect of this selective α1-adrenoceptor antagonist to suppress prostate cancer cell growth by affecting cell proliferation and apoptosis. Here, we report that treatment of androgen-sensitive (LNCaP) and androgen-insensitive (PC-3) prostate cancer cells with labedipinedilol-A inhibited cell proliferation in concentration-dependent and time-dependent manners. Moreover, norepinephrine-stimulated proliferation of both cell lines are markedly inhibited by labedipinedilol-A. The probable involvement of α1-adrenoceptors in this cellular response is suggested. Labedipinedilol-A-induced growth inhibition was associated with G0/G1 arrest, and G2/M arrest depending upon concentrations. Cell cycle blockade was associated with reduced amounts of cyclin D1/2, cyclin E, Cdk2, Cdk4, and Cdk6 and increased levels of the Cdk inhibitory proteins (Cip1/p21 and Kip1/p27). In addition, labedipinedilol-A also induced apoptosis in PC-3 cells, as determined by using Hoechst 33342 staining, DNA fragmentation, and Annexin V staining assay. Furthermore, labedipinedilol-A triggered the mitochondrial apoptotic pathway, as indicated by increasing the expression of Bax, but decreasing the level of Bcl-2, resulting in mitochondrial membrane potential loss, cytochrome c release, and activation of caspase-9 and -3. We further investigated the role of MAPK cascades in the anti-proliferative and apoptosis effects of labedipinedilol-A, and confirmed that labedipinedilol-A could activate JNK1/2 but not p38 in both cell lines. Unlike JNK1/2, however, labedipinedilol-A treatment resulted in down-regulation of phospho-ERK1/2 expression. We concluded that labedipinedilol-A possessed the growth-suppressive and apoptotic effects on LNCaP and PC-3 cells by its α1-adrenoceptor blockade, and the apoptotic effects of labedipinedilol-A primarily through caspases and

  2. Protein kinase A antagonist inhibits β-catenin nuclear translocation, c-Myc and COX-2 expression and tumor promotion in ApcMin/+ mice

    Directory of Open Access Journals (Sweden)

    Brudvik Kristoffer W

    2011-12-01

    Full Text Available Abstract Background The adenomatous polyposis coli (APC protein is part of the destruction complex controlling proteosomal degradation of β-catenin and limiting its nuclear translocation, which is thought to play a gate-keeping role in colorectal cancer. The destruction complex is inhibited by Wnt-Frz and prostaglandin E2 (PGE2 - PI-3 kinase pathways. Recent reports show that PGE2-induced phosphorylation of β-catenin by protein kinase A (PKA increases nuclear translocation indicating two mechanisms of action of PGE2 on β-catenin homeostasis. Findings Treatment of ApcMin/+ mice that spontaneously develop intestinal adenomas with a PKA antagonist (Rp-8-Br-cAMPS selectively targeting only the latter pathway reduced tumor load, but not the number of adenomas. Immunohistochemical characterization of intestines from treated and control animals revealed that expression of β-catenin, β-catenin nuclear translocation and expression of the β-catenin target genes c-Myc and COX-2 were significantly down-regulated upon Rp-8-Br-cAMPS treatment. Parallel experiments in a human colon cancer cell line (HCT116 revealed that Rp-8-Br-cAMPS blocked PGE2-induced β-catenin phosphorylation and c-Myc upregulation. Conclusion Based on our findings we suggest that PGE2 act through PKA to promote β-catenin nuclear translocation and tumor development in ApcMin/+ mice in vivo, indicating that the direct regulatory effect of PKA on β-catenin nuclear translocation is operative in intestinal cancer.

  3. The Combination of Marketed Antagonists of α1b-Adrenergic and 5-HT2A Receptors Inhibits Behavioral Sensitization and Preference to Alcohol in Mice: A Promising Approach for the Treatment of Alcohol Dependence.

    Science.gov (United States)

    Trovero, Fabrice; David, Sabrina; Bernard, Philippe; Puech, Alain; Bizot, Jean-Charles; Tassin, Jean-Pol

    2016-01-01

    Alcohol-dependence is a chronic disease with a dramatic and expensive social impact. Previous studies have indicated that the blockade of two monoaminergic receptors, α1b-adrenergic and 5-HT2A, could inhibit the development of behavioral sensitization to drugs of abuse, a hallmark of drug-seeking and drug-taking behaviors in rodents. Here, in order to develop a potential therapeutic treatment of alcohol dependence in humans, we have blocked these two monoaminergic receptors by a combination of antagonists already approved by Health Agencies. We show that the association of ifenprodil (1 mg/kg) and cyproheptadine (1 mg/kg) (α1-adrenergic and 5-HT2 receptor antagonists marketed as Vadilex ® and Periactine ® in France, respectively) blocks behavioral sensitization to amphetamine in C57Bl6 mice and to alcohol in DBA2 mice. Moreover, this combination of antagonists inhibits alcohol intake in mice habituated to alcohol (10% v/v) and reverses their alcohol preference. Finally, in order to verify that the effect of ifenprodil was not due to its anti-NMDA receptors property, we have shown that a combination of prazosin (0.5 mg/kg, an α1b-adrenergic antagonist, Mini-Press ® in France) and cyproheptadine (1 mg/kg) could also reverse alcohol preference. Altogether these findings strongly suggest that combined prazosin and cyproheptadine could be efficient as a therapy to treat alcoholism in humans. Finally, because α1b-adrenergic and 5-HT2A receptors blockade also inhibits behavioral sensitization to psychostimulants, opioids and tobacco, it cannot be excluded that this combination will exhibit some efficacy in the treatment of addiction to other abused drugs. PMID:26968030

  4. The Combination of Marketed Antagonists of α1b-Adrenergic and 5-HT2A Receptors Inhibits Behavioral Sensitization and Preference to Alcohol in Mice: A Promising Approach for the Treatment of Alcohol Dependence.

    Directory of Open Access Journals (Sweden)

    Fabrice Trovero

    Full Text Available Alcohol-dependence is a chronic disease with a dramatic and expensive social impact. Previous studies have indicated that the blockade of two monoaminergic receptors, α1b-adrenergic and 5-HT2A, could inhibit the development of behavioral sensitization to drugs of abuse, a hallmark of drug-seeking and drug-taking behaviors in rodents. Here, in order to develop a potential therapeutic treatment of alcohol dependence in humans, we have blocked these two monoaminergic receptors by a combination of antagonists already approved by Health Agencies. We show that the association of ifenprodil (1 mg/kg and cyproheptadine (1 mg/kg (α1-adrenergic and 5-HT2 receptor antagonists marketed as Vadilex ® and Periactine ® in France, respectively blocks behavioral sensitization to amphetamine in C57Bl6 mice and to alcohol in DBA2 mice. Moreover, this combination of antagonists inhibits alcohol intake in mice habituated to alcohol (10% v/v and reverses their alcohol preference. Finally, in order to verify that the effect of ifenprodil was not due to its anti-NMDA receptors property, we have shown that a combination of prazosin (0.5 mg/kg, an α1b-adrenergic antagonist, Mini-Press ® in France and cyproheptadine (1 mg/kg could also reverse alcohol preference. Altogether these findings strongly suggest that combined prazosin and cyproheptadine could be efficient as a therapy to treat alcoholism in humans. Finally, because α1b-adrenergic and 5-HT2A receptors blockade also inhibits behavioral sensitization to psychostimulants, opioids and tobacco, it cannot be excluded that this combination will exhibit some efficacy in the treatment of addiction to other abused drugs.

  5. Toll-like receptor 4 (TLR4) antagonist eritoran tetrasodium attenuates liver ischemia and reperfusion injury through inhibition of high-mobility group box protein B1 (HMGB1) signaling.

    Science.gov (United States)

    Mcdonald, Kerry-Ann; Huang, Hai; Tohme, Samer; Loughran, Patricia; Ferrero, Kimberly; Billiar, Timothy; Tsung, Allan

    2014-01-01

    Toll-like receptor 4 (TLR4) is ubiquitously expressed on parenchymal and immune cells of the liver and is the most studied TLR responsible for the activation of proinflammatory signaling cascades in liver ischemia and reperfusion (I/R). Since pharmacological inhibition of TLR4 during the sterile inflammatory response of I/R has not been studied, we sought to determine whether eritoran, a TLR4 antagonist trialed in sepsis, could block hepatic TLR4-mediated inflammation and end organ damage. When C57BL/6 mice were pretreated with eritoran and subjected to warm liver I/R, there was significantly less hepatocellular injury compared to control counterparts. Additionally, we found that eritoran is protective in liver I/R through inhibition of high-mobility group box protein B1 (HMGB1)-mediated inflammatory signaling. When eritoran was administered in conjunction with recombinant HMGB1 during liver I/R, there was significantly less injury, suggesting that eritoran blocks the HMGB1-TLR4 interaction. Not only does eritoran attenuate TLR4-dependent HMGB1 release in vivo, but this TLR4 antagonist also dampened HMGB1's release from hypoxic hepatocytes in vitro and thereby weakened HMGB1's activation of innate immune cells. HMGB1 signaling through TLR4 makes an important contribution to the inflammatory response seen after liver I/R. This study demonstrates that novel blockade of HMGB1 by the TLR4 antagonist eritoran leads to the amelioration of liver injury. PMID:25375408

  6. Antianginal Actions of Beta-Adrenoceptor Antagonists

    OpenAIRE

    O'Rourke, Stephen T.

    2007-01-01

    Angina pectoris is usually the first clinical sign of underlying myocardial ischemia, which results from an imbalance between oxygen supply and oxygen demand in the heart. This report describes the pharmacology of β-adrenoceptor antagonists as it relates to the treatment of angina. The β-adrenoceptor antagonists are widely used in long-term maintenance therapy to prevent acute ischemic episodes in patients with chronic stable angina. Beta-adrenoceptor antagonists competitively inhibit the bin...

  7. A Novel Muscarinic Antagonist R2HBJJ Inhibits Non-Small Cell Lung Cancer Cell Growth and Arrests the Cell Cycle in G0/G1

    OpenAIRE

    Hua, Nan; Wei, Xiaoli; Liu, Xiaoyan; Ma, Xiaoyun; He, Xinhua; Zhuo, Rengong; Zhao, Zhe; Wang, Liyun; Yan, Haitao; Zhong, Bohua; Zheng, Jianquan

    2012-01-01

    Lung cancers express the cholinergic autocrine loop, which facilitates the progression of cancer cells. The antagonists of mAChRs have been demonstrated to depress the growth of small cell lung cancers (SCLCs). In this study we intended to investigate the growth inhibitory effect of R2HBJJ, a novel muscarinic antagonist, on non-small cell lung cancer (NSCLC) cells and the possible mechanisms. The competitive binding assay revealed that R2HBJJ had a high affinity to M3 and M1 AChRs. R2HBJJ pre...

  8. Amine-free melanin-concentrating hormone receptor 1 antagonists: Novel 1-(1H-benzimidazol-6-yl)pyridin-2(1H)-one derivatives and design to avoid CYP3A4 time-dependent inhibition.

    Science.gov (United States)

    Igawa, Hideyuki; Takahashi, Masashi; Shirasaki, Mikio; Kakegawa, Keiko; Kina, Asato; Ikoma, Minoru; Aida, Jumpei; Yasuma, Tsuneo; Okuda, Shoki; Kawata, Yayoi; Noguchi, Toshihiro; Yamamoto, Syunsuke; Fujioka, Yasushi; Kundu, Mrinalkanti; Khamrai, Uttam; Nakayama, Masaharu; Nagisa, Yasutaka; Kasai, Shizuo; Maekawa, Tsuyoshi

    2016-06-01

    Melanin-concentrating hormone (MCH) is an attractive target for antiobesity agents, and numerous drug discovery programs are dedicated to finding small-molecule MCH receptor 1 (MCHR1) antagonists. We recently reported novel pyridine-2(1H)-ones as aliphatic amine-free MCHR1 antagonists that structurally featured an imidazo[1,2-a]pyridine-based bicyclic motif. To investigate imidazopyridine variants with lower basicity and less potential to inhibit cytochrome P450 3A4 (CYP3A4), we designed pyridine-2(1H)-ones bearing various less basic bicyclic motifs. Among these, a lead compound 6a bearing a 1H-benzimidazole motif showed comparable binding affinity to MCHR1 to the corresponding imidazopyridine derivative 1. Optimization of 6a afforded a series of potent thiophene derivatives (6q-u); however, most of these were found to cause time-dependent inhibition (TDI) of CYP3A4. As bioactivation of thiophenes to form sulfoxide or epoxide species was considered to be a major cause of CYP3A4 TDI, we introduced electron withdrawing groups on the thiophene and found that a CF3 group on the ring or a Cl adjacent to the sulfur atom helped prevent CYP3A4 TDI. Consequently, 4-[(5-chlorothiophen-2-yl)methoxy]-1-(2-cyclopropyl-1-methyl-1H-benzimidazol-6-yl)pyridin-2(1H)-one (6s) was identified as a potent MCHR1 antagonist without the risk of CYP3A4 TDI, which exhibited a promising safety profile including low CYP3A4 inhibition and exerted significant antiobesity effects in diet-induced obese F344 rats. PMID:27112449

  9. Benzodiazepine receptor antagonists for hepatic encephalopathy

    DEFF Research Database (Denmark)

    Als-Nielsen, B; Gluud, L L; Gluud, C

    2004-01-01

    Hepatic encephalopathy may be associated with accumulation of substances that bind to a receptor-complex in the brain resulting in neural inhibition. Benzodiazepine receptor antagonists may have a beneficial effect on patients with hepatic encephalopathy.......Hepatic encephalopathy may be associated with accumulation of substances that bind to a receptor-complex in the brain resulting in neural inhibition. Benzodiazepine receptor antagonists may have a beneficial effect on patients with hepatic encephalopathy....

  10. ACTH Antagonists

    Science.gov (United States)

    Clark, Adrian John; Forfar, Rachel; Hussain, Mashal; Jerman, Jeff; McIver, Ed; Taylor, Debra; Chan, Li

    2016-01-01

    Adrenocorticotropin (ACTH) acts via a highly selective receptor that is a member of the melanocortin receptor subfamily of type 1 G protein-coupled receptors. The ACTH receptor, also known as the melanocortin 2 receptor (MC2R), is unusual in that it is absolutely dependent on a small accessory protein, melanocortin receptor accessory protein (MRAP) for cell surface expression and function. ACTH is the only known naturally occurring agonist for this receptor. This lack of redundancy and high degree of ligand specificity suggests that antagonism of this receptor could provide a useful therapeutic aid and a potential investigational tool. Clinical situations in which this could be useful include (1) Cushing’s disease and ectopic ACTH syndrome – especially while preparing for definitive treatment of a causative tumor, or in refractory cases, or (2) congenital adrenal hyperplasia – as an adjunct to glucocorticoid replacement. A case for antagonism in other clinical situations in which there is ACTH excess can also be made. In this article, we will explore the scientific and clinical case for an ACTH antagonist, and will review the evidence for existing and recently described peptides and modified peptides in this role. PMID:27547198

  11. HIV-1 entry inhibition by small-molecule CCR5 antagonists: A combined molecular modeling and mutant study using a high-throughput assay

    International Nuclear Information System (INIS)

    Based on the attrition rate of CCR5 small molecule antagonists in the clinic the discovery and development of next generation antagonists with an improved pharmacology and safety profile is necessary. Herein, we describe a combined molecular modeling, CCR5-mediated cell fusion, and receptor site-directed mutagenesis approach to study the molecular interactions of six structurally diverse compounds (aplaviroc, maraviroc, vicriviroc, TAK-779, SCH-C and a benzyloxycarbonyl-aminopiperidin-1-yl-butane derivative) with CCR5, a coreceptor for CCR5-tropic HIV-1 strains. This is the first study using an antifusogenic assay, a model of the interaction of the gp120 envelope protein with CCR5. This assay avoids the use of radioactivity and HIV infection assays, and can be used in a high throughput mode. The assay was validated by comparison with other established CCR5 assays. Given the hydrophobic nature of the binding pocket several binding models are suggested which could prove useful in the rational drug design of new lead compounds.

  12. Purification and partial characterization of a novel calcium-binding protein from Bacillus cereus T spores and inhibition of germination by calmodulin antagonists

    International Nuclear Information System (INIS)

    A novel calcium-binding protein has been purified from the dormant spores of Bacillus cereus T. B. cereus T spores were extensively washed, broken, and heated at 90 degree C for 2 min. Using calcium-dependent hydrophobic interaction chromatography plus DEAE-cellulose and hydroxylapatite columns, a single protein was obtained which possessed calcium-binding capacity and some characteristics of calmodulin. This heat-stable protein was retained by hydrophobic matrices or a calmodulin antagonist in a calcium-dependent manner. The crude spore extract displaced bovine brain calmodulin from its antibody in a radioimmunoassay and the immunoreactive specific activity of the partially purified fraction which eluted from phenyl-Sepharose was ca. 200-fold greater than the crude spore extract. Purity of this protein was verified by sodium dodecyl sulfate-polyarcylamide gel electrophoresis and reversed-phase HPLC. Calcium-binding ability was verified with a competitive calcium binding assay using Chelex-100 resin and 45Ca autoradiography. SDS-PAGE and amino acid composition indicated the molecular weight of the protein was 24-kDa. The effects of two calmodulin antagonists, trifluoperazine (TFP) and N-(6-aminohexyl)-5-chloro-1-naphthalene sulfonamide (W-7) on L-alanine-induced germination of Bacillus cereus T spores were examined by measuring commitment to germination, loss of heat resistance, release of calcium, decrease in optical density at 660 nm and phase-contrast microscopy

  13. D1 and D2 antagonists reverse the effects of appetite suppressants on weight loss, food intake, locomotion, and rebalance spiking inhibition in the rat NAc shell.

    Science.gov (United States)

    Kalyanasundar, B; Perez, Claudia I; Luna, Alvaro; Solorio, Jessica; Moreno, Mario G; Elias, David; Simon, Sidney A; Gutierrez, Ranier

    2015-07-01

    Obesity is a worldwide health problem that has reached epidemic proportions. To ameliorate this problem, one approach is the use of appetite suppressants. These compounds are frequently amphetamine congeners such as diethylpropion (DEP), phentermine (PHEN), and bupropion (BUP), whose effects are mediated through serotonin, norepinephrine, and dopaminergic pathways. The nucleus accumbens (NAc) shell receives dopaminergic inputs and is involved in feeding and motor activity. However, little is known about how appetite suppressants modulate its activity. Therefore, we characterized behavioral and neuronal NAc shell responses to short-term treatments of DEP, PHEN, and BUP. These compounds caused a transient decrease in weight and food intake while increasing locomotion, stereotypy, and insomnia. They evoked a large inhibitory imbalance in NAc shell spiking activity that correlated with the onset of locomotion and stereotypy. Analysis of the local field potentials (LFPs) showed that all three drugs modulated beta, theta, and delta oscillations. These oscillations do not reflect an aversive-malaise brain state, as ascertained from taste aversion experiments, but tracked both the initial decrease in weight and food intake and the subsequent tolerance to these drugs. Importantly, the appetite suppressant-induced weight loss and locomotion were markedly reduced by intragastric (and intra-NAc shell) infusions of dopamine antagonists SCH-23390 (D1 receptor) or raclopride (D2 receptor). Furthermore, both antagonists attenuated appetite suppressant-induced LFP oscillations and partially restored the imbalance in NAc shell activity. These data reveal that appetite suppressant-induced behavioral and neuronal activity recorded in the NAc shell depend, to various extents, on dopaminergic activation and thus point to an important role for D1/D2-like receptors (in the NAc shell) in the mechanism of action for these anorexic compounds. PMID:25972577

  14. GABAA receptor partial agonists and antagonists

    DEFF Research Database (Denmark)

    Krall, Jacob; Balle, Thomas; Krogsgaard-Larsen, Niels;

    2015-01-01

    A high degree of structural heterogeneity of the GABAA receptors (GABAARs) has been revealed and is reflected in multiple receptor subtypes. The subunit composition of GABAAR subtypes is believed to determine their localization relative to the synapses and adapt their functional properties to the...... antagonists have been essential in defining the tonic current but both remaining issues concerning the GABAARs involved and the therapeutic possibilities of modulating tonic inhibition underline the need for GABAAR antagonists with improved selectivity....

  15. Morphine, a potential antagonist of cisplatin cytotoxicity, inhibits cisplatin-induced apoptosis and suppression of tumor growth in nasopharyngeal carcinoma xenografts

    Science.gov (United States)

    Cao, Long-Hui; Li, Hui-Ting; Lin, Wen-Qian; Tan, Hong-Ying; Xie, Lan; Zhong, Zhong-Jian; Zhou, Jian-Hua

    2016-01-01

    Morphine is an opioid analgesic drug often used for pain relief in cancer patients. However, there is growing evidence that morphine may modulate tumor growth, progression and metastasis. In this study, we evaluated whether morphine modulates cisplatin-induced apoptosis in human nasopharyngeal carcinoma CNE-2 cells and whether morphine affects the antitumor activity of cisplatin on tumor growth in human nasopharyngeal carcinoma CNE-2 xenografts in nude mice. We showed that a pretreatment with morphine (1 μg/ml) inhibited the sensitivity of CNE-2 cells to cisplatin by inhibiting cisplatin-induced CNE-2 cell apoptosis, decreasing caspase-3 activity and increasing the Bcl-2/Bax ratio. However, a high dose of morphine (1000 μg/ml) had the opposite effect. We also showed that at a low dose, morphine enhances chemoresistance in an in vivo nasopharyngeal carcinoma (NPC) model by inhibiting cisplatin-induced apoptosis and decreasing neovascularization. Taken together, our results indicate that a low dose of morphine may lead to chemoresistance of cisplatin in NPC models in vitro and in vivo by inhibiting cisplatin-induced apoptosis and decreasing neovascularization. PMID:26729257

  16. Pharmacokinetics and Pharmacodynamics of Edoxaban, a Non-Vitamin K Antagonist Oral Anticoagulant that Inhibits Clotting Factor Xa.

    Science.gov (United States)

    Parasrampuria, Dolly A; Truitt, Kenneth E

    2016-06-01

    Edoxaban, a once daily non-vitamin K antagonist oral anticoagulant, is a direct, selective, reversible inhibitor of factor Xa (FXa). In healthy subjects, single oral doses of edoxaban result in peak plasma concentrations within 1.0-2.0 h of administration, followed by a biphasic decline. Exposure is approximately dose proportional for once daily doses of 15-150 mg. Edoxaban is predominantly absorbed from the upper gastrointestinal tract, and oral bioavailability is approximately 62 %. Food does not affect total exposure to edoxaban. The terminal elimination half-life in healthy subjects ranges from 10 to 14 h, with minimal accumulation upon repeat once daily dosing up to doses of 120 mg. The steady-state volume of distribution is approximately 107 L, and total clearance is approximately 22 L/h; renal clearance accounts for approximately 50 % of total clearance, while metabolism and biliary secretion account for the remaining 50 %. Intrinsic factors, such as age, sex and race, do not affect edoxaban pharmacokinetics after renal function is taken into account. Oral administration of edoxaban results in rapid changes in anticoagulatory biomarkers, with peak effects on anticoagulation markers (such as anti-FXa), the prothrombin time and the activated partial thromboplastin time occurring within 1-2 h of dosing. PMID:26620048

  17. Selective inhibition of acetaminophen oxidation and toxicity by cimetidine and other histamine H2-receptor antagonists in vivo and in vitro in the rat and in man.

    OpenAIRE

    Mitchell, M C; Schenker, S.; Speeg, K V

    1984-01-01

    Acetaminophen-induced hepatotoxicity results from hepatic enzymatic oxidation of acetaminophen to a toxic, electrophilic intermediate. Acetaminophen is ordinarily eliminated after conjugation with glucuronic acid and sulfate to nontoxic derivatives. Cimetidine has been shown to inhibit the hepatic oxidation of a number of drugs and to protect rats from acetaminophen-induced hepatic necrosis. The aim of this study was to define the mechanism by which cimetidine reduced acetaminophen-induced he...

  18. Quantification of the Contribution of GLP-1 to Mediating Insulinotropic Effects of DPP-4 Inhibition With Vildagliptin in Healthy Subjects and Patients With Type 2 Diabetes Using Exendin [9-39] as a GLP-1 Receptor Antagonist.

    Science.gov (United States)

    Nauck, Michael A; Kind, Joachim; Köthe, Lars D; Holst, Jens J; Deacon, Carolyn F; Broschag, Matthias; He, Yan Ling; Kjems, Lise; Foley, James

    2016-08-01

    We quantified the contribution of GLP-1 as a mediator of the therapeutic effects of dipeptidyl peptidase 4 (DPP-4) inhibition (vildagliptin) by using the GLP-1 receptor antagonist exendin [9-39] in patients with type 2 diabetes and in healthy subjects. Thirty-two patients with type 2 diabetes and 29 age- and weight-matched healthy control subjects were treated in randomized order with 100 mg once daily vildagliptin or placebo for 10 days. Meal tests were performed (days 9 and 10) without and with a high-dose intravenous infusion of exendin [9-39]. The main end point was the ratio of the areas under the curve (AUCs) of integrated insulin secretion rates (total AUCISR) and glucose (total AUCglucose) over 4 h after the meal. Vildagliptin treatment more than doubled responses of intact GLP-1 and glucose-dependent insulinotropic polypeptide and lowered glucose responses without changing AUCISR/AUCglucose in healthy subjects. Vildagliptin significantly increased this ratio by 10.5% in patients with type 2 diabetes, and exendin [9-39] reduced it (both P 39] was significantly smaller after vildagliptin treatment than after placebo treatment (P = 0.026) and was equivalent to 47 ± 5% of the increments due to vildagliptin. Thus, other mediators appear to contribute significantly to the therapeutic effects of DPP-4 inhibition. PMID:27207543

  19. An antagonist of the platelet-activating factor receptor inhibits adherence of both nontypeable Haemophilus influenzae and Streptococcus pneumoniae to cultured human bronchial epithelial cells exposed to cigarette smoke

    Directory of Open Access Journals (Sweden)

    Shukla SD

    2016-07-01

    cells. In silico analyses identified a binding pocket for PAF/WEB-2086 in the predicted PAFr structure.Conclusion: WEB-2086 represents an innovative class of candidate drugs for inhibiting PAFr-dependent lung infections caused by the main bacterial drivers of smoking-related COPD. Keywords: airway epithelium, NTHi, pneumococci, WEB-2086, platelet-activating factor receptor, PAFr antagonist

  20. Corticospinal control of antagonistic muscles in the cat.

    Science.gov (United States)

    Ethier, Christian; Brizzi, Laurent; Giguère, Dominic; Capaday, Charles

    2007-09-01

    We recently suggested that movement-related inter-joint muscle synergies are recruited by selected excitation and selected release from inhibition of cortical points. Here we asked whether a similar cortical mechanism operates in the functional linking of antagonistic muscles. To this end experiments were done on ketamine-anesthetized cats. Intracortical microstimulation (ICMS) and intramuscular electromyographic recordings were used to find and characterize wrist, elbow and shoulder antagonistic motor cortical points. Simultaneous ICMS applied at two cortical points, each evoking activity in one of a pair of antagonistic muscles, produced co-contraction of antagonistic muscle pairs. However, we found an obvious asymmetry in the strength of reciprocal inhibition; it was always significantly stronger on physiological extensors than flexors. Following intravenous injection of a single bolus of strychnine, a cortical point at which only a physiological flexor was previously activated also elicited simultaneous activation of its antagonist. This demonstrates that antagonistic corticospinal neurons are closely grouped, or intermingled. To test whether releasing a cortical point from inhibition allows it to be functionally linked with an antagonistic cortical point, one of three GABA(A) receptor antagonists, bicuculline, gabazine or picrotoxin, was injected iontophoretically at one cortical point while stimulation was applied to an antagonistic cortical point. This coupling always resulted in co-contraction of the represented antagonistic muscles. Thus, antagonistic motor cortical points are linked by excitatory intracortical connections held in check by local GABAergic inhibition, with reciprocal inhibition occurring at the spinal level. Importantly, the asymmetry of cortically mediated reciprocal inhibition would appear significantly to bias muscle maps obtained by ICMS in favor of physiological flexors. PMID:17880397

  1. From the Cover: Glutamate antagonists limit tumor growth

    Science.gov (United States)

    Rzeski, Wojciech; Turski, Lechoslaw; Ikonomidou, Chrysanthy

    2001-05-01

    Neuronal progenitors and tumor cells possess propensity to proliferate and to migrate. Glutamate regulates proliferation and migration of neurons during development, but it is not known whether it influences proliferation and migration of tumor cells. We demonstrate that glutamate antagonists inhibit proliferation of human tumor cells. Colon adenocarcinoma, astrocytoma, and breast and lung carcinoma cells were most sensitive to the antiproliferative effect of the N-methyl-D-aspartate antagonist dizocilpine, whereas breast and lung carcinoma, colon adenocarcinoma, and neuroblastoma cells responded most favorably to the -amino-3-hydroxy-5-methyl-4-isoxazole-propionate antagonist GYKI52466. The antiproliferative effect of glutamate antagonists was Ca2+ dependent and resulted from decreased cell division and increased cell death. Morphological alterations induced by glutamate antagonists in tumor cells consisted of reduced membrane ruffling and pseudopodial protrusions. Furthermore, glutamate antagonists decreased motility and invasive growth of tumor cells. These findings suggest anticancer potential of glutamate antagonists.

  2. Dual motor response to l-dopa and nociceptin/orphanin FQ receptor antagonists in 1-methyl-4-phenyl-1,2,5,6-tetrahydropyridine (MPTP) treated mice: Paradoxical inhibition is relieved by D(2)/D(3) receptor blockade.

    Science.gov (United States)

    Viaro, Riccardo; Marti, Matteo; Morari, Michele

    2010-06-01

    Motor activity of mice acutely treated with the parkinsonian toxin 1-methyl-4-phenyl-1,2,5,6-tetrahydropyridine (MPTP) was monitored for 6 days using behavioral tests which provide complementary information on motor function: the bar, reaction time, drag, stair climbing, grip, rotarod and footprinting tests. These tests consistently disclosed a prolonged motor impairment characterized by akinesia, bradykinesia, speed reduction, loss of coordination and gait patterns. This impairment was associated with approximately 60% loss of striatal dopamine terminals, as revealed by tyrosine hydroxylase immunohistochemistry, and was attenuated by dopaminergic drugs. Indeed, the dopamine precursor, l-dopa (1-10 mg/kg), and the D(3)/D(2) receptor agonist pramipexole (0.0001-0.001 mg/kg) promoted stepping activity in the drag test (a test for akinesia/bradykinesia). The novel nociceptin/orphanin FQ receptor (NOP) antagonist 1-[1-(cyclooctylmethyl)-1,2,3,6-tetrahydro-5-(hydroxymethyl)-4-pyridinyl]-3-ethyl-1,3-dihydro-2H-benzimidazol-2-one (Trap-101, 0.001-0.1 mg/kg), an analogue of 1-[(3R,4R)-1-cyclooctylmethyl-3-hydroxymethyl-4-piperidyl]-3-ethyl-1,3-dihydro-2H-benzimidazol-2-one (J-113397), also promoted stepping and synergistically or additively (depending on test) attenuated parkinsonism when combined to dopamine agonists. High doses of l-dopa (100 mg/kg), pramipexole (0.1 mg/kg), Trap-101 and J-113397 (1 mg/kg), however, failed to modulate stepping, worsening immobility time and/or rotarod performance. Low doses of amisulpride (0.1 mg/kg) reversed motor inhibition induced by l-dopa and J-113397, suggesting involvement of D(2)/D(3) receptors. This study brings further evidence for a dopamine-dependent motor phenotype in MPTP-treated mice reinforcing the view that this model can be predictive of symptomatic antiparkinsonian activity provided the appropriate test is used. Moreover, it offers mechanistic interpretation to clinical reports of paradoxical worsening of parkinsonism

  3. A Foldable Antagonistic Actuator

    OpenAIRE

    Shintake, Jun; Rosset, Samuel; Schubert, Bryan Edward; Floreano, Dario; Shea, Herbert

    2015-01-01

    We report on an actuator based on dielectric elastomers that is capable of antagonistic actuation and passive folding. This actuator enables foldability in robots with simple structures. Unlike other antagonistic dielectric elastomer devices, our concept uses elastic hinges to allow the folding of the structure, which also provides an additional design parameter. To validate the actuator concept through a specific application test, a foldable elevon actuator with outline size of 70 mm × 130 m...

  4. Inhibition Effect of Antagonist Yeasts on Postharvest Green Mold (Penicillum digitatum) of Shatangju Mandarin%拮抗酵母菌对沙糖桔采后绿霉病的抑制作用

    Institute of Scientific and Technical Information of China (English)

    黄雪梅; 汪跃华; 徐兰英; 庞学群; 张昭其

    2011-01-01

    The effects of 4 yeasts, Rhodotorula glutinis, Debaryomyces hansenii, Pichia membranaefaciens and Rhodotorula rubra, on the control of green mold (Penicillum digitatum ) were evaluated on harvested Citrus reticulata cv. ‘Shatangju’ fruit, by culturing both the yeast and the pathogen in nutrient yeast dextros agar (NYDB) suspension, and then inoculating the fruit with the cultures. Results showed that P. membranaefaciens and R. rubra apparently inhibited the germination and growth of P. digitatum spores. Adding 2%of NaHCO3 significantly increased the inhibitory effect of P. membranaefaciens while adding 2% of CaCl2 slightly enhanced the effect of R. rubra. The inoculation of fruit with these yeast preparations increased the chitinase activity in fruit peel The best inhibitory effect was the combination of P. membranaefaciens with 2%NaHCO3.The results suggested that P. membranaefaciens and R. rubra could be used as antagonists against postharvest Shatangju fruit rot, and that NaHCO3 was suitable as an active ingredient in commercial yeast preparations for its remarkably activating effect on chitinase which was thought to play an important role in combating fungus diseases in plants.%采用在NYDB上共培养酵母菌与绿霉菌Penicillium digitatum孢子、酵母菌防御接种沙糖桔果实后,挑战接种绿霉菌孢子的方法,研究了几株酵母菌对沙糖桔采后绿霉病的控制效果.结果表明,膜醭毕赤酵母Pichia membranae faciens Hansen和深红酵母Rhodotorula rubra Demme Lodder显著抑制绿霉菌孢子萌发和芽管生长,有效减少沙糖桔绿霉病发生率及病斑数;添加2%NaHCO3可增强膜醭毕赤酵母的抗病效果,添加2%CaCl2对深红酵母的抗病效果有轻微的增强作用.4个拮抗剂组合均能提高沙糖桔果皮几丁质酶活性,以添加2%NaHCO3的拮抗菌制剂的几丁质酶活性最高.膜醭毕赤酵母和深红酵母可作为防治沙糖桔采后病害的拮抗菌,NaHCO3适合作为膜醭

  5. Screening of antagonistic activity of microorganisms against Colletotrichum acutatum and Colletotrichum gloeosporioides

    OpenAIRE

    Živković Svetlana; Stojanović S.; Ivanović Ž.; Gavrilović V.; Popović Tatjana; Balaž Jelica

    2010-01-01

    The antagonistic activities of five biocontrol agents: Trichoderma harzianum, Gliocladium roseum, Bacillus subtilis, Streptomyces noursei and Streptomyces natalensis, were tested in vitro against Colletotrichum acutatum and Colletotrichum gloeosporioides, the causal agents of anthracnose disease in fruit crops. The microbial antagonists inhibited mycelial growth in the dual culture assay and conidial germination of Colletotrichum isolates. The two Streptomyces species exhibited the strongest ...

  6. Impact of Trichoderma spp. on Soybean Seed Germination and Potential Antagonistic Effect on Sclerotinia sclerotiorum

    OpenAIRE

    Sonja Tančić; Jelica Skrobonja; Mirjana Lalošević; Radivoje Jevtić; Miloš Vidić

    2013-01-01

    Trichoderma species have been registered as species with important plant growth promoting potential and antagonistic effect against various phytopathogens. Trichoderma isolates originating from different soil types from the Vojvodina region (Serbia) were screened using dual culture test for their antagonistic effect against the pathogen Sclerotinia sclerotiorum. All tested isolates had high radial growth inhibition (RGI) factors of the pathogen and high col...

  7. Selective orexin receptor antagonists.

    Science.gov (United States)

    Lebold, Terry P; Bonaventure, Pascal; Shireman, Brock T

    2013-09-01

    The orexin, or hypocretin, neuropeptides (orexin-A and orexin-B) are produced on neurons in the hypothalamus which project to key areas of the brain that control sleep-wake states, modulation of food intake, panic, anxiety, emotion, reward and addictive behaviors. These neuropeptides exert their effects on a pair of G-protein coupled receptors termed the orexin-1 (OX1) and orexin-2 (OX2) receptors. Emerging biology suggests the involvement of these receptors in psychiatric disorders as they are thought to play a key role in the regulation of multiple systems. This review is intended to highlight key selective OX1 or OX2 small-molecule antagonists. PMID:23891187

  8. About the use of antagonistic bacteria and fungi

    OpenAIRE

    Tilcher, R.; Schmidt, C.; Lorenz, D.; Wolf, G. A.

    2002-01-01

    Microorganisms isolated from the phylloplane of vine and cereal plants inhibiting different phytopathogenic fungi were tested as biological control agents against Plasmopara viticola (downy mildew of grapevine). Based on screening in vitro against Phytophthora infestans, P. parasitica, Pythium ultimum, Botrytis cinerea 62 bacterial isolates were selected for tests with Plasmopara viticola.. Antifungal bacterial strains were assayed for antagonistic activity towards the grapevine dieback fungu...

  9. Medium-Induced Antagonistic Behavior in Staphylococcus Aureus.

    Science.gov (United States)

    Benathen, Isaiah A.

    1992-01-01

    Antagonism is the production of substances by microorganisms that inhibit or prevent the growth of other bacteria. This paper demonstrates the antagonistic behavior of gram-positive coccus on the B. subtilis and Enterococcus faecalis gram-positive microorganisms, showing that the process of antagonism is sometimes dependent on the nutritional…

  10. Bicycloorthocarboxylate convulsants. Potent GABAA receptor antagonists

    International Nuclear Information System (INIS)

    4-t-Butyl-1-(4-bromophenyl)-bicycloorthocarboxylate antagonizes gamma-aminobutyric acid (GABA)-mediated relaxation at a functional insect nerve-muscle synapse, mimicking the action of picrotoxinin, suggesting that it causes GABA antagonism through blockade of the chloride ionophore. It is also a potent GABAA receptor antagonist, inhibiting the binding of [35S]t-butyl-bicyclophosphorothionate ([35S]TBPS) to EDTA/water-dialyzed human brain P2 membranes. Structure-activity relationships of 74 1,4-bis-substituted bicycloorthocarboxylates, mostly new compounds, reveal that for high potency as a GABAA receptor antagonist the optimal 4-substituent is a C4 to C6 branched chain alkyl or cycloalkyl group (e.g., t-butyl, s-butyl, or cyclohexyl) and the optimal 1-substituent is a phenyl moiety with one or more electron-withdrawing groups (e.g., 4-cyano, 4-bromo, 4-chloro, 3,4-dichloro, or pentafluoro). Bicycloorthocarboxylate inhibitors of [35S]TBPS binding with IC50 values of 5-10 nM exceed by several-fold the potency of any GABAA receptor antagonist previously reported. The 4-t-butyl-1-(4-azidophenyl) analog, synthesized as a candidate photoaffinity label, gives an IC50 of 315 nM. The potency of bicycloorthocarboxylates for decreasing [35S]TBPS binding generally correlates with their toxicity, i.e., compounds without inhibitory activity in this brain receptor assay are of low toxicity on intraperitoneal administration to mice, and the analogs most potent as inhibitors are generally those most toxic to mice (e.g., IC50 of 5 nM and LD50 of 0.06 mg/kg for 4-t-butyl-1-(4-cyanophenyl)-bicycloorthocarboxylate). The effects of phenyl substituents on the potency of the orthobenzoates as GABAA receptor antagonists are similar to those on toxicity

  11. A novel antagonistic role of natural compound icariin on neurotoxicity of amyloid β peptide

    Directory of Open Access Journals (Sweden)

    Jianhui Liu

    2015-01-01

    Interpretation & conclusions: The results indicated a novel antagonistic role of icariin in the neurotoxicity of Aβ1-42 via inhibiting its aggregation, suggesting that icariin might have potential therapeutic benefits to delay or modify the progression of AD.

  12. 拮抗菌C23对松苗猝倒病原菌的抑制效果及在松苗根际的定殖%Inhibition Effect of Antagonistic Bacteria C23 on Pathogens of Damping-off and Colonization in the Rhizosphere of Slash Pine

    Institute of Scientific and Technical Information of China (English)

    霍宪起; 陈京元

    2009-01-01

    C23 of Burkhloderia cepacia was one antagonistic bacteria from Slash pine roots. After the antagonistic bacterica were cultured for two days, their culture exerted obvious inhibition on pathogenic fungi of Slash pine damping-off such as Rhizoctonia solani and Alternaria alternata. But C23 didn't show any inhibition on Fusarium sp. In the indoor experiment, C23 showed certain control effects. But outdoor, C23 didn't show any prevention effect. Strain C23 could be colonized in Slash pine root. But the distribution of C23 in different parts of the root showed no rules. In the process of colonization, the number of C23 kept rising with the time passing. Forty days later, there was the most amount of C23 within the root, then gradually reduced.%洋葱伯克霍尔德菌C23是一株从湿地松根部分离到的拮抗细菌.在培养2d后,其培养物对丝核菌(Rhizoctonia solani)和链格孢菌(Alternara alternata)均表现出明显抑制效果,但对镰刀菌(Fusarium sp)几乎 没有抑制作用.在室内防病试验时,C23表现出一定的防病效果,但在室外,没有表现出防病效果.菌株C23可在湿地松根部定殖,但是在根部不同部位的分布并没有规律可循.在定殖过程中,C23菌株在松苗根部的菌量随着时间的增长而增加.接种后40d,菌量达到峰值,而后数量逐渐减少.

  13. Biocontrol of Some Tomato Disease Using Some Antagonistic Microorganisms

    Directory of Open Access Journals (Sweden)

    Ilham M. El–Rafai

    2003-01-01

    Full Text Available Four biocontrol�agents, namely : Trichoderma harzianum, T. hamatum, Bacillus subtilis and Pseudomonas fluorescens, have been tested for their potential antagonism for controlling fusarium wilt, verticillium wilt and early blight diseases of tomato. In vitro studies showed that culture filtrates of all antagonistic organisms significantly decrease the spore germination and germ tube-length of the tested pathogens, F. oxysporum f. sp. lycopersici, Verticillium dahliae and Alternaria solani. The linear growth and sporulation of the concerned pathogens were also inhibited the degree of inhibition was varied according to the tested antagonistic filtrate. In vivo studies, three treatments were applied; inoculation of the soil with antagonist period to sowing, soaking tomato seeds in the filtrate of the tested antagonist before sowing and coating of tomato seeds with spores of the antagonist before planting. Soil inoculation and seed coating with T. hamatum spores completely controlled the concerned diseases and improved the yield. However, P. fluorescens seed coating controlled the early blight disease and improved the tomato growth as well. Concerning the chemical assessment, T. hamatum soil inoculation and seed coating treatments gave the highest increase for chlorophyll a, b and cartenoids. Also the same treatments showed the highest increase of phenolic compounds (free and conjugated and the lowest percentage for sugars content of tomato leaves infected with the concerned pathogens.

  14. Discovery of small molecule antagonists of TRPV1.

    Science.gov (United States)

    Rami, Harshad K; Thompson, Mervyn; Wyman, Paul; Jerman, Jeffrey C; Egerton, Julie; Brough, Stephen; Stevens, Alexander J; Randall, Andrew D; Smart, Darren; Gunthorpe, Martin J; Davis, John B

    2004-07-16

    Small molecule antagonists of the vanilloid receptor 1 (TRPV1, also known as VR1) are disclosed. Ureas such as 5 (SB-452533) were used to explore the structure activity relationship with several potent analogues identified. Pharmacological studies using electrophysiological and FLIPR Ca(2+) based assays showed compound 5 was an antagonist versus capsaicin, noxious heat and acid mediated activation of TRPV1. Study of a quaternary salt of 5 supports a mode of action in which compounds from this series cause inhibition via an extracellularly accessible binding site on the TRPV1 receptor. PMID:15203132

  15. [Antagonistic properties of Lactobacillus plantarum strains, isolated from traditional fermented products of Ukraine].

    Science.gov (United States)

    Vasyliuk, O M; Kovalenko, N K; Harmasheva, I L

    2014-01-01

    The antagonistic activity of 109 lactobacillus strains, isolated from traditional fermented products of Ukraine, has been investigated and it has been shown that the significant part of strains show different levels of inhibition of opportunistic and phytopathogenic microorganisms. It has been shown that the antagonistic effect of Lactobacillus plantarum strains on the opportunistic and phytopathogenic microorganisms was dependent on the sources of Lactobacillus strains isolation. L. plantarum strains show a higher level of inhibition against phytopathogenic microorganisms than opportunistic test-strains. Eleven strains of L. plantarum demonstrated antagonistic activity for all used test-strains. PMID:25007440

  16. The muscarinic antagonists scopolamine and atropine are competitive antagonists at 5-HT3 receptors.

    Science.gov (United States)

    Lochner, Martin; Thompson, Andrew J

    2016-09-01

    Scopolamine is a high affinity muscarinic antagonist that is used for the prevention of post-operative nausea and vomiting. 5-HT3 receptor antagonists are used for the same purpose and are structurally related to scopolamine. To examine whether 5-HT3 receptors are affected by scopolamine we examined the effects of this drug on the electrophysiological and ligand binding properties of 5-HT3A receptors expressed in Xenopus oocytes and HEK293 cells, respectively. 5-HT3 receptor-responses were reversibly inhibited by scopolamine with an IC50 of 2.09 μM. Competitive antagonism was shown by Schild plot (pA2 = 5.02) and by competition with the 5-HT3 receptor antagonists [(3)H]granisetron (Ki = 6.76 μM) and G-FL (Ki = 4.90 μM). The related molecule, atropine, similarly inhibited 5-HT evoked responses in oocytes with an IC50 of 1.74 μM, and competed with G-FL with a Ki of 7.94 μM. The reverse experiment revealed that granisetron also competitively bound to muscarinic receptors (Ki = 6.5 μM). In behavioural studies scopolamine is used to block muscarinic receptors and induce a cognitive deficit, and centrally administered concentrations can exceed the IC50 values found here. It is therefore possible that 5-HT3 receptors are also inhibited. Studies that utilise higher concentrations of scopolamine should be mindful of these potential off-target effects. PMID:27108935

  17. Selection of Antagonistic Bacteria against Citrus Green Mold and Its Inhibition Activity on Shatang Mandarin Fruit%柑桔绿霉病拮抗细菌的筛选、鉴定及其抑制效果

    Institute of Scientific and Technical Information of China (English)

    郝卫宁; 李辉; 胡美英; 耿鹏; 杨柳

    2011-01-01

    A bacterial strain HC-03, isolated from rhizosphere soil of citrus fanns, exhibited extensive antagonistic effect on 12 fruit pathogens. The strain was identified as Bacillus amyloliquefaciens based on 16S rDNA sequence homology, specific PCR detection, physiological and biochemical characteristics and morphological observation. Effect of different treatments of strain HC-03 against disease caused by Penicillium digitatum on inoculated shatang mandarin was also investigated. Results showed that citrus green mold incidence of shatang mandarin treated by cell culture, cell-free filtrate and cell suspension of strain HC-03 were all less than 20%, and lesion diameter were all below 10 mm.%从采集的柑桔园根际土壤中筛选得到1株对柑桔绿霉菌Penicillium digitatum具有较强拮抗活性的菌株HC-03.该菌株对柑桔绿霉菌、柑桔青霉菌Penicillium italicum、柑桔酸腐菌Geotrichum candidum等12种水果病原菌均有不同程度的拮抗作用,表现出广谱抗菌活性.菌落形态观察、生理生化特性分析及16S rDNA 序列测定和特异性PCR检测结果表明,该菌株为解淀粉芽孢杆菌Bacillus amyloliquefaciens.对沙糖桔的活体接种试验表明,菌株HC-03的发酵液、菌悬液及发酵滤液处理柑桔绿霉病的发生率均低于20%,病斑直径均在10mm以下.

  18. The Cultivation of Antagonistic Bacteria in Irradiated Sludge for Biological Control of Soft Rot Erwinias : Screening of Antagonistic Bacteria for biological Control of Soft Rot Erwinias

    International Nuclear Information System (INIS)

    Pure cultures of 57 bacterial isolates for antagonistic activity screening were isolated from three areas of soft rot infested vegetable soil and 58 isolates were obtained from commercial seed compost and seed compost product of Division of Soil and Water Conservation, Department of Land Development. A total of 115 bacterial isolates were evaluated for antagonizing activity against Erwinia carotovora subsp. atroceptica in vitro. Out of them, 18 isolates were antagonists by showing zone of inhibition ranging from 1 to 17 mm by diameter. Most of antagonistic bacteria were identified as Bacillus spp. whereas only one isolate was Pseudomonas vesicularis

  19. Effect of calmodulin antagonists on contraction and45Ca movements in rat aorta

    NARCIS (Netherlands)

    Wermelskirchen, D.; Koch, P.; Wilhelm, D.; Nebel, U.; Leidig, A.; Wilffert, B.; Peters, Thies

    1989-01-01

    To study the selectivity of calmodulin antagonists it was assumed that they should inhibit noradrenaline (NA)- and K+-induced contractions similarly without an accompanying inhibition of45Ca uptake. Therefore, in isolated rat aorta the effects of W-7, calmidazolium and trifluoperazine on contraction

  20. Construction, purification, and characterization of a chimeric TH1 antagonist

    Directory of Open Access Journals (Sweden)

    Javier-González Luís

    2006-05-01

    Full Text Available Abstract Background TH1 immune response antagonism is a desirable approach to mitigate some autoimmune and inflammatory reactions during the course of several diseases where IL-2 and IFN-γ are two central players. Therefore, the neutralization of both cytokines could provide beneficial effects in patients suffering from autoimmune or inflammatory illnesses. Results A chimeric antagonist that can antagonize the action of TH1 immunity mediators, IFN-γ and IL-2, was designed, engineered, expressed in E. coli, purified and evaluated for its in vitro biological activities. The TH1 antagonist molecule consists of the extracellular region for the human IFNγ receptor chain 1 fused by a four-aminoacid linker peptide to human 60 N-terminal aminoacid residues of IL-2. The corresponding gene fragments were isolated by RT-PCR and cloned in the pTPV-1 vector. E. coli (W3110 strain was transformed with this vector. The chimeric protein was expressed at high level as inclusion bodies. The protein was partially purified by pelleting and washing. It was then solubilized with strong denaturant and finally refolded by gel filtration. In vitro biological activity of chimera was demonstrated by inhibition of IFN-γ-dependent HLA-DR expression in Colo 205 cells, inhibition of IFN-γ antiproliferative effect on HEp-2 cells, and by a bidirectional effect in assays for IL-2 T-cell dependent proliferation: agonism in the absence versus inhibition in the presence of IL-2. Conclusion TH1 antagonist is a chimeric protein that inhibits the in vitro biological activities of human IFN-γ, and is a partial agonist/antagonist of human IL-2. With these attributes, the chimera has the potential to offer a new opportunity for the treatment of autoimmune and inflammatory diseases.

  1. Alternation of Agonists and Antagonists During Turtle Hindlimb Motor Rhythms

    OpenAIRE

    Stein, Paul S.G.

    2010-01-01

    In a variety of vertebrates, including turtle, many classical and contemporary studies of spinal cord neuronal networks generating rhythmic motor behaviors emphasize a Reciprocal Model with alternation of agonists and antagonists, alternation of excitatory and inhibitory postsynaptic potentials, and reciprocal inhibition. Some studies of spinal cord neuronal networks, including those in turtle during scratch motor rhythms, describe a Balanced Model with concurrent excitatory and inhibitory po...

  2. Excitatory amino acid receptor antagonists

    DEFF Research Database (Denmark)

    Johansen, T N; Frydenvang, Karla Andrea; Ebert, B;

    1997-01-01

    We have previously shown that (RS)-2-amino-2-(5-tert-butyl-3-hydroxyisoxazol-4-yl)acetic acid (ATAA) is an antagonist at N-methyl-D-aspartic acid (NMDA) and (RS)-2-amino-3-(3-hydroxy-5-methylisoxazol-4-yl)propionic acid (AMPA) receptors. We have now resolved ATAA via diastereomeric salt formation...

  3. Biological Control of Apple Anthracnose by Paenibacillus polymyxa APEC128, an Antagonistic Rhizobacterium

    OpenAIRE

    Kim, Young Soo; Balaraju, Kotnala; Jeon, Yongho

    2016-01-01

    The present study investigated the suppression of the disease development of anthracnose caused by Colletotrichum gloeosporioides and C. acutatum in harvested apples using an antagonistic rhizobacterium Paenibacillus polymyxa APEC128 (APEC128). Out of 30 bacterial isolates from apple rhizosphere screened for antagonistic activity, the most effective strain was APEC128 as inferred from the size of the inhibition zone. This strain showed a greater growth in brain-heart infusion (BHI) broth comp...

  4. Therapeutic potential for cytokine antagonists: Thalidomide and pentoxifylline in Hansen’s disease

    OpenAIRE

    1995-01-01

    Cytokine antagonists are a group of drugs defined by their actions on specific cytokines. Cytokine antagonists can inhibit action of cytokines by acting directly on receptors, by affecting production of cytokines or by binding to cytokines and preventing their subsequent action. Recent evidence suggests that Hansen’s disease, which is characterized by reactional states, is associated with elevated serum levels of tumour necrosis factor-α (tnf-α) and interleukin-1β during these reactional stat...

  5. Effect of calmodulin antagonists on the growth and graviresponsiveness of primary roots of maize

    Science.gov (United States)

    Stinemetz, C. L.; Hasenstein, K. H.; Young, L. M.; Evans, M. L.

    1992-01-01

    We examined the effect of calmodulin (CaM) antagonists applied at the root tip on root growth, gravity-induced root curvature, and the movement of calcium across the root tip and auxin (IAA) across the elongation zone of gravistimulated roots. All of the CaM antagonists used in these studies delayed gravity-induced curvature at a concentration (1 micromole) that did not affect root growth. Calmodulin antagonists (> or = 1 micromole) inhibited downward transport of label from 45Ca2+ across the caps of gravistimulated roots relative to the downward transport of 45Ca2+ in gravistimulated roots which were not treated with CaM antagonists. Application of CaM antagonists at the root tip (> or = 1 micromole) also decreased the relative downward movement of label from 3H-IAA applied to the upper side of the elongation zone of gravistimulated roots. In general, tip application of antagonists inhibited neither the upward transport of 45Ca2+ in the root tip nor the upward movement of label from 3H-IAA in the elongation zone of gravistimulated roots. Thus, roots treated with CaM antagonists > or = 1 micromole become less graviresponsive and exhibit reduced or even a reversal of downward polarity of calcium transport across the root tip and IAA transport across the elongation zone. The results indicate that calmodulin-regulated events play a role in root gravitropism.

  6. The effect of H 1 and H 2 receptor antagonists on melanogenesis

    Directory of Open Access Journals (Sweden)

    Tag S Anbar

    2012-01-01

    Full Text Available Background: Histamine was found to stimulate melanogenesis in cultured human melanocytes specifically mediated by histamine H 2 receptors via protein kinase A activation. Based on this finding, the effect of topically applied H 2 antagonist on UVB-irradiated Guinea pigs′ skin was examined and found to be suppressive on the post-irradiation melanogenesis. Aims: In this study, we tried to explore the role of topically applied H 1 and H 2 receptor antagonists, in inhibition of UVB-induced melanization. Methods: The effect of topically applied H 1 and H 2 receptor antagonists in inhibition of melanization was done clinically and histochemically using Fontana Masson and DOPA reactions compared with placebo. Results: The post-irradiation pigmentation was found to be brownish/black instead of the original light brown color. This color change occurred below the shaved orange-red fur suggesting a switch of melanogenesis from pheomelanin to eumelanin. The induced pigmentation was suppressed by topically applied H 2 antagonist while both H 1 antagonist and vehicle had no effect. The microscopic examination showed that the keratinocytes in the H 2 antagonist-treated areas contained few melanosomes while the nearby dendrites are full of them. Conclusion: H 2 antagonists′ inhibition of UVB-induced pigmentation is not only due to suppression of melanization but also due to a specific action on melanosomes′ transfer.

  7. Identification of short-acting κ-opioid receptor antagonists with anxiolytic-like activity.

    Science.gov (United States)

    Peters, Matthew F; Zacco, Anna; Gordon, John; Maciag, Carla M; Litwin, Linda C; Thompson, Carolann; Schroeder, Patricia; Sygowski, Linda A; Piser, Timothy M; Brugel, Todd A

    2011-07-01

    The κ-opioid receptor plays a central role in mediating the response to stressful life events. Inhibiting κ-opioid receptor signaling is proposed as a mechanism for treating stress-related conditions such as depression and anxiety. Preclinical testing consistently confirms that disruption of κ-opioid signaling is efficacious in animal models of mood disorders. However, concerns about the feasibility of developing antagonists into drugs stem from an unusual pharmacodynamic property of prototypic κ-opioid receptor-selective antagonists; they inhibit receptor signaling for weeks to months after a single dose. Several fundamental questions include - is it possible to identify short-acting antagonists; is long-lasting inhibition necessary for efficacy; and is it safe to develop long-acting antagonists in the clinic. Here, we test representative compounds (AZ-ECPC, AZ-MTAB, and LY-DMPF) from three new chemical series of κ-opioid receptor ligands for long-lasting inhibition. Each compound dose-dependently reversed κ-opioid agonist-induced diuresis. However, unlike the prototypic antagonist, nBNI, which fully inhibited evoked diuresis for at least four weeks, the new compounds showed no inhibition after one week. The two compounds with greater potency and selectivity were tested in prenatally-stressed rats on the elevated plus maze, an exploration-based model of anxiety. Spontaneous exploration of open arms in the elevated plus maze was suppressed by prenatal stress and restored with both compounds. These findings indicate that persistent inhibition is not an inherent property of κ-opioid-selective antagonists and that post-stress dosing with transient inhibitors can be effective in a mood disorder model. This further supports κ-opioid receptor as a promising target for developing novel psychiatric medications. PMID:21539838

  8. Characterization of a novel non-steroidal glucocorticoid receptor antagonist

    Energy Technology Data Exchange (ETDEWEB)

    Li, Qun-Yi; Zhang, Meng [The National Center for Drug Screening, Shanghai (China); State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai (China); Hallis, Tina M.; DeRosier, Therese A. [Cell Systems Division, Invitrogen, Madison, WI (United States); Yue, Jian-Min; Ye, Yang [State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai (China); Mais, Dale E. [The National Center for Drug Screening, Shanghai (China); MPI Research, Mattawan, MI (United States); Wang, Ming-Wei, E-mail: wangmw@mail.shcnc.ac.cn [The National Center for Drug Screening, Shanghai (China); State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai (China)

    2010-01-15

    Selective antagonists of the glucocorticoid receptor (GR) are desirable for the treatment of hypercortisolemia associated with Cushing's syndrome, psychic depression, obesity, diabetes, neurodegenerative diseases, and glaucoma. NC3327, a non-steroidal small molecule with potent binding affinity to GR (K{sub i} = 13.2 nM), was identified in a high-throughput screening effort. As a full GR antagonist, NC3327 greatly inhibits the dexamethasone (Dex) induction of marker genes involved in hepatic gluconeogenesis, but has a minimal effect on matrix metalloproteinase 9 (MMP-9), a GR responsive pro-inflammatory gene. Interestingly, the compound recruits neither coactivators nor corepressors to the GR complex but competes with glucocorticoids for the interaction between GR and a coactivator peptide. Moreover, NC3327 does not trigger GR nuclear translocation, but significantly blocks Dex-induced GR transportation to the nucleus, and thus appears to be a 'competitive' GR antagonist. Therefore, the non-steroidal compound, NC3327, may represent a new class of GR antagonists as potential therapeutics for a variety of cortisol-related endocrine disorders.

  9. Characterization of a novel non-steroidal glucocorticoid receptor antagonist

    International Nuclear Information System (INIS)

    Selective antagonists of the glucocorticoid receptor (GR) are desirable for the treatment of hypercortisolemia associated with Cushing's syndrome, psychic depression, obesity, diabetes, neurodegenerative diseases, and glaucoma. NC3327, a non-steroidal small molecule with potent binding affinity to GR (Ki = 13.2 nM), was identified in a high-throughput screening effort. As a full GR antagonist, NC3327 greatly inhibits the dexamethasone (Dex) induction of marker genes involved in hepatic gluconeogenesis, but has a minimal effect on matrix metalloproteinase 9 (MMP-9), a GR responsive pro-inflammatory gene. Interestingly, the compound recruits neither coactivators nor corepressors to the GR complex but competes with glucocorticoids for the interaction between GR and a coactivator peptide. Moreover, NC3327 does not trigger GR nuclear translocation, but significantly blocks Dex-induced GR transportation to the nucleus, and thus appears to be a 'competitive' GR antagonist. Therefore, the non-steroidal compound, NC3327, may represent a new class of GR antagonists as potential therapeutics for a variety of cortisol-related endocrine disorders.

  10. Antagonistic activity of marine sponges associated Actinobacteria

    Institute of Scientific and Technical Information of China (English)

    Selvakumar Dharmaraj; Dhevendaran Kandasamy

    2016-01-01

    Objective: To focus on the isolation and preliminary characterization of marine sponges associated Actinobacteria particularly Streptomyces species and also their antagonistic activities against bacterial and fungal pathogens. Methods: The sponges were collected from Kovalam and Vizhinjam port of south-west coast of Kerala, India. Isolation of strains was carried out from sponge extracts using international Streptomyces project media. For preliminary identification of the strains, morphological (mycelial colouration, soluble pigments, melanoid pigmentation, spore morphology), nutritional uptake (carbon utilisation, amonoacids influence, sodium chloride tolerance), physiological (pH, temperature) and chemotaxonomical characterization were done. Antimicrobial studies were also carried out for the selected strains. Results: With the help of the spicule structures, the collected marine sponges were identified as Callyspongia diffusa, Mycale mytilorum, Tedania anhelans and Dysidea fragilis. Nearly 94 strains were primarily isolated from these sponges and further they were sub-cultured using international Streptomyces project media. The strains exhibited different mycelial colouration (aerial and substrate), soluble and melanoid pigmentations. The strains possessed three types of sporophore morphology namely rectus flexibilis, spiral and retinaculiaperti. Among the 94 isolates, seven exhibited antibacterial and antifungal activities with maximal zone of inhibition of 30 mm. The nutritional, physiological and chemotaxonomical characteristic study helped in the conventional identification of the seven strains and they all suggest that the strains to be grouped under the genus Streptomyces. Conclusions: The present study clearly helps in the preliminary identification of the isolates associated with marine sponges. Antagonistic activities prove the production of antimicrobial metabolites against the pathogens. Marine sponges associated Streptomyces are universally well

  11. Effective use of TNF antagonists

    OpenAIRE

    Yocum, David

    2004-01-01

    Tumor necrosis factor (TNF) antagonists are biologic response modifiers that have significantly improved functional outcomes in patients with rheumatoid arthritis (RA). RA is a progressive disease in which structural joint damage can continue to develop even in the face of symptomatic relief. Before the introduction of biologic agents, the management of RA involved the use of disease-modifying antirheumatic drugs (DMARDs) early in the course of disease. This focus on early treatment, combined...

  12. μ Opioid receptor: novel antagonists and structural modeling

    Science.gov (United States)

    Kaserer, Teresa; Lantero, Aquilino; Schmidhammer, Helmut; Spetea, Mariana; Schuster, Daniela

    2016-02-01

    The μ opioid receptor (MOR) is a prominent member of the G protein-coupled receptor family and the molecular target of morphine and other opioid drugs. Despite the long tradition of MOR-targeting drugs, still little is known about the ligand-receptor interactions and structure-function relationships underlying the distinct biological effects upon receptor activation or inhibition. With the resolved crystal structure of the β-funaltrexamine-MOR complex, we aimed at the discovery of novel agonists and antagonists using virtual screening tools, i.e. docking, pharmacophore- and shape-based modeling. We suggest important molecular interactions, which active molecules share and distinguish agonists and antagonists. These results allowed for the generation of theoretically validated in silico workflows that were employed for prospective virtual screening. Out of 18 virtual hits evaluated in in vitro pharmacological assays, three displayed antagonist activity and the most active compound significantly inhibited morphine-induced antinociception. The new identified chemotypes hold promise for further development into neurochemical tools for studying the MOR or as potential therapeutic lead candidates.

  13. Effects of certain muscarinic antagonists on the actions of anticholinesterases on cat skeletal muscle.

    Science.gov (United States)

    Brimblecombe, R W; French, M C; Webb, S N

    1979-04-01

    1. The effects of some muscarinic antagonists, namely, N-ethyl-2-pyrrolidylmethyl-cyclopentylphenyl glycollate (PMCG), N-methyl-4-piperidyl-phenylcyclohexyl glycollate (PPCG, racemate and R and S enantiomers) and 4'-N-methyl-piperidyl-1-phenyl-cyclopentane carboxylate (G3063) on organophosphate (sarin, soman)- and carbamate (neostigmine)-induced twitch augmentation have been studied in cat soleus muscle. 2. The results of a preliminary study comparing the potency of sarin and soman in inhibiting the acetylcholinesterase activity of muscle in relation to the effect on the maximal twitch response indicated that there is not a simple relationship between degree of enzyme inhibition by these drugs and alteration of muscle function. 3. The muscarinic antagonists studied were capable of preventing or reversing sarin-, soman- or neostigmine-induced twitch augmentation. Doses sufficient to give complete protection from the effects of the anticholinesterase agents had little or no effect on the twitch response of normal muscle. 4. The protective action of these muscarinic antagonists is dose-dependent but independent of known antagonist actions at muscarinic receptors. 5. The effects of some local anaesthetics (lignocaine, prilocaine, cinchocaine, procaine) and other membrane stabilizers (quinine, ketamine, chlorpromazine, triflupromazine) were compared with those of the muscarinic antagonists in an attempt to elucidate the mode of action of these acetylcholine antagonists. The evidence is insufficient to exclude the involvement of a membrane stabilizing action. PMID:435681

  14. Endothelin receptors and their antagonists.

    Science.gov (United States)

    Maguire, Janet J; Davenport, Anthony P

    2015-03-01

    All three members of the endothelin (ET) family of peptides, ET-1, ET-2, and ET-3, are expressed in the human kidney, with ET-1 being the predominant isoform. ET-1 and ET-2 bind to two G-protein-coupled receptors, ETA and ETB, whereas at physiological concentrations ET-3 has little affinity for the ET(A) receptor. The human kidney is unusual among the peripheral organs in expressing a high density of ET(B). The renal vascular endothelium only expresses the ET(B) subtype and ET-1 acts in an autocrine or paracrine manner to release vasodilators. Endothelial ETB in kidney, as well as liver and lungs, also has a critical role in scavenging ET-1 from the plasma. The third major function is ET-1 activation of ET(B) in in the nephron to reduce salt and water re-absorption. In contrast, ET(A) predominate on smooth muscle, causing vasoconstriction and mediating many of the pathophysiological actions of ET-1. The role of the two receptors has been delineated using highly selective ET(A) (BQ123, TAK-044) and ET(B) (BQ788) peptide antagonists. Nonpeptide antagonists, bosentan, macitentan, and ambrisentan, that are either mixed ET(A)/ET(B) antagonists or display ET(A) selectivity, have been approved for clinical use but to date are limited to pulmonary hypertension. Ambrisentan is in clinical trials in patients with type 2 diabetic nephropathy. This review summarizes ET-receptor antagonism in the human kidney, and considers the relative merits of selective versus nonselective antagonism in renal disease. PMID:25966344

  15. Antagonistic neural networks underlying differentiated leadership roles.

    Science.gov (United States)

    Boyatzis, Richard E; Rochford, Kylie; Jack, Anthony I

    2014-01-01

    The emergence of two distinct leadership roles, the task leader and the socio-emotional leader, has been documented in the leadership literature since the 1950s. Recent research in neuroscience suggests that the division between task-oriented and socio-emotional-oriented roles derives from a fundamental feature of our neurobiology: an antagonistic relationship between two large-scale cortical networks - the task-positive network (TPN) and the default mode network (DMN). Neural activity in TPN tends to inhibit activity in the DMN, and vice versa. The TPN is important for problem solving, focusing of attention, making decisions, and control of action. The DMN plays a central role in emotional self-awareness, social cognition, and ethical decision making. It is also strongly linked to creativity and openness to new ideas. Because activation of the TPN tends to suppress activity in the DMN, an over-emphasis on task-oriented leadership may prove deleterious to social and emotional aspects of leadership. Similarly, an overemphasis on the DMN would result in difficulty focusing attention, making decisions, and solving known problems. In this paper, we will review major streams of theory and research on leadership roles in the context of recent findings from neuroscience and psychology. We conclude by suggesting that emerging research challenges the assumption that role differentiation is both natural and necessary, in particular when openness to new ideas, people, emotions, and ethical concerns are important to success. PMID:24624074

  16. Antagonistic Neural Networks Underlying Differentiated Leadership Roles

    Directory of Open Access Journals (Sweden)

    Richard Eleftherios Boyatzis

    2014-03-01

    Full Text Available The emergence of two distinct leadership roles, the task leader and the socio-emotional leader, has been documented in the leadership literature since the 1950’s. Recent research in neuroscience suggests that the division between task oriented and socio-emotional oriented roles derives from a fundamental feature of our neurobiology: an antagonistic relationship between two large-scale cortical networks -- the Task Positive Network (TPN and the Default Mode Network (DMN. Neural activity in TPN tends to inhibit activity in the DMN, and vice versa. The TPN is important for problem solving, focusing of attention, making decisions, and control of action. The DMN plays a central role in emotional self-awareness, social cognition, and ethical decision making. It is also strongly linked to creativity and openness to new ideas. Because activation of the TPN tends to suppress activity in the DMN, an over-emphasis on task oriented leadership may prove deleterious to social and emotional aspects of leadership. Similarly, an overemphasis on the DMN would result in difficulty focusing attention, making decisions and solving known problems. In this paper, we will review major streams of theory and research on leadership roles in the context of recent findings from neuroscience and psychology. We conclude by suggesting that emerging research challenges the assumption that role differentiation is both natural and necessary, in particular when openness to new ideas, people, emotions, and ethical concerns are important to success.

  17. Studies on antagonistic marine streptomycetes

    Digital Repository Service at National Institute of Oceanography (India)

    Chandramohan, D.; Nair, S.

    three strains inhibited all the test cultures. In addition to the above test cultures marine bacteria (Vibrio sp., Aeromonas spp., Flavobacterium spp., Bacillus sp. and Micrococcus sp.) resistant to few known antibiotics (tetracycline, penicillin...

  18. Screening of Antagonistic Bacteria from Phyllosphere towards Tobacco Brown Spot Fungus Alternaria alternata

    Institute of Scientific and Technical Information of China (English)

    ZHANG Chengsheng; KONG Fanyu; LI Duochuan; WANG Jing; WANG Fenglong

    2006-01-01

    The possibility of employing antagonistic bacteria for the control of tobacco brown spot was studied. Approximately 136 strains of bacteria were isolated from phyllospheres of tobacco and 9 of these possessed high levels of antagonistic properties. They significantly reduced brown spot in detached tobacco leaves when artificially inoculated with Alternaria alternata. Culture filtrate of the most effective bacterial isolate which designated as Tpb88 was shown to be very efficient in inhibiting mycelial growth of A alternata in dual cultures. Culture filtrate of Tpb88 inhibited germination and germ tube elongation of A alternata. The results showed that the culture filtrate directly inhibited spore germination of A. alternata, especially during the first hours of the paired cultivation. The rate of antagonistic activity of culture filtrate of Tpb88 depended on its concentration in the mixture. The greatest inhibition of spore germination was ob served at the highest concentration of filtrate (filtrate to fungal spores inocula mixed in proportion 1: 50). These suggest that the hypothetic mechanism of Tpb88 against tobacco brown spot is to produce antagonistic substances.

  19. Antimicrobial activity of extracellular metabolites from antagonistic bacteria isolated from potato (Solanum phureja) crops

    OpenAIRE

    Sinar David Granada García; Antoni Rueda Lorza; Carlos Alberto Peláez

    2014-01-01

    Microorganisms for biological control are capable of producing active compounds that inhibit the development of phytopathogens, constituting a promising tool toob tain active principles that could replace synthetic pesticides. This study evaluatedtheability of severalpotentialbiocontrol microorganismsto produce active extracellular metabolites. In vitro antagonistic capability of 50 bacterial isolates from rhizospheric soils of "criolla" potato (Solanum phureja) was tested through dual cultur...

  20. Antagonistic action of Streptococcus salivarius and Streptococcus faecalis to Mycobacterium tuberculosis.

    Science.gov (United States)

    Darling, C L; Hart, G D

    1976-01-01

    Streptococcus salivarius and Streptococcus faecalis were found to inhibit the growth of Mycobacterium tuberculosis on Löwenstein-Jensen and Middlebrook 7H11 agars, but not on the latter medium when antibacterial drugs were added. S. faecalis was found to be more inhibitory than S. salivarius to 15 strains of M. tuberculosis. S. salivarius produced little or no inhibition of growth of Runyon group III organisms but was very antagonistic to Runyon group I mycobacteria. Images PMID:824304

  1. Client Perceptions of Two Antagonist Programs.

    Science.gov (United States)

    Capone, Thomas A.; And Others

    1980-01-01

    Reports results of a questionnaire administered to participants in an antagonist drug outpatient clinic and an antagonist drug work-release program to obtain awareness of acceptance of the program participants. Naltrexone patients recommended an alternative method of administering the drug and changing the money system to award deserving inmates…

  2. NMDA antagonist properties of the putative antiaddictive drug, ibogaine.

    Science.gov (United States)

    Popik, P; Layer, R T; Fossom, L H; Benveniste, M; Geter-Douglass, B; Witkin, J M; Skolnick, P

    1995-11-01

    Both anecdotal reports in humans and preclinical studies indicate that ibogaine interrupts addiction to a variety of abused substances including alcohol, opiates, nicotine and stimulants. Based on the similarity of these therapeutic claims to recent preclinical studies demonstrating that N-methyl-D-aspartate (NMDA) antagonists attenuate addiction-related phenomena, we examined the NMDA antagonist properties of ibogaine. Pharmacologically relevant concentrations of ibogaine produce a voltage-dependent block of NMDA receptors in hippocampal cultures (Ki, 2.3 microM at -60 mV). Consistent with this observation, ibogaine competitively inhibits [3H]1-[1-(2-thienyl)-cyclohexyl]piperidine binding to rat forebrain homogenates (Ki, 1.5 microM) and blocks glutamate-induced cell death in neuronal cultures (IC50, 4.5 microM). Moreover, at doses previously reported to interfere with drug-seeking behaviors, ibogaine substitutes as a discriminative stimulus (ED50, 64.9 mg/kg) in mice trained to discriminate the prototypic voltage-dependent NMDA antagonist, dizocilpine (0.17 mg/kg), from saline. Consistent with previous reports, ibogaine reduced naloxone-precipitated jumping in morphine-dependent mice (ED50, 72 mg/kg). Although pretreatment with glycine did not affect naloxone-precipitated jumping in morphine-dependent mice, it abolished the ability of ibogaine to block naloxone-precipitated jumping. Taken together, these findings link the NMDA antagonist actions of ibogaine to a putative "antiaddictive" property of this alkaloid, its ability to reduce the expression of morphine dependence. PMID:7473163

  3. Zearalenone detoxification by zearalenone hydrolase is important for the antagonistic ability of Clonostachys rosea against mycotoxigenic Fusarium graminearum

    DEFF Research Database (Denmark)

    Kosawang, Chatchai; Karlsson, Magnus; Vélëz, Heriberto;

    2014-01-01

    The fungus Clonostachys rosea is antagonistic against plant pathogens, including Fusarium graminearum, which produces the oestrogenic mycotoxin zearalenone (ZEA). ZEA inhibits other fungi, and C. rosea can detoxify ZEA through the enzyme zearalenone lactonohydrolase (ZHD101). As the relevance of...

  4. SIRT1 IS REQUIRED FOR ANTAGONIST-INDUCED TRANSCRIPTIONAL REPRESSION OF ANDROGEN-RESPONSIVE GENES BY THE ANDROGEN RECEPTOR

    OpenAIRE

    Dai, Yan; Ngo, Duyen; Forman, Lora W.; Qin, David C.; Jacob, Johanna; Faller, Douglas V

    2007-01-01

    Androgen antagonists or androgen deprivation is a primary therapeutic modality for the treatment of prostate cancer. Invariably, however, the disease becomes progressive and unresponsive to androgen ablation therapy (hormone refractory). The molecular mechanisms by which the androgen antagonists inhibit prostate cancer proliferation are not fully defined. In this report, we demonstrate that SIRT1, a nicotinamide adenosine dinucleotide-dependent histone deacetylase linked to the regulation of ...

  5. Nucleoside-Derived Antagonists to A3 Adenosine Receptors Lower Mouse Intraocular Pressure and Act across Species

    OpenAIRE

    Wang, Zhao; Do, Chi Wai; Avila, Marcel Y.; Peterson-Yantorno, Kim; Stone, Richard A.; Gao, Zhan-Guo; Joshi, Bhalchandra; Besada, Pedro; Jeong, Lak Shin; Jacobson, Kenneth A.; Civan, Mortimer M.

    2009-01-01

    The purpose of the study was to determine whether novel, selective antagonists of human A3 adenosine receptors (ARs) derived from the A3-selective agonist Cl-IB-MECA lower intraocular pressure (IOP) and act across species. IOP was measured invasively with a micropipette by the Servo-Null Micropipette System (SNMS) and by non-invasive pneumotonometry during topical drug application. Antagonist efficacy was also assayed by measuring inhibition of adenosine-triggered shrinkage of native bovine n...

  6. Management of Fusarium Head Blight of Wheat and Deoxynivalenol Accumulation Using Antagonistic Microorganisms

    Directory of Open Access Journals (Sweden)

    G.M. Riungu

    2008-01-01

    Full Text Available Laboratory and green house studies were conducted at the Faculty of Agriculture, University of Nairobi, to evaluate the efficacy of Epicoccum sp., Alternaria sp., Trichoderma sp. and Bacillus sp. in control of Fusarium head blight of wheat caused by F. graminearum. Fungicides folicur® and copper oxychloride were used as standard checks. Laboratory assay was carried out by paired cultures and antagonism was measured as reduction in pathogen colony diameter. Green house experiments involved dual inoculation of pathogen and antagonist onto wheat ears and head blight severity and grain yield determined. Doxynivalenol content in the resulting grain was determined by competitive direct ELISA. The antagonists and fungicides significantly reduced the growth of Fusarium graminearum colonies in culture. Folicur® and copper oxychloride completely inhibited the growth of the pathogen while Trichoderma sp. showed 64% colony growth reduction. However, the antagonists showed limited reduction in head blight severity in green house trials. Trichoderma sp. reduced head blight severity by 18% while folicur® reduced the disease by 28%. All the antagonists had little or no significant effect on grain yield. Only folicur®, copper oxychloride and Alternaria sp. reduced DON in grain by 76 to 93%. Obtained results indicate that microbial antagonists may offer potential benefit in FHB management and screening of more antagonists both under controlled and field conditions is necessary.

  7. Physico-chemical pathways in radioprotective action of calmodulin antagonists

    International Nuclear Information System (INIS)

    Ghost membranes prepared from erythrocytes of Swiss albino mice were irradiated with gamma rays at a dose rate of 0.9 Gy/s. The fluidity of membrane decreased with radiation dose and in the presence of calmodulin antagonists (CA) like chlorpromazine (CPZ), promethazine (PMZ), and trimeprazone (TMZ) it increased. Radiation induced release of Ca2+ from membranes. This release was inhibited by CA mainly by CPZ and PMZ. Being Ca2+ dependent, the changes in the activity of acetylcholine estrase (AchE) following irradiation was also studied. Radiation decreased the activity of AchE in dose dependent manner. Presence of CPZ and PMZ diminished the radiation induced inhibition of AchE but not in the presence of TMZ at the lower concentration tested. It is suggested that apart from scavenging of free radicals, CA perhaps exert their euxoic radioprotective effect through Ca2+ dependent processes. (author)

  8. Calcium-antagonists and islet function. Pt. 5

    International Nuclear Information System (INIS)

    R33711, a new drug with presumed potent calcium-antagonistic property, was found to suppress the insulinotropic action of glucose und gliclazide but not that of theophylline. A 0.2 μM concentration of R33711 was sufficient to abolish glucose-induced insulin release. At this concentration, R33711 inhibited the net uptake of 45Ca2+ by isolated islets, whether in the absence or presence of either glucose or sulfonylurea. In the isolated islets, R33711 failed to affect the glucose-stimulated production of lactate, the rate of 45Ca2+ efflux, the inhibitory action of glucose upon such an efflux and its increase in response to theophylline. These data are compatible with the view that R33711 inhibits entry of Ca2+ into the B-cell and that integrity of such an inward cationic movement usually plays a permissive role in the maintenance of the Ca2+-dependent insulin secretory process. (orig.)

  9. Discovery of tetrahydroisoquinoline-based CXCR4 antagonists.

    Science.gov (United States)

    Truax, Valarie M; Zhao, Huanyu; Katzman, Brooke M; Prosser, Anthony R; Alcaraz, Ana A; Saindane, Manohar T; Howard, Randy B; Culver, Deborah; Arrendale, Richard F; Gruddanti, Prahbakar R; Evers, Taylor J; Natchus, Michael G; Snyder, James P; Liotta, Dennis C; Wilson, Lawrence J

    2013-11-14

    A de novo hit-to-lead effort involving the redesign of benzimidazole-containing antagonists of the CXCR4 receptor resulted in the discovery of a novel series of 1,2,3,4-tetrahydroisoquinoline (TIQ) analogues. In general, this series of compounds show good potencies (3-650 nM) in assays involving CXCR4 function, including both inhibition of attachment of X4 HIV-1IIIB virus in MAGI-CCR5/CXCR4 cells and inhibition of calcium release in Chem-1 cells. Series profiling permitted the identification of TIQ-(R)-stereoisomer 15 as a potent and selective CXCR4 antagonist lead candidate with a promising in vitro profile. The drug-like properties of 15 were determined in ADME in vitro studies, revealing low metabolic liability potential. Further in vivo evaluations included pharmacokinetic experiments in rats and mice, where 15 was shown to have oral bioavailability (F = 63%) and resulted in the mobilization of white blood cells (WBCs) in a dose-dependent manner. PMID:24936240

  10. Implications of hedgehog signaling antagonists for cancer therapy

    Institute of Scientific and Technical Information of China (English)

    Jingwu Xie

    2008-01-01

    The hedgehog(Hh)pathway,initially discovered inDrosophila by two Nobel laureates,Dr.Eric Wieschaus and Dr.Christiane Nusslein-Volhard,is a major regulator for cell differentiation,tissue polarity and cell proliferation.Studies from many laboratories,including ours,reveal activation of this pathway in most basal cell carcinomas and in approximately 30% of extracutaneous human cancers,including medulloblastomas,gastrointestinal,lung,breast and prostate cancers.Thus,it is believed that targeted inhibition of Hh signaling may be effective in treating and preventing many types of human cancers.Even more exciting is the discovery and synthesis of specific signaling antagonists for the Hh pathway,which have significant clinical implications in novel cancer therapeutics.This review discusses the major advances in the current understanding of Hh signaling activation in different types of human cancers,the molecular basis of Hh signaling activation,the major antagonists for Hh signaling inhibition and their potential clinical application in human cancer therapy.

  11. Histamine H3 receptor antagonist decreases cue-induced alcohol reinstatement in mice.

    Science.gov (United States)

    Nuutinen, Saara; Mäki, Tiia; Rozov, Stanislav; Bäckström, Pia; Hyytiä, Petri; Piepponen, Petteri; Panula, Pertti

    2016-07-01

    We have earlier found that the histamine H3 receptor (H3R) antagonism diminishes motivational aspects of alcohol reinforcement in mice. Here we studied the role of H3Rs in cue-induced reinstatement of alcohol seeking in C57BL/6J mice using two different H3R antagonists. Systemic administration of H3R antagonists attenuated cue-induced alcohol seeking suggesting that H3R antagonists may reduce alcohol craving. To understand how alcohol affects dopamine and histamine release, a microdialysis study was performed on C57BL/6J mice and the levels of histamine, dopamine and dopamine metabolites were measured in the nucleus accumbens. Alcohol administration was combined with an H3R antagonist pretreatment to reveal whether modulation of H3R affects the effects of alcohol on neurotransmitter release. Alcohol significantly increased the release of dopamine in the nucleus accumbens but did not affect histamine release. Pretreatment with H3R antagonist ciproxifan did not modify the effect of alcohol on dopamine release. However, histamine release was markedly increased with ciproxifan. In conclusion, our findings demonstrate that H3R antagonism attenuates cue-induced reinstatement of alcohol seeking in mice. Alcohol alone does not affect histamine release in the nucleus accumbens but H3R antagonist instead increases histamine release significantly suggesting that the mechanism by which H3R antagonist inhibits alcohol seeking found in the present study and the decreased alcohol reinforcement, reward and consumption found earlier might include alterations in the histaminergic neurotransmission in the nucleus accumbens. These findings imply that selective antagonists of H3Rs could be a therapeutic strategy to prevent relapse and possibly diminish craving to alcohol use. This article is part of the Special Issue entitled 'Histamine Receptors'. PMID:26107118

  12. Antagonistic formation motion of cooperative agents

    Institute of Scientific and Technical Information of China (English)

    卢婉婷; 代明香; 薛方正

    2015-01-01

    This paper investigates a new formation motion problem of a class of first-order multi-agent systems with antagonis-tic interactions. A distributed formation control algorithm is proposed for each agent to realize the antagonistic formation motion. A sufficient condition is derived to ensure that all agents make an antagonistic formation motion in a distributed manner. It is shown that all agents can be spontaneously divided into several groups, and agents in the same group collab-orate while agents in different groups compete. Finally, a numerical simulation is included to demonstrate our theoretical results.

  13. Cytokine antagonists and their potential therapeutic use

    OpenAIRE

    Debets, Reno; Savelkoul, Huub

    1994-01-01

    textabstractNew and exciting developments in the understanding of the interaction between cytokines and their receptors, and the clinical application of cytokine antagonists, were discussed at a recent meeting. Here, Reno Debets and Huub Savelkoul revisit this progress.

  14. High-affinity neuropeptide Y receptor antagonists.

    OpenAIRE

    Daniels, A J; Matthews, J. E.; Slepetis, R J; Jansen, M; Viveros, O. H.; Tadepalli, A.; Harrington, W; Heyer, D; Landavazo, A; Leban, J J

    1995-01-01

    Neuropeptide Y (NPY) is one of the most abundant peptide transmitters in the mammalian brain. In the periphery it is costored and coreleased with norepinephrine from sympathetic nerve terminals. However, the physiological functions of this peptide remain unclear because of the absence of specific high-affinity receptor antagonists. Three potent NPY receptor antagonists were synthesized and tested for their biological activity in in vitro, ex vivo, and in vivo functional assays. We describe he...

  15. Bovine pancreatic polypeptide as an antagonist of muscarinic cholinergic receptors

    International Nuclear Information System (INIS)

    In dispersed acini from rat pancreas, it was found that bovine pancreatic polypeptide (BPP) and its C-fragment hexapeptide amide (PP-6), at concentrations of 0.1 and 30 μM, respectively, could significantly inhibit amylase secretion stimulated by carbachol, and this inhibition by BPP was dose dependent. 45Ca outflux induced by carbachol was also inhibited by BPP or PP-6, but they had no effect on cholecystokinin octapeptide- (CCK-8) or A23187-stimulated 45Ca outflux. BPP was also capable of displacing the specific binding of [3H]-quinuclidinyl benzilate to its receptors, and it possessed a higher affinity (K/sub i/35nM) than carbachol (K/sub i/ 1.8 μM) in binding with M-receptors. It is concluded from this study that BPP acts as an antagonist of muscarinic cholinergic receptors in rat pancreatic acini. In addition, BPP inhibited the potentiation of amylase secretion caused by the combination of carbachol plus secretin or vasoactive intestinal peptide. This may be a possible explanation of the inhibitory effect of BPP on secretin-induced pancreatic enzyme secretion shown in vivo, since pancreatic enzyme secretion stimulated by secretin under experimental conditions may be the result of potentiation of enzyme release produced by the peptide in combination with a cholinergic stimulant

  16. GABAA receptor modulating steroid antagonists (GAMSA) are functional in vivo.

    Science.gov (United States)

    Johansson, Maja; Strömberg, Jessica; Ragagnin, Gianna; Doverskog, Magnus; Bäckström, Torbjörn

    2016-06-01

    GABAA receptor modulating steroid antagonists (GAMSA) selectively inhibit neurosteroid-mediated enhancement of GABA-evoked currents at the GABAA receptor. 3α-hydroxy-neurosteroids, notably allopregnanolone and tetrahydrodeoxycorticosterone (THDOC), potentiate GABAA receptor-mediated currents. On the contrary, various 3β-hydroxy-steroids antagonize this positive neurosteroid-mediated modulation. Importantly, GAMSAs are specific antagonists of the positive neurosteroid-modulation of the receptor and do not inhibit GABA-evoked currents. Allopregnanolone and THDOC have both negative and positive actions. Allopregnanolone can impair encoding/consolidation and retrieval of memories. Chronic administration of a physiological allopregnanolone concentration reduces cognition in mice models of Alzheimer's disease. In humans an allopregnanolone challenge impairs episodic memory and in hepatic encephalopathy cognitive deficits are accompanied by increased brain ammonia and allopregnanolone. Hippocampal slices react in vitro to ammonia by allopregnanolone synthesis in CA1 neurons, which blocks long-term potentiation (LTP). Thus, allopregnanolone may impair learning and memory by interfering with hippocampal LTP. Contrary, pharmacological treatment with allopregnanolone can promote neurogenesis and positively influence learning and memory of trace eye-blink conditioning in mice. In rat the GAMSA UC1011 inhibits an allopregnanolone-induced learning impairment and the GAMSA GR3027 restores learning and motor coordination in rats with hepatic encephalopathy. In addition, the GAMSA isoallopregnanolone antagonizes allopregnanolone-induced anesthesia in rats, and in humans it antagonizes allopregnanolone-induced sedation and reductions in saccadic eye velocity. 17PA is also an effective GAMSA in vivo, as it antagonizes allopregnanolone-induced anesthesia and spinal analgesia in rats. In vitro the allopregnanolone/THDOC-increased GABA-mediated GABAA receptor activity is antagonized

  17. ANTAGONISTIC EFFECT OF FOUR FUNGAL ISOLATES TO GANODERMA BONINENSE, THE CAUSAL AGENT OF BASAL STEM ROT OF OIL PALM

    Directory of Open Access Journals (Sweden)

    OKKY SETYAWATI DHARMAPUTRA

    1990-01-01

    Full Text Available Four fungal isolates from soils obtained from three sites of the oil palm plantations in North Sumatra were found antagonistic to Ganoderma boninense, the causal agent of basal stem rot of oil palm. Penicillium citrinum inhibited the growth of the pathogen and formed a zone of inhibition on the agar media. Trichoderma harzianum BIO - 1 as well as BIO - 2 and T. viride not only repressed the growth of the pathogen but also caused lysis of the hyphae, and the colony was totally overgrown by the antagonists.

  18. Structure-based design of eugenol analogs as potential estrogen receptor antagonists.

    Science.gov (United States)

    Anita, Yulia; Radifar, Muhammad; Kardono, Leonardus Bs; Hanafi, Muhammad; Istyastono, Enade P

    2012-01-01

    Eugenol is an essential oil mainly found in the buds and leaves of clove (Syzygium aromaticum (L.) Merrill and Perry), which has been reported to have activity on inhibition of cell proliferation and apoptosis induction in human MCF-7 breast cancer cells. This biological activity is correlated to its activity as an estrogen receptor antagonist. In this article, we present the construction and validation of structure-based virtual screening (SBVS) protocols to identify the potent estrogen receptor α (ER) antagonists. The selected protocol, which gave acceptable enrichment factors as a virtual screening protocol, subsequently used to virtually screen eugenol, its analogs and their dimers. Based on the virtual screening results, dimer eugenol of 4-[4-hydroxy-3-(prop-2-en-1- yl)phenyl]-2-(prop-2-en-1-yl)phenol is recommended to be developed further in order to discover novel and potent ER antagonists. PMID:23144548

  19. Fluorescent Pseudomonads in the Phyllosphere of Wheat: Potential Antagonists Against Fungal Phytopathogens.

    Science.gov (United States)

    Müller, Thomas; Behrendt, Undine; Ruppel, Silke; von der Waydbrink, Grit; Müller, Marina E H

    2016-04-01

    Fluorescent pseudomonads isolated from wheat leaves were characterized regarding their antagonistic potential and taxonomy in relation to protect crop plants from infestation by Fusarium and Alternaria fungi causing diseases in wheat. Using a dual culture assay, inhibition of fungal growth was found for 40 isolates of 175 fluorescent pseudomonads. Twenty-two of the antagonists were able to suppress strains of Fusarium as well as Alternaria. By means of real-time qPCR, the phlD gene encoding the antibiotic 2,4-diacetylphloroglucinol was detected in 20 isolates. On the basis of matrix-assisted laser desorption/ionization time-of-flight mass spectrometry spectral patterns, the isolates with antagonistic activity were assigned to the phylogenetic subgroup Pseudomonas fluorescens and the closely related Pseudomonas gessardii subgroup. The results of the study suggest that pseudomonads in the phyllosphere of crop plants may possibly contribute to natural plant protection. PMID:26687461

  20. Central actions of a novel and selective dopamine antagonist

    International Nuclear Information System (INIS)

    Receptors for the neurotransmitter dopamine traditionally have been divided into two subgroups: the D1 class, which is linked to the stimulation of adenylate cyclase-activity, and the D2 class which is not. There is much evidence suggesting that it is the D2 class which is not. There is much evidence suggesting that it is the D2 dopamine receptor that mediates the physiological and behavioral actions of dopamine in the intact animal. However, the benzazepine SCH23390 is a dopamine antagonist which has potent behavioral actions while displaying apparent neurochemical selectivity for the D1 class of dopamine receptors. The purpose of this dissertation was to (1) confirm and characterize this selectivity, and (2) test certain hypothesis related to possible modes of action of SCH233390. The inhibition of adenylate cyclase by SCH23390 occurred via an action at the dopamine receptor only. A radiolabeled analog of SCH23390 displayed the receptor binding properties of a specific high-affinity ligand, and regional receptor densities were highly correlated with dopamine levels. The subcellular distribution of [3H]-SCH23390 binding did not correspond completely with that of dopamine-stimulated adenylate cyclase. The neurochemical potency of SCH23390 as a D1 receptor antagonist was preserved following parental administration. A variety of dopamine agonists and antagonists displayed a high correlation between their abilities to compete for [3H]-SCH23390 binding in vitro and to act at an adenylate cyclase-linked receptor. Finally, the relative affinities of dopamine and SCH23390 for both D1 receptors and [3H]-SCH23390 binding sites were comparable. It is concluded that the behavioral effects of SCH23390 are mediated by actions at D1 dopamine receptors only, and that the physiological importance of this class of receptors should be reevaluated

  1. Apoptotic death of prostate cancer cells by a gonadotropin-releasing hormone-II antagonist.

    Directory of Open Access Journals (Sweden)

    Sumi Park

    Full Text Available Gonadotropin-releasing hormone-I (GnRH-I has attracted strong attention as a hormonal therapeutic tool, particularly for androgen-dependent prostate cancer patients. However, the androgen-independency of the cancer in advanced stages has spurred researchers to look for new medical treatments. In previous reports, we developed the GnRH-II antagonist Trp-1 to inhibit proliferation and stimulate the autophagic death of various prostate cancer cells, including androgen-independent cells. We further screened many GnRH-II antagonists to identify molecules with higher efficiency. Here, we investigated the effect of SN09-2 on the growth of PC3 prostate cancer cells. SN09-2 reduced the growth of prostate cancer cells but had no effect on cells derived from other tissues. Compared with Trp-1, SN09-2 conspicuously inhibited prostate cancer cell growth, even at low concentrations. SN09-2-induced PC3 cell growth inhibition was associated with decreased membrane potential in mitochondria where the antagonist was accumulated, and increased mitochondrial and cytosolic reactive oxygen species. SN09-2 induced lactate dehydrogenase release into the media and annexin V-staining on the PC3 cell surface, suggesting that the antagonist stimulated prostate cancer cell death by activating apoptotic signaling pathways. Furthermore, cytochrome c release from mitochondria to the cytosol and caspase-3 activation occurred in a concentration- and time-dependent manner. SN09-2 also inhibited the growth of PC3 cells xenotransplanted into nude mice. These results demonstrate that SN09-2 directly induces mitochondrial dysfunction and the consequent ROS generation, leading to not only growth inhibition but also apoptosis of prostate cancer cells.

  2. Pathophysiology of the cysteinyl leukotrienes and effects of leukotriene receptor antagonists in asthma.

    Science.gov (United States)

    Bisgaard, H

    2001-01-01

    Cysteinyl leukotrienes, synthesized de novo from cell membrane phospholipids, are proinflammatory mediators that play an important role in the pathophysiology of asthma. These mediators are among the most potent of bronchoconstrictors and cause vasodilation, increased microvascular permeability, exudation of macromolecules and edema. The cysteinyl leukotrienes also have potent chemoattractant properties for eosinophils, causing an influx of eosinophils into the airway mucosa, which further fuels the inflammatory process. In addition, the cysteinyl leukotrienes are potent secretagogues and reduce ciliary motility, which may hinder mucociliary clearance. Asthmatic patients demonstrate increased production of cysteinyl leukotrienes during naturally occurring asthma and acute asthma attacks as well as after allergen and exercise challenge. The leukotriene receptor antagonists montelukast, zafirlukast and pranlukast inhibit bronchoconstriction in asthmatic patients undergoing allergen, exercise, cold air or aspirin challenge. They attenuate the hallmarks of asthmatic inflammation, including eosinophilia in the airway mucosa and peripheral blood. Moreover, exhaled nitric oxide concentrations, another correlate of airway inflammation, are decreased during montelukast treatment in children. Cysteinyl leukotriene synthesis is not blocked by corticosteroid therapy. This important observation suggests that the leukotriene receptor antagonists represent a novel therapeutic approach, one that may provide benefits that are additive with corticosteroid therapy. This supposition is supported by clinical observations that treatment with leukotriene receptor antagonists significantly improve asthma control when added to inhaled corticosteroid therapy. Moreover, the bronchodilator properties of the leukotriene receptor antagonists are additive with those of beta agonists. These data provide strong support for the use of leukotriene receptor antagonists for treating asthma. PMID

  3. Evodiamine as a novel antagonist of aryl hydrocarbon receptor

    Energy Technology Data Exchange (ETDEWEB)

    Yu, Hui [State Key Laboratory of Trauma, Burns, and Combined Injury, Department 1, Research Institute of Surgery, Daping Hospital, The Third Military Medical University, Chongqing 400042 (China); Department of Laboratory Medicine, The Affiliated Tenth People' s Hospital, Tongji University, Shanghai 200072 (China); Tu, Yongjiu; Zhang, Chun; Fan, Xia; Wang, Xi [State Key Laboratory of Trauma, Burns, and Combined Injury, Department 1, Research Institute of Surgery, Daping Hospital, The Third Military Medical University, Chongqing 400042 (China); Wang, Zhanli [College of Pharmaceutical Science, Zhejiang University of Technology, Hangzhou 310014 (China); Liang, Huaping, E-mail: huaping_liang@yahoo.com.cn [State Key Laboratory of Trauma, Burns, and Combined Injury, Department 1, Research Institute of Surgery, Daping Hospital, The Third Military Medical University, Chongqing 400042 (China)

    2010-11-05

    Research highlights: {yields} Evodiamine interacted with the AhR. {yields} Evodiamine inhibited the specific binding of [{sup 3}H]-TCDD to the AhR. {yields} Evodiamine acts as an antagonist of the AhR. -- Abstract: Evodiamine, the major bioactive alkaloid isolated from Wu-Chu-Yu, has been shown to interact with a wide variety of proteins and modify their expression and activities. In this study, we investigated the interaction between evodiamine and the aryl hydrocarbon receptor (AhR). Molecular modeling results revealed that evodiamine directly interacted with the AhR. Cytosolic receptor binding assay also provided the evidence that evodiamine could interact with the AhR with the K{sub i} value of 28.4 {+-} 4.9 nM. In addition, we observed that evodiamine suppressed the 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) induced nuclear translocation of the AhR and the expression of CYP1A1 dose-dependently. These results suggested that evodiamine was able to bind to the AhR as ligand and exhibit antagonistic effects.

  4. Novel potent selective phenylglycine antagonists of metabotropic glutamate receptors.

    Science.gov (United States)

    Bedingfield, J S; Jane, D E; Kemp, M C; Toms, N J; Roberts, P J

    1996-08-01

    The metabotropic glutamate (mGlu) receptor antagonist properties of novel phenylglycine analogues were investigated in adult rat cortical slices (mGlu receptors negatively coupled to adenylyl cyclase), neonatal rat cortical slices and in cultured rat cerebellar granule cells (mGlu receptors coupled to phosphoinositide hydrolysis). (RS)-alpha-methyl-4-phosphonophenylglycine (MPPG), (RS)-alpha-methyl-4-sulphonophenylglycine (MSPG), (RS)-alpha-methyl-4-tetrazolylphenylglycine (MTPG), (RS)-alpha-methyl-3-carboxymethyl-4-hydroxyphenylglycine (M3CM4HPG) and (RS)-alpha-methyl-4-hydroxy-3-phosphonomethylphenylglycine (M4H3PMPG) were demonstrated to have potent and selective effects against 10 microM L-2-amino-4-phosphonobutyrate (L-AP4)- and 0.3 microM (2S,1'S,2'S)-2-(2-carboxycyclopropyl)glycine (L-CCG-1)-mediated inhibition of forskolin-stimulated cAMP accumulation in the adult rat cortex. In contrast, these compounds demonstrated either weak or no antagonism at mGlu receptors coupled to phosphoinositide hydrolysis in either neonatal rat cortex or in cultured cerebellar granule cells. These compounds thus appear to be useful discriminatory pharmacological tools for mGlu receptors and form the basis for the further development of novel antagonists. PMID:8864696

  5. Nucleoside-derived antagonists to A3 adenosine receptors lower mouse intraocular pressure and act across species.

    Science.gov (United States)

    Wang, Zhao; Do, Chi Wai; Avila, Marcel Y; Peterson-Yantorno, Kim; Stone, Richard A; Gao, Zhan-Guo; Joshi, Bhalchandra; Besada, Pedro; Jeong, Lak Shin; Jacobson, Kenneth A; Civan, Mortimer M

    2010-01-01

    The purpose of the study was to determine whether novel, selective antagonists of human A3 adenosine receptors (ARs) derived from the A3-selective agonist Cl-IB-MECA lower intraocular pressure (IOP) and act across species. IOP was measured invasively with a micropipette by the Servo-Null Micropipette System (SNMS) and by non-invasive pneumotonometry during topical drug application. Antagonist efficacy was also assayed by measuring inhibition of adenosine-triggered shrinkage of native bovine nonpigmented ciliary epithelial (NPE) cells. Five agonist-based A3AR antagonists lowered mouse IOP measured with SNMS tonometry by 3-5 mm Hg within minutes of topical application. Of the five agonist derivatives, LJ 1251 was the only antagonist to lower IOP measured by pneumotonometry. No effect was detected pneumotonometrically over 30 min following application of the other four compounds, consonant with slower, smaller responses previously measured non-invasively following topical application of A3AR agonists and the dihydropyridine A3AR antagonist MRS 1191. Latanoprost similarly lowered SNMS-measured IOP, but not IOP measured non-invasively over 30 min. Like MRS 1191, agonist-based A3AR antagonists applied to native bovine NPE cells inhibited adenosine-triggered shrinkage. In summary, the results indicate that antagonists of human A3ARs derived from the potent, selective A3 agonist Cl-IB-MECA display efficacy in mouse and bovine cells, as well. When intraocular delivery was enhanced by measuring mouse IOP invasively, five derivatives of the A3AR agonist Cl-IB-MECA lowered IOP but only one rapidly reduced IOP measured non-invasively after topical application. We conclude that derivatives of the highly-selective A3AR agonist Cl-IB-MECA can reduce IOP upon reaching their intraocular target, and that nucleoside-based derivatives are promising A3 antagonists for study in multiple animal models. PMID:19878673

  6. Biological control of soybean damping-off by antagonistic rhizobacteria.

    Science.gov (United States)

    Sharifi Tehrani, A; Zebarjad, A; Hedjaroud, Gh A; Mohammadi, M

    2002-01-01

    Experiments were carried out with 133 bacterial isolates that were collected from soybean rhizosphere. These strains were used to investigate their biocontrol traits in vitro and their ability to suppress the soybean damping-off in vivo (soil and seed treatments). Three highly effective isolates were selected from these antagonists for subsequent studies. According to the biochemical, physiological and morphological tests, these isolates (B-2, B-12 and B-80) were identified as Bacillus spp. In soil treatment, the isolate B-3 with 70.8%, B-12 with 66.7%, B-80 with 54.2% had the highest effect on reducing the soybean damping-off. In seed treatment, the isolates B-43 with 62.5%, B-12 with 58.4 and B-80 with 45.8%, had the greatest effect on reducing the disease. These isolates produced volatile metabolites that inhibited mycelial growth of Phytophthora sojae. PMID:12701446

  7. Effects of TNF antagonists on immune and neuroendocrine system

    Directory of Open Access Journals (Sweden)

    M. Cutolo

    2011-09-01

    Full Text Available In the article, the literature on the effects of TNFa-antagonists (etanercept, infliximab and adalimumab on the immune system is reviewed. These biologic agents are employed in chronic inflammatory diseases such as rheumatoid arthritis, seronegative spondyloarthritides, as well as psoriasis and Crohn’s disease. The differences of these drugs, testified by the different effects on the immune response, are discussed. These molecules exert their effect through cytokine inhibition, but they present striking differences since they can modulate macrophage activity, T cells apoptosis, leukocyte migration, and angiogenesis to a different degree. Some studies showed that these agents also affect the hypothalamo- pituitary-adrenal axis. The potential immunogenicity of these biologic agents is also discussed.

  8. Histamine-2 Receptor Antagonists and Semen Quality.

    Science.gov (United States)

    Banihani, Saleem A

    2016-01-01

    Histamine-2 receptor antagonists are a class of drugs used to treat the acid-related gastrointestinal diseases such as ulcer and gastro-oesophageal reflux disease. Although such drugs, especially ranitidine and famotidine, are still widely used, their effects on semen quality, and hence on male infertility, is still unclear. This MiniReview systematically addresses and summarizes the effect of histamine-2 receptor antagonists (cimetidine, ranitidine, nizatidine and famotidine) on semen quality, particularly, on sperm function. Cimetidine appears to have adverse effects on semen quality. While the effects of ranitidine and nizatidine on semen quality are still controversial, famotidine does not appear to change semen quality. Therefore, additional studies will be required to clarify whether histamine-2 receptor-independent effects of these drugs play a role in semen quality as well as further clinical studies including direct comparison of the histamine-2 receptor antagonists. PMID:26176290

  9. Auxin-Oxylipin Crosstalk: Relationship of Antagonists

    Institute of Scientific and Technical Information of China (English)

    Maik Hoffmann; Mathias Hentrich; Stephan Pollmann

    2011-01-01

    Phytohormones regulate a wide array of developmental processes throughout the life cycle of plants. Herein, the various plant hormones may interact additively, synergistically, or antagonistically. By their cooperation they create a delicate regulatory network whose net output largely depends on the action of specific phytohormone combinations rather than on the independent activities of separate hormones. While most classical studies of plant hormonal control have focused mainly on the action of single hormones or on the synergistic interaction of hormones in regulating various developmental processes, recent work is beginning to shed light on the crosstalk of nominally antagonistic plant hormones, such as gibberellins and auxins with oxylipins or abscisic acid. In this review, we summarize our current understanding of how two of the first sight antagonistic plant hormones, i.e. auxins and oxylipins,interact in controlling plant responses and development.

  10. Cross-domain inhibition of TACE ectodomain

    DEFF Research Database (Denmark)

    Tape, Christopher J; Willems, Sofie H; Dombernowsky, Sarah L;

    2011-01-01

    target for the treatment of cancer and arthritis. Prior attempts to antagonize cell-surface TACE activity have focused on small-molecule inhibition of the metalloprotease active site. Given the highly conserved nature of metalloprotease active sites, this paradigm has failed to produce a truly specific...... individual antibody variable domains to desired epitopes. The resulting "cross-domain" human antibody is a previously undescribed selective TACE antagonist and provides a unique alternative to small-molecule metalloprotease inhibition....

  11. Endothelin receptor B antagonists decrease glioma cell viability independently of their cognate receptor

    International Nuclear Information System (INIS)

    Endothelin receptor antagonists inhibit the progression of many cancers, but research into their influence on glioma has been limited. We treated glioma cell lines, LN-229 and SW1088, and melanoma cell lines, A375 and WM35, with two endothelin receptor type B (ETRB)-specific antagonists, A-192621 and BQ788, and quantified viable cells by the capacity of their intracellular esterases to convert non-fluorescent calcein AM into green-fluorescent calcein. We assessed cell proliferation by labeling cells with carboxyfluorescein diacetate succinimidyl ester and quantifying the fluorescence by FACS analysis. We also examined the cell cycle status using BrdU/propidium iodide double staining and FACS analysis. We evaluated changes in gene expression by microarray analysis following treatment with A-192621 in glioma cells. We examined the role of ETRB by reducing its expression level using small interfering RNA (siRNA). We report that two ETRB-specific antagonists, A-192621 and BQ788, reduce the number of viable cells in two glioma cell lines in a dose- and time-dependent manner. We describe similar results for two melanoma cell lines. The more potent of the two antagonists, A-192621, decreases the mean number of cell divisions at least in part by inducing a G2/M arrest and apoptosis. Microarray analysis of the effects of A-192621 treatment reveals up-regulation of several DNA damage-inducible genes. These results were confirmed by real-time RT-PCR. Importantly, reducing expression of ETRB with siRNAs does not abrogate the effects of either A-192621 or BQ788 in glioma or melanoma cells. Furthermore, BQ123, an endothelin receptor type A (ETRA)-specific antagonist, has no effect on cell viability in any of these cell lines, indicating that the ETRB-independent effects on cell viability exhibited by A-192621 and BQ788 are not a result of ETRA inhibition. While ETRB antagonists reduce the viability of glioma cells in vitro, it appears unlikely that this effect is mediated by

  12. Behavioral sensitization to apomorphine in pigeons (Columba livia) : blockade by the D₁ dopamine antagonist SCH-23390

    OpenAIRE

    Acerbo, Martin J.; Delius, Juan

    2004-01-01

    Repeated administration of apomorphine leads to a context-dependent pecking response sensitization. Previously sensitized pigeons (Columba livia) challenged with saline in the same context show a conditioned response (CR). The authors studied the effects of intrastriatal injections of the dopamine (D₁) antagonist SCH-23390 on both the sensitized response and the CR. When coadministered with apomorphine, SCH-23390 inhibited the initial response to apomorphine, prevented the development of sens...

  13. Inhibitory effect of the CA2+ antagonist nifedipine on histamine release from rat peritoneal mast cells.

    Directory of Open Access Journals (Sweden)

    Tanizaki,Yoshiro

    1983-06-01

    Full Text Available 45Ca uptake and histamine release was examined in mast cells from rats sensitized with ovalbumin and Bordetella Bertussis as an adjuvant. The uptake of 45Ca by the mast cells was significantly increased by stimulation with ovalbumin as was the release of histamine from the mast cells. Nifedipine, a calcium antagonist, inhibited the increase in both 45Ca uptake and histamine release stimulated by ovalbumin, though the effect on 45Ca uptake was stronger than that on histamine release.

  14. Inhibitory effect of the CA2+ antagonist nifedipine on histamine release from rat peritoneal mast cells.

    OpenAIRE

    Tanizaki,Yoshiro; Komagoe,Haruki; Sudo,Michiyasu; Ohtani,Jun; Kimura,Ikuro; Akagi,Katsumi; Townley, Robert G.

    1983-01-01

    45Ca uptake and histamine release was examined in mast cells from rats sensitized with ovalbumin and Bordetella Bertussis as an adjuvant. The uptake of 45Ca by the mast cells was significantly increased by stimulation with ovalbumin as was the release of histamine from the mast cells. Nifedipine, a calcium antagonist, inhibited the increase in both 45Ca uptake and histamine release stimulated by ovalbumin, though the effect on 45Ca uptake was stronger than that on histamine release.

  15. Apoptotic Death of Prostate Cancer Cells by a Gonadotropin-Releasing Hormone-II Antagonist

    OpenAIRE

    Park, Sumi; Han, Ji Man; Cheon, Jun; Hwang, Jong-Ik; Seong, Jae Young

    2014-01-01

    Gonadotropin-releasing hormone-I (GnRH-I) has attracted strong attention as a hormonal therapeutic tool, particularly for androgen-dependent prostate cancer patients. However, the androgen-independency of the cancer in advanced stages has spurred researchers to look for new medical treatments. In previous reports, we developed the GnRH-II antagonist Trp-1 to inhibit proliferation and stimulate the autophagic death of various prostate cancer cells, including androgen-independent cells. We furt...

  16. An interleukin-1 receptor antagonist blocks lipopolysaccharide-induced colony-stimulating factor production and early endotoxin tolerance.

    OpenAIRE

    Henricson, B E; Neta, R; Vogel, S N

    1991-01-01

    In this report, administration of a recombinant interleukin-1 receptor antagonist protein to mice was found to inhibit induction of colony-stimulating factor as well as induction of early endotoxin tolerance by lipopolysaccharide. These findings provide direct evidence that interleukin-1 is an intermediate in these two lipopolysaccharide-induced phenomena.

  17. Oxazolidinones as novel human CCR8 antagonists.

    Science.gov (United States)

    Jin, Jian; Wang, Yonghui; Wang, Feng; Kerns, Jeffery K; Vinader, Victoria M; Hancock, Ashley P; Lindon, Matthew J; Stevenson, Graeme I; Morrow, Dwight M; Rao, Parvathi; Nguyen, Cuc; Barrett, Victoria J; Browning, Chris; Hartmann, Guido; Andrew, David P; Sarau, Henry M; Foley, James J; Jurewicz, Anthony J; Fornwald, James A; Harker, Andy J; Moore, Michael L; Rivero, Ralph A; Belmonte, Kristen E; Connor, Helen E

    2007-03-15

    High-throughput screening of the corporate compound collection led to the discovery of a novel series of N-substituted-5-aryl-oxazolidinones as potent human CCR8 antagonists. The synthesis, structure-activity relationships, and optimization of the series that led to the identification of SB-649701 (1a), are described. PMID:17267215

  18. Azines as histamine H4 receptor antagonists.

    Science.gov (United States)

    Lazewska, Dorota; Kiec-Kononowicz, Katarzyna

    2012-01-01

    Since 2000, when the histamine H4 receptor (H4R) was cloned, it has constituted an interesting target for drug development. Pharmacological studies suggest the potential utility of histamine H4R antagonists/inverse agonists in the treatment of inflammatory diseases, e.g. allergic rhinitis, asthma, atopic dermatitis, colitis, or pruritus. The first H4R ligands were non-selective compounds, but intensive chemical and pharmacological work has led to the discovery of highly potent and selective H4R antagonists (e.g. JNJ7777120, CZC-13788, PF-2988403, A-940894, A-987306). The first compound (UR-63325) has finally entered into clinical studies for the treatment of allergic respiratory diseases (completing the phase I ascending dose trial) and has been found to be safe and well tolerated. The number of scientific publications and patent applications in the H4 field is increasing annually. Among the diverse chemical structures of the H4R antagonists described a 2-aminopyrimidine scaffold is repeatedly found. This review looked at recent advances in the search for H4R antagonists as reflected in patent applications/patents and peer-reviewed publications over the last two years. The work concerns azines (mono-, di-, triazines) and their fused analogues. The chemistry and pharmacology has been described. PMID:22202103

  19. Genetic factors influencing pyrimidine-antagonist chemotherapy

    NARCIS (Netherlands)

    Maring, JG; Groen, HJM; Wachters, FM; Uges, DRA; de Vries, EGE

    2005-01-01

    Pyrimidine antagonists, for example, 5-fluorouracil (5-FU), cytarabine (ara-C) and gemcitabine (dFdC), are widely used in chemotherapy regimes for colorectal, breast, head and neck, non-small-cell lung cancer, pancreatic cancer and leukaemias. Extensive metabolism is a prerequisite for conversion of

  20. 7-Chloroarctinone-b as a new selective PPARγ antagonist potently blocks adipocyte differentiation

    Institute of Scientific and Technical Information of China (English)

    Yong-tao LI; Li LI; Jing CHEN; Tian-cen HU; Jin HUANG; Yue-wei GUO; Hua-liang JIANG; Xu SHEN

    2009-01-01

    Aim: Peroxisome proliferator-activated receptor gamma (PPARy) is a therapeutic target for obesity, cancer and diabetes mellitus. In order to develop potent lead compounds for obesity treatment, we screened a natural product library for novel PPARy antagonists with inhibitory effects on adipocyte differentiation. Methods: Surface plasmon resonance (SPR) technology and cell-based transactivation assay were used to screen for PPARy antago-nists. To investigate the antagonistic mechanism of the active compound, we measured its effect on PPARy/RXRα heterodimerization and PPARy co-activator recruitment using yeast two-hybrid assay, Gal4/UAS cell-based assay and SPR based assay. The 3T3-L1 cell differentiation assay was used to evaluate the effect of the active compound on adipocyte differentiation. Results: A new thiophene-acetylene type of natural product, 7-chloroarctinone-b (CAB), isolated from the roots of Rhaponticum uniflo-rum, was discovered as a novel PPARγ antagonist capable of inhibiting rosiglitazone-induced PPARγ transcriptional activity. SPR analy-sis suggested that CAB bound tightly to PPARγ and considerably antagonized the potent PPARy agonist rosigtitazone-stimulated PPARγ-LBD/RXRα-LBD binding. Gal4/UAS and yeast two-hybrid assays were used to evaluate the antagonistic activity of CAB on rosiglitazone-induced recruitment of the coactivator for PPARy. CAB could efficiently antagonize both hormone and rosiglitazone-induced adipocyte differentiation in cell culture. Conclusion: CAB shows antagonistic activity to PPARγ and can block the adipocyte differentiation, indicating it may be of potential use as a lead therapeutic compound for obesity.

  1. 5-HT6 Receptor Antagonists: Potential Efficacy for the Treatment of Cognitive Impairment in Schizophrenia.

    Science.gov (United States)

    de Bruin, Natasja M W J; Kruse, Chris G

    2015-01-01

    5-hydroxytryptamine6 receptor (5-HT6R) antagonists have shown efficacy in animal models for cognitive impairment in multiple cognitive domains relevant for schizophrenia. Improvements were found with 5-HT6R antagonists in preclinical tests for episodic memory, social cognition, executive function, working memory and several other tests for both learning and memory. In contrast, there is little evidence for efficacy on attention. It will be interesting to further investigate 5-HT6R antagonists in neurodevelopmental animal models which are based on prenatal exposure to specific environmental insults, and are characterized by a high level of face, construct and predictive validity for cognitive impairments associated with schizophrenia. It is also important to do more add-on preclinical studies of 5-HT6 antagonists with antipsychotics. Possible mechanisms of action to improve cognition have been described. 5-HT6R antagonists decrease GABA release and GABAergic interneuron excitability, which subsequently disinhibits glutamate and/or acetylcholine release and results in enhancement of synaptic plasticity. Furthermore, cognition could be improved by 5-HT6R antagonists, because these compounds increase the number of NCAM PSA-immunoreactive neurons in the dendate gyrus, inhibit mTOR and Fyn-tyrosine kinase and interact with DARPP-32. Interestingly, there is increasing preclinical evidence that could support additional benefits of 5-HT6R ligandson comorbid conditions in schizophrenia such as drug abuse, depression, anxiety, obesity andantipsychotic-induced EPS. Finally, we briefly give an overview of the 5-HT6R compounds that are currently in clinical development for the treatment of cognitive impairment in both schizophrenia and Alzheimer's disease. PMID:26044973

  2. Non-specific actions of the non-peptide tachykinin receptor antagonists, CP-96,345, RP 67580 and SR 48968, on neurotransmission.

    Science.gov (United States)

    Wang, Z Y; Tung, S R; Strichartz, G R; Håkanson, R

    1994-01-01

    1. Three non-peptide tachykinin receptor antagonists, CP-96,345, RP 67580 and SR 48968, were found to inhibit the electrically-evoked, tachykinin-mediated contractile responses of the rabbit iris sphincter in a concentration-dependent fashion; the pIC50 values were 5.6 +/- 0.01, 5.4 +/- 0.07 and 4.8 +/- 0.03, respectively. 2. These antagonists also inhibited the electrically-evoked, parasympathetic response of the rabbit iris sphincter and the sympathetic response of the guinea-pig vas deferens in a concentration-dependent manner; the pIC50 values were 0.3-1.2 log units lower than those recorded for the tachykinin-mediated responses. 3. Two local anaesthetics, bupivacaine and oxybuprocaine, were also found to inhibit the tachykinin-mediated, cholinergic and sympathetic contractile responses in these tissues in a concentration-dependent manner; the concentration ranges for producing the inhibition were similar to those of the non-peptide tachykinin receptor antagonists. 4. On the sciatic nerves of frogs, the tachykinin receptor antagonists inhibited action potentials in a concentration-dependent manner; the potency of the three drugs was similar to that of bupivacaine. 5. Our results suggest that, in addition to blocking tachykinin receptors, the non-peptide tachykinin receptor antagonists, CP-96,345, RP 67580 and SR 48968, may exert non-specific inhibitory effects on neurotransmission. PMID:8012694

  3. Endothelin A Receptor Antagonist, Atrasentan, Attenuates Renal and Cardiac Dysfunction in Dahl Salt-Hypertensive Rats in a Blood Pressure Independent Manner

    OpenAIRE

    Samad, Mohammed A.; Kim, Ui Kyoung; Kang, Joshua J.; Ke, Qingen; Kang, Peter M.

    2015-01-01

    Proteinuria is a hallmark of chronic kidney disease (CKD) and cardiovascular disease (CVD), and a good predictor of clinical outcome. Selective endothelin A (ETA) receptor antagonist used with renin-angiotensin system (RAS) inhibitors prevents development of proteinuria in CKD. However, whether the improvement in proteinuria would have beneficial effects on CVD, independent of RAS inhibition, is not well understood. In this study, we investigated whether atrasentan, an ETA receptor antagonist...

  4. Electrophysiological effects of Ca antagonists, tetrodotoxin, [Ca]o and [Na]o on myocardium of hibernating chipmunks: possible involvement of Na-Ca exchange mechanism.

    OpenAIRE

    Kondo, N

    1987-01-01

    The electrophysiological performance of myocardium of hibernating chipmunks was investigated in the presence of Ca antagonists and tetrodotoxin, and the effects of high [Ca]o and low [Na]o were examined. The action potential of the preparations was characterized by the low amplitude of the plateau phase (APp). Ca antagonists, nifedipine (10(-6) M) and nitrendipine (2 X 10(-6) M), did not significantly inhibit this APp or the contraction. These nifedipine-insensitive electromechanical response...

  5. The substance P/NK-1 receptor system: NK-1 receptor antagonists as anti-cancer drugs

    Indian Academy of Sciences (India)

    Miguel Muñoz; Rafael Coveñas; Francisco Esteban; Maximino Redondo

    2015-06-01

    The substance P (SP)/neurokinin (NK)-1 receptor system plays an important role in cancer. SP promotes the proliferation of tumour cells, angiogenesis and the migration of tumour cells. We review the involvement of SP, the NK-1 receptor and NK-1 receptor antagonists in cancer. Tumour cells overexpress NK-1 receptors, which are involved in their viability. This overexpression suggests the possibility of specific treatment against tumour cells using NK-1 receptor antagonists, thus promoting a considerable decrease in the side effects of the treatment. This strategy opens up new approaches for cancer treatment, since these antagonists, after binding to their molecular target, induce the death of tumour cells by apoptosis, exert an antiangiogenic action and inhibit the migration of tumour cells. The use of NK-1 receptor antagonists such as aprepitant (used in clinical practice) as antitumour agents could be a promising innovation. The value of aprepitant as an antitumour agent could be determined faster than for less well-known compounds because many studies addressing its safety and characterization have already been completed. The NK-1 receptor may be a promising target in the treatment of cancer; NK-1 receptor antagonists could act as specific drugs against tumour cells; and these antagonists could be new candidate anti-cancer drugs.

  6. Molecular characterizations of microbial antagonists and development of bioformulations for management of bacterial wilt of Naga Chilli (Capsicum chinens Jacq. in Assam

    Directory of Open Access Journals (Sweden)

    Lohit Kataki, Kuldeep Talukdar

    2015-04-01

    Full Text Available Aggressive strains of five different saprophytic antagonists Trichoderma parareesei TPJ-S-1, Trichoderma viride TVJ-S-1, Paecilomyces variotii Isolate-1, Bacillus thuringiensis BTJ-S-1 and Citrobacter farmeri CTJ-S-1 and their consortial formulations were evaluated during 2012-14, for their effectiveness in management of bacterial wilt disease (c. o. Ralstonia solanacearum of Naga chilli (Capsicum chinens Jacq.. The molecular characterization of selected antagonists was undertaken to determine their distinctiveness from their close relatives through sequencing of the 18S & 28S region of ribosomal DNA in case of fungal antagonists and 16S region in case of bacterial antagonists along with its phylogenetic analysis. The antagonistic potential of the five microbes were tested in vitro singly and in consortia against R. solanacearum adopting dual culture method. Altogether 31 treatment combinations were compared; the inhibition zones (mm and percent inhibitions were recorded and analyzed. The highest inhibition (91.47% against R. solanacearum was recorded in consortia of T. parareesei, T. viride and B. thuringiensis followed by the consortia of T. parareesei, T. viride, P. variotii, B. thuringiensis and C. farmeri (82.22%. Quantitative aspect of population dynamics of selected antagonists in three different substrate carrier viz. vermicompost, talcum powder (TP and mustard oil cake (MOC were compared to evaluate their shelf – life at different days of storage

  7. Cetirizine inhibits skin reactions but not mediator release in immediate and developing late-phase allergic cutaneous reactions. A double-blind, placebo-controlled study

    DEFF Research Database (Denmark)

    Nielsen, P N; Skov, P S; Poulsen, Lars K.;

    2001-01-01

    Recent reports have indicated cetirizine, a potent H(1)-receptor antagonist, to possess a number of anti-inflammatory effects, e.g. inhibition of mast cell degranulation and inhibition of leucocyte migration and activation....

  8. Streptomycetes and micromycetes as perspective antagonists of fungal phytopathogens.

    Science.gov (United States)

    Postolaky, O; Syrbu, T; Poiras, N; Baltsat, K; Maslobrod, S; Boortseva, S

    2012-01-01

    Among natural factors that permanently influence on the plants, the soil microorganisms play a special role for the growing of plants as habitants of their rhizosphere. Mainly they are the representatives of actinomycetes genus Streptomyces and fungal genus Penicillium and their metabolic products stimulate plant growth and inhibit the growth of pathogenic fungi and bacteria. The aim of our study was to determine the antagonism of actinomycetes and micromycetes isolated from soils of R. Moldova against the fungal pathogens of agricultural plants. The strains were isolated from 5 types of chernozem (black soil) from central zone of R. Moldova, with different concentration of humus. Most of micromycetes and streptomycetes were isolated from soil sample 1 (monoculture of maize) and soil sample 2 (Poltava road border) with similar humus content (2.4-2.6%). The antifungal activity of micromycetes strains was occurring mostly against Fusarium solani and Thelaviopsis basicola, at streptomycetes against Alternaria alternata and Botrytis cinerea. It was revealed the strains completely inhibit the growth of Alt. alternata (streptomycetes strains 23, 33, 37), B. cinerea (Streptomyces sp. 17), and F. solani (Penicillium sp. 104). Our results allow to consider the actinomycetes Streptomyces sp.9, Streptomyces sp. 12, Streptomyces sp. 17, Streptomyces sp. 37 Streptomyces sp. 66 and micromycetes Penicillium sp. 5, Penicillium sp. 65, Penicillium sp. 104 isolated from soils of R. Moldova, as prospective strains-antagonists against the phytopathogenic fungus, the causative agents of agricultural plants deseasis. PMID:23878981

  9. The Oxytocin-Oxytocin Receptor System and Its Antagonists as Tocolytic Agents

    Directory of Open Access Journals (Sweden)

    Nikolaos Vrachnis

    2011-01-01

    Full Text Available Oxytocin, a hormone involved in numerous physiologic processes, plays a central role in the mechanisms of parturition and lactation. It acts through its receptor, which belongs to the G-protein-coupled receptor superfamily, while Gq/phospholipase C (PLC/inositol 1,4,5-triphosphate (InsP3 is the main pathway via which it exerts its action in the myometrium. Changes in receptor levels, receptor desensitization, and locally produced oxytocin are factors that influence the effect of oxytocin on uterine contractility in labor. Activation of oxytocin receptor causes myometrial contractions by increasing intracellular Ca+2 and production of prostaglandins. Since oxytocin induces contractions, the inhibition of its action has been a target in the management of preterm labor. Atosiban is today the only oxytocin receptor antagonist that is available as a tocolytic. However, the quest for oxytocin receptor antagonists with a better pharmacological profile has led to the synthesis of peptide and nonpeptide molecules such as barusiban, retosiban, L-368,899, and SSR-126768A. Many of these oxytocin receptor antagonists are used only as pharmacological tools, while others have tocolytic action. In this paper, we summarize the action of oxytocin and its receptor and we present an overview of the clinical and experimental data of oxytocin antagonists and their tocolytic action.

  10. The Tunisian oasis ecosystem is a source of antagonistic Bacillus spp. producing diverse antifungal lipopeptides.

    Science.gov (United States)

    El Arbi, Amel; Rochex, Alice; Chataigné, Gabrielle; Béchet, Max; Lecouturier, Didier; Arnauld, Ségolène; Gharsallah, Néji; Jacques, Philippe

    2016-01-01

    The use of microbial products has become a promising alternative approach to controlling plant diseases caused by phytopathogenic fungi. Bacteria isolated from the date palm tree rhizosphere of the Tunisian oasis ecosystem could provide new biocontrol microorganisms adapted to extreme conditions, such as drought, salinity and high temperature. The aim of this study was to screen bacteria isolated from the rhizosphere of the date palm tree for their ability to inhibit phytopathogenic fungi, and to identify molecules responsible for their antifungal activity. Screening for antifungal activity was performed on twenty-eight isolates. Five antagonistic isolates were selected and identified as different species of Bacillus using phenotypical methods and a molecular approach. The five antagonistic Bacillus isolated showed tolerance to abiotic stresses (high temperature, salinity, drought). Their ability to produce lipopeptides was investigated using a combination of two techniques: PCR amplification and MALDI-ToF mass spectrometry. Analyses revealed that the antagonistic isolates produced a high diversity of lipopeptides that belonged to surfactin, fengycin, iturin and kurstakin families. Their antagonistic activity, related to their capacity for producing diverse antifungal lipopeptides and their tolerance to abiotic stresses, highlighted Bacillus strains isolated from the rhizosphere of the date palm tree as potential biocontrol agents for combatting plant diseases in extreme environments. PMID:26428248

  11. Vasopressin receptor antagonists: Characteristics and clinical role.

    Science.gov (United States)

    Rondon-Berrios, Helbert; Berl, Tomas

    2016-03-01

    Hyponatremia, the most common electrolyte disorder in hospitalized patients is associated with increased risk of mortality even when mild and apparently asymptomatic. Likewise morbidity manifested as attention deficits, gait disturbances, falls, fractures, and osteoporosis is more prevalent in hyponatremic subjects. Hyponatremia also generates a significant financial burden. Therefore, it is important to explore approaches that effectively and safely treat hyponatremia. Currently available strategies are physiologically sound and affordable but lack evidence from clinical trials and are limited by variable efficacy, slow response, and/or poor compliance. The recent emergence of vasopressin receptor antagonists provides a class of drugs that target the primary pathophysiological mechanism, namely vasopressin mediated impairment of free water excretion. This review summarizes the historical development, pharmacology, clinical trials supporting efficacy and safety, shortcomings, as well as practical suggestions for the use of vasopressin receptor antagonists. PMID:27156765

  12. Functionalized Congeners of P2Y1 Receptor Antagonists:

    Energy Technology Data Exchange (ETDEWEB)

    de Castro, Sonia [National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health; Maruoka, Hiroshi [National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health; Hong, Kunlun [ORNL; Kilbey, II, S Michael [ORNL; Costanzi, Stefano [National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health; Hechler, Béatrice [University of Strasbourg; Gachet, Christian [EFS-Alsace, Strasbourg, France; Harden, T. Kendall [University of North Carolina School of Medicine; Jacobson, Kenneth A. [National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health

    2010-01-01

    The P2Y{sub 1} receptor is a prothrombotic G protein-coupled receptor (GPCR) activated by ADP. Preference for the North (N) ring conformation of the ribose moiety of adenine nucleotide 3',5'-bisphosphate antagonists of the P2Y{sub 1} receptor was established by using a ring-constrained methanocarba (a bicyclo[3.1.0]hexane) ring as a ribose substitute. A series of covalently linkable N{sup 6}-methyl-(N)-methanocarba-2'-deoxyadenosine-3',5'-bisphosphates containing extended 2-alkynyl chains was designed, and binding affinity at the human (h) P2Y{sub 1} receptor determined. The chain of these functionalized congeners contained hydrophilic moieties, a reactive substituent, or biotin, linked via an amide. Variation of the chain length and position of an intermediate amide group revealed high affinity of carboxylic congener 8 (K{sub i} 23 nM) and extended amine congener 15 (K{sub i} 132 nM), both having a 2-(1-pentynoyl) group. A biotin conjugate 18 containing an extended {epsilon}-aminocaproyl spacer chain exhibited higher affinity than a shorter biotinylated analogue. Alternatively, click coupling of terminal alkynes of homologous 2-dialkynyl nucleotide derivatives to alkyl azido groups produced triazole derivatives that bound to the P2Y{sub 1} receptor following deprotection of the bisphosphate groups. The preservation of receptor affinity of the functionalized congeners was consistent with new P2Y{sub 1} receptor modeling and ligand docking. Attempted P2Y{sub 1} antagonist conjugation to PAMAM dendrimer carriers by amide formation or palladium-catalyzed reaction between an alkyne on the dendrimer and a 2-iodopurine-derivatized nucleotide was unsuccessful. A dialkynyl intermediate containing the chain length favored in receptor binding was conjugated to an azide-derivatized dendrimer, and the conjugate inhibited ADP-promoted human platelet aggregation. This is the first example of attaching a strategically functionalized P2Y receptor

  13. Antagonistic parent-offspring co-adaptation.

    Directory of Open Access Journals (Sweden)

    Mathias Kölliker

    Full Text Available BACKGROUND: In species across taxa, offspring have means to influence parental investment (PI. PI thus evolves as an interacting phenotype and indirect genetic effects may strongly affect the co-evolutionary dynamics of offspring and parental behaviors. Evolutionary theory focused on explaining how exaggerated offspring solicitation can be understood as resolution of parent-offspring conflict, but the evolutionary origin and diversification of different forms of family interactions remains unclear. METHODOLOGY/PRINCIPAL FINDINGS: In contrast to previous theory that largely uses a static approach to predict how "offspring individuals" and "parental individuals" should interact given conflict over PI, we present a dynamic theoretical framework of antagonistic selection on the PI individuals obtain/take as offspring and the PI they provide as parents to maximize individual lifetime reproductive success; we analyze a deterministic and a stochastic version of this dynamic framework. We show that a zone for equivalent co-adaptation outcomes exists in which stable levels of PI can evolve and be maintained despite fast strategy transitions and ongoing co-evolutionary dynamics. Under antagonistic co-adaptation, cost-free solicitation can evolve as an adaptation to emerging preferences in parents. CONCLUSIONS/SIGNIFICANCE: We show that antagonistic selection across the offspring and parental life-stage of individuals favors co-adapted offspring and parental behavior within a zone of equivalent outcomes. This antagonistic parent-offspring co-adaptation does not require solicitation to be costly, allows for rapid divergence and evolutionary novelty and potentially explains the origin and diversification of the observed provisioning forms in family life.

  14. Aminopyrimidine derivatives as adenosine antagonists / Janke Kleynhans

    OpenAIRE

    Kleynhans, Janke

    2013-01-01

    Aims of this project - The aim of this study was to design and synthesise novel 2-aminopyrimidine derivatives as potential adenosine A1 and A2A receptor antagonists. Background and rationale - Parkinson’s disease is the second most common neurodegenerative disorder (after Alzheimer’s disease) and is characterised by the selective death of the dopaminergic neurons of the nigro-striatal pathway. Distinctive motor symptoms include bradykinesia, muscle rigidity and tremor, while non-m...

  15. Antagonistic neural networks underlying differentiated leadership roles

    OpenAIRE

    Boyatzis, Richard E.; Rochford, Kylie; Jack, Anthony I.

    2014-01-01

    The emergence of two distinct leadership roles, the task leader and the socio-emotional leader, has been documented in the leadership literature since the 1950s. Recent research in neuroscience suggests that the division between task-oriented and socio-emotional-oriented roles derives from a fundamental feature of our neurobiology: an antagonistic relationship between two large-scale cortical networks – the task-positive network (TPN) and the default mode network (DMN). Neural activity in TPN...

  16. Preliminary evidence that ketamine inhibits spreading depolarizations in acute human brain injury

    DEFF Research Database (Denmark)

    Sakowitz, Oliver W; Kiening, Karl L; Krajewski, Kara L;

    2009-01-01

    inhibited by the noncompetitive N-methyl-d-aspartate receptor antagonist ketamine. This restored electrocorticographic activity. CONCLUSIONS: These anecdotal electrocorticographic findings suggest that ketamine has an inhibitory effect on spreading depolarizations in humans. This is of potential interest...

  17. Medicinal chemistry of competitive kainate receptor antagonists.

    Science.gov (United States)

    Larsen, Ann M; Bunch, Lennart

    2011-02-16

    Kainic acid (KA) receptors belong to the group of ionotropic glutamate receptors and are expressed throughout in the central nervous system (CNS). The KA receptors have been shown to be involved in neurophysiological functions such as mossy fiber long-term potentiation (LTP) and synaptic plasticity and are thus potential therapeutic targets in CNS diseases such as schizophrenia, major depression, neuropathic pain and epilepsy. Extensive effort has been made to develop subtype-selective KA receptor antagonists in order to elucidate the physiological function of each of the five subunits known (GluK1-5). However, to date only selective antagonists for the GluK1 subunit have been discovered, which underlines the strong need for continued research in this area. The present review describes the structure-activity relationship and pharmacological profile for 10 chemically distinct classes of KA receptor antagonists comprising, in all, 45 compounds. To the medicinal chemist this information will serve as reference guidance as well as an inspiration for future effort in this field. PMID:22778857

  18. Antagonist capacity of Newly Isolated Strains of Pseudomonas Fluorescens against Three Important Phytopathogenic Bacteria

    Directory of Open Access Journals (Sweden)

    Reynaldo D.L. Cruz-Quiroz

    2011-01-01

    Full Text Available Problem statement: Phytopatogenic bacteria cause several damages to plants with important economical consequences. They provoke losses of product quality affecting all commercial chain of crops, for this reason, their control is a priority. Approach: We evaluated antagonist capacity of newly isolated Pseudonomas fluorescens strains against three important phytopatogenic bacteria (Clavibacter michiganensis, Xanthomonas axonopodis and Erwinia carotovora. Soils from commercial cropping of Capsicum annum L of several Mexican regions were used to isolate P. fluorescens strains. Results: Isolates producing flourescein were purified on King B agar and biochemically identified. Crude extracts with and without cells were produced in King B broths and their antagonist capacities were evaluated by the plate diffusion procedure on nutritive agar. Conclusion: Obtained results demonstrated that cell free extracts exhibited a limited antagonist capacity in comparison of those extracts with cells, which showed an excellent capacity to inhibit the growth of C. michiganensis, X. axonopodis and E. carotovora, demonstrating the intracellular nature of the bioactive metabolites associated to bacterial growth inhibition.

  19. Calcium antagonist properties of the bisbenzylisoquinoline alkaloid cycleanine.

    Science.gov (United States)

    Martínez, J A; Bello, A; Rubio, L L; Rodríguez, C; Galán, L; Caudales, E; Alvarez, J L

    1998-01-01

    The alkaloid cycleanine ([12aR-(12aR,24aR)]-2,3,12a,13,14,15,24,24a-octa hydro-5,6,17,18- tetramethoxy-1,13-dimethyl-8, 11:20,23-dietheno-1H,12H [1,10]dioxacyclooctadecino[2,3,4-ij:11,12,13-i'j']diisoquinolin e) was extracted from the bulbs of Stephania glabra (Roxb) Miers and its effects on cardiac and smooth muscle preparations were studied and compared to those of nifedipine (1,4-dihydro-2, 6-dimethyl-4-(2-nitrophenyl)-3,5-pyridine dicarboxylic acid dimethylesther). Cycleanine inhibited the KCl-induced contraction of rabbit aortic rings with higher potency than nifedipine. IC50s for cycleanine and nifedipine were 0.8 and 7.10(-9) M respectively. Cycleanine had minor effects on the norepinephrine-induced contraction of rabbit aortic rings. Cycleanine and nifedipine also depressed the contraction of rat ventricular preparations but with lower potency (IC50 = 3 and 0.03.10(-6) M respectively). Action potential duration of rat right ventricular strips was decreased by both compounds. L-type Ca-current (ICaL) of single rat ventricular cardiomyocytes was inhibited by cycleanine in a voltage- and frequency-dependent manner. With a higher potency nifedipine inhibited ICaL in a tonic and almost frequency-independent manner. The results suggest that cycleanine can act as a potent vascular selective Ca-antagonist. PMID:9565772

  20. Antagonistic Effects of Sodium Butyrate and N-(4-Hydroxyphenyl-retinamide on Prostate Cancer

    Directory of Open Access Journals (Sweden)

    Rainer Kuefer

    2007-03-01

    Full Text Available Butyrates and retinoids are promising antineoplastic agents. Here we analyzed effects of sodium butyrate and N-(4-hydroxyphenyl-retinamide (4-HPR on prostate cancer cells as monotherapy or in combination in vitro and in vivo. Sodium butyrate and 4-HPR induced concentration-dependent growth inhibition in prostate cancer cells in vitro. The isobologram analysis revealed that sodium butyrate and 4-HPR administered together antagonize effects of each other. For the in vivo studies, a water-soluble complex (4-HPR with a cyclodextrin was created. A single dose of sodium butyrate and 4-HPR showed a peak level in chicken plasma within 30 minutes. Both compounds induced inhibition of proliferation and apoptosis in xenografts of the chicken chorioallantoic membrane. Analysis of the cytotoxic effects of the drugs used in combination demonstrated an antagonistic effect on inhibition of proliferation and on induction of apoptosis. Prolonged jun N-terminal kinase phosphorylation induced by sodium butyrate and 4-HPR was strongly attenuated when both compounds were used in combination. Both compounds induced inhibition of NF-κ,B. This effect was strongly antagonized in LNCaP cells when the compounds were used in combination. These results indicate that combinational therapies have to be carefully investigated due to potential antagonistic effects in the clinical setting despite promising results of a monotherapy.

  1. Screening of antagonistic activity of microorganisms against Colletotrichum acutatum and Colletotrichum gloeosporioides

    Directory of Open Access Journals (Sweden)

    Živković Svetlana

    2010-01-01

    Full Text Available The antagonistic activities of five biocontrol agents: Trichoderma harzianum, Gliocladium roseum, Bacillus subtilis, Streptomyces noursei and Streptomyces natalensis, were tested in vitro against Colletotrichum acutatum and Colletotrichum gloeosporioides, the causal agents of anthracnose disease in fruit crops. The microbial antagonists inhibited mycelial growth in the dual culture assay and conidial germination of Colletotrichum isolates. The two Streptomyces species exhibited the strongest antagonism against isolates of C. acutatum and C. gloeosporioides. Microscopic examination showed that the most common mode of action was antibiosis. The results of this study identify T. harzianum, G. roseum, B. subtilis, S. natalensis and S. noursei as promising biological control agents for further testing against anthracnose disease in fruits. .

  2. AMD3465, a monomacrocyclic CXCR4 antagonist and potent HIV entry inhibitor

    DEFF Research Database (Denmark)

    Hatse, Sigrid; Princen, Katrien; De Clercq, Erik;

    2005-01-01

    3100, AMD3465 was even 10-fold more effective as a CXCR4 antagonist, while showing no interaction whatsoever with CCR5. As expected, AMD3465 proved highly potent against X4 HIV strains (IC50: 1-10 nM), but completely failed to inhibit the replication of CCR5-using (R5) viruses. In conclusion, AMD3465......The chemokine receptors CCR5 and CXCR4 function as coreceptors for human immunodeficiency virus (HIV) and are attractive targets for the development of anti-HIV drugs. The most potent CXCR4 antagonists described until today are the bicyclams. The prototype compound, AMD3100, exhibits potent and...... selective anti-HIV activity against CXCR4-using (X4) viruses and showed antiviral efficacy in X4 HIV-1-infected persons in a phase II clinical trial. However, AMD3100 lacks oral bioavailability due to its high overall positive charge. Initial structure-activity relationship studies with bicyclam analogues...

  3. In vitro competitive adhesion and production of antagonistic compounds by lactic acid bacteria against fish pathogens.

    Science.gov (United States)

    Balcázar, José Luis; Vendrell, Daniel; de Blas, Ignacio; Ruiz-Zarzuela, Imanol; Gironés, Olivia; Múzquiz, José Luis

    2007-06-21

    The present study describes the screening of five lactic acid bacteria (LAB) for use as probiotics based on their competitive adhesion and production of antagonistic substances against some fish pathogens. A reduction of adhesion of all pathogenic strains tested was obtained with three of the LAB strains (Lactococcus lactis subsp. lactis CLFP100, Lactococcus lactis subsp. cremoris CLFP102 and Lactobacillus curvatus CLFP150). With the exception of fish pathogens Flavobacterium psychrophilum and Renibacterium salmoninarum that were not inhibited by LAB strains, production of antagonistic compounds by all tested LAB was observed against at least one of the indicator strains. Based on mucus adhesion, competitive exclusion, and suppression of fish pathogen growth, the selected LAB strains can be considered for future challenge experiments in fish as a very promising alternative to the use of chemotherapeutic agents. PMID:17336468

  4. Non-specific actions of the non-peptide tachykinin receptor antagonists, CP-96,345, RP 67580 and SR 48968, on neurotransmission.

    OpenAIRE

    Wang, Z. Y.; Tung, S. R.; Strichartz, G R; Håkanson, R

    1994-01-01

    1. Three non-peptide tachykinin receptor antagonists, CP-96,345, RP 67580 and SR 48968, were found to inhibit the electrically-evoked, tachykinin-mediated contractile responses of the rabbit iris sphincter in a concentration-dependent fashion; the pIC50 values were 5.6 +/- 0.01, 5.4 +/- 0.07 and 4.8 +/- 0.03, respectively. 2. These antagonists also inhibited the electrically-evoked, parasympathetic response of the rabbit iris sphincter and the sympathetic response of the guinea-pig vas defere...

  5. A high-throughput screening assay to identify bacterial antagonists against Fusarium verticillioides.

    Science.gov (United States)

    Figueroa-López, Alejandro Miguel; Cordero-Ramírez, Jesús Damián; Quiroz-Figueroa, Francisco Roberto; Maldonado-Mendoza, Ignacio Eduardo

    2014-07-01

    A high-throughput antagonistic assay was developed to screen for bacterial isolates capable of controlling the maize fungal phytopathogen Fusarium verticillioides. This assay combines a straightforward methodology, in which the fungus is challenged with bacterial isolates in liquid medium, with a novel approach that uses the plant lectin wheat germ agglutinin (WGA) coupled to a fluorophore (Alexa-Fluor® 488) under the commercial name of WGA, Alexa Fluor® 488 conjugate. The assay is performed in a 96-well plate format, which reduces the required laboratory space and streamlines quantitation and automation of the process, making it fast and accurate. The basis of our assay is that fungal biomass can be assessed by WGA, Alexa Fluor® 488 conjugate staining, which recognizes the chitin in the fungal cell wall and thus permits the identification of potential antagonistic bacteria that inhibit fungal growth. This principle was validated by chitin-competition binding assays against WGA, Alexa Fluor® 488 conjugate; confocal laser microscopy confirmed that the fluorescent WGA, Alexa Fluor® 488 conjugate binds to the chitin of the fungal cell wall. The majority of bacterial isolates did not bind to the WGA, Alexa Fluor® 488 conjugate. Furthermore, including washing steps significantly reduced any bacterial staining to background levels, even in the rare cases where bacterial isolates were capable of binding to WGA. Confirmatory conventional agar plate antagonistic assays were also conducted to validate our technique. We are now successfully employing this large-scale antagonistic assay as a pre-screening step for potential fungal antagonists in extensive bacteria collections (on the order of thousands of isolates). PMID:23787812

  6. Antagonistic Activity of Probiotic Organism Against Vibrio cholerae and Cryptococcus neoformans

    Directory of Open Access Journals (Sweden)

    Vidya, R.

    2010-01-01

    Full Text Available The microbes are useful in many ways in the modern world. Probiotics one of them, which refers to, acid adherence bacteria in the intestinal cells, are able to survive at low pH and produce large amount of lactic acid. The present investigation deals with the antagonistic activity of Lactobacillus acidophilus organism against pathogens. The organism was isolated from the curd sample. Identification of bacteria was done by various biochemical testing. The present study revealed that L. acidophilus inhibits Vibrio cholerae more efficiently than Streptococcus pneumoniae and Shigella dysentriae. When L. acidophilus and V. cholerae were grown together, L. acidophilus dominated the growth and competitively inhibited the growth of V. cholerae. L. acidophilus was also found to inhibit Cryptococcus neoformans.

  7. Lactobacillus acidophilus antagonistic action against pathogenic strains inoculated in the fermented milk

    Directory of Open Access Journals (Sweden)

    Neila Mello Cortez

    2016-03-01

    Full Text Available With the present study aimed to evaluate the antagonistic action of Lactobacillus acidophilus front of Escherichia coli, Staphylococcus aureus and Listeria monocytogenes. In vitro tests were performed using Petri dishes with MRS agar and the milk fermented with Lactobacillus acidophilus also analyzed the chemistry and physical characteristics of the product during 35 days of storage under refrigeration. It has been observed in vitro formation of inhibition zones, ranging from 6 to 18 mm diameter, compared to the tested pathogens by lactic culture raises, indicating the possibility of producing organic acids, bacteriocins or other growth-inhibiting substances. In the fermented milk prepared, during storage, the probiotic micro-organism tested was able to inhibit the growth of E. coli O157: H7 and L. monocytogenes; and the log cycle reduction of S. aureus.

  8. Evaluation of antagonistic activity of milk fermented with kefir grains of different origins

    Directory of Open Access Journals (Sweden)

    João Paulo Victorino Santos

    2013-10-01

    Full Text Available In this study, the potential of kefir grains, obtained from three different towns/cities in the Southeast Region of Brazil to inhibit the growth of the five pathogenic microorganisms was evaluated. The samples showed the growth inhibition from 42.80-69.15 for Staphylococcus aureus ATCC 6538, 30.73-59.89 for Escherichia coli ATCC 11229, 44.99-73.05 for Salmonela typhi ATCC 6539, 41.45-54.18 for Listeria monocytogenes ATCC 15313 and 70.38-86.80 for Bacillus cereus RIBO 1222-173-S4. These results indicated that the kefir grains evaluated had antagonistic activity toward the different pathogens tested. The ability to inhibit, although differently depending on the regional microbiota, indicated a potential for their use as a functional food.

  9. Regulating role of acetylcholine and its antagonists in inward rectified K+ channels from guard cell protoplasts of Vicia faba

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    The inward rectified potassium current of Vicia faba guard cell protoplasts treated with acetylcholine (ACh) or the antagonists of its receptors were recorded by employing the patch clamp technique. The results show that ACh at lower concentrations increases the inward K+ current, in contrast, ACh at higher concentrations inhibits it. Treated with d-Tubocurarine (d-Tub), an antagonist of the nicotine ACh receptor (nAChR) inhibits the inward K+ current by 30%. Treated with atropine (Atr), an antagonist of the muscarine (Mus) ACh receptor (mAChR) also inhibits it by 36%.However,if guard cell protoplasts are treated with d-Tub and Atr together, the inward K+ current is inhibited by 60%-75%. Tetraethylammonium chloride (TEA), a strong inhibitor of K+ channels has no effect on the inward K+ current regulated by ACh, suggesting that there are inward K+ channels modulated by AChRs on the membrane of the guard cell protoplasts. These data demonstrate an ACh-regulated mechanism for stomatal movement.

  10. Regulating role of acetylcholine and its antagonists in inward rectified K~+ channels from guard cell protoplasts of Vicia faba

    Institute of Scientific and Technical Information of China (English)

    冷强; 花宝光; 郭玉海; 娄成后

    2000-01-01

    The inward rectified potassium current of Vicia faba guard cell protoplasts treated with acetylcholine (ACh) or the antagonists of its receptors were recorded by employing the patch clamp technique. The results show that ACh at lower concentrations increases the inward K+ current, in contrast, ACh at higher concentrations inhibits it. Treated with d-Tubocurarine (d-Tub), an antagonist of the nicotine ACh receptor (nAChR) inhibits the inward K+ current by 30%. Treated with atropine (Atr), an antagonist of the muscarine (Mus) ACh receptor (mAChR) also inhibits it by 36%. However, if guard cell protoplasts are treated with d-Tub and Atr together, the inward K+ current is inhibited by 60%-75%. Tetraethylammonium chloride (TEA), a strong inhibitor of K+ channels has no effect on the inward K+ current regulated by ACh, suggesting that there are inward K+ channels modulated by AChRs on the membrane of the guard cell protoplasts. These data demonstrate an ACh-regulated mechanism for stomatal movement.

  11. Implementation of a fluorescence-based screening assay identifies histamine H3 receptor antagonists clobenpropit and iodophenpropit as subunit-selective N-methyl-D-aspartate receptor antagonists

    DEFF Research Database (Denmark)

    Hansen, Kasper Bø; Mullasseril, Praseeda; Dawit, Sara; Kurtkaya, Natalie L; Yuan, Hongjie; Vance, Katie M; Orr, Anna G; Kvist, Trine; Ogden, Kevin K; Le, Phuong; Vellano, Kimberly M; Lewis, Iestyn; Kurtkaya, Serdar; Du, Yuhong; Qui, Min; Murphy, T J; Snyder, James P; Bräuner-Osborne, Hans; Traynelis, Stephen F

    2010-01-01

    NMDA receptor function, including the histamine H3 receptor antagonists clobenpropit and iodophenpropit, as well as the vanilloid receptor transient receptor potential cation channel, subfamily V, member 1 (TRPV1) antagonist capsazepine. These compounds are noncompetitive antagonists and the histamine...

  12. Receptor residence time trumps drug-likeness and oral bioavailability in determining efficacy of complement C5a antagonists.

    Science.gov (United States)

    Seow, Vernon; Lim, Junxian; Cotterell, Adam J; Yau, Mei-Kwan; Xu, Weijun; Lohman, Rink-Jan; Kok, W Mei; Stoermer, Martin J; Sweet, Matthew J; Reid, Robert C; Suen, Jacky Y; Fairlie, David P

    2016-01-01

    Drug discovery and translation are normally based on optimizing efficacy by increasing receptor affinity, functional potency, drug-likeness (rule-of-five compliance) and oral bioavailability. Here we demonstrate that residence time of a compound on its receptor has an overriding influence on efficacy, exemplified for antagonists of inflammatory protein complement C5a that activates immune cells and promotes disease. Three equipotent antagonists (3D53, W54011, JJ47) of inflammatory responses to C5a (3nM) were compared for drug-likeness, receptor affinity and antagonist potency in human macrophages, and anti-inflammatory efficacy in rats. Only the least drug-like antagonist (3D53) maintained potency in cells against higher C5a concentrations and had a much longer duration of action (t1/2 ~ 20 h) than W54011 or JJ47 (t1/2 ~ 1-3 h) in inhibiting macrophage responses. The unusually long residence time of 3D53 on its receptor was mechanistically probed by molecular dynamics simulations, which revealed long-lasting interactions that trap the antagonist within the receptor. Despite negligible oral bioavailability, 3D53 was much more orally efficacious than W54011 or JJ47 in preventing repeated agonist insults to induce rat paw oedema over 24 h. Thus, residence time on a receptor can trump drug-likeness in determining efficacy, even oral efficacy, of pharmacological agents. PMID:27094554

  13. Receptor residence time trumps drug-likeness and oral bioavailability in determining efficacy of complement C5a antagonists

    Science.gov (United States)

    Seow, Vernon; Lim, Junxian; Cotterell, Adam J.; Yau, Mei-Kwan; Xu, Weijun; Lohman, Rink-Jan; Kok, W. Mei; Stoermer, Martin J.; Sweet, Matthew J.; Reid, Robert C.; Suen, Jacky Y.; Fairlie, David P.

    2016-01-01

    Drug discovery and translation are normally based on optimizing efficacy by increasing receptor affinity, functional potency, drug-likeness (rule-of-five compliance) and oral bioavailability. Here we demonstrate that residence time of a compound on its receptor has an overriding influence on efficacy, exemplified for antagonists of inflammatory protein complement C5a that activates immune cells and promotes disease. Three equipotent antagonists (3D53, W54011, JJ47) of inflammatory responses to C5a (3nM) were compared for drug-likeness, receptor affinity and antagonist potency in human macrophages, and anti-inflammatory efficacy in rats. Only the least drug-like antagonist (3D53) maintained potency in cells against higher C5a concentrations and had a much longer duration of action (t1/2 ~ 20 h) than W54011 or JJ47 (t1/2 ~ 1–3 h) in inhibiting macrophage responses. The unusually long residence time of 3D53 on its receptor was mechanistically probed by molecular dynamics simulations, which revealed long-lasting interactions that trap the antagonist within the receptor. Despite negligible oral bioavailability, 3D53 was much more orally efficacious than W54011 or JJ47 in preventing repeated agonist insults to induce rat paw oedema over 24 h. Thus, residence time on a receptor can trump drug-likeness in determining efficacy, even oral efficacy, of pharmacological agents. PMID:27094554

  14. Receptor residence time trumps drug-likeness and oral bioavailability in determining efficacy of complement C5a antagonists

    Science.gov (United States)

    Seow, Vernon; Lim, Junxian; Cotterell, Adam J.; Yau, Mei-Kwan; Xu, Weijun; Lohman, Rink-Jan; Kok, W. Mei; Stoermer, Martin J.; Sweet, Matthew J.; Reid, Robert C.; Suen, Jacky Y.; Fairlie, David P.

    2016-04-01

    Drug discovery and translation are normally based on optimizing efficacy by increasing receptor affinity, functional potency, drug-likeness (rule-of-five compliance) and oral bioavailability. Here we demonstrate that residence time of a compound on its receptor has an overriding influence on efficacy, exemplified for antagonists of inflammatory protein complement C5a that activates immune cells and promotes disease. Three equipotent antagonists (3D53, W54011, JJ47) of inflammatory responses to C5a (3nM) were compared for drug-likeness, receptor affinity and antagonist potency in human macrophages, and anti-inflammatory efficacy in rats. Only the least drug-like antagonist (3D53) maintained potency in cells against higher C5a concentrations and had a much longer duration of action (t1/2 ~ 20 h) than W54011 or JJ47 (t1/2 ~ 1–3 h) in inhibiting macrophage responses. The unusually long residence time of 3D53 on its receptor was mechanistically probed by molecular dynamics simulations, which revealed long-lasting interactions that trap the antagonist within the receptor. Despite negligible oral bioavailability, 3D53 was much more orally efficacious than W54011 or JJ47 in preventing repeated agonist insults to induce rat paw oedema over 24 h. Thus, residence time on a receptor can trump drug-likeness in determining efficacy, even oral efficacy, of pharmacological agents.

  15. BIOLOGICAL CONTROL OF DAMPING-OFF FUNGI OF AGOHO (CASUARINA EQUISETIFOLIA L. USING ANTAGONISTIC BACTERIA

    Directory of Open Access Journals (Sweden)

    F.A. DELA PEÑA

    1994-01-01

    Full Text Available A series of laboratory and nursery experiments were conducted specifically to determine the efficacy of 85 strains of Bacillus species and 15 actinomycetes against six fungal pathogens isolated from damped-off agoho. These damping-off fungi were: Fusarium oxysporum Schet., Rhizoctonia solani Kuhn., Phytophthora parasitica Dastur, Pythium debaryanum Hesse, and two unidentified pathogens temporarily designated as Unk 1 and Unk 2. Preliminary test using the agar-plug technique revealed that 18 of the bacterial isolates could suppress two or more of the six damping-off fungi. Fusarium oxysporum was inhibited by 17 bacterial isolates, R. solani by 8 isolates, P. parasitica by 14 isolates and P. debaryanum by 15 isolates. The unidentified damping-off fungi Unk 1 and Unk 2 were inhibited by 13 and 9 isolates, respectively. Further screening using the agar-diffusion method disclosed that 10 isolates were effective antagonists with Bacillus subtilis (Code No. R060, Bacillus sp. (Code No. R071, and Streptomyces sp. (Code No. R086 as the consistent and most effective inhibitors. Application of the three most promising antagonistic bacteria as seed treatment showed that they effectively inhibited the growth of the damping-off fungi in the laboratory as exhibited by an increase in percent germination. Bacillus subtilis however, was not able to antagonize the effect of P. debaryanum in this particular experiment. Seed germination and seedling survival were likewise improved with the application of the three most promising antagonistic bacteria as seed treatment. This was shown after three months under nursery conditions. There were possible mechanisms of control by the antagonistic bacteria against the damping-off fungi. The mycelium and spores of the pathogenic fungus may have been attacked and parasitized by the antagonist when they were simultaneously grown in culture media. There must have been a competitive interaction between the two microorganisms. Any

  16. Effects of different doses of four antagonists on their dopamine D2 receptor occupancy in rat striatum in vivo

    International Nuclear Information System (INIS)

    Objective: This study was to evaluate the effect of different doses of Haloperidol, Spiperone, (s)-IBZM and (s)-Sulpiride on their dopamine D2 receptor occupancy in rat striatum in vivo. Methods: One hundred rats were divided into four groups, which were subdivided into five subgroups. Using different doses of the four antagonists respectively performed in vivo competitive inhibition experiment of 125I-IBZM, and the receptor occupancy was estimated. Results: The specific binding of 125I-IBZM can be inhibited competitively by dopamine D2 receptor antagonist respectively. The OC50 values of Haloperidol, spiperone, (s)-IBZM and (s)-Sulpiride are 21.0, 9.4, 22.0 and 1605 nmol/rat respectively. For the four antagonists, a dose-dependent relationship with their striatum D2 receptor occupancy has been demonstrated in some range. Conclusion: The results of this study suggested that radio-iodinated IBZM can be used for SPECT imaging of dopamine D2 receptors in human brain. For the four antagonists, the dose-dependent occupation of striatal D2 binding sites can be benefit for optimizing the therapeutic dose of typical neuroleptic agents

  17. Competitive binding of antagonistic peptides fine-tunes stomatal patterning.

    Science.gov (United States)

    Lee, Jin Suk; Hnilova, Marketa; Maes, Michal; Lin, Ya-Chen Lisa; Putarjunan, Aarthi; Han, Soon-Ki; Avila, Julian; Torii, Keiko U

    2015-06-25

    During development, cells interpret complex and often conflicting signals to make optimal decisions. Plant stomata, the cellular interface between a plant and the atmosphere, develop according to positional cues, which include a family of secreted peptides called epidermal patterning factors (EPFs). How these signalling peptides orchestrate pattern formation at a molecular level remains unclear. Here we report in Arabidopsis that Stomagen (also called EPF-LIKE9) peptide, which promotes stomatal development, requires ERECTA (ER)-family receptor kinases and interferes with the inhibition of stomatal development by the EPIDERMAL PATTERNING FACTOR 2 (EPF2)-ER module. Both EPF2 and Stomagen directly bind to ER and its co-receptor TOO MANY MOUTHS. Stomagen peptide competitively replaced EPF2 binding to ER. Furthermore, application of EPF2, but not Stomagen, elicited rapid phosphorylation of downstream signalling components in vivo. Our findings demonstrate how a plant receptor agonist and antagonist define inhibitory and inductive cues to fine-tune tissue patterning on the plant epidermis. PMID:26083750

  18. Iontophoretic studies on rat hippocampus with some novel GABA antagonists.

    Science.gov (United States)

    Dalkara, T; Saederup, E; Squires, R F; Krnjevic, K

    1986-08-01

    Twelve substances which appear to be GABA antagonists, judging by their ability to reverse the inhibitory effect of GABA on 35S-TBPS binding to rat brain membranes, were tested iontophoretically on population spikes in the rat hippocampus. Eight of them, including seven which completely reversed the inhibitory action of GABA on 35S-TBPS binding, caused a marked enhancement of population spikes, with slow onset and long duration and they antagonized the inhibition of population spikes by GABA. These effects were similar to those produced by bicuculline. Electrophysiologically, the most potent of the "complete reversers" were bathophenanthroline disulfonate and brucine. In vitro, amoxapine and brucine most effectively reversed the inhibitory action of GABA on 35S-TBPS binding. Of the five substances which only partly reversed the inhibitory effect of GABA on 35S-TBPS binding, four depressed the population spikes and potentiated the inhibitory action of GABA. The fifth "partial reverser", pipazethate, potently increased the population spikes, like the "complete reversers". Although other interpretations are possible the results are consistent with the existence of several GABA-A receptor types in brain, only some of which are blocked by certain partial reversers. PMID:2874465

  19. Antagonistic coevolution between quantitative and Mendelian traits.

    Science.gov (United States)

    Yamamichi, Masato; Ellner, Stephen P

    2016-03-30

    Coevolution is relentlessly creating and maintaining biodiversity and therefore has been a central topic in evolutionary biology. Previous theoretical studies have mostly considered coevolution between genetically symmetric traits (i.e. coevolution between two continuous quantitative traits or two discrete Mendelian traits). However, recent empirical evidence indicates that coevolution can occur between genetically asymmetric traits (e.g. between quantitative and Mendelian traits). We examine consequences of antagonistic coevolution mediated by a quantitative predator trait and a Mendelian prey trait, such that predation is more intense with decreased phenotypic distance between their traits (phenotype matching). This antagonistic coevolution produces a complex pattern of bifurcations with bistability (initial state dependence) in a two-dimensional model for trait coevolution. Furthermore, with eco-evolutionary dynamics (so that the trait evolution affects predator-prey population dynamics), we find that coevolution can cause rich dynamics including anti-phase cycles, in-phase cycles, chaotic dynamics and deterministic predator extinction. Predator extinction is more likely to occur when the prey trait exhibits complete dominance rather than semidominance and when the predator trait evolves very rapidly. Our study illustrates how recognizing the genetic architectures of interacting ecological traits can be essential for understanding the population and evolutionary dynamics of coevolving species. PMID:27009218

  20. Sexually antagonistic selection in human male homosexuality.

    Science.gov (United States)

    Camperio Ciani, Andrea; Cermelli, Paolo; Zanzotto, Giovanni

    2008-01-01

    Several lines of evidence indicate the existence of genetic factors influencing male homosexuality and bisexuality. In spite of its relatively low frequency, the stable permanence in all human populations of this apparently detrimental trait constitutes a puzzling 'Darwinian paradox'. Furthermore, several studies have pointed out relevant asymmetries in the distribution of both male homosexuality and of female fecundity in the parental lines of homosexual vs. heterosexual males. A number of hypotheses have attempted to give an evolutionary explanation for the long-standing persistence of this trait, and for its asymmetric distribution in family lines; however a satisfactory understanding of the population genetics of male homosexuality is lacking at present. We perform a systematic mathematical analysis of the propagation and equilibrium of the putative genetic factors for male homosexuality in the population, based on the selection equation for one or two diallelic loci and Bayesian statistics for pedigree investigation. We show that only the two-locus genetic model with at least one locus on the X chromosome, and in which gene expression is sexually antagonistic (increasing female fitness but decreasing male fitness), accounts for all known empirical data. Our results help clarify the basic evolutionary dynamics of male homosexuality, establishing this as a clearly ascertained sexually antagonistic human trait. PMID:18560521

  1. Sexually antagonistic selection in human male homosexuality.

    Directory of Open Access Journals (Sweden)

    Andrea Camperio Ciani

    Full Text Available Several lines of evidence indicate the existence of genetic factors influencing male homosexuality and bisexuality. In spite of its relatively low frequency, the stable permanence in all human populations of this apparently detrimental trait constitutes a puzzling 'Darwinian paradox'. Furthermore, several studies have pointed out relevant asymmetries in the distribution of both male homosexuality and of female fecundity in the parental lines of homosexual vs. heterosexual males. A number of hypotheses have attempted to give an evolutionary explanation for the long-standing persistence of this trait, and for its asymmetric distribution in family lines; however a satisfactory understanding of the population genetics of male homosexuality is lacking at present. We perform a systematic mathematical analysis of the propagation and equilibrium of the putative genetic factors for male homosexuality in the population, based on the selection equation for one or two diallelic loci and Bayesian statistics for pedigree investigation. We show that only the two-locus genetic model with at least one locus on the X chromosome, and in which gene expression is sexually antagonistic (increasing female fitness but decreasing male fitness, accounts for all known empirical data. Our results help clarify the basic evolutionary dynamics of male homosexuality, establishing this as a clearly ascertained sexually antagonistic human trait.

  2. A full factorial analysis of nine factors influencing in vitro antagonistic screens for potential biocontrol agents.

    Science.gov (United States)

    Dickie, G A; Bell, C R

    1995-03-01

    The effect of nine factors on the outcome of classic in vitro screens testing the antagonistic action of endophytic bacterial isolates from grape vines against virulent Agrobacterium vitis has been examined. These factors were (i) the strain of A. vitis, (ii) the strain of endophyte, (iii) the growth medium of the pathogen, (iv) the growth medium of the endophyte, (v) the temperature of growth of the pathogen, (vi) the temperature of growth of the endophyte, (vii) the pH of growth of the pathogen, (viii) the pH of growth of the endophyte, and (ix) the medium of the assay plate. Analyses of variance of the full factorial design incorporating main effects and two- and three-way interactions accounted for 66% of the variance. All nine factors had a significant effect on the diameter of inhibition zones (p antagonism (especially the composition of the growth medium and the temperature of growth), had a profound effect on the outcome of the test. Generally the more chemically defined media produced less inhibition whereas the lower growth temperature of 15 degrees C produced more inhibition. These findings could be relevant to in situ inhibitory activity. The method used to conduct the inhibitory screen (order of strain application and the medium of the assay plate) had a profound influence on the results. These influences add to the caution necessary in the use of in vitro antagonistic screens for finding successful biocontrol agents. PMID:7736357

  3. The NK-1 Receptor Antagonist L-732,138 Induces Apoptosis and Counteracts Substance P-Related Mitogenesis in Human Melanoma Cell Lines

    International Nuclear Information System (INIS)

    It has been recently demonstrated that substance P (SP) and neurokinin-1 (NK-1) receptor antagonists induce cell proliferation and cell inhibition in human melanoma cells, respectively. However, the antitumor action of the NK-1 receptor antagonist L-732,138 on such cells is unknown. The aim of this study was to demonstrate an antitumor action of L-732,138 against three human melanoma cell lines (COLO 858, MEL HO, COLO 679). We found that L-732,138 elicits cell growth inhibition in a concentration dependent manner in the melanoma cells studied. Moreover, L-732,138 blocks SP mitogen stimulation. The specific antitumor action of L-732,138 occurred through the NK-1 receptor and melanoma cell death was by apoptosis. These findings indicate that the NK-1 receptor antagonist L-732,138 could be a new antitumor agent in the treatment of human melanoma

  4. Pharmacological Actions of NGB 2904, a Selective Dopamine D3 Receptor Antagonist, in Animal Models of Drug Addiction

    OpenAIRE

    Xi, Zheng-Xiong; Gardner, Eliot L

    2007-01-01

    As a continuation of our work with SB-277011A, we have examined the effects of another highly elective dopamine (DA) D3 receptor antagonist, N-(4-[4-{2,3-dichlorophenyl}-1-piperazinyl]butyl)-2-fluorenylcarboxamide (NGB 2904), in animal models of addiction. Our results indicate that by systemic administration, NGB 2904 inhibits intravenous cocaine self-administration maintained under a progressive-ratio (PR) reinforcement schedule, cocaine-or cocaine cue–induced reinstatement of cocaine-seekin...

  5. Discovery and Characterization of Vicriviroc (SCH 417690), a CCR5 Antagonist with Potent Activity against Human Immunodeficiency Virus Type 1

    OpenAIRE

    Strizki, Julie M.; Tremblay, Cecile; Xu, Serena; Wojcik, Lisa; Wagner, Nicole; Gonsiorek, Waldemar; Hipkin, R. William; Chou, Chuan-Chu; Pugliese-Sivo, Catherine; Xiao, Yushi; Tagat, Jayaram R.; Cox, Kathleen; Priestley, Tony; Sorota, Steve; Huang, Wei

    2005-01-01

    Inhibiting human immunodeficiency virus type 1 (HIV-1) infection by blocking the host cell coreceptors CCR5 and CXCR4 is an emerging strategy for antiretroviral therapy. Currently, several novel coreceptor inhibitors are being developed in the clinic, and early results have proven promising. In this report, we describe a novel CCR5 antagonist, vicriviroc (formerly SCH-D or SCH 417690), with improved antiviral activity and pharmacokinetic properties compared to those of SCH-C, a previously des...

  6. Biological control of cucumber and sugar beet damping-off caused by Pythium ultimum with bacterial and fungal antagonists

    OpenAIRE

    Georgakopoulos, D. G.; Fiddaman, P.; Leifert, C.; Malathrakis, N.E.

    2002-01-01

    Aims: Five bacterial strains belonging to Bacillus subtilis , Pseudomonas fluorescens and Ps . corrugata and two fungal strains belonging to Trichoderma viride and Gliocladium virens were evaluated for their efficacy in controlling sugar beet and cucumber damping-off caused by Pythium ultimum . Methods and Results: The in vitro antagonistic activity of bacteria against various Pythium spp. was evaluated with dual cultures in various media. Pseudomonas strains inhibited the pathogen better tha...

  7. Administration of orexin receptor 1 antagonist into the rostral ventromedial medulla increased swim stress-induced antinociception in rat

    OpenAIRE

    Neda Soliemani; Alireza Moslem; Ali Shamsizadeh; Hassan Azhdari-Zarmehri

    2016-01-01

    Objective(s): Intracerebroventricular injection of orexin-A (hypocretin-1) antagonist has been shown to inhibit stress-induced analgesia. However the locations of central sites that may mediate these effects have not been totally demonstrated. This study was performed to investigate the role of rostral ventromedial medulla (RVM) orexin receptor 1 in stress-induced analgesia (SIA). Materials and Methods: Forced swim stress in water was employed to adult male rats (200-250 g). Nociceptive respo...

  8. Quantitative toxicoproteomic analysis of zebrafish embryos exposed to a retinoid X receptor antagonist UVI3003.

    Science.gov (United States)

    Zheng, Liang; Yu, Jianlan; Shi, Huahong; Xia, Liang; Xin, Qi; Zhang, Qiang; Zhao, Heng; Luo, Ji; Jin, Wenhai; Li, Daoji; Zhou, Junliang

    2015-09-01

    Retinoid X receptor (RXR) antagonists, including some environmental endocrine disruptors, have a teratogenic effect on vertebrate embryos. To investigate the toxicological mechanism on the protein expression level, a quantitative proteomic study was conducted to analyze the proteome alterations of zebrafish (Danio rerio) embryos exposed to gradient concentrations of a representative RXR antagonist UVI3003. Using isobaric Tags for Relative and Absolute Quantitation (iTRAQ) labeling coupled nano high-performance liquid chromatography-tandem mass spectrometry (nano HPLC-MS/MS), in total 6592 proteins were identified, among which 195 proteins were found to be differentially expressed by more than a two-fold change in exposed groups compared with the control. Gene ontology analysis showed that these differential proteins were mostly involved in anatomical structure development, biosynthetic process, ion binding and oxidoreductase activity. Moreover, the biological pathways of translation, lipoprotein metabolism, cell survival and gluconeogenesis were intensively inhibited after exposure. Some significantly downregulated proteins such as apolipoprotein A-I and vitellogenin and upregulated proteins such as calcium activated nucleotidase 1b, glutathione S-transferase and glucose 6-dehydrogenases showed a strong dose-dependent response. The results provided new insight into the molecular details of RXR antagonist-induced teratogenicity and added novel information of pathways and potential biomarkers for evaluation of RXR interfering activity. PMID:25581642

  9. Calcium antagonistic effects of Chinese crude drugs: Preliminary investigation and evaluation by 45Ca

    International Nuclear Information System (INIS)

    Coronary and other diseases in cardiac or brain blood vessels are considered to be due to the excessive influx of Ca2+ into cytoplasm. If Ca2+ channels in cell membrane are blocked by medicines or other substances with considerable calcium antagonistic effects, these diseases might be cured or controlled. The influence of some Chinese crude drugs, including Crocus sativus, Carthamus tinctorius, Ginkgo biloba and Bulbus allii macrostemi on Ca2+ influx in isolated rat aortas was investigated by using 45Ca as a radioactive tracer, and their calcium antagonistic effects were evaluated. It can be noted that Ca2+ uptake in isolated rat aorta rings in normal physiological status was not markedly altered by these drugs, whereas the Ca2+ influxes induced by norepinephrine of 1.2 μmol/L and KCl of 100 mmol/L were significantly inhibited by Crocus, Carthamus and Bulbus in a concentration-dependent manner, but not by Ginkgo. The results show that extracellular Ca2+ influx through receptor-operated Ca2+channels and potential-dependent Ca2+channels can be blocked by Crocus, Carthamus and Bulbus. This implies that these Chinese crude drugs have obvious calcium antagonistic effects

  10. Diversity and Antagonistic Activity of Actinomycete Strains From Myristica Swamp Soils Against Human Pathogens

    Directory of Open Access Journals (Sweden)

    Varghese Rlnoy

    2014-05-01

    Full Text Available Under the present investigation Actinomycetes were isolated from the soils of Myristica swamps of southern Western Ghats and the antagonistic activity against different human bacterial pathogens was evaluated. Results of the present study revealed that Actinomycetes population in the soils of Myristica swamp was spatially and seasonally varied. Actinomycetes load was varied from 24×104 to 71×103, from 129×103 to 40×103 and from 31×104 to 84×103 in post monsoon, monsoon and pre monsoon respectively. A total of 23 Actinomycetes strains belonging to six genera were isolated from swamp soils. Identification of the isolates showed that most of the isolates belonged to the genus Streptomyces (11, followed by Nocardia (6, Micromonospora (3, Pseudonocardia (1, Streptosporangium (1, and Nocardiopsis (1. Antagonistic studies revealed that 91.3% of Actinomycete isolates were active against one or more tested pathogens, of that 56.52% exhibited activity against Gram negative and 86.95% showed activity against Gram positive bacteria. 39.13% isolates were active against all the bacterial pathogens selected and its inhibition zone diameter was also high. 69.5% of Actinomycetes were exhibited antibacterial activity against Listeria followed by Bacillus cereus (65.21%, Staphylococcus (60.86%, Vibrio cholera (52.17%, Salmonella (52.17% and E. coli (39.13%. The results indicate that the Myristica swamp soils of Southern Western Ghats might be a remarkable reserve of Actinomycetes with potential antagonistic activity.

  11. The Attractiveness of Opposites: Agonists and Antagonists.

    LENUS (Irish Health Repository)

    O'Brien, Tony

    2015-02-02

    ABSTRACT Opioid-induced bowel dysfunction, of which constipation is the most common aspect, is a major limiting factor in the use of opioids for pain management. The availability of an oral, long-acting formulation of oxycodone and naloxone represents a highly significant development in pain management. The combination of an opioid analgesic with an opioid antagonist offers reliable pain control with a significant reduction in the burden of opioid-induced constipation. This report is adapted from paineurope 2014; Issue 3, ©Haymarket Medical Publications Ltd, and is presented with permission. paineurope is provided as a service to pain management by Mundipharma International, LTD and is distributed free of charge to healthcare professionals in Europe. Archival issues can be accessed via the website: http:\\/\\/www.paineurope.com at which European health professionals can register online to receive copies of the quarterly publication.

  12. Mutually-antagonistic interactions in baseball networks

    Science.gov (United States)

    Saavedra, Serguei; Powers, Scott; McCotter, Trent; Porter, Mason A.; Mucha, Peter J.

    2010-03-01

    We formulate the head-to-head matchups between Major League Baseball pitchers and batters from 1954 to 2008 as a bipartite network of mutually-antagonistic interactions. We consider both the full network and single-season networks, which exhibit structural changes over time. We find interesting structure in the networks and examine their sensitivity to baseball’s rule changes. We then study a biased random walk on the matchup networks as a simple and transparent way to (1) compare the performance of players who competed under different conditions and (2) include information about which particular players a given player has faced. We find that a player’s position in the network does not correlate with his placement in the random walker ranking. However, network position does have a substantial effect on the robustness of ranking placement to changes in head-to-head matchups.

  13. Mutually-Antagonistic Interactions in Baseball Networks

    CERN Document Server

    Saavedra, Serguei; McCotter, Trent; Porter, Mason A; Mucha, Peter J

    2009-01-01

    We formulate the head-to-head matchups between Major League Baseball pitchers and batters from 1954 to 2008 as a bipartite network of mutually-antagonistic interactions. We consider both the full network and single-season networks, which exhibit interesting structural changes over time. We also find that these networks exhibit a significant network structure that is sensitive to baseball's rule changes. We then study a biased random walk on the matchup networks as a simple and transparent way to compare the performance of players who competed under different conditions. We find that a player's position in the network does not correlate with his success in the random walker ranking but instead has a substantial effect on its sensitivity to changes in his own aggregate performance.

  14. Vitamin K antagonists in heart disease: Current status and perspectives (Section III). Position Paper of the ESC Working Group on Thrombosis - Task Force on Anticoagulants in Heart Disease

    NARCIS (Netherlands)

    Caterina, R. de; Husted, S.; Wallentin, L.; Andreotti, F.; Arnesen, H.; Bachmann, F.; Baigent, C.; Huber, K.; Jespersen, J.; Kristensen, S.D.; Lip, G.Y.; Morais, J.; Rasmussen, L.H.; Siegbahn, A.; Verheugt, F.W.A.; Weitz, J.I.

    2013-01-01

    Oral anticoagulants are a mainstay of cardiovascular therapy, and for over 60 years vitamin K antagonists (VKAs) were the only available agents for long-term use. VKAs interfere with the cyclic inter-conversion of vitamin K and its 2,3 epoxide, thus inhibiting gamma-carboxylation of glutamate residu

  15. Functional potencies of dopamine agonists and antagonists at human dopamine D₂ and D₃ receptors.

    Science.gov (United States)

    Tadori, Yoshihiro; Forbes, Robert A; McQuade, Robert D; Kikuchi, Tetsuro

    2011-09-01

    We measured the functional agonist potencies of dopamine agonists including antiparkinson drugs, and functional antagonist potencies of antipsychotics at human dopamine D(2) and D(3) receptors. In vitro pharmacological assessment included inhibition of forskolin-stimulated cAMP accumulation and the reversal of dopamine-induced inhibition in clonal Chinese hamster ovary cells expressing low and high densities of human dopamine D(2L) and D(2S) receptors (hD(2L)-Low, hD(2L)-High, hD(2S)-Low and hD(2S)-High, respectively) and human dopamine D(3) Ser-9 and D(3) Gly-9 receptors (hD(3)-Ser-9 and hD(3)-Gly-9, respectively). Cabergoline, bromocriptine, pergolide, (±)-7-hydroxy-N,N-di-n-propyl-2-aminotetralin (7-OH-DPAT), talipexole, pramipexole, R-(+)-trans-3,4,4a,10b-tetrahydro-4-propyl-2H,5H-[1]benzopyrano[4,3-b]-1,4-oxazin-9-olhydrochloride (PD128907) and ropinirole behaved as dopamine D(2) and D(3) receptor full agonists and showed higher potencies in hD(2L)-High and hD(2S)-High compared to hD(2L)-Low and hD(2S)-Low. In hD(3)-Ser-9 and hD(3)-Gly-9 compared to hD(2L)-Low and hD(2S)-Low, dopamine, ropinirole, PD128907, and pramipexole potencies were clearly higher; talipexole and 7-OH-DPAT showed slightly higher potencies; pergolide showed slightly lower potency; and, cabergoline and bromocriptine potencies were lower. Aripiprazole acted as an antagonist in hD(2L)-Low; a low intrinsic activity partial agonist in hD(2S)-Low; a moderate partial agonist in hD(3)-Ser-9 and hD(3)-Gly-9; a robust partial agonist in hD(2L)-High; and a full agonist in hD(2S)-High. Amisulpride, sulpiride and perphenazine behaved as preferential antagonists; and chlorpromazine and asenapine behaved as modest preferential antagonists; whereas fluphenazine, haloperidol, and blonanserin behaved as non-preferential antagonists in hD(2S)-Low and hD(2S)-High compared to hD(3)-Ser-9 and hD(3)-Gly-9. These findings may help to elucidate the basis of therapeutic benefit observed with these drugs, with

  16. Serotonin 2A receptor antagonists for treatment of schizophrenia

    DEFF Research Database (Denmark)

    Ebdrup, Bjørn Hylsebeck; Rasmussen, Hans; Arnt, Jørn; Glenthøj, Birte Yding

    2011-01-01

    receptor antagonists is evaluated. Moreover, the investigational pipeline of major pharmaceutical companies is examined and an Internet search conducted to identify other pharmaceutical companies investigating 5-HT2A receptor antagonists for the treatment of schizophrenia. Expert opinion: 5-HT2A receptor...

  17. DEFICIENCY OF INTERLEUKIN-1 RECEPTOR ANTAGONIST RESPONSIVE TO ANAKINRA

    OpenAIRE

    SCHNELLBACHER, CHARLOTTE; CIOCCA, GIOVANNA; MENENDEZ, ROXANNA; Aksentijevich, Ivona; Goldbach-Mansky, Raphaela; DUARTE, ANAM.; RIVAS-CHACON, RAFAEL

    2012-01-01

    We describe a 3-month-old infant who presented to our institution with interleukin (IL)-1 receptor antagonist deficiency (DIRA), which consists of neutrophilic pustular dermatosis, periostitis, aseptic multifocal osteomyelitis, and persistently high acutephase reactants. Skin findings promptly improved upon initiation of treatment with anakinra (recombinant human IL-1 receptor antagonist), and the bony lesions and systemic inflammation resolved with continued therapy.

  18. Antagonistic and Bargaining Games in Optimal Marketing Decisions

    Science.gov (United States)

    Lipovetsky, S.

    2007-01-01

    Game theory approaches to find optimal marketing decisions are considered. Antagonistic games with and without complete information, and non-antagonistic games techniques are applied to paired comparison, ranking, or rating data for a firm and its competitors in the market. Mix strategy, equilibrium in bi-matrix games, bargaining models with…

  19. Pros and cons of vitamin K antagonists and non-vitamin K antagonist oral anticoagulants.

    Science.gov (United States)

    Riva, Nicoletta; Ageno, Walter

    2015-03-01

    Anticoagulant treatment can be currently instituted with two different classes of drugs: the vitamin K antagonists (VKAs) and the newer, "novel" or non-vitamin K antagonist oral anticoagulant drugs (NOACs). The NOACs have several practical advantages over VKAs, such as the rapid onset/offset of action, the lower potential for food and drug interactions, and the predictable anticoagulant response. However, the VKAs currently have a broader spectrum of indications, a standardized monitoring test, and established reversal strategies. The NOACs emerged as alternative options for the prevention and treatment of venous thromboembolism and for the prevention of stroke and systemic embolism in patients with nonvalvular atrial fibrillation. Nevertheless, there remain some populations for whom the VKAs remain the most appropriate anticoagulant drug. This article discusses the advantages and disadvantages of VKAs and NOACs. PMID:25703519

  20. Effects of autacoid inhibitors and of an antagonist on malaria infection in mice

    Directory of Open Access Journals (Sweden)

    Iwalewa E.O.

    2004-01-01

    Full Text Available The effects of p-chlorophenylalanine, an inhibitor of serotonin synthesis, indomethacin, an inhibitor of prostaglandin synthesis, cyproheptadine, a serotonin, bradykinin and histamine antagonist, were assessed separately and in combination with chloroquine (CQ in Vom strains of Swiss albino mice (18-22 g of either sex infected intraperitoneally with 1 x 10(7 Plasmodium yoelii nigeriensis-induced malaria. As prophylactic, these agents reduced from 31.9 ± 4.5 to 16.1 ± 8.1% the level of parasitemia relative to control but had no appreciable activity as curative agents when administered subcutaneously once daily for 4 days after 72 h of parasites innoculum in vivo. However, CQ alone and the combination of these agents with CQ in curative and prophylactic treatments significantly reduced (from 50.3 ± 5.8 to 4.9 ± 0.75% the level of parasitemia (P < 0.05, which was taken only once 72 h after the parasites innoculum. The prophylactic result was shown to produce better results than the curative treatment. The data indicate that inhibitors and an antagonist can reduce the parasitemia load (the extent of damage and the severity of infection as well as enhance the effects of CQ when combined with it for malaria therapy. The study reveals that the production of autacoids in established infection renders autacoid inhibitors and an antagonist ineffective for radical cure in malarial mice; however, selective inhibition of local hormones implicated in the pathological manifestations of malaria infection by autacoid inhibitors and an antagonist may be a possible pathway to reduce the severity of infection and the associated tissue damage and to enhance the efficacy of available anti-malarials.

  1. Isolation and characterization of actinomycete antagonists of a fungal root pathogen.

    Science.gov (United States)

    Crawford, D L; Lynch, J M; Whipps, J M; Ousley, M A

    1993-11-01

    By use of selective media, 267 actinomycete strains were isolated from four rhizosphere-associated and four non-rhizosphere-associated British soils. Organic media with low nutrient concentrations were found to be best for isolating diverse actinomycetes while avoiding contamination and overgrowth of isolation media by eubacteria and fungi. While all isolates grew well at pHs 6.5 to 8.0, a few were unable to grow at pH 6.0 and a significant number failed to grow at pH 5.5. Eighty-two selected isolates were screened for in vitro antagonism towards Pythium ultimum by use of a Difco cornmeal agar assay procedure. Five isolates were very strong antagonists of the fungus, four were strong antagonists, and ten others were weakly antagonistic. The remaining isolates showed no antagonism by this assay. Additional studies showed that several of the P. ultimum antagonists also strongly inhibited growth of other root-pathogenic fungi. Twelve isolates showing antifungal activity in the in vitro assay were also tested for their effects on the germination and short-term growth of lettuce plants in glasshouse pot studies in the absence of pathogens. None of the actinomycetes prevented seed germination, although half of the isolates retarded seed germination and outgrowth of the plants by 1 to 3 days. During 18-day growth experiments, biomass yields of some actinomycete-inoculated plants were reduced in comparison with untreated control plants, although all plants appeared healthy and well rooted. None of the actinomycetes significantly enhanced plant growth over these short-term experiments. For some, but not all, actinomycetes, some correlations between delayed seed germination and reduced 18-day plant biomass yields were seen. For others, plant biomass yields were not reduced despite an actinomycete-associated delay in seed germination and plant outgrowth. Preliminary glasshouse experiments indicated that some of the actinomycetes protect germinating lettuce seeds against

  2. Differential effects of GABAA receptor antagonists in the control of respiratory neuronal discharge patterns.

    Science.gov (United States)

    Dogas, Z; Krolo, M; Stuth, E A; Tonkovic-Capin, M; Hopp, F A; McCrimmon, D R; Zuperku, E J

    1998-11-01

    To ascertain the role of the inhibitory neurotransmitter gamma-aminobutyric acid (GABA) in shaping and controlling the phasic discharge patterns of medullary respiratory premotor neurons, localized pressure applications of the competitive GABAA receptor antagonist bicuculline (BIC) and the noncompetitive GABAA receptor antagonist picrotoxin (PIC) were studied. Multibarrel micropipettes were used in halothane anesthetized, paralyzed, ventilated, vagotomized dogs to record single unit activity from inspiratory and expiratory neurons in the caudal ventral respiratory group and to picoeject GABAA receptor antagonists. The moving time average of phrenic nerve activity was used to determine respiratory phase durations and to synchronize cycle-triggered histograms of discharge patterns. Picoejection of BIC and PIC had qualitatively different effects on the discharge patterns of respiratory neurons. BIC caused an increase in the discharge rate during the neuron's active phase without inducing activity during the neuron's normally silent phase. The resulting discharge patterns were amplified replicas (x2-3) of the underlying preejection phasic patterns. In contrast, picoejection of PIC did not increase the peak discharge rate during the neuron's active phase but induced a tonic level of activity during the neuron's normally silent phase. The maximum effective BIC dose (15 +/- 1.8 pmol/min) was considerably smaller than that for PIC (280 +/- 53 pmol/min). These findings suggest that GABAA receptors with differential pharmacology mediate distinct functions within the same neuron, 1) gain modulation that is BIC sensitive but PIC insensitive and 2) silent-phase inhibition blocked by PIC. These studies also suggest that the choice of an antagonist is an important consideration in the determination of GABA receptor function within the respiratory motor control system. PMID:9819249

  3. Pharmacokinetic interactions with calcium channel antagonists (Part I).

    Science.gov (United States)

    Schlanz, K D; Myre, S A; Bottorff, M B

    1991-11-01

    Calcium channel antagonists are a diverse class of drugs widely used in combination with other therapeutic agents. The potential exists for many clinically significant pharmacokinetic interactions between these and other concurrently administered drugs. The mechanisms of calcium channel antagonist-induced changes in drug metabolism include altered hepatic blood flow and impaired hepatic enzyme metabolising activity. Increases in serum concentrations and/or reductions in clearance have been reported for several drugs used with a number of calcium channel antagonists. A number of reports and studies of calcium channel antagonist interactions have yielded contradictory results and the clinical significance of pharmacokinetic changes seen with these agents is ill-defined. The first part of this article deals with interactions between calcium antagonists and marker compounds, theophylline, midazolam, lithium, doxorubicin, oral hypoglycaemics and cardiac drugs. PMID:1773549

  4. Characterization of a novel, hydrophilic dihydropyridine, NKY-722, as a Ca2+ antagonist in bovine cultured adrenal chromaffin cells.

    OpenAIRE

    Ohue, T.; Lee, K; Koshimura, K.; Miwa, S

    1991-01-01

    1. To characterize NKY-722, a novel hydrophilic dihydropyridine derivative, as a Ca2+ antagonist, we examined its effects on 45Ca2+ influx, intracellular free Ca2+ concentrations [( Ca2+]i), and release of noradrenaline and adrenaline in bovine cultured adrenal chromaffin cells. 2. NKY-722 had little effect on basal 45Ca2+ influx into the resting cells, but inhibited high K+ (35.9 mM)-evoked 45Ca2+ influx in a concentration-dependent manner with an IC50 value of 5.2 nM. 3. NKY-722 inhibited h...

  5. CXCRl/CXCR2受体拮抗剂-G31P抑制前列腺癌血管新生的体内实验%Inhibition of G31P : Chemokine Receptor CXCR1/CXCR2 Antagonist, in Angiogenesis of Human Prostate Cancer Cells in vivo

    Institute of Scientific and Technical Information of China (English)

    刘欣; 戴晓冬; 李星云; 王晓丽; 李芳

    2012-01-01

    Objective To investigate the inhibition of G31P on the angiogenesis of the prostate cancer PC-3 cell in vivo. Methods The effect of G31P on angiogenesis of human prostate tumor of nude mice were observed in nude mice by building a human androgen-independent prostate cancer PC-3 (GFP-labeled) or-thotopic transplantation tumor cells model. Results The tumor angiogenesis of G31P treated group (1. 26 ±0.46)was significantly reduced (0. 49±0. 12,P<0. 05) compared with the control group. VEGF(P< 0. 01) and NF-KB(P<0. 01) expression of G31P treated groupwas significantly reduced (immunohisto-chemistry) compared with the control group. Conclusion G31P could inhibit the angiogenesis of the prostate cancer PC-3 cell in vivo.%目的 探讨G31P(CXCR1/CXCR2受体拮抗剂)对人前列腺癌PC-3细胞的体内血管新生的抑制作用.方法 建立体内绿色荧光蛋白(GFP)标记的人雄激素非依赖性前列腺癌细胞PC-3的裸鼠原位移植瘤模型,观察G31P对裸鼠前列腺原位移植瘤血管新生的影响.结果 与对照组(1.26±0.46)相比,G31P处理组明显抑制前列腺肿瘤的血管新生(0.49±0.12,P<0.05),与对照组相比,G31P处理组VEGF(P<0.01)和NF-kB(P<0.01)的表达具有统计学意义(免疫组织化学法).结论 在裸鼠原位移植瘤模型中G31P对人雄激素非依赖性前列腺癌的血管新生有明显抑制作用.

  6. The influence of glutamatergic receptor antagonists on biochemical and ultrastructural changes in myelin membranes of rats subjected to experimental autoimmune encephalomyelitis.

    Science.gov (United States)

    Dąbrowska-Bouta, Beata; Strużyńska, Lidia; Chalimoniuk, Małgorzata; Frontczak-Baniewicz, Małgorzata; Sulkowski, Grzegorz

    2015-01-01

    Elevated extracellular glutamate in the synaptic cleft causes overactivation of glutamate receptors and kills neurons by an excitotoxic mechanism. Recent studies have shown that glutamate can also lead to toxic injury of white matter oligodendrocytes in myelin sheaths and consequently to axon demyelination. The present study was performed using the rodent model of multiple sclerosis known as experimental autoimmune encephalomyelitis (EAE). The aim of the study was to test the effects of the glutamatergic receptor antagonists amantadine and memantine (antagonists of NMDA receptors), LY 367384 (an antagonist of mGluR1), and MPEP (an mGluR5 antagonist) on the development of neurological symptoms in immunized animals, morphological changes in cerebral myelin, and expression of mRNA of the principal myelin proteins PLP, MBP, MOG, MAG, and CNPase. Pharmacological inhibition of NMDA receptors by amantadine and memantine was found to suppress neurological symptoms in EAE rats, whereas antagonists of the group I metabotropic glutamate receptors (mGluRs G I) did not function positively. In the symptomatic phase of the disease we observed destruction of myelin sheaths via electron microscopy and decreased levels of mRNA for all of the principal myelin proteins. The results reveal that glutamate receptor antagonists have a positive effect on the expression of mRNA MBP and glycoproteins MAG and MOG but not on myelin ultrastructure. PMID:26785366

  7. LY303870, a centrally active neurokinin-1 antagonist with a long duration of action.

    Science.gov (United States)

    Iyengar, S; Hipskind, P A; Gehlert, D R; Schober, D; Lobb, K L; Nixon, J A; Helton, D R; Kallman, M J; Boucher, S; Couture, R; Li, D L; Simmons, R M

    1997-02-01

    The selective neurokinin (NK)-1 antagonist LY303870 has high affinity and specificity for human and guinea pig brain NK-1 receptors labeled with 125I-substance P. It has approximately 15- to 30-fold lower affinity for rat and mouse brain NK-1 receptors, consistent with previously reported species differences in the affinities of nonpeptide antagonists for NK-1 receptors. In vivo, LY303870 blocked the characteristic, caudally directed, biting and scratching response elicited by intrathecal administration of the selective NK-1 agonist Ac-[Arg6,Sar9,Met(O2)11]substance P6-11 in conscious mice. The potentiation of the tail-flick response elicited by intrathecal administration of the NK-1 agonist [Sar9,Met(O2)11]substance P in rats was also selectively blocked by LY303870. When tested in a model of persistent nociceptive activation induced by tissue injury (the formalin test), LY303870 blocked licking behavior in the late phase of the formalin test, in a dose-dependent manner. After oral administration of 10 mg/kg, the blockade of the late-phase licking behavior was evident for at least 24 hr. Ex vivo binding studies in guinea pigs showed that orally administered LY303870 potently inhibited binding to central and peripheral NK-1 receptors labeled with 125I-substance P. This inhibition was long-lasting, consistent with other in vivo activities. LY306155, the opposite enantiomer of LY303870, was less active in all of the functional assays. In rodents, LY303870 did not exhibit any neurological, motor, cardiovascular, gastrointestinal or autonomic side effects at doses of < or = 50 mg/kg p.o. Thus, LY303870 is a potent, centrally active, NK-1 antagonist in vivo, with long-lasting oral activity. PMID:9023291

  8. Clinical and preclinical characterization of the histamine H(4) receptor antagonist JNJ-39758979.

    Science.gov (United States)

    Thurmond, Robin L; Chen, Bin; Dunford, Paul J; Greenspan, Andrew J; Karlsson, Lars; La, David; Ward, Peter; Xu, Xie L

    2014-05-01

    The histamine H4 receptor (H(4)R) has been shown to have preclinical involvement in both inflammatory and pruritic responses. JNJ-39758979 [(R)-4-(3-amino-pyrrolidin-1-yl)-6-isopropyl-pyrimidin-2-ylamine] is a potent and selective H(4)R antagonist with a Ki at the human receptor of 12.5 ± 2.6 nM and greater than 80-fold selectivity over other histamine receptors. The compound also exhibited excellent selectivity versus other targets. JNJ-39758979 showed dose-dependent activity in models of asthma and dermatitis consistent with other H(4)R antagonists. Preclinical toxicity studies of up to 6 months in rats and 9 months in monkeys indicated an excellent safety profile, supporting the clinical testing of the compound. An oral formulation of JNJ-39758979 was studied in a phase 1 human volunteer study to assess safety, pharmacokinetics, and pharmacodynamics. The compound was well tolerated, with the exception of dose-dependent nausea, and no safety issues were noted in the phase 1 study. JNJ-39758979 exhibited good pharmacokinetics upon oral dosing with a plasma half-life of 124-157 hours after a single oral dose. In addition, dose-dependent inhibition of histamine-induced eosinophil shape change was detected, suggesting that the H4R was inhibited in vivo. In conclusion, JNJ-39758979 is a potent and selective H(4)R antagonist that exhibited good preclinical and phase 1 safety in healthy volunteers with evidence of a pharmacodynamics effect in humans. PMID:24549371

  9. In vitro antagonistic activities of animal intestinal strains against swine-associated pathogens.

    Science.gov (United States)

    Klose, Viviana; Bayer, Katharina; Bruckbeck, Romy; Schatzmayr, Gerd; Loibner, Andreas-Paul

    2010-08-26

    A wide range of enteropathogens cause costly diarrhoeal diseases in fattening piglets and account for food-related infections in humans. The objective of this study was to screen beneficial bacterial strains from the gastrointestinal tract of various animal sources for antagonistic activity against diverse pathogens associated with hazardous pig production times. Using agar spot assays, 15 well-characterized strains belonging to Lactobacillus, Enterococcus, Bifidobacterium and Bacillus were studied for inhibition of Clostridium perfringens type A, various serovars of enterotoxigenic Escherichia coli and Salmonella enterica, as well as Brachyspira pilosicoli. Strong antagonists were further analyzed by studying their cell-free supernatants with and without pH neutralization, proteinase K and catalase treatment. Enterobacteriaceae were effectively inhibited by Lactobacillus salivarius and Lactobacillus reuteri strains, independent from the animal source, and on a lower level by single strains belonging to Lactobacillus mucosae, Lactobacillus amylovorus and Bifidobacterium thermophilum, due to organic acid production. The Bacillus subtilis strain was found to produce an anti-clostridial and anti-Brachyspira metabolite of proteinaceous nature. Homofermentative lactobacilli and B. thermophilum could suppress the growth of B. pilosicoli, the causative agent of intestinal spirochaetosis, whereas heterofermentative strains belonging to L. reuteri and L. mucosae had no effect. The lactic acid bacteria exerted their activity primarily by organic acid release, except one Enterococcus faecium and L. amylovorus strain, which exhibited antagonism through joint activity of lactate and hydrogen peroxide. The findings of this study provide a basis for further in vitro studies and encourage feeding studies to evaluate the antagonistic potential of promising strains in pig production. PMID:20226602

  10. Biological Control of Apple Anthracnose by Paenibacillus polymyxa APEC128, an Antagonistic Rhizobacterium.

    Science.gov (United States)

    Kim, Young Soo; Balaraju, Kotnala; Jeon, Yongho

    2016-06-01

    The present study investigated the suppression of the disease development of anthracnose caused by Colletotrichum gloeosporioides and C. acutatum in harvested apples using an antagonistic rhizobacterium Paenibacillus polymyxa APEC128 (APEC128). Out of 30 bacterial isolates from apple rhizosphere screened for antagonistic activity, the most effective strain was APEC128 as inferred from the size of the inhibition zone. This strain showed a greater growth in brain-heart infusion (BHI) broth compared to other growth media. There was a reduction in anthracnose symptoms caused by the two fungal pathogens in harvested apples after their treatment with APEC128 in comparison with non-treated control. This effect is explained by the increased production of protease and amylase by APEC128, which might have inhibited mycelial growth. In apples treated with different APEC128 suspensions, the disease caused by C. gloeosporioides and C. acutatum was greatly suppressed (by 83.6% and 79%, respectively) in treatments with the concentration of 1 × 10(8) colony forming units (cfu)/ml compared to other lower dosages, suggesting that the suppression of anthracnose development on harvested apples is dose-dependent. These results indicated that APEC128 is one of the promising agents in the biocontrol of apple anthracnose, which might help to increase the shelf-life of apple fruit during the post-harvest period. PMID:27298600

  11. Screening and Identification of Cotton Verticillium Wilt Antagonistic Bacteria Strain 7-30%棉花黄萎病拮抗细菌7-30菌株的筛选与鉴定

    Institute of Scientific and Technical Information of China (English)

    雷白时; 姜军坡; 王伟; 张冬冬; 王全; 朱宝成

    2008-01-01

    [Objective]The aim of this study was to screen the antagonistic spore-forming bacteria of Verticillium dahliae and identify its physiological and biochemical characteristics. [Method]Taking the cotton verticillium wilt pathogen Verticillium dahliae V-190 as the test microorganism, the antagonistic spore-forming bacteria were screened. Through the preliminary screening and secondary screening, an antagonistic bacteria strain 7-30 with stronger antibacterial activity was obtained, and its morphological characteristics, physiological and biochemical characteristics were also identified. [Result]84 antagonistic bacteria strains were isolated from soil in various places by the preliminary screening. Especially, 18 strains with better antagonistic ability were screened again, so an antagonistic bacteria strain 7-30 with the diameter of inhibition zone 18.9 mm and stronger antibacterial activity was obtained. According to its morphological characteristics, physiological and biochemical characteristics, the antagonistic bacteria strain 7-30 was identified as Bacillus subtilis primarily. [Conclusion]The strain 7-30 was obtained as the antagonistic spore-forming bacteria of Verticillium dahliae.

  12. ANTAGONISTIC ACTIVITY OF SERRATIA MARCESCENS AGAINST PYRICULARIA ORYZAE

    Directory of Open Access Journals (Sweden)

    V. JAIGANESH

    2007-08-01

    Full Text Available Rice is an important crop, widely affected by quite a number of diseases that results in higher yield losses. Among the fungal diseases, blast incited by Pyricularia oryzae is a major disease. The biological method of plant disease management seems to be an alternative to chemical fungicides in managing the blast disease. A new bio control agent viz., Serratia marcescens appears to be an ideal agent for the control of P. oryzae, because it produces chitinolytic enzymes which causes degradation of the fungal cell walls, induction of plant defence reaction and certain antifungal low molecular weight molecules. A study was undertaken to investigate the effect of a new bio control agent like S. marcescens against P. oryzae. The talc based formulation of S. marcescens (@ 1.0, 1.5, 2.0 and 2.5 kg/ha was sprayed on old IR 50 rice plants in fields. Out of the six-bio protectants tested, S. marcescens was found very effective against P. oryzae under in vitro conditions. S. marcescens could be isolated from shoots as well as roots emerging from the treated seeds and the plant parts from treated seeds inhibited P. oryzae. The antagonist S. marcescens survived in the phyllosphere even 80 days after spray. The results revealed that rice blast control was achieved by spraying S. marcescens @ 1.0 kg/ha. The increasing dose of talc-based inoculum when applied on foliage increased the phyllosphere population of S. marcescens and controlled rice blast. The maximum disease control was achieved when inoculum was applied at 2.5 kg/ha.

  13. NR2B受体拮抗剂抑制成年大鼠齿状回新生神经元诱导的长时程增强%NR2B receptor antagonist Ro25-6981 inhibits newborn neuron induced long-term potentiation in the dentate gyrus of adult rats

    Institute of Scientific and Technical Information of China (English)

    张文平; 张亘瑷; 仇玉兰; 张策

    2009-01-01

    BACKGROUND: Newborn neurons have bean shown to induce long-term potentiation (LTP). Activation of N-methyl-D-aspartic acid (NMDA) receptor subunit NR2B plays an important role in mature neurons-induced LTP. But there have been no reports addressing on the effects of NR2B activation on newborn neuron-induced LTP.OBJECTIVE: To investigate the effects of NR2B receptor antagonist Ro25-6981 on LTP induced by newborn neurons in adult rat dentate gyrus.DESIGN, TIME AND SETTING: An electrophysiological recording trial was performed at the Department of Neuroblology,Shanxi Medical University from February to June 2007.MATERIALS: Twenty-six male Wistar rats, aged 3 months, were provided by Laboratory Animal Center, Shanxi Medical University.METHODS: Following sacrifice for brain harvesting under anesthesia, the hippocempus was taken to preparation of 400 μ mol/L brain slices. Using extracellular field potential recordings, low-frequency stimulation was performed in the medial molecular layer of dentate gyrus with insulated bipolar tungsten electrodes. After having stable recordings, LTP was induced under high-frequency tetanic stimulation. LTP was induced with a protocol developed previously (4 trains, 500 ms each, 100 Hz within the train, repeated every 20 s). Only those slices which produced the field excitatory postsynaptic potential of 1 mV or cerebrospinal fluid (ACSF)-induced LTP (ACSF-LTP): brain slices were divided into 2 groups: ACSF group, in which, slices were continuously perfused using ACSF bubbled with 95% O2 and 5% CO2; ACSF+ Ro25-6981 group: a 10-minute treatment with 3μ mol/L Ro25-6981 was performed prior to tetanic stimulation, and the remaining procedures were the same as ACSF divided into 2 groups: BIC group: a 10-minute treatment with 10 μmol/L BIC was performed prior to titanic stimulation; BIC+Ro25-6981 group: 3μ mol/L Ro25-6981 and 10μ mol/L BIC were simultaneously perfused 10 minutes prior to tetanic stimulation.MAIN OUTCOME MEASURES: LTP

  14. Endothelin receptor antagonists in pulmonary arterial hypertension.

    Science.gov (United States)

    Dupuis, J; Hoeper, M M

    2008-02-01

    The endothelin (ET) system, especially ET-1 and the ET(A) and ET(B) receptors, has been implicated in the pathogenesis of pulmonary arterial hypertension (PAH). Together with prostanoids and phosphodiesterase 5 inhibitors, ET receptor antagonists have become mainstays in the current treatment of PAH. Three substances are currently available for the treatment of PAH. One of these substances, bosentan, blocks both ET(A) and ET(B) receptors, whereas the two other compounds, sitaxsentan and ambrisentan, are more selective blockers of the ET(A) receptor. There is ongoing debate as to whether selective or nonselective ET receptor blockade is advantageous in the setting of PAH, although there is no clear evidence that receptor selectivity is relevant with regard to the clinical effects of these drugs. For the time being, other features, such as safety profiles and the potential for pharmacokinetic interactions with other drugs used in the treatment of PAH, may be more important than selectivity or nonselectivity when selecting treatments for individual patients. PMID:18238950

  15. Multiple Targeting Approaches on Histamine H3 Receptor Antagonists

    Directory of Open Access Journals (Sweden)

    Mohammad eKhanfar

    2016-05-01

    Full Text Available With the very recent market approval of pitolisant (Wakix®, the interest in clinical applications of novel multifunctional histamine H3 receptor antagonists has clearly increased. Since histamine H3 receptor antagonists in clinical development have been tested for a variety of different indications, the combination of pharmacological properties in one molecule for improved pharmacological effects and reduced unwanted side-effects is rationally based on the increasing knowledge on the complex neurotransmitter regulations. The polypharmacological approaches on histamine H3 receptor antagonists on different G-protein coupled receptors, transporters, enzymes as well as on NO-signaling mechanism are described, supported with some lead structures.

  16. The Comparison of Antagonistic Effects of Normal Vaginal Lactobacilli and Some Commonly used Antibiotics on Isolated Bacteria of Uterine Infections in Dairy Cows

    Directory of Open Access Journals (Sweden)

    Pouya Dini

    2012-12-01

    Full Text Available Uterine infections are one of the major reproductive complications during postpartum. The antibiotics and antiseptic agents used in the treatment of postpartum infections have residues in food, induce bacterial resistance, increase the financial costs and cause failure in defense mechanism of host. On the other hand, nowadays the administration of probiotics is considered as an alternative method for the prevention and treatment of infections. Therefore, preventive treatment with probiotic product could decrease the usage of antibiotic and bring advantages in dairy farm systems. The objective of this study was screening of the antagonistic properties of isolated vaginal Lactic Acid Bacteria (LAB against the most prevalent bacteria in uterine infections in order to investigate their probiotic potentials as an alternative approach for prevention of uterine infections. LAB were isolated from sampling of cranial part of vagina during estrus phase and luteal phase of Holstein dairy cattle and pathogens bacteria were isolated from merits and endometritis specimens which referred to our veterinary laboratory. The antagonistic activity of isolated LAB against uterine pathogens was tested by Agar spot test. Antibiotic susceptibilities of pathogenic strains to commonly used antibiotics were investigated by using disc diffusion method. Inhibition zones around both the probiotic spots and the antibiotic discs were classified to weak, moderate and strong categories and their antagonistic efficacies were compared. Isolated LAB had antagonistic effects against all the pathogenic strains including both gram negative and gram positive, Arcanobacterium pyogenes and Pseudomonas aeroginosa were the most sensitive bacteria (with 12.60 and 14 mm an average inhibition zone, respectively. LAB had the least antagonistic effects on Clostridium perfringens (3.6 mm of an average inhibition zone. Comparing the antagonistic efficacies, the percentages of overall

  17. Antagonistic effect of TNF-α on leptin-mediated inhibition of insulin synthesis and secretion in INS-1E cells and rat pancreatic islets%肿瘤坏死因子-α拮抗瘦素抑制胰岛素合成及分泌作用的实验观察

    Institute of Scientific and Technical Information of China (English)

    张阳; 卢永辉; 缪洪明; 卢忠燕; 甘立霞

    2011-01-01

    level of insulin secretion, and subsequently stimulated with high-concen-tration glucose ( 16. 7 mmoL/L) for 1 h to test GSIS by radioimmunoassay. The expression of proinsulin mRNA was determined by RT-PCR. Intracellular insulin contents were detected after ultrasonic cell disruption. Results High-concentration leptin (10 nmol/L) or TNF-α (20 ng/ml) significantly suppressed GSIS (P < 0. 05 ) and reduced the intracellular proinsulin mRNA level and insulin content (P <0. 01 ) in INS-1E cells and pancreatic 13 cells. However, low-concentration leptin (0.5 nmol/L) or TNF-α (2 ng/ml) did not show such activities. Additionally, when the cultured INS-1E cells or islets were treated with high-concentration leptin ( 10 nmol/L) plus TNF-α (20 ng/ml), the intracellular proinsulin mRNA level and insulin content were not further decreased but significantly increased as compared with the results after high-concentration leptin ( 10 nmol/L) treatment (P <0. 05 ), indicating that TNF-α may antagonize the inhibition effect of leptin on insulin synthesis and secretion. Conclusion TNF-α can interfere with leptin-mediated inhibition of insulin synthesis and secretion in pancreatic 3 cells, and TNF-α level increase may contribute to the genesis of hyperinsulinemia and glucose metabolism disorder in people with obesity.

  18. An antagonistic activity of etizolam on platelet-activating factor (PAF). In vitro effects on platelet aggregation and PAF receptor binding.

    Science.gov (United States)

    Mikashima, H; Takehara, S; Muramoto, Y; Khomaru, T; Terasawa, M; Tahara, T; Maruyama, Y

    1987-08-01

    The antagonistic effect of etizolam, an anti-anxiety drug, on platelet-activating factor (PAF) was investigated in rabbit platelets in vitro. Etizolam inhibited PAF-induced aggregation in a dose-dependent manner, with an IC50 of 3.8 microM, about one tenth that of triazolam (IC50 = 30 microM). At 300 microM, it inhibited both ADP and arachidonic acid-induced aggregation only slightly, while the other anti-anxiety drugs tested had no effect on PAF-induced aggregation even at this concentration. Etizolam and triazolam inhibited the specific binding of 3H-PAF to PAF receptor sites on washed rabbit platelets with IC50 values of 22 nM and 320 nM, respectively. Diazepam and estazolam were inactive even at 1 microM. These results indicate that etizolam is a specific antagonist of PAF. PMID:2890779

  19. Preclinical development of a novel class of CXCR4 antagonist impairing solid tumors growth and metastases.

    Directory of Open Access Journals (Sweden)

    Luigi Portella

    Full Text Available The CXCR4/CXCL12 axis plays a role in cancer metastases, stem cell mobilization and chemosensitization. Proof of concept for efficient CXCR4 inhibition has been demonstrated in stem cell mobilization prior to autologous transplantation in hematological malignancies. Nevertheless CXCR4 inhibitors suitable for prolonged use as required for anticancer therapy are not available. To develop new CXCR4 antagonists a rational, ligand-based approach was taken, distinct from the more commonly used development strategy. A three amino acid motif (Ar-Ar-X in CXCL12, also found in the reverse orientation (X-Ar-Ar in the vMIP-II inhibitory chemokine formed the core of nineteen cyclic peptides evaluated for inhibition of CXCR4-dependent migration, binding, P-ERK1/2-induction and calcium efflux. Peptides R, S and I were chosen for evaluation in in vivo models of lung metastases (B16-CXCR4 and KTM2 murine osteosarcoma cells and growth of a renal cells xenograft. Peptides R, S, and T significantly reduced the association of the 12G5-CXCR4 antibody to the receptor and inhibited CXCL12-induced calcium efflux. The four peptides efficiently inhibited CXCL12-dependent migration at concentrations as low as 10 nM and delayed CXCL12-mediated wound healing in PES43 human melanoma cells. Intraperitoneal treatment with peptides R, I or S drastically reduced the number of B16-CXCR4-derived lung metastases in C57/BL mice. KTM2 osteosarcoma lung metastases were also reduced in Balb/C mice following CXCR4 inhibition. All three peptides significantly inhibited subcutaneous growth of SN12C-EGFP renal cancer cells. A novel class of CXCR4 inhibitory peptides was discovered. Three peptides, R, I and S inhibited lung metastases and primary tumor growth and will be evaluated as anticancer agents.

  20. Secondary prevention with calcium antagonists after acute myocardial infarction

    DEFF Research Database (Denmark)

    Hansen, J F

    1992-01-01

    Experimental studies have demonstrated that the 3 calcium antagonists nifedipine, diltiazem, and verapamil have a comparable effect in the prevention of myocardial damage during ischaemia. Secondary prevention trials after acute myocardial infarction, which aimed at improving survival and...

  1. TRPV1 Antagonists and Chronic Pain: Beyond Thermal Perception

    OpenAIRE

    Brandt, Michael R.; Beyer, Chad E; Stahl, Stephen M.

    2012-01-01

    In the last decade, considerable evidence as accumulated to support the development of Transient Receptor Potential Vanilloid 1 (TRPV1) antagonists for the treatment of various chronic pain conditions. Whereas there is a widely accepted rationale for the development of TRPV1 antagonists for the treatment of various inflammatory pain conditions, their development for indications of chronic pain, where conditions of tactical, mechanical and spontaneous pain predominate, is less clear. Preclinic...

  2. Bradykinin antagonists modified with dipeptide mimetic beta-turn inducers.

    Science.gov (United States)

    Alcaro, Maria C; Vinci, Valerio; D'Ursi, Anna M; Scrima, Mario; Chelli, Mario; Giuliani, Sandro; Meini, Stefania; Di Giacomo, Marcello; Colombo, Lino; Papini, Anna Maria

    2006-05-01

    Bradykinin (BK) is involved in a wide variety of pathophysiological processes. Potent BK peptide antagonists can be developed introducing constrained unnatural amino acids, necessary to force the secondary structure of the molecule. In this paper, we report a structure-activity relationship study of two peptide analogues of the potent B2 antagonist HOE 140 by replacing the D-Tic-Oic dipeptide with conformationally constrained dipeptide mimetic beta-turn inducers. PMID:16504505

  3. The Apolipoprotein E Antagonistic Pleiotropy Hypothesis: Review and Recommendations

    OpenAIRE

    Tuminello, Elizabeth R.; S Duke Han

    2011-01-01

    Research on apolipoprotein E (APOE) has consistently revealed a relationship between the gene's ε 4 allele and risk for development of Alzheimer's disease (AD). However, research with younger populations of ε 4 carriers has suggested that the APOE ε 4 allele may in fact be beneficial in earlier ages and may only confer risk of cognitive decline later in life. Accordingly, we and others have proposed that APOE may represent an example of antagonistic pleiotropy. Antagonistic pleiotropy is an e...

  4. Deficiency of interleukin-1 receptor antagonist responsive to anakinra.

    Science.gov (United States)

    Schnellbacher, Charlotte; Ciocca, Giovanna; Menendez, Roxanna; Aksentijevich, Ivona; Goldbach-Mansky, Raphaela; Duarte, Ana M; Rivas-Chacon, Rafael

    2013-01-01

    We describe a 3-month-old infant who presented to our institution with interleukin (IL)-1 receptor antagonist deficiency (DIRA), which consists of neutrophilic pustular dermatosis, periostitis, aseptic multifocal osteomyelitis, and persistently high acute-phase reactants. Skin findings promptly improved upon initiation of treatment with anakinra (recombinant human IL-1 receptor antagonist), and the bony lesions and systemic inflammation resolved with continued therapy. PMID:22471702

  5. Interleukin-2 receptor antagonists as induction therapy after heart transplantation

    DEFF Research Database (Denmark)

    Møller, Christian H; Gustafsson, Finn; Gluud, Christian;

    2008-01-01

    About half of the transplantation centers use induction therapy after heart transplantation. Interleukin-2 receptor antagonists (IL-2Ras) are used increasingly for induction therapy. We conducted a systematic review of randomized trials assessing IL-2Ras.......About half of the transplantation centers use induction therapy after heart transplantation. Interleukin-2 receptor antagonists (IL-2Ras) are used increasingly for induction therapy. We conducted a systematic review of randomized trials assessing IL-2Ras....

  6. Catharanthine alkaloids are noncompetitive antagonists of muscle-type nicotinic acetylcholine receptors.

    Science.gov (United States)

    Arias, Hugo R; Feuerbach, Dominik; Targowska-Duda, Katarzyna M; Jozwiak, Krzysztof

    2010-09-01

    We compared the interaction of several catharanthine alkaloids including, ibogaine, vincristine, and vinblastine, with that for the noncompetitive antagonist phencyclidine (PCP) at muscle nicotinic acetylcholine receptors (AChRs) in different conformational states. The results established that catharanthine alkaloids: (a) inhibit, in a noncompetitive manner, (+/-)-epibatidine-induced Ca(2+) influx in TE671-halpha1beta1gammadelta cells with similar potencies (IC(50)=17-25microM), (b) inhibit [(3)H]TCP binding to the desensitized Torpedo AChR with higher affinity compared to the resting AChR, and (c) enhance [(3)H]cytisine binding to resting but activatable Torpedo AChRs, suggesting desensitizing properties. Interestingly, PCP inhibits [(3)H]ibogaine binding to the AChR in a steric fashion. This is corroborated by additional docking experiments indicating that the amino groups of neutral ibogaine form hydrogen bonds with the serine ring (position 6'), a location shared with PCP. Since protonated ibogaine forms a salt bridge with one of the acidic residues at the outer ring (position 20'), this ligand could be first attracted to the entrance of the channel by electrostatic interactions. Our data indicate that the catharanthine moiety is a minimum structural requirement for AChR inhibition including, ion channel blocking and desensitization, and that ibogaine and PCP bind to overlapping sites in the desensitized AChR ion channel. PMID:20493225

  7. Effects of α-adrenoreceptor antagonists on apoptosis and proliferation of pancreatic cancer cells in vitro

    Institute of Scientific and Technical Information of China (English)

    Su-Gang Shen; Dong Zhang; Heng-Tong Hu; Jun-Hui Li; Zheng Wang; Qing-Yong Ma

    2008-01-01

    AIM: To discuss the expression of α-adrenoreceptors in pancreatic cancer cell lines PC-2 and PC-3 and the effects of α1- and α2-adrenoreceptor antagonists, yohimbine and urapidil hydrochloride, on the cell lines in vitro.METHODS: We cultured the human ductal pancreatic adenocarcinoma cell lines PC-2 and PC-3 and analyzed the mRNA expression of α1- and α2-adrenergic receptors by reverse transcription polymerase chain reaction (RT-PCR).The effects of yohimbine and urapidil hydrochloride on cell proliferation were assessed by 3-(4,5-dimethylthiasol-2-yl)2,4,-diphenyltetrazolium bromide (MTT) assay. Apoptosis was detected using the terminal deoxyribonucleoticlyl transferase (TdT)-mediated biotin-16-dUTP nick-end labeling (TUNEL) assay and flow cytometry (FCM).RESULTS: PC-2 expressed rnRNA in α1- and α2-adrenoreceptors. MTT assays showed that urapidil hydrochloride had no effect on PC-3 cell lines. However,exposure to urapidil hydrochloride increased DNA synthesis in PC-2 cell lines as compared to the control group. PC-2 cell lines were sensitive to both drugs. The proliferation of the 2 cell lines was inhibited by yohimbine.Cell proliferation was inhibited by yohimbine via apoptosis induction.CONCLUSION: The expression of α1-and α2-adrenoreceptors is different in PC-2 and PC-3 cell lines,which might be indicative of their different functions. Theα2-adrenoceptor antagonist, yohimbine, can inhibit the proliferation of both cell lines and induce their apoptosis,suggesting that yohimbine can be used as an anticancer drug for apoptosis of PC-2 and PC-3 cells.

  8. Antagonist properties of Conus parius peptides on N-methyl-D-aspartate receptors and their effects on CREB signaling.

    Directory of Open Access Journals (Sweden)

    Shailaja Kunda

    Full Text Available Three members of a family of small neurotoxic peptides from the venom of Conus parius, conantokins (Con Pr1, Pr2, and Pr3, function as antagonists of N-methyl-D-aspartate receptors (NMDAR. We report structural characterizations of these synthetic peptides, and also demonstrate their antagonistic properties toward ion flow through NMDAR ion channels in primary neurons. ConPr1 and ConPr2 displayed moderate increases in α-helicity after addition of Mg(2+. Native apo-ConPr3 possessed an α-helical conformation, and the helicity increased only slightly on addition of Mg(2+. Additionally, these peptides diminished NMDA/Gly-mediated currents and intracellular Ca(2+ (iCa(2+ influx in mature rat primary hippocampal neurons. Electrophysiological data showed that these peptides displayed slower antagonistic properties toward the NMDAR than conantokins from other species of cone snails, e.g., ConT and ConG. Furthermore, to demonstrate selectivity of the C. parius-derived conantokins towards specific NMDAR subunits, cortical neurons from GluN2A(-/- and GluN2B(-/- mice were utilized. Robust inhibition of NMDAR-mediated stimulation in GluN2A(-/--derived mouse neurons, as compared to those isolated from GluN2B(-/--mouse brains, was observed, suggesting a greater selectivity of these antagonists towards the GluN2B subunit. These C. parius conantokins mildly inhibited NMDAR-induced phosphorylation of CREB at Ser(133, suggesting that the peptides modulated iCa(2+ entry and, thereby, activation of CREB, a transcription factor that is required for maintaining long-term synaptic activity. Our data mechanistically show that while these peptides effectively antagonize NMDAR-directed current and iCa(2+ influx, receptor-coupled CREB signaling is maintained. The consequence of sustained CREB signaling is improved neuronal plasticity and survival during neuropathologies.

  9. CV-6209, a highly potent antagonist of platelet activating factor in vitro and in vivo.

    Science.gov (United States)

    Terashita, Z; Imura, Y; Takatani, M; Tsushima, S; Nishikawa, K

    1987-07-01

    2-[N-acetyl-N-(2-methoxy-3-octadecylcarbamoyloxypropoxycarbonyl) aminomethyl]-1-ethylpyridinium chloride (CV-6209) inhibited aggregation of rabbit and human platelets induced by platelet activating factor (PAF) with the IC50 values of 7.5 X 10(-8) and 1.7 X 10(-7) M, respectively, and had little effects on the aggregation induced by arachidonic acid, ADP and collagen. The inhibitory effect of CV-6209 on the PAF-induced rabbit platelet aggregation was 104, 9, 8 and 3 times more potent than the PAF antagonists CV-3988, ONO-6240, Ginkgolide B and etizolam, respectively. CV-6209 inhibited [3H]serotonin release from rabbit platelets stimulated with PAF (3 X 10(-8) M) with a similar potency as the inhibition on the platelet aggregation. CV-6209 inhibited PAF (0.3 microgram/kg i.v.)-induced hypotension in rats (ED50, 0.009 mg/kg i.v.) with no effect on the hypotension induced by arachidonic acid, histamine, bradykinin and isoproterenol. CV-6209 (1 mg/kg) inhibited slightly the acetylcholine-induced hypotension. In rats, post-treatment with CV-6209 reversed the PAF (1 microgram/kg i.v.)-induced hypotension rapidly (ED50, 0.0046 mg/kg i.v.); CV-6209 was 74, 20, 185 and over 2100 times more potent than CV-3988, ONO-6240, Ginkgolide B and etizolam, respectively. Thus, the relative potency of the anti-PAF action of PAF analog (CV-6209, CV-3988 and ONO-6240) differed little between the inhibition of PAF-induced platelet aggregation and the reversal of PAF-induced hypotension, but that of nonPAF analogs (Ginkgolide B and etizolam) differed greatly with these assay systems, when standardized with CV-6209.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:3612533

  10. Slow receptor dissociation kinetics differentiate macitentan from other endothelin receptor antagonists in pulmonary arterial smooth muscle cells.

    Directory of Open Access Journals (Sweden)

    John Gatfield

    Full Text Available Two endothelin receptor antagonists (ERAs, bosentan and ambrisentan, are currently approved for the treatment of pulmonary arterial hypertension (PAH, a devastating disease involving an activated endothelin system and aberrant contraction and proliferation of pulmonary arterial smooth muscle cells (PASMC. The novel ERA macitentan has recently concluded testing in a Phase III morbidity/mortality clinical trial in PAH patients. Since the association and dissociation rates of G protein-coupled receptor antagonists can influence their pharmacological activity in vivo, we used human PASMC to characterize inhibitory potency and receptor inhibition kinetics of macitentan, ambrisentan and bosentan using calcium release and inositol-1-phosphate (IP(1 assays. In calcium release assays macitentan, ambrisentan and bosentan were highly potent ERAs with K(b values of 0.14 nM, 0.12 nM and 1.1 nM, respectively. Macitentan, but not ambrisentan and bosentan, displayed slow apparent receptor association kinetics as evidenced by increased antagonistic potency upon prolongation of antagonist pre-incubation times. In compound washout experiments, macitentan displayed a significantly lower receptor dissociation rate and longer receptor occupancy half-life (ROt(1/2 compared to bosentan and ambrisentan (ROt(1/2:17 minutes versus 70 seconds and 40 seconds, respectively. Because of its lower dissociation rate macitentan behaved as an insurmountable antagonist in calcium release and IP(1 assays, and unlike bosentan and ambrisentan it blocked endothelin receptor activation across a wide range of endothelin-1 (ET-1 concentrations. However, prolongation of the ET-1 stimulation time beyond ROt(1/2 rendered macitentan a surmountable antagonist, revealing its competitive binding mode. Bosentan and ambrisentan behaved as surmountable antagonists irrespective of the assay duration and they lacked inhibitory activity at high ET-1 concentrations. Thus, macitentan is a competitive

  11. Slow receptor dissociation kinetics differentiate macitentan from other endothelin receptor antagonists in pulmonary arterial smooth muscle cells.

    Science.gov (United States)

    Gatfield, John; Mueller Grandjean, Celia; Sasse, Thomas; Clozel, Martine; Nayler, Oliver

    2012-01-01

    Two endothelin receptor antagonists (ERAs), bosentan and ambrisentan, are currently approved for the treatment of pulmonary arterial hypertension (PAH), a devastating disease involving an activated endothelin system and aberrant contraction and proliferation of pulmonary arterial smooth muscle cells (PASMC). The novel ERA macitentan has recently concluded testing in a Phase III morbidity/mortality clinical trial in PAH patients. Since the association and dissociation rates of G protein-coupled receptor antagonists can influence their pharmacological activity in vivo, we used human PASMC to characterize inhibitory potency and receptor inhibition kinetics of macitentan, ambrisentan and bosentan using calcium release and inositol-1-phosphate (IP(1)) assays. In calcium release assays macitentan, ambrisentan and bosentan were highly potent ERAs with K(b) values of 0.14 nM, 0.12 nM and 1.1 nM, respectively. Macitentan, but not ambrisentan and bosentan, displayed slow apparent receptor association kinetics as evidenced by increased antagonistic potency upon prolongation of antagonist pre-incubation times. In compound washout experiments, macitentan displayed a significantly lower receptor dissociation rate and longer receptor occupancy half-life (ROt(1/2)) compared to bosentan and ambrisentan (ROt(1/2):17 minutes versus 70 seconds and 40 seconds, respectively). Because of its lower dissociation rate macitentan behaved as an insurmountable antagonist in calcium release and IP(1) assays, and unlike bosentan and ambrisentan it blocked endothelin receptor activation across a wide range of endothelin-1 (ET-1) concentrations. However, prolongation of the ET-1 stimulation time beyond ROt(1/2) rendered macitentan a surmountable antagonist, revealing its competitive binding mode. Bosentan and ambrisentan behaved as surmountable antagonists irrespective of the assay duration and they lacked inhibitory activity at high ET-1 concentrations. Thus, macitentan is a competitive ERA with

  12. Blockade of Cocaine or σ Receptor Agonist Self Administration by Subtype-Selective σ Receptor Antagonists.

    Science.gov (United States)

    Katz, Jonathan L; Hiranita, Takato; Kopajtic, Theresa A; Rice, Kenner C; Mesangeau, Christophe; Narayanan, Sanju; Abdelazeem, Ahmed H; McCurdy, Christopher R

    2016-07-01

    The identification of sigma receptor (σR) subtypes has been based on radioligand binding and, despite progress with σ1R cellular function, less is known about σR subtype functions in vivo. Recent findings that cocaine self administration experience will trigger σR agonist self administration was used in this study to assess the in vivo receptor subtype specificity of the agonists (+)-pentazocine, PRE-084 [2-(4-morpholinethyl) 1-phenylcyclohexanecarboxylate hydrochloride], and 1,3-di-o-tolylguanidine (DTG) and several novel putative σR antagonists. Radioligand binding studies determined in vitro σR selectivity of the novel compounds, which were subsequently studied for self administration and antagonism of cocaine, (+)-pentazocine, PRE-084, or DTG self administration. Across the dose ranges studied, none of the novel compounds were self administered, nor did they alter cocaine self administration. All compounds blocked DTG self administration, with a subset also blocking (+)-pentazocine and PRE-084 self administration. The most selective of the compounds in binding σ1Rs blocked cocaine self administration when combined with a dopamine transport inhibitor, either methylphenidate or nomifensine. These drug combinations did not decrease rates of responding maintained by food reinforcement. In contrast, the most selective of the compounds in binding σ2Rs had no effect on cocaine self administration in combination with either dopamine transport inhibitor. Thus, these results identify subtype-specific in vivo antagonists, and the utility of σR agonist substitution for cocaine self administration as an assay capable of distinguishing σR subtype selectivity in vivo. These results further suggest that effectiveness of dual σR antagonism and dopamine transport inhibition in blocking cocaine self administration is specific for σ1Rs and further support this dual targeting approach to development of cocaine antagonists. PMID:27189970

  13. Microbial diversity inside pumpkins: microhabitat-specific communities display a high antagonistic potential against phytopathogens.

    Science.gov (United States)

    Fürnkranz, Michael; Lukesch, Birgit; Müller, Henry; Huss, Herbert; Grube, Martin; Berg, Gabriele

    2012-02-01

    Recent and substantial yield losses of Styrian oil pumpkin (Cucurbita pepo L. subsp. pepo var. styriaca Greb.) are primarily caused by the ascomycetous fungus Didymella bryoniae but bacterial pathogens are frequently involved as well. The diversity of endophytic microbial communities from seeds (spermosphere), roots (endorhiza), flowers (anthosphere), and fruits (carposphere) of three different pumpkin cultivars was studied to develop a biocontrol strategy. A multiphasic approach combining molecular, microscopic, and cultivation techniques was applied to select a consortium of endophytes for biocontrol. Specific community structures for Pseudomonas and Bacillus, two important plant-associated genera, were found for each microenvironment by fingerprinting of 16S ribosomal RNA genes. All microenvironments were dominated by bacteria; fungi were less abundant. Of the 2,320 microbial isolates analyzed in dual culture assays, 165 (7%) were tested positively for in vitro antagonism against D. bryoniae. Out of these, 43 isolates inhibited the growth of bacterial pumpkin pathogens (Pectobacterium carotovorum, Pseudomonas viridiflava, Xanthomonas cucurbitae); here only bacteria were selected. Microenvironment-specific antagonists were found, and the spermosphere and anthosphere were revealed as underexplored reservoirs for antagonists. In the latter, a potential role of pollen grains as bacterial vectors between flowers was recognized. Six broad spectrum antagonists selected according to their activity, genotypic diversity, and occurrence were evaluated under greenhouse conditions. Disease severity on pumpkins of D. bryoniae was significantly reduced by Pseudomonas chlororaphis treatment and by a combined treatment of strains (Lysobacter gummosus, P. chlororaphis, Paenibacillus polymyxa, and Serratia plymuthica). This result provides a promising prospect to biologically control pumpkin diseases. PMID:21947430

  14. CRF receptor antagonist astressin-B reverses and prevents alopecia in CRF over-expressing mice.

    Directory of Open Access Journals (Sweden)

    Lixin Wang

    Full Text Available Corticotropin-releasing factor (CRF signaling pathways are involved in the stress response, and there is growing evidence supporting hair growth inhibition of murine hair follicle in vivo upon stress exposure. We investigated whether the blockade of CRF receptors influences the development of hair loss in CRF over-expressing (OE-mice that display phenotypes of Cushing's syndrome and chronic stress, including alopecia. The non-selective CRF receptors antagonist, astressin-B (5 µg/mouse injected peripherally once a day for 5 days in 4-9 months old CRF-OE alopecic mice induced pigmentation and hair re-growth that was largely retained for over 4 months. In young CRF-OE mice, astressin-B prevented the development of alopecia that occurred in saline-treated mice. Histological examination indicated that alopecic CRF-OE mice had hair follicle atrophy and that astressin-B revived the hair follicle from the telogen to anagen phase. However, astressin-B did not show any effect on the elevated plasma corticosterone levels and the increased weights of adrenal glands and visceral fat in CRF-OE mice. The selective CRF₂ receptor antagonist, astressin₂-B had moderate effect on pigmentation, but not on hair re-growth. The commercial drug for alopecia, minoxidil only showed partial effect on hair re-growth. These data support the existence of a key molecular switching mechanism triggered by blocking peripheral CRF receptors with an antagonist to reset hair growth in a mouse model of alopecia associated with chronic stress.

  15. Antagonistic effect of Pseudomonas aeruginosa isolates from various ecological niches on Vibrio species pathogenic to crustaceans

    Institute of Scientific and Technical Information of China (English)

    Prabhakaran Priyaja; Puthumana Jayesh; Neil Scolastin Correya; Balachandran Sreelakshmi; Naduthalmuriparambil S Sudheer; Rosamma Philip; Isaac Sarogeni Bright Singh

    2014-01-01

    Objective: To abrogate pathogenic vibrios in aquaculture by testing the potential of Pseudomonas isolates from fresh water, brackish and marine environments as probiotics.Methods:Antagonistic activity of the compound against 7 Vibrio spp. was performed. Influence of salinity on the production of pyocyanin and the toxicity was done through the compound using brine shrimp lethality assay. Molecular characterization was performed to confirm that the isolates werePseudomonas aeruginosa. Results: Salinity was found to regulate the levels of pyocyanin production, with 5-10 g/L as the optimum. All Pseudomonas isolates grew at salinities ranging from 5 to 70 g/L. Isolates of marine origin produced detectable levels of pyocyanin up to 45 g/L salinity. Brackish and freshwater isolates ceased to produce pyocyanin at salinities above 30 g/L and 20 g/L, respectively. Culture supernatants of all 5 Pseudomonas isolates possessed the ability to restrict the growth of Vibrio spp. and maximum antagonistic effect on Vibrio harveyi was obtained when they were grown at salinities of 5 to 10 g/L. The marine isolate MCCB117, even when grown at a salinity of 45 g/L possessed the ability to inhibit Vibrio spp.Conclusions:Purification and structural elucidation of antagonistic compound were carried out. ideal for application in freshwater, MCCB102 and MCCB103 in brackish water and MCCB117 and The present investigation showed that Pseudomonas aeruginosa MCCB119 would be MCCB118 in marine aquaculture systems as putative probiotics in the management of vibrios.

  16. Preladenant, a selective A(2A) receptor antagonist, is active in primate models of movement disorders.

    Science.gov (United States)

    Hodgson, Robert A; Bedard, Paul J; Varty, Geoffrey B; Kazdoba, Tatiana M; Di Paolo, Therese; Grzelak, Michael E; Pond, Annamarie J; Hadjtahar, Abdallah; Belanger, Nancy; Gregoire, Laurent; Dare, Aurelie; Neustadt, Bernard R; Stamford, Andrew W; Hunter, John C

    2010-10-01

    Parkinson's Disease (PD) and Extrapyramidal Syndrome (EPS) are movement disorders that result from degeneration of the dopaminergic input to the striatum and chronic inhibition of striatal dopamine D(2) receptors by antipsychotics, respectively. Adenosine A(2A) receptors are selectively localized in the basal ganglia, primarily in the striatopallidal ("indirect") pathway, where they appear to operate in concert with D(2) receptors and have been suggested to drive striatopallidal output balance. In cases of dopaminergic hypofunction, A(2A) receptor activation contributes to the overdrive of the indirect pathway. A(2A) receptor antagonists, therefore, have the potential to restore this inhibitor imbalance. Consequently, A(2A) receptor antagonists have therapeutic potential in diseases of dopaminergic hypofunction such as PD and EPS. Targeting the A(2A) receptor may also be a way to avoid the issues associated with direct dopamine agonists. Recently, preladenant was identified as a potent and highly selective A(2A) receptor antagonist, and has produced a significant improvement in motor function in rodent models of PD. Here we investigate the effects of preladenant in two primate movement disorder models. In MPTP-treated cynomolgus monkeys, preladenant (1 or 3 mg/kg; PO) improved motor ability and did not evoke any dopaminergic-mediated dyskinetic or motor complications. In Cebus apella monkeys with a history of chronic haloperidol treatment, preladenant (0.3-3.0 mg/kg; PO) delayed the onset of EPS symptoms evoked by an acute haloperidol challenge. Collectively, these data support the use of preladenant for the treatment of PD and antipsychotic-induced movement disorders. PMID:20655910

  17. Differential effect of glucocorticoid receptor antagonists on glucocorticoid receptor nuclear translocation and DNA binding

    Science.gov (United States)

    Spiga, Francesca; Knight, David M; Droste, Susanne K; Conway-Campbell, Becky; Kershaw, Yvonne; MacSweeney, Cliona P; Thomson, Fiona J; Craighead, Mark; Peeters, Bernard WMM; Lightman, Stafford L

    2016-01-01

    The effects of RU486 and S-P, a more selective glucocorticoid receptor antagonist from Schering-Plough, were investigated on glucocorticoid receptor nuclear translocation and DNA binding. In the in vitro study, AtT20 cells were treated with vehicle or with RU486, S-P or corticosterone (3–300 nM) or co-treated with vehicle or glucocorticoid receptor antagonists (3–300 nM) and 30 nM corticosterone. Both glucocorticoid receptor antagonists induced glucocorticoid receptor nuclear translocation but only RU486 induced DNA binding. RU486 potentiated the effect of corticosterone on glucocorticoid receptor nuclear translocation and DNA binding, S-P inhibited corticosterone-induced glucocorticoid receptor nuclear translocation, but not glucocorticoid receptor-DNA binding. In the in vivo study, adrenalectomized rats were treated with vehicle, RU486 (20 mg/kg) and S-P (50 mg/kg) alone or in combination with corticosterone (3 mg/kg). RU486 induced glucocorticoid receptor nuclear translocation in the pituitary, hippocampus and prefrontal cortex and glucocorticoid receptor-DNA binding in the hippocampus, whereas no effect of S-P on glucocorticoid receptor nuclear translocation or DNA binding was observed in any of the areas analysed. These findings reveal differential effects of RU486 and S-P on areas involved in regulation of hypothalamic–pituitary–adrenal axis activity in vivo and they are important in light of the potential use of this class of compounds in the treatment of disorders associated with hyperactivity of the hypothalamic–pituitary–adrenal axis. PMID:20093322

  18. Studies of the voltage-sensitive calcium channels in smooth muscle, neuronal, and cardiac tissues using 1,4-dihydropyridine calcium channel antagonists and activators

    International Nuclear Information System (INIS)

    This study describes the investigation of the voltage-sensitive Ca+ channels in vascular and intestinal smooth muscle, chick neural retina cells and neonatal rat cardiac myocytes using 1,4-dihydropyridine Ca2+ channel antagonists and activators. In rat aorta, the tumor promoting phorbol ester, 12-O-tetradecanoylphorbol-13-acetate (TPA) produced Ca2+-dependent contractile responses. The responses to TPA were blocked by the Ca2+ channel antagonists. The effects of the enantiomers of Bay K 8644 and 202-791 were characterized in both rat tail artery and guinea pig ileal longitudinal smooth muscle preparations using pharmacologic and radioligand binding assays. The (S)-enantiomers induced contraction and potentiated the responses to K+ depolarization. The (R)-enantiomers inhibited the tension responses to K+. All the enantiomers inhibited specific [3H]nitrendipine binding. The pharmacologic activities of both activator and antagonist ligands correlated on a 1:1 basis with the binding affinities. In chick neural retina cells the (S)-enantiomers of Bay K 8644 and 202-791 enhanced Ca2+ influx. In contrast, the (R)-enantiomers inhibited Ca2+ influx. The enantiomers of Bay K 8644 and 202-791 inhibited specific [3H]PN 200-110 binding competitively. Binding of 1,4-dihydropyridines was characterized in neonatal rat heart cells

  19. Effects of GABA receptor antagonists on thresholds of P23H rat retinal ganglion cells to electrical stimulation of the retina

    Science.gov (United States)

    Jensen, Ralph J.; Rizzo, Joseph F., III

    2011-06-01

    An electronic retinal prosthesis may provide useful vision for patients suffering from retinitis pigmentosa (RP). In animal models of RP, the amount of current needed to activate retinal ganglion cells (RGCs) is higher than in normal, healthy retinas. In this study, we sought to reduce the stimulation thresholds of RGCs in a degenerate rat model (P23H-line 1) by blocking GABA receptor mediated inhibition in the retina. We examined the effects of TPMPA, a GABAC receptor antagonist, and SR95531, a GABAA receptor antagonist, on the electrically evoked responses of RGCs to biphasic current pulses delivered to the subretinal surface through a 400 µm diameter electrode. Both TPMPA and SR95531 reduced the stimulation thresholds of ON-center RGCs on average by 15% and 20% respectively. Co-application of the two GABA receptor antagonists had the greatest effect, on average reducing stimulation thresholds by 32%. In addition, co-application of the two GABA receptor antagonists increased the magnitude of the electrically evoked responses on average three-fold. Neither TPMPA nor SR95531, applied alone or in combination, had consistent effects on the stimulation thresholds of OFF-center RGCs. We suggest that the effects of the GABA receptor antagonists on ON-center RGCs may be attributable to blockage of GABA receptors on the axon terminals of ON bipolar cells.

  20. "Synthesis and smooth muscle Calcium channel antagonist effect of Alkyl, Aminoalkyl 1,4-Dihydro-2,6-Dimethyl-4-Nitroimidazole-3,5 Pyridine Dicarboxylates "

    Directory of Open Access Journals (Sweden)

    Miri R

    2001-08-01

    Full Text Available The discovery that 1,4-dihydropyridine (DHP class of calcium channel antagonist inhibits the Ca+² influx represented a major therapeutic advance in the treatment of cardiovascular diseases such as hypertension, angina pectoris and other spastic smooth muscle disorders. A novel class of calcium channel antagonist of flunarizine containing arylpiperazinyl moiety has recently been reported. It was therefore of interest to determine the effect that selected C-3 substituents contained amino alkyl and arylpiperazine, in conjunction with a C-4 1-methyl-5-nitro-2-imidazolyl substituents on calcium channel antagonist activity. The unsymmetrical analogues were prepared by a procedure reported by Meyer in which 1-methyl-5-nitro-imidazol-2-carboxaldehyde was reacted with acetoacetic esters and alkyl 3-aminocrotonate. In vitro calcium channel antagonist activities were determined by the use of high K+ contraction of guinea pig ileal longitudinal smooth muscle. All compounds exhibited comparable calcium channel antagonist activity (IC50=10^-9 to 10^-11 M against reference drug nifedipine (IC50=2.75±0.36 x 10^-10 M.

  1. Radioprotective effects of histamine H2 receptor antagonists famotidine and ranitidine on gamma ray induced chromosome damage

    International Nuclear Information System (INIS)

    Histamine H2 receptor antagonist such as Cimetidine, Famotidine and Ranitidine are used in the clinical treatment of peptic ulcer. In vitro metaphase analysis and micronucleus assay were used to test the effects of famotidine and ranitidine on Cobalt 60 γ-ray induced clastogenic effects. Heparinised whole blood was obtained from healthy non-smoker volunteers. Blood samples were irradiated at a dose of 3Gy and incubated at 37 deg C for 1h. Lymphocyte cultures were initiated for metaphase chromosomes and cytochalasin B blocked micronucleus analysis. Aqueous solution of Famotidine (150 g/ml) and Ranitidine (500 g/ml) was added to the whole blood cultures at 0h and 24h. Cultures were harvested and processed at 48h and 72h for chromosome aberrations and micronucleus analysis respectively. Cultures treated with Famotidine at 0h and 24h after 3Gy γ-ray irradiation induce 60.90% and 56.52% inhibition in dicentrics, 48.70% and 43.61% inhibition in total aberrations. Ranitidine at 0h and 24h after 3Gy γ-ray irradiation induce 52.17% and 43.47% inhibition in dicentrics, 33.60% and 46.15% inhibition in total aberrations, when compared with 3Gy γ-ray irradiation alone. 43-54% inhibition in Binucleated cells with micronuclei and 47.72% inhibition in micronuclei at 0h treatment respectively. In conclusion radioprotective effects of Histamine H2 receptor antagonists famotidine and ranitidine on γ-ray induced chromosome damage is observed and the drugs effectively reduced the frequency of radiation induced chromosome aberrations and micronucleus. Famotidine was found to be more effective. The mechanism in which these drugs reduce clastogenic effect of γ-radiation is not fully understood. It might be due to their antioxidant and free radical-scavenging properties. (author)

  2. Penicillium expansum versus antagonist yeasts and patulin degradation in vitro

    Directory of Open Access Journals (Sweden)

    Alexandre Rodrigo Coelho

    2007-07-01

    Full Text Available Taking into account the preliminary antagonistic/biodegradation property showed by Pichia membranifaciens and Sporobolomyces roseus, which decreased the initial patulin concentration of 588.4 to 290.0 µg/mL, ability of P. ohmeri 158 in biocontrol against Penicillium expansum and patulin decrease in vitro was performed. The culture supernatant of P. ohmeri 158 was effective against 66.17% micelial growth, indicating antibiosis related with the killer phenomenon. The initial patulin concentration of 223 µg in the presence of P. ohmeri 158 cells was decreased over 83% of the original concentration, when incubated at 25ºC/2 days and > 99% after 5 days incubation time, with undetectable patulin level after 15 days. The initial pH 4.0 decreased to pH 3.3 along 15 days experiment, suggesting that patulin decrease was an active process and a consequence of yeast metabolism. The results suggested that P. ohmeri 158 could be a promising alternative for the inhibition of P. expansum growth and patulin degradation.Considerando o antagonismo e degradação de patulina detectados em Pichia membranifaciens e Sporobolomyces roseus no estudo preliminar, este trabalho avaliou o efeito antagônico de Pichia ohmeri 158 no desenvolvimento de Penicillium expansum e a degradação de patulina "in vitro". O sobrenadante do cultivo de P. ohmeri 158 inibiu 66,17% do desenvolvimento micelial, indicando antibiose relacionada ao fator killer. A concentração inicial de patulina (223 µg na presença de células íntegras de P. ohmeri foi reduzida em mais de 83% após dois dias de incubação a 25ºC e superior a 99% após 5 dias, com níveis indetectáveis no 15º dia. O decréscimo do pH 4,0 inicial para pH 3,3 sugeriu que a eliminação de patulina é um processo ativo e uma conseqüência do metabolismo da levedura. Os resultados obtidos concluem que P. ohmeri 158 é uma alternativa promissora na inibição do desenvolvimento de P. expansum e na degradação de

  3. MDM2 antagonist Nutlin-3a potentiates antitumour activity of cytotoxic drugs in sarcoma cell lines

    Directory of Open Access Journals (Sweden)

    Lothe Ragnhild A

    2011-05-01

    Full Text Available Abstract Background Frequent failure and severe side effects of current sarcoma therapy warrants new therapeutic approaches. The small-molecule MDM2 antagonist Nutlin-3a activates the p53 pathway and efficiently induces apoptosis in tumours with amplified MDM2 gene and overexpression of MDM2 protein. However, the majority of human sarcomas have normal level of MDM2 and the therapeutic potential of MDM2 antagonists in this group is still unclear. We have investigated if Nutlin-3a could be employed to augment the response to traditional therapy and/or reduce the genotoxic burden of chemotherapy. Methods A panel of sarcoma cell lines with different TP53 and MDM2 status were treated with Nutlin-3a combined with Doxorubicin, Methotrexate or Cisplatin, and their combination index determined. Results Clear synergism was observed when Doxorubicin and Nutlin-3a were combined in cell lines with wild-type TP53 and amplified MDM2, or with Methotrexate in both MDM2 normal and amplified sarcoma cell lines, allowing for up to tenfold reduction of cytotoxic drug dose. Interestingly, Nutlin-3a seemed to potentiate the effect of classical drugs as Doxorubicin and Cisplatin in cell lines with mutated TP53, but inhibited the effect of Methotrexate. Conclusion The use of Nutlin in combination with classical sarcoma chemotherapy shows promising preclinical potential, but since clear biomarkers are still lacking, clinical trials should be followed up with detailed tumour profiling.

  4. Antimicrobial activity of extracellular metabolites from antagonistic bacteria isolated from potato (Solanum phureja crops

    Directory of Open Access Journals (Sweden)

    Sinar David Granada García

    2014-09-01

    Full Text Available Microorganisms for biological control are capable of producing active compounds that inhibit the development of phytopathogens, constituting a promising tool toob tain active principles that could replace synthetic pesticides. This study evaluatedtheability of severalpotentialbiocontrol microorganismsto produce active extracellular metabolites. In vitro antagonistic capability of 50 bacterial isolates from rhizospheric soils of "criolla" potato (Solanum phureja was tested through dual culture in this plant with different plant pathogenic fungi and bacteria. Isolates that showed significantly higher antagonistic activity were fermented in liquid media and crude extracts from the supernatants had their biological activities assessed by optical density techniques. Inhibitory effecton tested pathogens was observed for concentrations between 0.5% and 1% of crude extracts. There was a correlation between the antimicrobial activity of extracts and the use of nutrient-rich media in bacteria fermentation. Using a bioguided method, a peptidic compound, active against Fusarium oxysporum, was obtained from the 7ANT04 strain (Pyrobaculum sp.. Analysis by nuclear magnetic resonance and liquid chromatography coupled to mass detector evidenced an 11-amino acid compound. Bioinformatic software using raw mass data confirmed the presence of a cyclic peptide conformed by 11 mostly non-standard amino acids.

  5. A novel Nogo-66 receptor antagonist peptide promotes neurite regeneration in vitro.

    Science.gov (United States)

    Sun, Zhongqing; Dai, Xiaoyong; Li, Yu; Jiang, Shuwen; Lou, Guofeng; Cao, Qiaoyu; Hu, Rendong; Huang, Yadong; Su, Zhijian; Chen, Meiwan; Luo, Huanmin; Lin, Xi; Sun, Jun; Xiao, Fei

    2016-03-01

    The Nogo-66 receptor (NgR1), a receptor for Nogo-A, contributes to the inhibition of axonal regeneration in the adult central nervous system after traumatic injuries. Thus, NgR1 has been considered a critical target in axon regeneration therapy. Here, we identified a specific NgR1 antagonist peptide (HIYTALV, named NAP2) which promotes neurite regeneration in vitro from a phage display heptapeptide library. NAP2 was co-localized with NgR1 on the surface of PC12 cells and cerebellar granule cells (CGCs) by immunofluorescence assay. Horseradish peroxidase (HRP)-streptavidin-biotin assay further showed that NAP2 binds to NgR1 and the dissociation constant (Kd) was 0.45μM Functional analyses indicated that NAP2 could reduce the inhibitory effects of Nogo-66 on neurite outgrowth in differentiated PC12 cells and CGCs by blocking the Nogo-66-induced activation of Rho-associated coiled coil-containing protein kinase (ROCK), collapsin response mediator protein 2 (CRMP2) and myosin light chain (MLC). Taken together, the small molecule NgR1 antagonist peptide NAP2 (MW: 815.98Da) has a potential ability in crossing blood brain barrier and will be a promising therapeutic agent for the treatment of spinal cord injury and neurodegenerative diseases. PMID:26711806

  6. Potent Antagonistic Activity of Egyptian Lactobacillus plantarum against multiresistant and Virulent Food-associated Pathogens

    Directory of Open Access Journals (Sweden)

    Lamiaa eAl-Madboly

    2015-05-01

    Full Text Available Recent years have showed a growing interest to replace the administration of antibiotics with the application of probiotics. The aim of our investigation was to screen for promising strains with broad antimicrobial activity and also more resistant to the challenges met in the gastrointestinal tract. In our study, only 32 out of the 50 (64% probiotic isolates showed antagonistic activity against certain major extensively and pandrug-resistant Gram-positive and -negative food-borne pathogens. Fifteen L. plantarum isolates had a broad antibacterial spectrum. Among these isolates, only five presented potent antibacterial activity relative to previous studies. The recorded inhibition zone diameter ranged from 25 to 44 mm. Pronounced cell-free supernatant activities (6400-25600 AU/ml were commonly detected at the end of the logarithmic phase at 37°C. A marked increase in the range of activity (12800-51200 AU/ml was recorded after the addition of 0.9% NaCl to the media. Moreover, subjecting these isolates to different stressors, including high temperature, low pH, and different concentrations of bile and NaCl, revealed different responses, and only two out of the five L. plantarum isolates showed marked resistance to all of the stress factors. This study highlights the intense and broad antagonistic activity induced by L. plantarum against various food associated pathogens, and their ability to resist different stressors suggests that they can be used in the food and pharmaceutical industry.

  7. Isolation, identification, and optimal cultivation of a marine bacterium antagonistic to Magnaporthe grisea.

    Science.gov (United States)

    Zhang, W J; Guo, P; Liu, M; Yang, B L; Wang, J H; Jiang, J

    2016-01-01

    In this paper, a plate confrontation method was used to isolate bacteria antagonistic to the rice blast fungus Magnaporthe grisea from samples collected from China's Dalian Bay. The antagonist strain LM-031 was obtained. We studied this strain's morphological, physiological and biochemical characteristics and analyzed its 16S rDNA sequence. We compared the effects of different culture conditions (type of media, carbon and nitrogen source, incubation temperature and time, and initial pH value) on the inhibitory effect against M. grisea. Strain LM-031 was preliminarily identified as Bacillus pumilus and was found to strongly inhibit M. grisea, especially when grown on BPY medium at an initial pH 7 for 72 h at 30°C. The optimum carbon and nitrogen sources for growth were lactose and peptone, respectively. The most suitable carbon and nitrogen sources for production of active substances were glucose and NH4Cl, respectively. Our results show that development and utilization of B. pumilus LM-031 has great potential for biological control of M. grisea. PMID:27323038

  8. New metabolically stabilized analogues of lysophosphatidic acid: agonists, antagonists and enzyme inhibitors.

    Science.gov (United States)

    Prestwich, G D; Xu, Y; Qian, L; Gajewiak, J; Jiang, G

    2005-12-01

    Lysophosphatidic acid (LPA) is a metabolically labile natural phospholipid with a bewildering array of physiological effects. We describe herein a variety of long-lived receptor-specific agonists and antagonists for LPA receptors. Several LPA and PA (phosphatidic acid) analogues also inhibit LPP (lipid phosphate phosphatase). The sn-1 or sn-2 hydroxy groups have been replaced by fluorine, difluoromethyl, difluoroethyl, O-methyl or O-hydroxyethoxy groups to give non-migrating LPA analogues that resist acyltransferases. Alkyl ether replacement of acyl esters produced lipase and acyltransferase-resistant analogues. Replacement of the bridging oxygen in the monophosphate by an alpha-monofluoromethylene-, alpha-bromomethylene- or alpha,alpha-difluoromethylenephosphonate gave phosphatase-resistant analogues. Phosphorothioate analogues with O-acyl and O-alkyl chains are potent, long-lived agonists for LPA1 and LPA3 receptors. Most recently, we have (i) prepared stabilized O-alkyl analogues of lysobisphosphatidic acid, (ii) explored the structure-activity relationship of stabilized cyclic LPA analogues and (iii) synthesized neutral head group trifluoromethylsulphonamide analogues of LPA. Through collaborative studies, we have collected data for these stabilized analogues as selective LPA receptor (ant)agonists, LPP inhibitors, TREK (transmembrane calcium channel) K+ channel agonists, activators of the nuclear transcription factor PPAR-gamma (peroxisome-proliferator-activated receptor-gamma), promoters of cell motility and survival, and radioprotectants for human B-cells. PMID:16246118

  9. Preliminary Study on Isolating Antagonistic Bacteria f rom Soil and Antagonistic Activity Against Plant Pathogens%土壤拮抗细菌的分离与抗植物病原真菌活性初步研究

    Institute of Scientific and Technical Information of China (English)

    刘春来; 李新民; 王爽; 夏吉星; 杨帆; 刘宇; 苏宝华

    2015-01-01

    为了分离筛选出土壤中对植物病原真菌具有拮抗作用的细菌,以4种土传病害病原菌为诱导菌株,采用土壤颗粒撒布法,从不同生态区农田土壤样本中分离得到55株拮抗细菌菌株。测定了部分拮抗菌株及发酵滤液对植物病原菌的拮抗作用。结果表明:分离获得的细菌菌株对病原真菌均表现出一定程度的抑制作用,其中对菜豆根腐病菌(Fusarium solani)、小麦赤霉病菌(Fusarium graminearum)、番茄枯萎病菌(Fusarium oxysporum)菌丝抑制率达60%以上的拮抗菌株,分别有1、12和8株。9株拮抗菌发酵滤液对大豆菌核病菌(Sclerotinia sclerotiorum)、水稻稻瘟病菌(Pyricularia grisea)、玉米大斑病菌(Setosphaeria turcica)、小麦根腐病菌(Bipolaris sorokiniana)、水稻恶苗病菌(Fusarium moniliforme)和马铃薯早疫病菌(Alternaria so‐lani)6种植物病原菌表现出较高的抑菌效果,其中YS7菌株发酵产物对玉米大斑病菌、小麦根腐病菌、水稻恶苗病菌均表现较强的抑菌活性,对玉米大斑病菌抑菌圈直径最大达到了56.2 mm。从抗菌谱上看,27株拮抗菌株代谢产物对4种以上的拮抗对象表现有抑菌活性,表明拮抗菌株代谢产物具有较为广谱的抑菌效果。%In order to screen antagonistic bacteria in soil for plant pathogens bio‐control .55 antagonistic bacteria strains were isolated from soil samples in different ecological regions by the soil sprinkling method baited with 4 soil borne diseases .Part of antagonistic bacteria strains were evaluated for the antagonistic activity against plant pathogens .The result showed that more than 60% mycelial inhibition against Fusarium solani ,Fusarium graminearum ,Fusarium oxysporum were 1 ,12 and 8 stains ,respectively .Fermentation filtrate of 9 antagonis‐tic bacteria strains showed higher inhibition effect for Sclerotinia sclerotiorum ,Pyricularia grisea

  10. Control of Wilt and Blight Diseases of Cumin through Antagonistic Fungi under in Vitro and Field Conditions

    Directory of Open Access Journals (Sweden)

    P. DEEPAK

    2008-08-01

    Full Text Available The experiment was carried out to assess their possible use as bio-agents for several antagonistic fungi on growth of two cumin fungal pathogens under in vitro and field conditions. Under in vitro conditions maximum inhibition (82.86% of radial growth of Fusarium oxysporum f. sp. cumini was observed with the treatment of Trichoderma harzianum strain I, whereas maximum inhibition (85.45% of the mycelial growth of Alternaria burnsii was observed in the presence of Trichoderma harzianum strain II. The antagonists who showed maximum inhibition of the pathogen in laboratory conditions were applied in field conditions as soil treatment/seed treatment or as foliar spray. The incidence of wilt disease was found to be lowest (PDI 27.40% when soil was treated with Trichoderma harzianium strain I at the rate of 24g / 6m2 (weight of fungus with sorghum seeds. Minimum blight disease incidence was observed when T. harzianum strain II was applied to the soil at the rate of 24g / 6m2 (36.15% or when 10% spore suspension of T. harzianum strain II was applied as seed treatment at the time of sowing and as spray at the time of flowering (PDI 35.10%. Thus treatments of Trichoderma harzianum strain I for wilt and Trichoderma harzianum strain II for blight diseases of cumin under both the conditions @ 24g / 6m2 or 40kg / ha seems promising for sustainable management of crop diseases.

  11. Mediation of endothelin-1-induced inhibition of platelet aggregation via the ETB receptor.

    OpenAIRE

    McMurdo, L.; Lidbury, P. S.; Thiemermann, C.; Vane, J. R.

    1993-01-01

    1. The effects of FR139317 (ETA antagonist) or PD145065 (non-selective ETA/ETB antagonist) on endothelin-1 (ET-1)-induced changes in blood pressure and inhibition of ex vivo platelet aggregation were investigated in the anaesthetized rabbit. 2. ET-1 (1 nmol kg-1, i.a. bolus) caused a sustained increase in mean arterial pressure (MAP) (peak increase 47 +/- 5 mmHg, n = 8). Intravenous infusion of FR139317 at 0.2 (n = 4) or 0.6 mg kg-1 min-1 (n = 4) inhibited the ET-1 pressor response by 83 or 8...

  12. P2X antagonists inhibit styryl dye entry into hair cells

    OpenAIRE

    Crumling, Mark A.; Tong, Mingjie; Aschenbach, Krista L.; Liu, Li Qian; Pipitone, Christine M.; Duncan, R Keith

    2009-01-01

    The styryl pyridinium dyes, FM1-43 and AM1-43, are fluorescent molecules that can permeate the mechanotransduction channels of hair cells, the sensory receptors of the inner ear. When these dyes are applied to hair cells, they enter the cytoplasm rapidly, resulting in a readily detectable increase in intracellular fluorescence that is often used as a molecular indication of mechanotransduction channel function. However, such dyes can also permeate the ATP receptor, P2X2. Therefore, we explore...

  13. Increased central facilitation of antagonist reciprocal inhibition at the onset of dorsiflexion following explosive strength training

    DEFF Research Database (Denmark)

    Geertsen, Svend Sparre; Jensen, Jesper Lundbye; Nielsen, Jens Bo

    2008-01-01

    measured as the depression of the soleus H reflex following conditioning stimulation of the peroneal nerve (1.1 x motor threshold) at an interval of 2-3 ms. At the onset of dorsiflexion the amount of DRI measured relative to DRI at rest increased significantly from 6% before the training to 22% after the...... plantar flexors at the onset of dorsiflexion is larger the quicker the movement, it was hypothesized that DRI may be increased when subjects are trained to perform dorsiflexion movements as quickly as possible For this purpose, 14 healthy human subjects participated in explosive strength training of the...... ankle dorsiflexor muscles 3 times a week for 4 wk. Test sessions were conducted before, shortly after, and 2 wk after the training period. The rate of torque development measured at 30, 50, 100, and 200 ms after onset of voluntary explosive isometric dorsiflexion increased by 24-33% (P < 0.05). DRI was...

  14. Novel synthetic antagonists of canonical Wnt signaling inhibit colorectal cancer cell growth

    Czech Academy of Sciences Publication Activity Database

    Waaler, J.; Machoň, Ondřej; von Kries, J.P.; Wilson, S.R.; Lundenes, E.; Wedlich, D.; Gradl, D.; Paulsen, J.E.; Machoňová, O.; Dembinski, J.L.; Dinh, H.; Krauss, S.

    2011-01-01

    Roč. 71, č. 1 (2011), s. 197-205. ISSN 0008-5472 Institutional research plan: CEZ:AV0Z50520514 Keywords : beta catenin * cyclooxygenase-2 inhibitor * transcription Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 7.856, year: 2011

  15. Biological Control of Rhizoctonia solani, the Causal Agent of Rice Sheath Blight by Antagonistics Bacteria in Greenhouse and Field Conditions

    Directory of Open Access Journals (Sweden)

    Mostapha Niknejad Kazempour

    2004-01-01

    Full Text Available Pseudomonas fluorescens isolates that inhibited growth of Rhizoctonia solani Kühn, the rice sheath blight pathogen were collected the rhizosplane and surrounding soil of healthy and rice sheath blight disease in farming of the Guilan province, Iran. Two hundred eighty eight isolates tested and among them only antagonistic ability of 8 isolates were demonstrated by using the dual culture method. According to the results of biochemical and morphological trials all isolates were identified as P. fluorescens biovar 3. By determining the effects of volatile metabolites, secretion of extracellular and antibiotics of these isolates inhibited mycelial growth of R. solani in vitro. All P. fluorescens isolates produced siderophore on King`s medium B, inhibited the mycelial growth of the R. solani. Antagonistics isolates reduced the germination and cause the lysis of sclerotia of R. solani. In greenhouse conditions antagonistic isolates were used by seed coating, soil drenching and foliar spray. Statistical analysis of data indicated that there existed significant differences between seed, soil and plant treatments. All of the isolates in seed coating are more effective. In the field conditions foliar spray of isolate B41 mixed with benlate were applied. The disease intensity in B41 isolate for seed coating, soil drenching and seed coating + foliar spray were 10.5, 11.75 and 18.75%, respectively, while the control plants showed 52% disease intensity. These results suggest that the P. fluorescens isolates studied have an excellent potential to be used as biocontrol agents of R. solani in rice at the field conditions.

  16. Isolation and Characterization of Trichoderma spp. for Antagonistic Activity Against Root Rot and Foliar Pathogens.

    Science.gov (United States)

    Kumar, Krishna; Amaresan, N; Bhagat, S; Madhuri, K; Srivastava, R C

    2012-06-01

    Trichoderma, soil-borne filamentous fungi, are capable of parasitising several plant pathogenic fungi. Twelve isolates of Trichoderma spp. isolated from different locations of South Andaman were characterized for their cultural, morphological and antagonistic activity against soil borne and foliar borne pathogens. The sequencing of these isolates showed seven different species. The isolates revealed differential reaction patterns against the test pathogens viz., Sclerotium rolfsii, Colletotrichum gloeosporioides and C. capsici. However, the isolates, TND1, TWN1, TWC1, TGD1 and TSD1 were most effective in percentage inhibition of mycelial growth of test pathogens. Significant chitinase and β-1,3-glucanase activities of all Trichoderma isolates has been recorded in growth medium. T. viride was found with highest chitinase whereas T. harzianum was recorded with highest β-1,3-glucanase activities. PMID:23729873

  17. The angiotensin II type 1 receptor antagonist Losartan binds and activates bradykinin B2 receptor signaling

    DEFF Research Database (Denmark)

    Bonde, Marie Mi; Olsen, Kristine Boisen; Erikstrup, Niels;

    2011-01-01

    The angiotensin II type 1 receptor (AT1R) blocker (ARB) Losartan has cardioprotective effects during ischemia-reperfusion injury and inhibits reperfusion arrhythmias -effects that go beyond the benefits of lowering blood pressure. The renin-angiotensin and kallikrein-kinin systems are intricately...... connected and some of the cardioprotective effects of Losartan are abolished by blocking the bradykinin B2 receptor (B2R) signaling. In this study, we investigated the ability of six clinically available ARBs to specifically bind and activate the B2R. First, we investigated their ability to activate...... phosphoinositide (PI) hydrolysis in COS-7 cells transiently expressing the B2R. We found that only Losartan activated the B2R, working as a partial agonist compared to the endogenous ligand bradykinin. This effect was blocked by the B2R antagonist HOE 140. A competitive binding analysis revealed that Losartan does...

  18. P2Y12-ADP receptor antagonists: Days of future and past.

    Science.gov (United States)

    Laine, Marc; Paganelli, Franck; Bonello, Laurent

    2016-05-26

    Antiplatelet therapy is the cornerstone of the therapeutic arsenal in coronary artery disease. Thanks to a better understanding in physiology, pharmacology and pharmacogenomics huge progress were made in the field of platelet reactivity inhibition thus allowing the expansion of percutaneous coronary intervention. Stent implantation requires the combination of two antiplatelet agents acting in a synergistic way. Asprin inhibit the cyclo-oxygenase pathway of platelet activation while clopidogrel is a P2Y12 adenosine diphosphate (ADP)-receptor antagonist. This dual antiplatelet therapy has dramatically improved the prognosis of stented patients. However, due to pharmacological limitations of clopidogrel (interindividual variability in its biological efficacy, slow onset of action, mild platelet reactivity inhibition) ischemic recurrences remained high following stent implantation especially in acute coronary syndrome patients. Thus, more potent P2Y12-ADP receptor inhibitors were developped including prasugrel, ticagrelor and more recently cangrelor to overcome these pitfalls. These new agents reduced the rate of thrombotic events in acute coronary syndrome patients at the cost of an increased bleeding risk. The abundance in antiplatelet agents allow us to tailor our strategy based on the thrombotic/bleeding profile of each patient. Recently, the ACCOAST trial cast a doubt on the benefit of pre treatment in non-ST segment elevation acute coronary syndrome. The aim of the present review is to summarize the results of the main studies dealing with antiplatelet therapy in stented/acute coronary syndromes patients. PMID:27231519

  19. P2Y12-ADP receptor antagonists: Days of future and past

    Science.gov (United States)

    Laine, Marc; Paganelli, Franck; Bonello, Laurent

    2016-01-01

    Antiplatelet therapy is the cornerstone of the therapeutic arsenal in coronary artery disease. Thanks to a better understanding in physiology, pharmacology and pharmacogenomics huge progress were made in the field of platelet reactivity inhibition thus allowing the expansion of percutaneous coronary intervention. Stent implantation requires the combination of two antiplatelet agents acting in a synergistic way. Asprin inhibit the cyclo-oxygenase pathway of platelet activation while clopidogrel is a P2Y12 adenosine diphosphate (ADP)-receptor antagonist. This dual antiplatelet therapy has dramatically improved the prognosis of stented patients. However, due to pharmacological limitations of clopidogrel (interindividual variability in its biological efficacy, slow onset of action, mild platelet reactivity inhibition) ischemic recurrences remained high following stent implantation especially in acute coronary syndrome patients. Thus, more potent P2Y12-ADP receptor inhibitors were developped including prasugrel, ticagrelor and more recently cangrelor to overcome these pitfalls. These new agents reduced the rate of thrombotic events in acute coronary syndrome patients at the cost of an increased bleeding risk. The abundance in antiplatelet agents allow us to tailor our strategy based on the thrombotic/bleeding profile of each patient. Recently, the ACCOAST trial cast a doubt on the benefit of pre treatment in non-ST segment elevation acute coronary syndrome. The aim of the present review is to summarize the results of the main studies dealing with antiplatelet therapy in stented/acute coronary syndromes patients. PMID:27231519

  20. Leukotriene receptor antagonists--risks and benefits for use in paediatric asthma.

    Science.gov (United States)

    Spahr, Jonathan E; Krawiec, Marzena E

    2004-05-01

    Leukotrienes (LTs) are important mediators of the pathophysiology of asthma, specifically, bronchoconstriction, airway inflammation and oedema and mucus hypersecretion. The LT receptor antagonists (LTRAs) inhibit these potent effects by selectively blocking the cysteinyl LT 1 receptor. These are the first novel therapies for asthma since the introduction of inhaled corticosteroids (ICS) in 1972. Unlike generalised inhibition of airway inflammation by ICS, the LTRAs target inhibition of specific mediators. In general, paediatric data concerning these agents remain quite limited. However, they have demonstrated efficacy against allergen- and exercise-induced bronchospasm in both adults and children. Recently, their potential role for the treatment of viral-induced wheeze in young children has been explored. In multiple, placebo-controlled trials, the LTRAs have demonstrated efficacy for the treatment of mild persistent asthma, additive benefit in the management of symptomatic moderate asthmatics on maintenance ICS and evidence of significant steroid-sparing. Findings from these clinical trials and real-world experience support the use of the LTRAs as controller agents for persistent asthma. Based on their excellent safety profiles, tolerance and ease of administration (including once daily dosing with montelukast), this drug class may offer several important features for use as controller therapy, particularly in asthmatic children as young as 1 year of age, however, this must continue to be reviewed as new paediatric data become available. PMID:15155146

  1. Serotonin antagonists fail to alter MDMA self-administration in rats.

    Science.gov (United States)

    Schenk, Susan; Foote, Jason; Aronsen, Dane; Bukholt, Natasha; Highgate, Quenten; Van de Wetering, Ross; Webster, Jeremy

    2016-09-01

    Acute exposure to ±3,4-methylenedioxymethamphetamine (MDMA) preferentially increases release of serotonin (5-HT), and a role of 5-HT in many of the behavioral effects of acute exposure to MDMA has been demonstrated. A role of 5-HT in MDMA self-administration in rats has not, however, been adequately determined. Therefore, the present study measured the effect of pharmacological manipulation of some 5-HT receptor subtypes on self-administration of MDMA. Rats received extensive experience with self-administered MDMA prior to tests with 5-HT ligands. Doses of the 5-HT1A antagonist, WAY 100635 (0.1-1.0mg/kg), 5-HT1B antagonist, GR 127935 (1.0-3.0mg/kg), and the 5-HT2A antagonist, ketanserin (1.0-3.0mg/kg) that have previously been shown to decrease self-administration of other psychostimulants and that decreased MDMA-produced hyperactivity in the present study did not alter MDMA self-administration. Experimenter-administered injections of MDMA (10.0mg/kg, ip) reinstated extinguished drug-taking behavior, but this also was not decreased by any of the antagonists. In contrast, both WAY 100635 and ketanserin, but not GR 127935, decreased cocaine-produced drug seeking in rats that had been trained to self-administered cocaine. The 5-HT1A agonist, 8-OH-DPAT (0.1-1.0mg/kg), but not the 5-HT1B/1A agonist, RU 24969 (0.3-3.0mg/kg), decreased drug-seeking produced by the reintroduction of a light stimulus that had been paired with self-administered MDMA infusions. These findings suggest a limited role of activation of 5-HT1A, 5-HT1B or 5-HT2 receptor mechanisms in MDMA self-administration or in MDMA-produced drug-seeking following extinction. The data suggest, however, that 5-HT1A agonists inhibit cue-induced drug-seeking following extinction of MDMA self-administration and might, therefore, be useful adjuncts to therapies to limit relapse to MDMA use. PMID:27264435

  2. First Irish birth following IVF therapy using antagonist protocol.

    LENUS (Irish Health Repository)

    Mocanu, E V

    2012-02-01

    BACKGROUND: During in vitro fertilization (IVF), the prevention of a premature LH surge was traditionally achieved using a gonadotrophin releasing hormone agonist (GnRH-a), and more recently, a GnRH antagonist. AIMS: We report a case of a 37 year old treated using the GnRH antagonist in a second completed cycle of IVF. METHODS: IVF was performed for primary infertility of 5-year duration due to frozen pelvis secondary to endometriosis. RESULTS: Following controlled ovarian hyperstimulation, oocyte recovery and fertilization, cleavage and transfer of two zygotes, a pregnancy established. A twin gestation was diagnosed at 7-weeks scan and pregnancy ended with the delivery of twin girls by emergency caesarean section. CONCLUSION: This is a first report of a delivery following IVF using the antagonist protocol in Ireland. Such therapy is patient friendly and its use should be introduced on a larger scale in clinical practice.

  3. ANTAGONISTIC BACTERIA AGAINST SCHIZOPHYLLUM COMMUNE FR. IN PENINSULAR MALAYSIA

    Directory of Open Access Journals (Sweden)

    ANTARJO DIKIN

    2006-01-01

    Full Text Available Schizophyllum commune Fr., is one of the important fungi, causes brown germ and seed rot of oil palm. Biodiversity of antagonistic bacteria from oil palm plantations in Peninsular Malaysia is expected to support in development of biopesticide. Isolation with liquid assay and screening antagonistic bacteria using dual culture assay were carried out in the bioexploration. A total of 265 bacterial isolates from plant parts of oil palm screened 52 antagonistic bacterial isolates against 5. commune. Bacterial isolates were identified by using Biolog* Identification System i.e. Bacillus macroccanus, B. thermoglucosidasius, Burkholderia cepacia, B. gladioli, B. multivorans, B pyrrocinia, B. spinosa, Corynebacterium agropyri, C. misitidis, Enterobacter aerogenes, Microbacterium testaceum, Pseudomonas aeruginosa, P. citronellolis, Rhodococcus rhodochrous, Serratia ficaria, Serratia sp., S. marcescens, Staphylococcus sciuri, Sternotrophomonas maltophilia.

  4. Identification of a series of 4-[3-(quinolin-2-yl)-1,2,4-oxadiazol-5-yl]piperazinyl ureas as potent smoothened antagonist hedgehog pathway inhibitors.

    Science.gov (United States)

    Ontoria, Jesus M; Bufi, Laura Llauger; Torrisi, Caterina; Bresciani, Alberto; Giomini, Claudia; Rowley, Michael; Serafini, Sergio; Bin, Hu; Hao, Wu; Steinkühler, Christian; Jones, Philip

    2011-09-15

    The Hedgehog (Hh-) signalling pathway is a key developmental pathway and there is a growing body of evidence showing that this pathway is aberrantly reactivated in a number of human tumors. Novel agents capable of inhibiting this pathway are sought, and an entirely novel series of smoothened (Smo) antagonists capable of inhibiting the pathway have been identified through uHTS screening. Extensive exploration of the scaffold identified the key functionalities necessary for potency, enabling potent nanomolar Smo antagonists like 91 and 94 to be developed. Optimization resulted in the most advanced compounds displaying low serum shift, clean off-targets profile, and moderate clearance in both rats and dogs. These compounds are valuable tools with which to probe the biology of the Hh-pathway. PMID:21803580

  5. Antagonistic effects of a covalently dimerized insulin derivative on insulin receptors in 3T3-L1 adipocytes.

    OpenAIRE

    Weiland, M; Brandenburg, C; Brandenburg, D.; Joost, H. G.

    1990-01-01

    In the present study we describe the antagonistic effects of the covalently dimerized insulin derivative B29,B29'-suberoyl-insulin on insulin receptors in 3T3-L1 mouse cells. In differentiated 3T3-L1 adipocytes, the derivative fully inhibits binding of 125I-labeled insulin to its receptor with about the same affinity as unlabeled insulin. In contrast, the dimerized derivative only partially (approximately 20%) mimics insulin's effects on glucose transport and DNA synthesis in the absence of i...

  6. Oxytocin antagonists for the management of preterm birth: a review.

    Science.gov (United States)

    Usta, Ihab M; Khalil, Ali; Nassar, Anwar H

    2011-06-01

    Preterm birth, the leading cause of neonatal morbidity and mortality, is estimated at incidence of 12.7% of all births, which has not decreased over the last four decades despite intensive antenatal care programs aimed at high-risk groups, the widespread use of tocolytics, and a series of other preventive and therapeutic interventions. Oxytocin antagonists, namely atosiban, represent an appealing choice that seems to be effective with apparently fewer side effects than the traditional tocolytics. This article reviews the available literature on the pharmacokinetics, mode of administration, and clinical utility of oxytocin antagonists for acute and maintenance tocolysis with special emphasis on its safety profile. PMID:21170825

  7. Pharmacokinetic interactions with calcium channel antagonists (Part II).

    Science.gov (United States)

    Schlanz, K D; Myre, S A; Bottorff, M B

    1991-12-01

    Since calcium channel antagonists are a diverse class of drugs frequently administered in combination with other agents, the potential for clinically significant pharmacokinetic drug interactions exists. These interactions occur most frequently via altered hepatic blood flow and impaired hepatic enzyme activity. Part I of the article, which appeared in the previous issue of the Journal, dealt with interactions between calcium antagonists and marker compounds, theophylline, midazolam, lithium, doxorubicin, oral hypoglycaemics and cardiac drugs. Part II examines interactions with cyclosporin, anaesthetics, carbamazepine and cardiovascular agents. PMID:1782739

  8. Gliclazide directly inhibits arginine-induced glucagon release

    DEFF Research Database (Denmark)

    Cejvan, Kenan; Coy, David H; Holst, Jens Juul;

    2002-01-01

    Arginine-stimulated insulin and somatostatin release is enhanced by the sulfonylurea gliclazide. In contrast, gliclazide inhibits the glucagon response. The aim of the present study was to investigate whether this inhibition of glucagon release was mediated by a direct suppressive effect of...... specific antagonist of type 2 somatostatin receptor, DC-41-33 (2 micro mol/l), which fully antagonizes the suppressive somatostatin effect on rat A cells. Gliclazide (30 micro mol/l) inhibited glucagon release by 54% in the perfusion experiments, whereas the somatostatin response was nearly abolished. In...... islet perifusions with DC-41-33, arginine-induced glucagon release was inhibited by 66%. We therefore concluded that gliclazide inhibits glucagon release by a direct action on the pancreatic A cell....

  9. Pancreatic polypepetide inhibits pancreatic enzyme secretion via a cholinergic pathway

    International Nuclear Information System (INIS)

    In rat pancreatic slices, rat pancreatic polypeptide (PP) or C-terminal hexapeptide of PP [PP-(31-36)] inhibited potassium-stimulated amylase release in a dose-dependent manner. The inhibition was unaffected by addition of hexamethonium but blocked by atropine. In contrast, PP-(31-36) did not have any effect on acetylcholine- or cholecystokinin octapeptide-stimulated amylase release. In addition, when pancreatic slices were incubated with [3H]choline, PP-(31-36) inhibited the potassium-evoked release of synthesized [3H]acetylcholine in a dose-dependent manner. The inhibitory action of PP was unaffected by adrenergic, dopaminergic, or opioid receptor antagonists. Thus PP inhibits pancreatic enzyme secretion via presynaptic modulation of acetylcholine release. This newly identified pathway provides a novel mechanism for hormonal inhibition of pancreatic enzyme secretion via modulation of the classic neurotransmitter function

  10. Astressin B, a Nonselective Corticotropin-Releasing Hormone Receptor Antagonist, Prevents the Inhibitory Effect of Ghrelin on Luteinizing Hormone Pulse Frequency in the Ovariectomized Rhesus Monkey

    OpenAIRE

    Vulliémoz, Nicolas R; Xiao, Ennian; Xia-Zhang, Linna; Rivier, Jean; Ferin, Michel

    2007-01-01

    Administration of ghrelin, a key peptide in the regulation of energy homeostasis, has been shown to decrease LH pulse frequency while concomitantly elevating cortisol levels. Because increased endogenous CRH release in stress is associated with an inhibition of reproductive function, we have tested here whether the pulsatile LH decrease after ghrelin may reflect an activated hypothalamic-pituitary-adrenal axis and be prevented by a CRH antagonist. After a 3-h baseline LH pulse frequency monit...

  11. Effects of 5-HT uptake inhibitors, agonists and antagonists on the burying of harmless objects by mice; a putative test for anxiolytic agents.

    OpenAIRE

    Njung'e, K.; Handley, S. L.

    1991-01-01

    1. The effects of 5-hydroxytryptamine (5-HT) uptake inhibitors, agonists and antagonists have been evaluated on mouse marble-burying behaviour, a putative test for anxiolytic agents. The high levels of locomotor activity occurring on first exposure to a circular runway (runway were used as a separate test of non-specific drug effects. 2. Fluvoxamine, zimeldine, indalpine and citalopram dose-dependently inhibited burying without affecting runway activity. 5-Hydroxytryptophan (5-HTP, with carbi...

  12. Control of Anthracnose Caused by Colletotrichum musae on Curcuma alismatifolia Gagnep. Using Antagonistic Bacillus spp.

    OpenAIRE

    Supuk Mahadtanapuk; Mondhon Sanguansermsri; Robert W. Cutler; Vicha Sardsud; Somboon Anuntalabhochai

    2007-01-01

    Over 400 bacterial strains, isolated from leaf surfaces of Curcuma alismatifolia Gagnep. and hot springs in the Chiang Mai province of northern Thailand, were screened in vitro for antagonistic activity against Colletotrichum musae, an anthracnose fungus. Three isolates provided greater than 75% growth inhibition of the fungus in vitro and were identified as Bacillus licheniformis, B. amyloliquefaciens and B. subtilis. Using in planta tests, B. amyloliquefaciens and B. subtilis were shown to ...

  13. Gemfibrozil, a lipid-lowering drug, upregulates interleukin-1 receptor antagonist in mouse cortical neurons: Implications for neuronal self-defense

    OpenAIRE

    Corbett, Grant T.; Roy, Avik; Pahan, Kalipada

    2012-01-01

    Chronic inflammation is becoming a hallmark of several neurodegenerative disorders and accordingly, interleukin-1 beta (IL-1β), a proinflammatory cytokine, is implicated in the pathogenesis of neurodegenerative diseases. While IL-1β binds to its high-affinity receptor, interleukin-1 receptor (IL-1R), and upregulates proinflammatory signaling pathways, interleukin-1 receptor antagonist (IL-1Ra) adheres to the same receptor and inhibits proinflammatory cell signaling. Therefore, upregulation of...

  14. Evaluation of the Endothelin Receptor Antagonists Ambrisentan, Bosentan, Macitentan, and Sitaxsentan as Hepatobiliary Transporter Inhibitors and Substrates in Sandwich-Cultured Human Hepatocytes

    OpenAIRE

    Lepist, Eve-Irene; Gillies, Hunter; Smith, William; Hao, Jia; Hubert, Cassandra; St. Claire, Robert L.; Brouwer, Kenneth R.; Ray, Adrian S.

    2014-01-01

    Background Inhibition of the transporter-mediated hepatobiliary elimination of bile salts is a putative mechanism for liver toxicity observed with some endothelin receptor antagonists (ERAs). Methods Sandwich-cultured human hepatocytes were used to study the hepatobiliary distribution and accumulation of exogenous taurocholate, ERAs and endogenous bile acids. The molecular mechanisms for findings in hepatocytes or clinical observations were further explored using either vesicular assays (effl...

  15. EVALUATION OF PHOSPHATE SOLUBILIZING MICROORGANISMS (PSMs FROM RHIZOSPHERE SOIL OF DIFFERENT CROP PLANTS AND ITS ANTAGONISTIC ACTIVITY

    Directory of Open Access Journals (Sweden)

    Samikan Krishnakumar

    2014-04-01

    Full Text Available Indigenous rhizosphere soil samples were collected during study period (October 2011 – March 2012 of different crop plant from Thiruvannamalai District, Tamilnadu, India for the enumeration of Phosphate solubilizing microorganisms (PSMs. Efficient phosphate solubilizing bacteria, fungi and heterotrophic bacteria were enumerated. Maximum heterotrophic bacterial populations (19.4 X105, phosphate solubilizing bacteria (4.7 X 105 were recorded in the month of February and phosphate solubilizing fungi (3.9 X 102 were documented in the month of December in rhizosphere soil of ground nut. Minimum bacterial populations (14.3 X 105 were observed in rhizosphere soil of chilli in the month of March. Lowest phosphate solubilizing bacteria (1.2 X105 and phosphate solubilzing fungi (1.2 X 102 were observed in rhizosphere soil of paddy during the month of October. Phosphate solubilizing bacteria Pseudomonassp. - BS1, Bacillus sp. – BS2, Micrococcus sp. – BS3 and fungi Aspergillus sp. – FS1, Penicillium sp. – FS2.and Trichoderma sp. – FS3 were identified. Pseudomonas sp. - BS1. exhibited maximum solubilizing efficiency (SE and solubilizing index (SI of 300.0 and 4.0 respectively. In fungi Aspergillus sp. – FS1 showed a maximum solubilizing efficiency (SE and solubilizing index(SI of 283.3 and 3.8 respectively. Antagonistic activity of P-solubilizing Pseudomonassp. - BS1 was deliberated against selected fungal plant pathogens. Among pathogens studied Aspergillus sp. showed a maximum inhibition activity (16 mm and minimum activity (12 mm was observed against Fusarium sp. Moreover inhibition efficiency (IE and inhibition index (II of Pseudomonas sp. - BS1. also calculated base on the antagonistic activity. Aspergillus sp. exhibited highest inhibition efficiency and inhibition index of 166.6 and 3.6 respectively.

  16. Vipegitide: a folded peptidomimetic partial antagonist of α2β1 integrin with antiplatelet aggregation activity

    Directory of Open Access Journals (Sweden)

    Momic T

    2015-01-01

    Full Text Available Tatjana Momic,1 Jehoshua Katzhendler,1 Ela Shai,2 Efrat Noy,3 Hanoch Senderowitz,3 Johannes A Eble,4 Cezary Marcinkiewicz,5 David Varon,2 Philip Lazarovici11School of Pharmacy Institute for Drug Research, Faculty of Medicine, The Hebrew University of Jerusalem, 2Department of Hematology, Coagulation Unit, Hadassah-Hebrew University Medical Center, Jerusalem, Israel; 3Department of Chemistry, Bar-Ilan University, Ramat-Gan, Israel; 4Institute for Physiological Chemistry and Pathobiochemistry, University of Münster, Münster, Germany; 5Department of Bioengineering, College of Engineering, Temple University, Philadelphia, PA, USAAbstract: Linear peptides containing the sequence WKTSRTSHY were used as lead compounds to synthesize a novel peptidomimetic antagonist of α2β1 integrin, with platelet aggregation-inhibiting activity, named Vipegitide. Vipegitide is a 13-amino acid, folded peptidomimetic molecule, containing two α-aminoisobutyric acid residues at positions 6 and 8 and not stable in human serum. Substitution of glycine and tryptophan residues at positions 1 and 2, respectively, with a unit of two polyethylene glycol (PEG molecules yielded peptidomimetic Vipegitide-PEG2, stable in human serum for over 3 hours. Vipegitide and Vipegitide-PEG2 showed high potency (7×10-10 M and 1.5×10-10 M, respectively and intermediate efficacy (40% and 35%, respectively as well as selectivity toward α2 integrin in inhibition of adhesion of α1/α2 integrin overexpressing cells toward respective collagens. Interaction of both peptidomimetics with extracellular active domain of α2 integrin was confirmed in cell-free binding assay with recombinant α2 A-domain. Integrin α2β1 receptor is found on the platelet membrane and triggers collagen-induced platelet aggregation. Vipegitide and Vipegitide-PEG2 inhibited α2β1 integrin-mediated adhesion of human and murine platelets under the flow condition, by 50%. They efficiently blocked adenosine diphosphate

  17. Using prepulse inhibition to detect functional D3 receptor antagonism: Effects of WC10 and WC44

    OpenAIRE

    WEBER, Martin; Chang, Wei-li; Durbin, John P.; Park, Paula E.; Luedtke, Robert R.; Mach, Robert H.; Swerdlow, Neal R.

    2009-01-01

    Prepulse inhibition of startle (PPI) is an operational measure of sensorimotor gating that is impaired in schizophrenia. Treatment with mixed dopamine D2/D3 antagonists diminishes schizophrenia symptoms, and opposes dopamine agonist-induced PPI deficits in rats. There are reasons to believe that functional D3 receptor antagonists might offer more favorable therapeutic profiles compared to current antipsychotics. However, D3-related drug discovery is hampered by the absence of assays sensitive...

  18. Meclizine Enhancement of Sensorimotor Gating in Healthy Male Subjects with High Startle Responses and Low Prepulse Inhibition

    OpenAIRE

    Larrauri, José A.; Kelley, Lisalynn D; Jenkins, Mason R; Westman, Eric C; Schmajuk, Nestor A; Rosenthal, M. Zachary; Levin, Edward D.

    2013-01-01

    Histamine H1 receptor systems have been shown in animal studies to have important roles in the reversal of sensorimotor gating deficits, as measured by prepulse inhibition (PPI). H1-antagonist treatment attenuates the PPI impairments caused by either blockade of NMDA glutamate receptors or facilitation of dopamine transmission. The current experiment brought the investigation of H1 effects on sensorimotor gating to human studies. The effects of the histamine H1 antagonist meclizine on the sta...

  19. Reversal of ethanol-seeking behavior by D1 and D2 antagonists in an animal model of relapse: differences in antagonist potency in previously ethanol-dependent versus nondependent rats.

    Science.gov (United States)

    Liu, Xiu; Weiss, Friedbert

    2002-03-01

    Mesocorticolimbic dopamine (DA) transmission has been implicated in the consummatory and, more recently, the incentive-motivational aspect of ethanol's actions. The purpose of this study was to test whether ethanol-seeking behavior induced by an ethanol-associated contextual stimulus is sensitive to antagonism of DA transmission. Male Wistar rats were trained to orally self-administer 10% ethanol and to associate olfactory discriminative stimuli with the availability of ethanol (S(+)) versus nonreward (S(-)). Ethanol-reinforced operant responding then was extinguished by withholding ethanol and the associated S(+). After reaching a predetermined extinction criterion, reinstatement tests were conducted in which the animals were presented noncontingently with only the S(+) or S(-). Exposure to the S(+) but not the S(-) reinstated responding at the previously active lever. The D1 antagonist R(+)-7-chloro-8-hydroxy-3-methyl-1-phenyl-2,3,4,5-tetrahydro-1H-3-benzazepine hydrochloride (SCH23390; 5, 10, 50 microg/kg s.c.) and the D2 antagonist eticlopride (5, 10, 50 microg/kg s.c.) dose dependently decreased the number of S(+)-induced responses and increased response latency. During a second test, conducted in the same rats, 3 weeks after withdrawal from a 12-day ethanol vapor inhalation procedure, the response-reinstating efficacy of the S(+) remained unaltered. However, the potency of both DA antagonists to inhibit the S(+)-induced drug-seeking response was significantly increased. The results confirm that ethanol-related contextual stimuli reliably elicit drug-seeking behavior and suggest that this effect requires activation of DA neurotransmission. The results also indicate that chronic ethanol exposure produces changes in D1 and D2 receptor function that lead to enhanced sensitivity to the behavioral effects of antagonists for these receptors. PMID:11861794

  20. Endothelin A receptor antagonist, atrasentan, attenuates renal and cardiac dysfunction in Dahl salt-hypertensive rats in a blood pressure independent manner.

    Directory of Open Access Journals (Sweden)

    Mohammed A Samad

    Full Text Available Proteinuria is a hallmark of chronic kidney disease (CKD and cardiovascular disease (CVD, and a good predictor of clinical outcome. Selective endothelin A (ETA receptor antagonist used with renin-angiotensin system (RAS inhibitors prevents development of proteinuria in CKD. However, whether the improvement in proteinuria would have beneficial effects on CVD, independent of RAS inhibition, is not well understood. In this study, we investigated whether atrasentan, an ETA receptor antagonist, has renal and cardiovascular effects independent of RAS inhibition. Male Dahl salt sensitive (DSS rats, at six weeks of age, received water with or without different doses of atrasentan and/or enalapril under high salt (HS diet or normal diet (ND for 6 weeks. At the end of 12th week, atrasentan at a moderate dose significantly attenuated proteinuria and serum creatinine without reducing mean arterial pressure (MAP, thereby preventing cardiac hypertrophy and improving cardiac function. ACE inhibitor enalapril at a dose that did not significantly lowered BP, attenuated cardiac hypertrophy while moderately improving cardiac function without reducing proteinuria and serum creatinine level. Nonetheless, combined therapy of atrasentan and enalapril that does not altering BP exerted additional cardioprotective effect. Based on these findings, we conclude that BP independent monotherapy of ETA receptor antagonist attenuates the progression of CKD and significantly mitigates CVD independent of RAS inhibition.

  1. Endothelin A receptor antagonist, atrasentan, attenuates renal and cardiac dysfunction in Dahl salt-hypertensive rats in a blood pressure independent manner.

    Science.gov (United States)

    Samad, Mohammed A; Kim, Ui Kyoung; Kang, Joshua J; Ke, Qingen; Kang, Peter M

    2015-01-01

    Proteinuria is a hallmark of chronic kidney disease (CKD) and cardiovascular disease (CVD), and a good predictor of clinical outcome. Selective endothelin A (ETA) receptor antagonist used with renin-angiotensin system (RAS) inhibitors prevents development of proteinuria in CKD. However, whether the improvement in proteinuria would have beneficial effects on CVD, independent of RAS inhibition, is not well understood. In this study, we investigated whether atrasentan, an ETA receptor antagonist, has renal and cardiovascular effects independent of RAS inhibition. Male Dahl salt sensitive (DSS) rats, at six weeks of age, received water with or without different doses of atrasentan and/or enalapril under high salt (HS) diet or normal diet (ND) for 6 weeks. At the end of 12th week, atrasentan at a moderate dose significantly attenuated proteinuria and serum creatinine without reducing mean arterial pressure (MAP), thereby preventing cardiac hypertrophy and improving cardiac function. ACE inhibitor enalapril at a dose that did not significantly lowered BP, attenuated cardiac hypertrophy while moderately improving cardiac function without reducing proteinuria and serum creatinine level. Nonetheless, combined therapy of atrasentan and enalapril that does not altering BP exerted additional cardioprotective effect. Based on these findings, we conclude that BP independent monotherapy of ETA receptor antagonist attenuates the progression of CKD and significantly mitigates CVD independent of RAS inhibition. PMID:25775254

  2. Synthesis and Structure-Activity Relationships of Amino Acid Conjugates of Cholanic Acid as Antagonists of the EphA2 Receptor

    Directory of Open Access Journals (Sweden)

    Alessio Lodola

    2013-10-01

    Full Text Available The Eph–ephrin system plays a critical role in tumor growth and vascular functions during carcinogenesis. We had previously identified cholanic acid as a competitive and reversible EphA2 antagonist able to disrupt EphA2-ephrinA1 interaction and to inhibit EphA2 activation in prostate cancer cells. Herein, we report the synthesis and biological evaluation of a set of cholanic acid derivatives obtained by conjugation of its carboxyl group with a panel of naturally occurring amino acids with the aim to improve EphA2 receptor inhibition. Structure-activity relationships indicate that conjugation of cholanic acid with linear amino acids of small size leads to effective EphA2 antagonists whereas the introduction of aromatic amino acids reduces the potency in displacement studies. The b-alanine derivative 4 was able to disrupt EphA2-ephrinA1 interaction in the micromolar range and to dose-dependently inhibit EphA2 activation on PC3 cells. These findings may help the design of novel EphA2 antagonists active on cancer cell lines.

  3. Investigation of 3-aryl-pyrimido[5,4-e][1,2,4]triazine-5,7-diones as small molecule antagonists of β-catenin/TCF transcription

    OpenAIRE

    Zeller, Jörg; Turbiak, Anjanette J.; Powelson, Ian A.; Lee, Surin; Sun, Duxin; Hollis Showalter, H. D.; Fearon, Eric R.

    2013-01-01

    Nearly all colorectal cancers (CRCs) and varied subsets of other cancers have somatic mutations leading to β-catenin stabilization and increased β-catenin/TCF transcriptional activity. Inhibition of stabilized β-catenin in CRC cell lines arrests their growth and highlights the potential of this mechanism for novel cancer therapeutics. We have pursued efforts to develop small molecules that inhibit β-catenin/TCF transcriptional activity. We used xanthothricin, a known β-catenin/TCF antagonist ...

  4. Voltage-Gated Calcium Channel Antagonists and Traumatic Brain Injury

    Directory of Open Access Journals (Sweden)

    Bruce Lyeth

    2013-06-01

    Full Text Available Traumatic brain injury (TBI is a leading cause of death and disability in the United States. Despite more than 30 years of research, no pharmacological agents have been identified that improve neurological function following TBI. However, several lines of research described in this review provide support for further development of voltage gated calcium channel (VGCC antagonists as potential therapeutic agents. Following TBI, neurons and astrocytes experience a rapid and sometimes enduring increase in intracellular calcium ([Ca2+]i. These fluxes in [Ca2+]i drive not only apoptotic and necrotic cell death, but also can lead to long-term cell dysfunction in surviving cells. In a limited number of in vitro experiments, both L-type and N-type VGCC antagonists successfully reduced calcium loads as well as neuronal and astrocytic cell death following mechanical injury. In rodent models of TBI, administration of VGCC antagonists reduced cell death and improved cognitive function. It is clear that there is a critical need to find effective therapeutics and rational drug delivery strategies for the management and treatment of TBI, and we believe that further investigation of VGCC antagonists should be pursued before ruling out the possibility of successful translation to the clinic.

  5. Neuroprotection by NMDA receptor antagonists in a variety of neuropathologies.

    Science.gov (United States)

    Palmer, G C

    2001-09-01

    Because of adverse reactions, early efforts to introduce high affinity competitive or use-dependent NMDA receptor antagonists into patients suffering from stroke, head trauma or epilepsy met with failure. Later it was discovered that both low affinity use-dependent NMDA receptor antagonists and compounds with selective affinity for the NR2B receptor subunit met the criteria for safe administration into patients. Furthermore, these low affinity antagonists exhibit significant mechanistic differences from their higher affinity counterparts. Success of the latter is attested to the ability of the following low affinity compounds to be marketed: 1) Cough suppressant-dextromethorphan (available for decades); 2) Parkinson's disease--amantadine, memantine and budipine; 3) Dementia--memantine; and 4) Epilepsy--felbamate. Moreover, Phase III clinical trials are ongoing with remacemide for epilepsy and Huntington's disease and head trauma for HU-211. A host of compounds are or were under evaluation for the possible treatment of stroke, head trauma, hyperalgesia and various neurodegenerative disorders. Despite the fact that other drugs with associated NMDA receptor mechanisms have reached clinical status, this review focuses only on those competitive and use-dependent NMDA receptor antagonists that reached clinical trails. The ensuing discussions link the in vivo pharmacological investigations that led to the success/mistakes/ failures for eventual testing of promising compounds in the clinic. PMID:11554551

  6. Synthesis and evaluation of 18F-labeled PPARγ antagonists

    International Nuclear Information System (INIS)

    Introduction: Peroxisome proliferator-activated receptor gamma (PPARγ) transcriptionally modulates fat metabolism and also plays a role in pathological conditions such as cancer, neurodegenerative disease and inflammation. PPARγ imaging agents are potential tools for investigating these diseases. Methods: Four analogs of GW9662, a PPARγ antagonist, with different fluorine-containing substituents at the para-position of the aniline ring were synthesized and evaluated using two different receptor binding assays for measuring PPARγ affinity. Micro-positron emission tomography (PET) imaging studies were performed in a transgenic mouse model having a heart-specific overexpression of PPARγ. Results: All four analogs were found to have binding affinities that were comparable to or better than the reference antagonist, GW9662, using a scintillation proximity assay (SPA). However, only the chloro-based analogs (compounds 3 and 4) had activity in a whole-cell assay measuring activation of the PPARγ/retinoid X receptor complex. The microPET imaging studies in an MHC-PPARγ transgenic mouse model showed high uptake and PPARγ-specific binding for the irreversible antagonist [18F]3, whereas the corresponding reversible methoxy analog ([18F]5) displayed only nonspecific uptake in heart. Conclusions: The results of this preliminary study show that the irreversible antagonist [18F]3 may represent a novel strategy for imaging PPARγ in vivo with PET.

  7. Reversal strategies for vitamin K antagonists in acute intracerebral hemorrhage

    NARCIS (Netherlands)

    Parry-Jones, Adrian R.; Di Napoli, Mario; Goldstein, Joshua N.; Schreuder, Floris H B M; Tetri, Sami; Tatlisumak, Turgut; Yan, Bernard; Van Nieuwenhuizen, Koen M.; Dequatre-Ponchelle, Nelly; Lee-Archer, Matthew; Horstmann, Solveig; Wilson, Duncan; Pomero, Fulvio; Masotti, Luca; Lerpiniere, Christine; Godoy, Daniel Agustin; Cohen, Abigail S.; Houben, Rik; Al-Shahi Salman, Rustam; Pennati, Paolo; Fenoglio, Luigi; Werring, David; Veltkamp, Roland; Wood, Edith; Dewey, Helen M.; Cordonnier, Charlotte; Klijn, Catharina J M; Meligeni, Fabrizio; Davis, Stephen M.; Huhtakangas, Juha; Staals, Julie; Rosand, Jonathan; Meretoja, Atte

    2015-01-01

    Objective There is little evidence to guide treatment strategies for intracerebral hemorrhage on vitamin K antagonists (VKA-ICH). Treatments utilized in clinical practice include fresh frozen plasma (FFP) and prothrombin complex concentrate (PCC). Our aim was to compare case fatality with different

  8. Reversal strategies for vitamin K antagonists in acute intracerebral hemorrhage

    NARCIS (Netherlands)

    Parry-Jones, A.R.; Napoli, M. Di; Goldstein, J.N.; Schreuder, F.H.; Tetri, S.; Tatlisumak, T.; Yan, B.; Nieuwenhuizen, K.M.; Dequatre-Ponchelle, N.; Lee-Archer, M.; Horstmann, S.; Wilson, D.; Pomero, F.; Masotti, L.; Lerpiniere, C.; Godoy, D.A.; Cohen, A.S.; Houben, R.; Al-Shahi Salman, R.; Pennati, P.; Fenoglio, L.; Werring, D.; Veltkamp, R.; Wood, E.; Dewey, H.M.; Cordonnier, C.; Klijn, C.J.M.; Meligeni, F.; Davis, S.M.; Huhtakangas, J.; Staals, J.; Rosand, J.; Meretoja, A.

    2015-01-01

    OBJECTIVE: There is little evidence to guide treatment strategies for intracerebral hemorrhage on vitamin K antagonists (VKA-ICH). Treatments utilized in clinical practice include fresh frozen plasma (FFP) and prothrombin complex concentrate (PCC). Our aim was to compare case fatality with different

  9. Epiminocyclohepta[b]indole analogs as 5-HT6 antagonists

    DEFF Research Database (Denmark)

    Henderson, Alan J; Guzzo, Peter R; Ghosh, Animesh; Kaur, Jagjit; Koo, Jia-Man; Nacro, Kassoum; Panduga, Shailaja; Pathak, Rashmi; Shimpukade, Bharat; Tan, Valentina; Xiang, Kai; Wierschke, Jonathan D; Isherwood, Matthew L

    2012-01-01

    A new series of epiminocyclohepta[b]indoles with potent 5-HT(6) antagonist activity were discovered and optimized using in vitro protocols. One compound from this series was progressed to advanced pharmacokinetic (PK) studies followed by 5-HT(6) receptor occupancy studies. The compound was found to...

  10. Precycle Estradiol in Synchronization and Scheduling of Antagonist Cycles.

    Science.gov (United States)

    Saple, Shilpa; Agrawal, Mukesh; Kawar, Simi

    2016-08-01

    Antagonist cycles have an inherent issue of lack of flexibility. As a result where batching of cycles is desired, it is not the preferred protocol in ART cycles. There is also the limitation of ovarian response in antagonist cycle due to the size heterogenesities of antral follicles at the start of stimulation. Among the different options available, use of estrogen in the luteal phase of the preceding cycle has definitely shown benefits with regard to better control of cycle as well as synchronization of follicles available for stimulation. The article gives a detailed analysis of the different options available for timing the egg collection in antagonist cycles, the advantages and drawbacks, and the method of use of estrogen. Whereas in the majority of the trials where estrogen pretreatment was used, the goal of scheduling of egg collection was definitely achieved, increased duration and dose of gonadotropin stimulation were required. There was definite advantage of higher oocyte yield in these cycles. The possibility of premature LH rise later during stimulation and subsequent poor implantation in these cycles has to be further evaluated. Nevertheless, batching of patient friendly antagonist cycles can be effectively possible by use of precycle estrogen treatment. PMID:27382226

  11. Possible site of action of CGRP antagonists in migraine

    DEFF Research Database (Denmark)

    Tfelt-Hansen, Peer; Olesen, Jes

    2011-01-01

    The calcitonin gene-related peptide (CGRP) receptor antagonists olcegepant and telcagepant are very potent drugs. Both are effective in migraine but in doses much higher than would be predicted from receptor binding and other in vitro results. This could perhaps suggest an effect of CGRP antagoni...

  12. How Hybrid Organizations Turn Antagonistic Assets into Complementarities

    DEFF Research Database (Denmark)

    Hockerts, Kai

    2015-01-01

    explicit social missions through business-inspired earned-income strategies, with the express goal of creating market disequilibria. This article demonstrates the challenges hybrids face and outlines how to overcome them by identifying hidden complementarities and creating new ones, by eliminating the need...... for complementarities, and by creating demands for antagonistic assets, or by using partnerships....

  13. Cultivable bacteria populations associated with leaves of banana and plantain plants and their antagonistic activity against Mycosphaerella fijiensis.

    Science.gov (United States)

    Ceballos, Isabel; Mosquera, Sandra; Angulo, Mónica; Mira, John J; Argel, Luz Edith; Uribe-Velez, Daniel; Romero-Tabarez, Magally; Orduz-Peralta, Sergio; Villegas, Valeska

    2012-10-01

    Mycosphaerella fijiensis is the etiological agent of Black Sigatoka, a fungal disease that affects production of banana and plantain crops in tropical regions. The sizes of cultivable epiphytic and endophytic bacterial populations, aerobic endospore forming bacteria (AEFB), and antagonist bacteria against M. fijiensis isolated from three Musa spp. cultivars from Urabá (Colombia) were studied, in order to find a suitable screening strategy to isolate antagonistic bacteria. Most of the variability found in the epiphytic and endophytic bacterial community sizes among fruit trees was explained by the cultivar differences. We found population sizes ranging from 1.25 × 10(3) to 9.64 × 10(5) CFU/g of fresh leaf and found that 44 % of total cultivable bacteria belong to the AEFB group. We isolated 648 AEFB from three different cultivars and assessed their antagonistic activity against M. fijiensis using the cell-free supernatant obtained from bacterial liquid cultures in three different in vitro assays. Five percent of those bacteria showed higher percent inhibition than the positive control Bacillus subtilis UA321 has (percent inhibition = 84 ± 5) in the screening phase. Therefore, they were selected as antagonistic bacteria against the pathogen. The strains with the highest percentage of antagonism were found in older leaves for the three cultivars, given support to recommend this group of leaves for future samplings. Some of these isolated bacteria affected the mycelium and ascospores morphology of the fungus. They also presented in vitro characteristics related to a successful colonization of the phylloplane such as indolic compounds, surfactant production, and biofilm formation, which makes them possible, potential candidates as biological control agents. PMID:22562105

  14. Effects of H1-receptor antagonists on 14C-aminopyrine accumulated in histamine-stimulated rabbit gastric glands

    International Nuclear Information System (INIS)

    After stimulation of gastric acid production there is a considerable delay before the acid starts to appear in the gastric lumen. The present study was carried out on isolated gastric glands to test the hypothesis that there may be a mechanisms in the parietal cell that contributes to this delay by preventing emptying of the secretory canaliculi. Glands were incubated with 14C-aminopyrine and stimulated with histamine. After accumulation of 14C-aminopyrine, various concentration of H1-receptor antagonists were added. Clemastine, promethazine, and hydroxyzine effectively and cetirizine and tripelennamine less effectively decreased the accumulated 14C-aminopyrine content in a dose-dependent manner without significantly reducing the oxygen consumption. The H1-receptor antagonists influenced the 14C-aminopyrine content in another manner than H2-receptor antagonists. No effects were obtained by atropine or lidocaine, indicating that the elimination of 14C-amionopyrine is not an inticholinergic effect or due to membrane effects as exerted by local anesthetics. Stimulation of glands by further addition of histamine did not significantly stimulate the uptake of 14C-aminopyrine in the glands, whereas stimulation with db-cAMP produced an increase that was most pronounced when low concentrations of hydroxyzine had been used. It is suggested that H1-receptor antagonists do not inhibit stimulation of acid production in the secretory canaliculi. They may, however, interfere with a mechanism preventing acid from leaving the parietal cell. Such a mechanism may contribute to the delay in appearance of acid in the gastric lumen after stimulation of gastric acid production. 37 refs., 7 figs

  15. The combination of glutamate receptor antagonist MK-801 with tamoxifen and its active metabolites potentiates their antiproliferative activity in mouse melanoma K1735-M2 cells

    International Nuclear Information System (INIS)

    Recent reports suggest that N-methyl-D-aspartate receptor (NMDAR) blockade by MK-801 decreases tumor growth. Thus, we investigated whether other ionotropic glutamate receptor (iGluR) antagonists were also able to modulate the proliferation of melanoma cells. On the other hand, the antiestrogen tamoxifen (TAM) decreases the proliferation of melanoma cells, and is included in combined therapies for melanoma. As the efficacy of TAM is limited by its metabolism, we investigated the effects of the NMDAR antagonist MK-801 in combination with TAM and its active metabolites, 4-hydroxytamoxifen (OHTAM) and endoxifen (EDX). The NMDAR blockers MK-801 and memantine decreased mouse melanoma K1735-M2 cell proliferation. In contrast, the NMDAR competitive antagonist APV and the AMPA and kainate receptor antagonist NBQX did not affect cell proliferation, suggesting that among the iGluR antagonists only the NMDAR channel blockers inhibit melanoma cell proliferation. The combination of antiestrogens with MK-801 potentiated their individual effects on cell biomass due to diminished cell proliferation, since it decreased the cell number and DNA synthesis without increasing cell death. Importantly, TAM metabolites combined with MK-801 promoted cell cycle arrest in G1. Therefore, the data obtained suggest that the activity of MK-801 and antiestrogens in K1735-M2 cells is greatly enhanced when used in combination. - Highlights: • MK-801 and memantine decrease melanoma cell proliferation. • The combination of MK-801 with antiestrogens inhibits melanoma cell proliferation. • These combinations greatly enhance the effects of the compounds individually. • MK-801 combined with tamoxifen active metabolites induces cell cycle arrest in G1. • The combination of MK-801 and antiestrogens is an innovative strategy for melanoma

  16. The combination of glutamate receptor antagonist MK-801 with tamoxifen and its active metabolites potentiates their antiproliferative activity in mouse melanoma K1735-M2 cells

    Energy Technology Data Exchange (ETDEWEB)

    Ribeiro, Mariana P.C. [Center for Neuroscience and Cell Biology, University of Coimbra, 3000-354 Coimbra (Portugal); Laboratory of Biochemistry, Faculty of Pharmacy, University of Coimbra, 3000-548 Coimbra (Portugal); Nunes-Correia, Isabel [Center for Neuroscience and Cell Biology, Flow Cytometry Unit, University of Coimbra, 3000-354 Coimbra (Portugal); Santos, Armanda E., E-mail: aesantos@ci.uc.pt [Center for Neuroscience and Cell Biology, University of Coimbra, 3000-354 Coimbra (Portugal); Laboratory of Biochemistry, Faculty of Pharmacy, University of Coimbra, 3000-548 Coimbra (Portugal); Custódio, José B.A. [Center for Neuroscience and Cell Biology, University of Coimbra, 3000-354 Coimbra (Portugal); Laboratory of Biochemistry, Faculty of Pharmacy, University of Coimbra, 3000-548 Coimbra (Portugal)

    2014-02-15

    Recent reports suggest that N-methyl-D-aspartate receptor (NMDAR) blockade by MK-801 decreases tumor growth. Thus, we investigated whether other ionotropic glutamate receptor (iGluR) antagonists were also able to modulate the proliferation of melanoma cells. On the other hand, the antiestrogen tamoxifen (TAM) decreases the proliferation of melanoma cells, and is included in combined therapies for melanoma. As the efficacy of TAM is limited by its metabolism, we investigated the effects of the NMDAR antagonist MK-801 in combination with TAM and its active metabolites, 4-hydroxytamoxifen (OHTAM) and endoxifen (EDX). The NMDAR blockers MK-801 and memantine decreased mouse melanoma K1735-M2 cell proliferation. In contrast, the NMDAR competitive antagonist APV and the AMPA and kainate receptor antagonist NBQX did not affect cell proliferation, suggesting that among the iGluR antagonists only the NMDAR channel blockers inhibit melanoma cell proliferation. The combination of antiestrogens with MK-801 potentiated their individual effects on cell biomass due to diminished cell proliferation, since it decreased the cell number and DNA synthesis without increasing cell death. Importantly, TAM metabolites combined with MK-801 promoted cell cycle arrest in G1. Therefore, the data obtained suggest that the activity of MK-801 and antiestrogens in K1735-M2 cells is greatly enhanced when used in combination. - Highlights: • MK-801 and memantine decrease melanoma cell proliferation. • The combination of MK-801 with antiestrogens inhibits melanoma cell proliferation. • These combinations greatly enhance the effects of the compounds individually. • MK-801 combined with tamoxifen active metabolites induces cell cycle arrest in G1. • The combination of MK-801 and antiestrogens is an innovative strategy for melanoma.

  17. Effects of the 5-HT3 receptor antagonist, GR38032F, on raised dopaminergic activity in the mesolimbic system of the rat and marmoset brain.

    OpenAIRE

    Costall, B; Domeney, A M; Naylor, R J; Tyers, M. B.

    1987-01-01

    1 The ability of the selective 5-HT3 receptor antagonist GR38032F to reduce raised mesolimbic dopaminergic activity was studied in behavioural experiments in the rat and marmoset. 2 GR38032F injected into the nucleus accumbens (0.01-1 ng) or peripherally (0.01-1 mg kg-1 i.p.) inhibited the locomotor hyperactivity caused by the acute intra-accumbens injection of amphetamine (10 micrograms) in the rat. Similar treatments with sulpiride and fluphenazine also inhibited the amphetamine-induced hyp...

  18. Accumulation of Deleterious Mutations Near Sexually Antagonistic Genes.

    Science.gov (United States)

    Connallon, Tim; Jordan, Crispin Y

    2016-01-01

    Mutation generates a steady supply of genetic variation that, while occasionally useful for adaptation, is more often deleterious for fitness. Recent research has emphasized that the fitness effects of mutations often differ between the sexes, leading to important evolutionary consequences for the maintenance of genetic variation and long-term population viability. Some forms of sex-specific selection-i.e., stronger purifying selection in males than females-can help purge a population's load of female-harming mutations and promote population growth. Other scenarios-e.g., sexually antagonistic selection, in which mutations that harm females are beneficial for males-inflate genetic loads and potentially dampen population viability. Evolutionary processes of sexual antagonism and purifying selection are likely to impact the evolutionary dynamics of different loci within a genome, yet theory has mostly ignored the potential for interactions between such loci to jointly shape the evolutionary genetic basis of female and male fitness variation. Here, we show that sexually antagonistic selection at a locus tends to elevate the frequencies of deleterious alleles at tightly linked loci that evolve under purifying selection. Moreover, haplotypes that segregate for different sexually antagonistic alleles accumulate different types of deleterious mutations. Haplotypes that carry female-benefit sexually antagonistic alleles preferentially accumulate mutations that are primarily male harming, whereas male-benefit haplotypes accumulate mutations that are primarily female harming. The theory predicts that sexually antagonistic selection should shape the genomic organization of genetic variation that differentially impacts female and male fitness, and contribute to sexual dimorphism in the genetic basis of fitness variation. PMID:27226163

  19. Mineralocorticoid receptor antagonists: emerging roles in cardiovascular medicine

    Directory of Open Access Journals (Sweden)

    Funder JW

    2013-10-01

    Full Text Available John W FunderPrince Henry's Institute, Clayton, Victoria, AustraliaAbstract: Spironolactone was first developed over 50 years ago as a potent mineralocorticoid receptor (MR antagonist with undesirable side effects; it was followed a decade ago by eplerenone, which is less potent but much more MR-specific. From a marginal role as a potassium-sparing diuretic, spironolactone was shown to be an extraordinarily effective adjunctive agent in the treatment of progressive heart failure, as was eplerenone in subsequent heart failure trials. Neither acts as an aldosterone antagonist in the heart as the cardiac MR are occupied by cortisol, which becomes an aldosterone mimic in conditions of tissue damage. The accepted term “MR antagonist”, (as opposed to “aldosterone antagonist” or, worse, “aldosterone blocker”, should be retained, despite the demonstration that they act not to deny agonist access but as inverse agonists. The prevalence of primary aldosteronism is now recognized as accounting for about 10% of hypertension, with recent evidence suggesting that this figure may be considerably higher: in over two thirds of cases of primary aldosteronism therapy including MR antagonists is standard of care. MR antagonists are safe and vasoprotective in uncomplicated essential hypertension, even in diabetics, and at low doses they also specifically lower blood pressure in patients with so-called resistant hypertension. Nowhere are more than 1% of patients with primary aldosteronism ever diagnosed and specifically treated. Given the higher risk profile in patients with primary aldosteronism than that of age, sex, and blood pressure matched essential hypertension, on public health grounds alone the guidelines for first-line treatment of all hypertension should mandate inclusion of a low-dose MR antagonist.Keywords: spironolactone, eplerenone, primary aldosteronism, public health, inverse agonists

  20. Insight into 144 patients with ocular vascular events during VEGF antagonist injections

    DEFF Research Database (Denmark)

    Mansour, Ahmad M; Shahin, Maha; Kofoed, Peter K;

    2012-01-01

    To record ocular vascular events following injections of vascular endothelium growth factor (VEGF) antagonists.......To record ocular vascular events following injections of vascular endothelium growth factor (VEGF) antagonists....

  1. Estrogen inhibits corticotropin-releasing hormone production in primary human placental cells

    Institute of Scientific and Technical Information of China (English)

    唐晓露; 倪鑫; 由振东; 何平; 惠宁; 顾清; 孙刚

    2003-01-01

    Objective: To study the inhibition effects of estrogen on the production of corticotropin-releasing hormone in human placental cells. Methods: Primary cultured placental cells were treated by ICI182, 780, a complete ER antagonist, and Tamoxifen, an ERα-mixed agonist/antagonist and ERβ antagonist for 24 h. The supernatant was havested for the radioimmunoassay of CRH. Results: 17β-estradiol inhibited the secretion of corticotropin-releasing hormone in human placental (P<0.05). ICI182, 780 stimulated the secretion of corticotropin-releasing hormone in human placental (P<0.05). Conclusion: Estrogen represses the synthesis and secretion of corticotropin-releasing hormone in human placental, which is possibly mediated by ERα.

  2. Neural cell adhesion molecule (N-CAM) domains and intracellular signaling pathways involved in the inhibition of astrocyte proliferation

    OpenAIRE

    Krushel, Leslie A.; Tai, Ming-Hong; Cunningham, Bruce A.; Edelman, Gerald M.; Crossin, Kathryn L.

    1998-01-01

    The neural cell adhesion molecule (N-CAM) inhibits astrocyte proliferation in vitro and in vivo, and this effect is partially reversed by the glucocorticoid antagonist RU-486. The present studies have tested the hypothesis that N-CAM-mediated inhibition of astrocyte proliferation is caused by homophilic binding and involves the activation of glucocorticoid receptors. It was observed that all N-CAM Ig domains inhibited astrocyte proliferation in parallel with their ability to influence N-CAM b...

  3. AB260. Role of µ, κ, and δ opioid receptors in tibial inhibition of bladder overactivity in cats

    OpenAIRE

    Zhang, Zhaocun; JIANG, XUEWEN; Shang, Zhenhua; Chen, Shouzhen; Tai, Changfeng; Shi, Benkang

    2016-01-01

    Background To study the impact of µ, κ, and δ opioid receptors on tibial inhibition of bladder overactivity in cats Methods In α-chloralose anesthetized cats we examined the role of opioid receptor (OR) subtypes (µ, κ, and δ) intibialnerve stimulation (TNS) induced inhibition of bladder overactivity elicited by intravesical infusion of 0.25% acetic acid (AA). The sensitivity of TNS inhibition to cumulative intravenous doses of selective OR antagonists (cyprodime for µ, nor-binaltorphimine for...

  4. The oxytocin/vasopressin receptor antagonist atosiban delays the gastric emptying of a semisolid meal compared to saline in human

    Directory of Open Access Journals (Sweden)

    Ekberg Olle

    2006-03-01

    Full Text Available Abstract Background Oxytocin is released in response to a meal. Further, mRNA for oxytocin and its receptor have been found throughout the gastrointestinal (GI tract. The aim of this study was therefore to examine whether oxytocin, or the receptor antagonist atosiban, influence the gastric emptying. Methods Ten healthy volunteers (five men were examined regarding gastric emptying at three different occasions: once during oxytocin stimulation using a pharmacological dose; once during blockage of the oxytocin receptors (which also blocks the vasopressin receptors and thereby inhibiting physiological doses of oxytocin; and once during saline infusion. Gastric emptying rate (GER was assessed and expressed as the percentage reduction in antral cross-sectional area from 15 to 90 min after ingestion of rice pudding. The assessment was performed by real-time ultrasonography. At the same time, the feeling of satiety was registered using visual satiety scores. Results Inhibition of the binding of endogenous oxytocin by the receptor antagonist delayed the GER by 37 % compared to saline (p = 0.037. In contrast, infusion of oxytocin in a dosage of 40 mU/min did not affect the GER (p = 0.610. Satiation scores areas in healthy subjects after receiving atosiban or oxytocin did not show any significant differences. Conclusion Oxytocin and/or vasopressin seem to be regulators of gastric emptying during physiological conditions, since the receptor antagonist atosiban delayed the GER. However, the actual pharmacological dose of oxytocin in this study had no effect. The effect of oxytocin and vasopressin on GI motility has to be further evaluated.

  5. AHR-16303B, a novel antagonist of 5-HT2 receptors and voltage-sensitive calcium channels

    International Nuclear Information System (INIS)

    In vivo and in vitro methods were used to characterize AHR-16303B, a novel compound with antagonistic action at 5-HT2 receptors and voltage-sensitive calcium channels. The 5-HT2 receptor-antagonistic properties of AHR-16303B were demonstrated by inhibition of (a) [3H]ketanserin binding to rat cerebral cortical membranes (IC50 = 165 nM); (b) 5-hydroxytryptamine (5-HT)-induced foot edema in rats (minimum effective dose, (MED) = 0.32 mg/kg orally, p.o.); (c) 5-HT-induced vasopressor responses in spontaneously hypertensive rats (SHR) (ID50 = 0.18 mg/kg intravenously (i.v.), 1.8 mg/kg p.o.), (d) 5-HT-induced antidiuresis in rats (MED = 1 mg/kg p.o.), and (e) platelet aggregation induced by 5-HT + ADP (IC50 = 1.5 mM). The calcium antagonist properties of AHR-16303B were demonstrated by inhibition of (a) [3H]nimodipine binding to voltage-sensitive calcium channels on rabbit skeletal muscle membranes (IC50 = 15 nM), (b) KCl-stimulated calcium flux into cultured PC12 cells (IC50 = 81 nM), and (c) CaCl2-induced contractions of rabbit thoracic aortic strips (pA2 = 8.84). AHR-16303B had little or no effect on binding of radioligands to dopamine2 (DA2) alpha 1, alpha 2, H1, 5-HT1 alpha, beta 2, muscarinic M1, or sigma opioid receptors; had no effect on 5-HT3 receptor-mediated vagal bradycardia; and had only minor negative inotropic, chronotropic, and dromotropic effects on isolated guinea pig atria. In conscious SHR, 30 mg/kg p.o. AHR-16303B completely prevented the vasopressor responses to i.v. 5-HT, and decreased blood pressure (BP) by 24% 3 h after dosing

  6. DIHYDROPYRIDINE CALCIUM ANTAGONISTS: DATA OF EVIDENCE BASED MEDICINE AND RECOM-MENDATIONS ON PRACTICAL USE

    Directory of Open Access Journals (Sweden)

    S. Y. Martsevich

    2015-12-01

    Full Text Available The classification of calcium antagonists is presented. There were considered the results of large randomized trials, which were devoted to study of influence of dihydropyridine calcium antagonists on the risk of cardiovascular complications. The place of dihydropyridine calcium antagonists in modern recommendations on treatment of arterial hypertension and ischemic heart disease is defined. The clinical importance of differences between various presentations of dihy-dropyridine calcium antagonists is stressed.

  7. Efficacy and putative mode of action of native and commercial antagonistic yeasts against postharvest pathogens of pear.

    Science.gov (United States)

    Lutz, M Cecilia; Lopes, Christian A; Rodriguez, M Eugenia; Sosa, M Cristina; Sangorrín, Marcela P

    2013-06-17

    Putative mechanisms of action associated with the biocontrol capacity of four yeast strains (Cryptoccocus albidus NPCC 1248, Pichia membranifaciens NPCC 1250, Cryptoccocus victoriae NPCC 1263 and NPCC 1259) against Penicillium expansum and Botrytis cinerea were studied by means of in vitro and in situ assays. C. albidus(YP), a commercial yeast was also evaluated for comparative purposes. The yeast strains exhibited a variety of different mechanisms including: wound colonization, germination inhibition, biofilm formation, secretion of killer toxins, competition for nutrient and secretion of hydrolytic enzymes (protease, chitinase and glucanase). The relationship between strains (and their associated antagonist mechanisms) and in situ antagonist activity was also evaluated. Results indicate that mechanisms such as production of hydrolytic enzymes, the ability for colonization of wounds, production of killer toxin and inhibition of germination are the most important for biocontrol activity. Our study indicate that multiple modes of action may explain why P. membranifaciens NPCC 1250 and C. victoriae NPCC 1263 provided excellent control of postharvest pears disease. PMID:23680800

  8. Effect of two human growth hormone receptor antagonists on glomerulosclerosis in streptozotocin-induced diabetic rats

    Institute of Scientific and Technical Information of China (English)

    Wei LI; Shui-xian SHEN; Li-hua ZHU; En-bi WANG; Zeng-can YE; Jun LIN; Li-he GUO; Fei-hong LUO; Xi-hong LIU; Xin FANG

    2004-01-01

    AIM: To explore the feasibility of human growth hormone (hGH) receptor antagonist in the treatment of end-stage diabetic renal complications. METHODS: Two hGH mutants, hGHA1 (Cys-hGH-dell-4, G120R, K168A, E174A,C182S, de1186-191) and hGHA2 (hGH-H21A, G120R, E174A) were expressed in E coli. The IC50 (Mean±SD)values for the mutants for inhibiting 125I-hGH binding to rabbit growth hormone receptor were (65±10) ng for hGHA1, (27±5.6) ng for hGHA2, and (10±0.6) ng for wild type hGH, respectively. RESULTS: After treatment for 12 weeks, the renal histology analysis showed that treatment with hGHA2 at 4 mg/kg body weight daily markedly suppressed glomerulosclerosis in streptozotocin-induced diabetic Sprague-Dawley (SD) rats; hGHA1 at the same dosage slightly increased the renal damage compared with saline; while wild type hGH at 1 U/kg body weight daily severely worsened the glomerulo-sclerosis in diabetic SD rats. CONCLUSION: The data indicated that hGHA2 inhibited the end-stage glomerulosclerosis in diabetic rats, but hGHA1 mildly increased the glomerulosclerosis.

  9. Control of Anthracnose Caused by Colletotrichum musae on Curcuma alismatifolia Gagnep. Using Antagonistic Bacillus spp.

    Directory of Open Access Journals (Sweden)

    Supuk Mahadtanapuk

    2007-01-01

    Full Text Available Over 400 bacterial strains, isolated from leaf surfaces of Curcuma alismatifolia Gagnep. and hot springs in the Chiang Mai province of northern Thailand, were screened in vitro for antagonistic activity against Colletotrichum musae, an anthracnose fungus. Three isolates provided greater than 75% growth inhibition of the fungus in vitro and were identified as Bacillus licheniformis, B. amyloliquefaciens and B. subtilis. Using in planta tests, B. amyloliquefaciens and B. subtilis were shown to efficiently colonize the curcuma bracts, provide a statistically significant growth suppression of C. musae over that of B. licheniformis, and all three isolates could provide 100% inhibition of conidial fungal germination. When B. licheniformis was co-inoculated in combination with either of the other two bacteria, the ability of B. amyloliquefaciens and B. subtilis to suppress the fungal disease was dramatically reduced. Both B. amyloliquefaciens and B. subtilis were found to contain an isoform of iturin A with antifungal activity against C. musae. As a preventative measure to control the spread of C. musae and reduce the severity of fungal infections, B. amyloliquefaciens could be used to inoculate curcuma flowers cost effectively and reduce the need for the toxic synthetic fungicides currently in use.

  10. Interaction of pyridostigmine with the 5-HT(3) receptor antagonist ondansetron in guinea pigs

    Energy Technology Data Exchange (ETDEWEB)

    Capacio, B.R.; Byers, C.E.; Matthews, R.L.; Anderson, D.R.; Anders, J.C.

    1993-05-13

    Serotonin receptor subtype three (5HT3) antagonists, such as the drug ondansetron (OND), have been developed as effective anti-emetic compounds. The purpose of this study was to assess the drug interactions of OND (10, 20 and 30 mg/kg) with the organophosphorus pretreatment compound pyridostigmine (PYR; 0.94 mg/kg) after simultaneous oral administration to guinea pigs. Compatibility was assessed by determining (1) OND pharmacokinetics in the absence (Phase 1) and presence (Phase 2) of pyridostigmine (PYR) and (2) PYR-induced acetylcholinesterase (AChE) inhibition kinetics in the absence (Phase 1) and the presence (Phase 2) of OND. AChE inhibition was examined because it has been shown to be an indicator of PYR efficacy against OP-induced lethality. The pharmacokinetics of OND alone and in the presence of PYR were linear and best described by a one-compartment model with first-order absorption and elimination rate kinetics. For OND 30 mg/kg the K10 was found to be significantly smaller in Phase 2 than Phase 1 (p < 0.05).

  11. Structure-activity studies on 1,4-dihydropyridine calcium channel antagonists and activators

    International Nuclear Information System (INIS)

    Four series of 1,4-dihydropyridine Ca2+ channel antagonists related to mifedipine were synthesized by a modified Hantzsch procedure to determine the effects of ester (C3 = CO2Me, C5 = CO2R) and phenyl (C4) substituents on pharmacological and radioligand binding ([H]nitrendipine) activities in guinea pig ileal longitudinal smooth muscle. Two series of Ca2+ channel activator 1,4-dihydropyridines, BAY K 8644 (C3 = NO2, C5 = CO2Me) and CGP 28392 (C2,3 = lactone, C5 = CO2Me) were biochemically evaluated by inhibition of [3H]nitrendipine binding in guinea pig ileal longitudinal smooth muscle membranes to establish fundamental structure-activity requirements. A homologous series of bis-1,4-dihydropyridines were synthesized, pharmacologically and biochemically evaluated in an attempt to explore the distribution of the 1,4-dihydropyridine receptor in guinea pig ileal longitudinal smooth muscle membranes. Several potential affinity labels including ester substituted 3- and 4-fluorosulfonyl benzoyl and isothiocyanate derivatives were synthesized and evaluated by inhibition of [3H]nitrendipine binding

  12. Introduction of some important antagonistic bacteria affecting on damping-off of canola.

    Science.gov (United States)

    Sarani, S

    2012-01-01

    Three hundred ninety five bacterial isolates were collected from canola Root and Rhizosphere in Golestan, Mazandaran, Guilan and Tehran provinces. At first, antagonistic effect of bacterial isolates on Rhizoctonia solani was studied using dual culture test assay. The results showed that 60 isolates had the ability to inhibit the growth of fungi on PDA medium. On the basis of the biochemical, physiological and morphological tests, isolates Pf41, Pf51, Pf411 and Pf412 were identified as Pseudomonas fluorescens, isolate Bu1 as Burkholderia cepacia, the isolates B1, B2, Bs44 and B6 were as Bacillus subtilis and S44, str45 as Streptomyces sp. Results of the studies on biocontrol mechanism showed that Isolates produced antibiotics and volatile metabolites that prevented the mycelial growth of the fungus. Also the isolates produced some of antimicrobial metabolites including hydrogen cyanide, protease and siderophore. Isolates effect inhibition of in vitro growth of the fungus. The effect of isolates on disease reduction in compare with control have significantly differentiated. None of the isolates were able completely to prevent disease occurrence. Isolates applied as soil treatment had a significantly higher disease control as compared to seed treatment. Isolates had considerable effect on reduction disease under the greenhouse conditions. PMID:23878984

  13. Biocontrol of Fusarium graminearum Growth and Deoxynivalenol Production in Wheat Kernels with Bacterial Antagonists

    Directory of Open Access Journals (Sweden)

    Cuijuan Shi

    2014-01-01

    Full Text Available Fusarium graminearum is the main causal pathogen affecting small-grain cereals, and it produces deoxynivalenol, a kind of mycotoxin, which displays a wide range of toxic effects in human and animals. Bacterial strains isolated from peanut shells were investigated for their activities against F. graminearum by dual-culture plate and tip-culture assays. Among them, twenty strains exhibited potent inhibition to the growth of F. graminearum, and the inhibition rates ranged from 41.41% to 54.55% in dual-culture plate assay and 92.70% to 100% in tip-culture assay. Furthermore, eighteen strains reduced the production of deoxynivalenol by 16.69% to 90.30% in the wheat kernels assay. Finally, the strains with the strongest inhibitory activity were identified by morphological, physiological, biochemical methods and also 16S rDNA and gyrA gene analysis as Bacillus amyloliquefaciens. The current study highlights the potential application of antagonistic microorganisms and their metabolites in the prevention of fungal growth and mycotoxin production in wheat kernels. As a biological strategy, it might avoid safety problems and nutrition loss which always caused by physical and chemical strategies.

  14. Oral mineralocorticoid antagonists for recalcitrant central serous chorioretinopathy

    Directory of Open Access Journals (Sweden)

    Chin EK

    2015-08-01

    Full Text Available Eric K Chin, David RP Almeida, C Nathaniel Roybal, Philip I Niles, Karen M Gehrs, Elliott H Sohn, H Culver Boldt, Stephen R Russell, James C FolkDepartment of Ophthalmology and Visual Sciences, University of Iowa, Iowa City, IA, USAPurpose: To evaluate the effect and tolerance of oral mineralocorticoid antagonists, eplerenone and/or spironolactone, in recalcitrant central serous chorioretinopathy.Methods: Retrospective consecutive observational case series. Primary outcome measures included central macular thickness (CMT, µm, macular volume (MV, mm3, Snellen visual acuity, and prior treatment failures. Secondary outcomes included duration of treatment, treatment dosage, and systemic side effects.Results: A total of 120 patients with central serous chorioretinopathy were reviewed, of which 29 patients were treated with one or more mineralocorticoid antagonists. The average age of patients was 58.4 years. Sixteen patients (69.6% were recalcitrant to other interventions prior to treatment with oral mineralocorticoid antagonists, with an average washout period of 15.3 months. The average duration of mineralocorticoid antagonist treatment was 3.9±2.3 months. Twelve patients (52.2% showed decreased CMT and MV, six patients (26.1% had increase in both, and five patients (21.7% had negligible changes. The mean decrease in CMT of all patients was 42.4 µm (range, -136 to 255 µm: 100.7 µm among treatment-naïve patients, and 16.9 µm among recalcitrant patients. The mean decrease in MV of all patients was 0.20 mm3 (range, -2.33 to 2.90 mm3: 0.6 mm3 among treatment-naïve patients, and 0.0 mm3 among recalcitrant patients. Median visual acuity at the start of therapy was 20/30 (range, 20/20–20/250, and at final follow-up it was 20/40 (range, 20/20–20/125. Nine patients (39.1% experienced systemic side effects, of which three patients (13.0% were unable to continue therapy.Conclusion: Mineralocorticoid antagonist treatment had a positive treatment

  15. GABA-mediated inhibition of locus coeruleus from the dorsomedial rostral medulla.

    Science.gov (United States)

    Ennis, M; Aston-Jones, G

    1989-08-01

    Recent anatomic studies in our laboratory (Aston-Jones et al., 1986) identified the nucleus prepositus hypoglossi (PrH) in the dorsomedial medulla as a major afferent of the locus coeruleus (LC). In the present studies, the influence of projections from PrH to LC was assessed in anesthetized rats. Focal electrical stimulation of PrH inhibited the spontaneous discharge of 42 of 47 LC neurons; the latency to onset of such inhibition was 19.8 +/- 2.5 msec and its duration was 172.4 +/- 10.4 msec. PrH-evoked inhibition of LC neurons was unaffected by administration of the opiate receptor antagonist naloxone or the alpha 2-receptor antagonist idazoxan but was substantially reduced by systemic picrotoxin, an antagonist of GABA. The GABAA receptor antagonist bicuculline methiodide blocked the inhibition from PrH, whether applied by local microinfusion or iontophoresis into the LC. These results lead us to propose that PrH provides a direct inhibitory synaptic input to LC, for which GABA is the likely transmitter. PMID:2769374

  16. Differential inhibitory effects of CysLT(1 receptor antagonists on P2Y(6 receptor-mediated signaling and ion transport in human bronchial epithelia.

    Directory of Open Access Journals (Sweden)

    Wendy Ka-hoi Lau

    Full Text Available BACKGROUND: Cysteinyl leukotriene (CysLT is one of the proinflammatory mediators released by the bronchi during inflammation. CysLTs exert their biological effects via specific G-protein-coupled receptors. CysLT(1 receptor antagonists are available for clinical use for the treatment of asthma. Recently, crosstalk between CysLT(1 and P2Y(6 receptors has been delineated. P2Y receptors are expressed in apical and/or basolateral membranes of virtually all polarized epithelia to control the transport of fluid and electrolytes. Previous research suggests that CysLT(1 receptor antagonists inhibit the effects of nucleotides acting at P2Y receptors. However, the detailed molecular mechanism underlying the inhibition remains unresolved. METHODOLOGY/PRINCIPAL FINDINGS: In this study, western blot analysis confirmed that both CysLT(1 and P2Y(6 receptors were expressed in the human bronchial epithelial cell line 16HBE14o-. All three CysLT(1 antagonists inhibited the uridine diphosphate (UDP-evoked I(SC, but only montelukast inhibited the UDP-evoked [Ca(2+](i increase. In the presence of forskolin or 8-bromoadenosine 3'5' cyclic monophosphate (8-Br-cAMP, the UDP-induced I(SC was potentiated but was reduced by pranlukast and zafirlukast but not montelukast. Pranlukast inhibited the UDP-evoked I(SC potentiated by an Epac activator, 8-(4-Chlorophenylthio-2'-O-methyladenosine-3',5'-cyclic monophosphate (8-CPT-2'-O-Me-cAMP, while montelukast and zafirlukast had no such effect. Pranlukast inhibited the real-time increase in cAMP changes activated by 8-CPT-2'-O-Me-cAMP as monitored by fluorescence resonance energy transfer imaging. Zafirlukast inhibited the UDP-induced I(SC potentiated by N(6-Phenyladenosine-3',5'-cyclic monophosphorothioate, Sp-isomer (Sp-6-Phe-cAMP; a PKA activator and UDP-activated PKA activity. CONCLUSIONS/SIGNIFICANCE: In summary, our data strongly suggest for the first time that in human airway epithelia, the three specific CysLT(1 receptor

  17. Fast silencing reveals a lost role for reciprocal inhibition in locomotion

    OpenAIRE

    Moult, Peter Robert; Cottrell, Glen Alfred; Li, Wenchang

    2013-01-01

    Summary Alternating contractions of antagonistic muscle groups during locomotion are generated by spinal “half-center” networks coupled in antiphase by reciprocal inhibition. It is widely thought that reciprocal inhibition only coordinates the activity of these muscles. We have devised two methods to rapidly and selectively silence neurons on just one side of Xenopus tadpole spinal cord and hindbrain, which generate swimming rhythms. Silencing activity on one side led to rapid cessation of ac...

  18. Selective inhibition of PAF-induced human platelet aggregation by garlic

    International Nuclear Information System (INIS)

    Garlic exudate (0.2-2.5 mg) prepared by squeezing fresh garlic cloves inhibited platelet aggregation induced by platelet activating factor (PAF) in a dose-dependent manner. No inhibition of aggregation was observed when adenosine-5-diphosphate (ADP) or arachidonic acid (AA) were used as aggregating agents. This selective effect of garlic against PAF-induced aggregation was also seen with aqueous or alcoholic garlic extracts. These results suggest that PAF antagonists are present in garlic. (author)

  19. Antagonistic activity of dairy lactobacilli against gram-foodborne pathogens - doi: 10.4025/actascitechnol.v36i1.18776

    Directory of Open Access Journals (Sweden)

    Marco Geria

    2014-01-01

    Full Text Available Thirty-five strains of lactic acid bacteria were isolated from artisanal raw milk cheese, presumptively identified and tested against one dairy Escherichia coli strain. Six lactobacilli, exhibiting antagonistic activity, were identified at the species level and their action was evaluated against four strains of Gram-foodborne pathogens (Escherichia coli O26, Escherichia coli O157:H7, Salmonella spp. 1023, and Salmonella Typhimurium and the control strain Escherichia coli ATCC 45922. The antagonistic activity was determined by spot method and the inhibition zones were measured by Autodesk AutoCAD 2007. Three strains, all Lactobacillus paracasei, were active against all the pathogens; the other strains, all Lactobacillus plantarum, showed antagonistic activity against some pathogens. This study highlights the intense and different antagonistic activity induced by lactobacilli against various foodborne pathogens thus demonstrating that using selected lactic acid bacteria strains as adjunct cultures could be an effective strategy to prevent the development of foodborne pathogens in artisanal raw milk cheeses, and thus improving their safety.

  20. Effects of ONO-6950, a novel dual cysteinyl leukotriene 1 and 2 receptors antagonist, in a guinea pig model of asthma.

    Science.gov (United States)

    Yonetomi, Yasuo; Sekioka, Tomohiko; Kadode, Michiaki; Kitamine, Tetsuya; Kamiya, Akihiro; inoue, Atsuto; Nakao, Takafumi; Nomura, Hiroaki; Murata, Masayuki; Nakao, Shintaro; Nambu, Fumio; Fujita, Manabu; Nakade, Shinji; Kawabata, Kazuhito

    2015-10-15

    We assessed in this study the anti-asthmatic effects of ONO-6950, a novel cysteinyl leukotriene 1 (CysLT1) and 2 (CysLT2) receptors dual antagonist, in normal and S-hexyl glutathione (S-hexyl GSH)-treated guinea pigs, and compared these effects to those of montelukast, a CysLT1 selective receptor antagonist. Treatment with S-hexyl GSH reduced animals LTC4 metabolism, allowing practical evaluation of CysLT2 receptor-mediated airway response. ONO-6950 antagonized intracellular calcium signaling via human and guinea pig CysLT1 and CysLT2 receptors with IC50 values of 1.7 and 25 nM, respectively (human receptors) and 6.3 and 8.2 nM, respectively (guinea pig receptors). In normal guinea pigs, both ONO-6950 (1 or 0.3 mg/kg, p.o.) and the CysLT1 receptor antagonist montelukast (0.3 or 0.1 mg/kg, p.o.) fully attenuated CysLT1-mediated bronchoconstriction and airway vascular hyperpermeability induced by LTD4. On the other hand, in S-hexyl GSH-treated guinea pigs ONO-6950 at 3 mg/kg, p.o. or more almost completely inhibited bronchoconstriction and airway vascular hyperpermeability elicited by LTC4, while montelukast showed only partial or negligible inhibition of these airway responses. In ovalbumin sensitized guinea pigs, treatment with S-hexyl GSH on top of pyrilamine and indomethacin rendered antigen-induced bronchoconstriction sensitive to both CysLT1 and CysLT2 receptor antagonists. ONO-6950 strongly inhibited this asthmatic response to the level attained by combination therapy with montelukast and BayCysLT2RA, a selective CysLT2 receptor antagonist. These results clearly demonstrate that ONO-6950 is an orally active dual CysLT1/LT2 receptor antagonist that may provide a novel therapeutic option for patients with asthma. PMID:26318198

  1. Definition of critical periods for Hedgehog pathway antagonist-induced holoprosencephaly, cleft lip, and cleft palate.

    Directory of Open Access Journals (Sweden)

    Galen W Heyne

    Full Text Available The Hedgehog (Hh signaling pathway mediates multiple spatiotemporally-specific aspects of brain and face development. Genetic and chemical disruptions of the pathway are known to result in an array of structural malformations, including holoprosencephaly (HPE, clefts of the lip with or without cleft palate (CL/P, and clefts of the secondary palate only (CPO. Here, we examined patterns of dysmorphology caused by acute, stage-specific Hh signaling inhibition. Timed-pregnant wildtype C57BL/6J mice were administered a single dose of the potent pathway antagonist vismodegib at discrete time points between gestational day (GD 7.0 and 10.0, an interval approximately corresponding to the 15th to 24th days of human gestation. The resultant pattern of facial and brain dysmorphology was dependent upon stage of exposure. Insult between GD7.0 and GD8.25 resulted in HPE, with peak incidence following exposure at GD7.5. Unilateral clefts of the lip extending into the primary palate were also observed, with peak incidence following exposure at GD8.875. Insult between GD9.0 and GD10.0 resulted in CPO and forelimb abnormalities. We have previously demonstrated that Hh antagonist-induced cleft lip results from deficiency of the medial nasal process and show here that CPO is associated with reduced growth of the maxillary-derived palatal shelves. By defining the critical periods for the induction of HPE, CL/P, and CPO with fine temporal resolution, these results provide a mechanism by which Hh pathway disruption can result in "non-syndromic" orofacial clefting, or HPE with or without co-occurring clefts. This study also establishes a novel and tractable mouse model of human craniofacial malformations using a single dose of a commercially available and pathway-specific drug.

  2. Definition of Critical Periods for Hedgehog Pathway Antagonist-Induced Holoprosencephaly, Cleft Lip, and Cleft Palate

    Science.gov (United States)

    Heyne, Galen W.; Melberg, Cal G.; Doroodchi, Padydeh; Parins, Kia F.; Kietzman, Henry W.; Everson, Joshua L.; Ansen-Wilson, Lydia J.; Lipinski, Robert J.

    2015-01-01

    The Hedgehog (Hh) signaling pathway mediates multiple spatiotemporally-specific aspects of brain and face development. Genetic and chemical disruptions of the pathway are known to result in an array of structural malformations, including holoprosencephaly (HPE), clefts of the lip with or without cleft palate (CL/P), and clefts of the secondary palate only (CPO). Here, we examined patterns of dysmorphology caused by acute, stage-specific Hh signaling inhibition. Timed-pregnant wildtype C57BL/6J mice were administered a single dose of the potent pathway antagonist vismodegib at discrete time points between gestational day (GD) 7.0 and 10.0, an interval approximately corresponding to the 15th to 24th days of human gestation. The resultant pattern of facial and brain dysmorphology was dependent upon stage of exposure. Insult between GD7.0 and GD8.25 resulted in HPE, with peak incidence following exposure at GD7.5. Unilateral clefts of the lip extending into the primary palate were also observed, with peak incidence following exposure at GD8.875. Insult between GD9.0 and GD10.0 resulted in CPO and forelimb abnormalities. We have previously demonstrated that Hh antagonist-induced cleft lip results from deficiency of the medial nasal process and show here that CPO is associated with reduced growth of the maxillary-derived palatal shelves. By defining the critical periods for the induction of HPE, CL/P, and CPO with fine temporal resolution, these results provide a mechanism by which Hh pathway disruption can result in “non-syndromic” orofacial clefting, or HPE with or without co-occurring clefts. This study also establishes a novel and tractable mouse model of human craniofacial malformations using a single dose of a commercially available and pathway-specific drug. PMID:25793997

  3. Pharmacological characterization of BR-A-657, a highly potent nonpeptide angiotensin II receptor antagonist

    International Nuclear Information System (INIS)

    The pharmacological profile of BR-A-657, 2-n-butyl-5-dimethylamino-thiocarbonyl-methyl-6-methyl-3 - {[2-(1H-tetrazole-5-yl)biphenyl-4-yl]methyl} - pyrimidin-4(3H)-one, a new nonpeptide AT1-selective angiotensin receptor antagonist, has been investigated in a variety of in vitro and in vivo experimental models. In the present study, BR-A-657 displaced [125I][Sar1-Ile8]angiotensin II (Ang II) from its specific binding sites to AT1 subtype receptors in membrane fractions of HEK-293 cells with an IC50 of 0.16 nM. In a functional assay using isolated rabbit thoracic aorta, BR-A-657 inhibited the contractile response to Ang II (pD'2: 9.15) with a significant reduction in the maximum. In conscious rats, BR-A-657 (0.01, 0.1, 1 mg/kg; intravenously (i.v.)) dose-dependently antagonized Ang II-induced pressor responses. In addition, BR-A-657 dose-dependently decreased mean arterial pressure in furosemide-treated rats and renal hypertensive rats. Moreover, BR-A-657 given orally at 1 and 3 mg/kg reduced blood pressure in conscious renal hypertensive rats. Taken together, these findings indicate that BR-A-657 is a potent and specific antagonist of Ang II at the AT1 receptor subtype, and reveal the molecular basis responsible for the marked lowering of blood pressure in conscious rats. (author)

  4. Antagonist effect of interferon-γ aerosol inhalation on pulmonary remodeling after γ-ray irradiation

    International Nuclear Information System (INIS)

    Objective: To observe the antagonistic effect of interferon-y aerosol inhalation on pulmonary remodeling after γ-ray irradiation, and explore its mechanisms. Methods: The Wistar rats were randomly divided into irradiation control group and irradiation + Interferon-γ antagonist group, which proceeded IFN-γ aerosol inhalation 3 days before 20 Gy 60Co γ-ray irradiation, then were sacrificed at 10, 20, 30 days after irradiation. Conventional histopathological sections of lung tissue were prepared, which were stained immunohistochemically for α-SMA and Sirius red. The contents of collagen IV were determined by Western blot. The expression of MMP-2, MMP-9 and TIMP-1 in lung homogenate was detected by ELISA. Results: The widen degrees of interalveolar septum, the deposition of collagen I, III, and the expression of α-SMA decreased significantly in IFN-γ treatment group as compared with those in the irradiation control group. The expression of collagen IV appeared an elevation trend, but this phenomenon attenuated after IFN-γ was used. The levels of MMP-2 and TIMP-1 decreased 10 days after administration with IFN-γ but the opposite trend appeared for MMP- 9. The expression of MMP-2, MMP-9 and TIMP-1 decreased 30 days after administration with IFN-γ. Conclusion: IFN-γ is effective in alleviating pulmonary injuries induced by irradiation in rats, possibly by decreasing the expression of TIMP-1 to relieve the inhibition to MMP-9, then degrading collagen IV to antagonize remodeling after lung injury. (authors)

  5. No effect of nutritional adenosine receptor antagonists on exercise performance in the heat.

    Science.gov (United States)

    Cheuvront, Samuel N; Ely, Brett R; Kenefick, Robert W; Michniak-Kohn, Bozena B; Rood, Jennifer C; Sawka, Michael N

    2009-02-01

    Nutritional adenosine receptor antagonists can enhance endurance exercise performance in temperate environments, but their efficacy during heat stress is not well understood. This double-blinded, placebo-controlled study compared the effects of an acute dose of caffeine or quercetin on endurance exercise performance during compensable heat stress (40 degrees C, 20-30% rh). On each of three occasions, 10 healthy men each performed 30-min of cycle ergometry at 50% Vo2peak followed by a 15-min performance time trial after receiving either placebo (Group P), caffeine (Group C; 9 mg/kg), or quercetin (Group Q; 2,000 mg). Serial blood samples, physiological (heart rate, rectal, and mean skin body temperatures), perceptual (ratings of perceived exertion, pain, thermal comfort, motivation), and exercise performance measures (total work and pacing strategy) were made. Supplementation with caffeine and quercetin increased preexercise blood concentrations of caffeine (55.62 +/- 4.77 microM) and quercetin (4.76 +/- 2.56 microM) above their in vitro inhibition constants for adenosine receptors. No treatment effects were observed for any physiological or perceptual measures, with the exception of elevated rectal body temperatures (0.20-0.30 degrees C; P affect total work performed (Groups P: 153.5 +/- 28.3, C: 157.3 +/- 28.9, and Q: 151.1 +/- 31.6 kJ; P > 0.05) or the self-selected pacing strategy employed. These findings indicate that the nutritional adenosine receptor antagonists caffeine and quercetin do not enhance endurance exercise performance during compensable heat stress. PMID:19020291

  6. Are peripheral opioid antagonists the solution to opioid side effects?

    LENUS (Irish Health Repository)

    Bates, John J

    2012-02-03

    Opioid medication is the mainstay of therapy for severe acute and chronic pain. Unfortunately, the side effects of these medications can affect patient comfort and safety, thus limiting their proven therapeutic potential. Whereas the main analgesic effects of opioids are centrally mediated, many of the common side effects are mediated via peripheral receptors. Novel peripheral opioid antagonists have been recently introduced that can block the peripheral actions of opioids without affecting centrally mediated analgesia. We review the clinical and experimental evidence of their efficacy in ameliorating opioid side effects and consider what further information might be useful in defining their role. IMPLICATIONS: The major analgesic effects of opioid medication are mediated within the brain and spinal cord. Many of the side effects of opioids are caused by activation of receptors outside these areas. Recently developed peripherally restricted opioid antagonists have the ability to block many opioid side effects without affecting analgesia.

  7. Lead optimization studies of cinnamic amide EP2 antagonists.

    Science.gov (United States)

    Ganesh, Thota; Jiang, Jianxiong; Yang, Myung-Soon; Dingledine, Ray

    2014-05-22

    Prostanoid receptor EP2 can play a proinflammatory role, exacerbating disease pathology in a variety of central nervous system and peripheral diseases. A highly selective EP2 antagonist could be useful as a drug to mitigate the inflammatory consequences of EP2 activation. We recently identified a cinnamic amide class of EP2 antagonists. The lead compound in this class (5d) displays anti-inflammatory and neuroprotective actions. However, this compound exhibited moderate selectivity to EP2 over the DP1 prostanoid receptor (∼10-fold) and low aqueous solubility. We now report compounds that display up to 180-fold selectivity against DP1 and up to 9-fold higher aqueous solubility than our previous lead. The newly developed compounds also display higher selectivity against EP4 and IP receptors and a comparable plasma pharmacokinetics. Thus, these compounds are useful for proof of concept studies in a variety of models where EP2 activation is playing a deleterious role. PMID:24773616

  8. Interleukin-1-receptor antagonist in type 2 diabetes mellitus

    DEFF Research Database (Denmark)

    Larsen, Claus M; Faulenbach, Mirjam; Vaag, Allan;

    2007-01-01

    proliferation, and apoptosis. METHODS: In this double-blind, parallel-group trial involving 70 patients with type 2 diabetes, we randomly assigned 34 patients to receive 100 mg of anakinra (a recombinant human interleukin-1-receptor antagonist) subcutaneously once daily for 13 weeks and 36 patients to receive......BACKGROUND: The expression of interleukin-1-receptor antagonist is reduced in pancreatic islets of patients with type 2 diabetes mellitus, and high glucose concentrations induce the production of interleukin-1beta in human pancreatic beta cells, leading to impaired insulin secretion, decreased cell...... (P=0.03); C-peptide secretion was enhanced (P=0.05), and there were reductions in the ratio of proinsulin to insulin (P=0.005) and in levels of interleukin-6 (P<0.001) and C-reactive protein (P=0.002). Insulin resistance, insulin-regulated gene expression in skeletal muscle, serum adipokine levels...

  9. Antagonistic otolith-visual units in cat vestibular nuclei

    Science.gov (United States)

    Daunton, Nancy G.; Christensen, Carol A.

    1992-01-01

    The nature of neural coding of visual (Vis) and vestibular (Vst) information on translational motion in the region of the vestibular nuclei was investigated using extracellular single-unit recordings in alert adult cats. Responses were recorded and averaged over 60 cycles of stimulation in the vertical and horizontal planes, which included the Vst (movement of the animal in the dark), Vis (movement within lighted visual surround), and combined Vis and Vst (movement of the animal within the lighted stationary visual surround). Data are reported on responses to stimulations along the axis showing maximal sensitivity. A small number of units were identified that showed an antagonistic relationship between their Vis and Vst responses (since they were maximally excited by Vis and by Vst stimulations in the same direction). Results suggest that antagonistic units may belong to an infrequently encountered, but functionally distinct, class of neurons.

  10. Histamine-2 receptor antagonists as immunomodulators: new therapeutic views?

    DEFF Research Database (Denmark)

    Nielsen, Hans Jørgen

    1996-01-01

    from such studies are currently accumulating and suggest that the histamine-2 receptor antagonists have potential beneficial effects in the treatment of certain malignant, autoimmune and skin diseases, either alone or in combination with other drugs. The beneficial effect of histamine-2 receptor......Considerable evidence has emerged to suggest that histamine participates in the regulation of the inflammatory response, immune reaction, coagulation cascade, and cardiovascular function. Furthermore, histamine may play a major role in the growth of normal and malignant tissue as a regulator of...... proliferation and angiogenesis. Specific histamine receptors have been identified on the surface of bone marrow cells, immune competent cells, endothelial cells, fibroblasts, and also on malignant cells. This has prompted research in regulation by specific histamine receptor agonists and antagonists. Results...

  11. Potential Clinical Implications of the Urotensin II Receptor Antagonists

    Directory of Open Access Journals (Sweden)

    Emilie Kane

    2011-07-01

    Full Text Available Urotensin-II (UII, which binds to its receptor UT, plays an important role in the heart, kidneys, pancreas, adrenal gland and CNS. In the vasculature, it acts as a potent endothelium-independent vasoconstrictor and endothelium-dependent vasodilator. In disease states, this constriction-dilation equilibrium is disrupted. There is an upregulation of the UII system in heart disease, metabolic syndrome and kidney failure. The increase in UII release and UT expression suggest that UII system may be implicated in the pathology and pathogenesis of these diseases by causing an increase in ACAT-1 activity leading to SMC proliferation and foam cell infiltration, insulin resistance (DMII, as well as inflammation, high blood pressure and plaque formation. Recently, UT antagonists such as SB-611812, palosuran, and most recently a piperazino-isoindolinone based antagonist have been developed in the hope of better understanding the UII system and treating its associated diseases.

  12. Endothelin receptor antagonists as disease modifiers in systemic sclerosis.

    Science.gov (United States)

    Shetty, Nagalakshmi; Derk, Chris T

    2011-02-01

    Systemic sclerosis (SSc) is a multisystem connective tissue disease of unknown etiology that is characterized by inflammation, vascular dysfunction and fibrosis of the skin and visceral organs. SSc is clinically diverse both in terms of the burden of skin and organ involvement and the rate of progression of the disease. Recent studies indicate that the endothelin system, especially ET-1 and the ETA and ETB receptors may play a key role in the pathogenesis of SSc. A new class of drugs, endothelin receptor antagonists has been introduced for treatment of patients with pulmonary arterial hypertension (PAH). Bosentan, a dual endothelin receptor antagonist as well as Sitaxsentan and Ambrisentan, selective blockers of the ETA receptor have proven effective in SSc-PAH. This effect may be mediated through both a vasodilatory and antifibrotic effect, thus making these agents attractive as potential disease modifying agents for SSc. PMID:21184655

  13. Montelukast: More than a Cysteinyl Leukotriene Receptor Antagonist?

    OpenAIRE

    Tintinger, Gregory R.; Charles Feldman; Theron, Annette J.; Ronald Anderson

    2010-01-01

    The prototype cysteinyl leukotriene receptor antagonist, montelukast, is generally considered to have a niche application in the therapy of exercise- and aspirin-induced asthma. It is also used as add-on therapy in patients whose asthma is poorly controlled with inhaled corticosteroid monotherapy, or with the combination of a long-acting β(2)-agonist and an inhaled corticosteroid. Recently, however, montelukast has been reported to possess secondary anti-inflammatory properties, apparently un...

  14. Surfen, a small molecule antagonist of heparan sulfate

    OpenAIRE

    Schuksz, Manuela; Fuster, Mark M.; Brown, Jillian R.; Crawford, Brett E.; Ditto, David P.; Lawrence, Roger; Glass, Charles A; Wang, Lianchun; Tor, Yitzhak; Esko, Jeffrey D

    2008-01-01

    In a search for small molecule antagonists of heparan sulfate, we examined the activity of bis-2-methyl-4-amino-quinolyl-6-carbamide, also known as surfen. Fluorescence-based titrations indicated that surfen bound to glycosaminoglycans, and the extent of binding increased according to charge density in the order heparin > dermatan sulfate > heparan sulfate > chondroitin sulfate. All charged groups in heparin (N-sulfates, O-sulfates, and carboxyl groups) contributed to binding, consistent with...

  15. Optimization of amide-based EP3 receptor antagonists.

    Science.gov (United States)

    Lee, Esther C Y; Futatsugi, Kentaro; Arcari, Joel T; Bahnck, Kevin; Coffey, Steven B; Derksen, David R; Kalgutkar, Amit S; Loria, Paula M; Sharma, Raman

    2016-06-01

    Prostaglandin E receptor subtype 3 (EP3) antagonism may treat a variety of symptoms from inflammation to cardiovascular and metabolic diseases. Previously, most EP3 antagonists were large acidic ligands that mimic the substrate, prostaglandin E2 (PGE2). This manuscript describes the optimization of a neutral small molecule amide series with improved lipophilic efficiency (LipE) also known as lipophilic ligand efficiency (LLE) ((a) Nat. Rev. Drug Disc.2007, 6, 881; (b) Annu. Rep. Med. Chem.2010, 45, 380). PMID:27107947

  16. Ondansetron, a 5-HT3 antagonist, improves cerebellar tremor.

    OpenAIRE

    Rice, G P; Lesaux, J; Vandervoort, P.; Macewan, L; Ebers, G C

    1997-01-01

    It has been previously shown that ondansetron, a 5-HT3 antagonist, can ameliorate vertigo in patients with acute brainstem disorders. A coincidental benefit was the improvement of cerebellar tremor in some patients with both vertigo and tremor. To further evaluate this effect, a placebo controlled, double blind, crossover study was conducted of a single dose of intravenous ondansetron in 20 patients with cerebellar tremor caused by multiple sclerosis, cerebellar degeneration, or drug toxicity...

  17. attracting antagonists: does floral nectar increase leaf herbivory?

    OpenAIRE

    Adler, L.S.; Bronstein, J. L.

    2004-01-01

    Traits that are attractive to mutualists may also attract antagonists, resulting in conflicting selection pressures. Here we develop the idea that increased floral nectar production can, in some cases, increase herbivory. In these situations, selection for increased nectar production to attract pollinators may be constrained by a linked cost of herbivore attraction. In support of this hypothesis, we report that experimentally supplementing nectar rewards in Datura stramonium led to increased ...

  18. Biological control of Fusarium graminearum on wheat by antagonistic bacteria

    OpenAIRE

    Javad Nourozian; Hassan Reza Etebarian; Gholam Khodakaramian

    2006-01-01

    Bacillus subtilis strains 53 and 71, Pseudomonas fluorescens biov1 strain 32 and Streptomyces sp. Strain 3 were evaluated as potential biological agents for control of fusarium head blight (FHB) caused by Fusarium graminearum. Mycelial growth of the pathogen was reduced by cell free and volatile metabolites of bacterial antagonists by 37%-97%. Streptomyces sp. Strain 3 reduced disease severity of FHB 21 d after inoculation. The yield of wheat from plants treated with Streptomyces sp. strain 3...

  19. ANTIHYPERTENSIVE TREATMENT IN ELDERLY PATIENTS WITH DIHYDROPYRIDINE CALCIUM ANTAGONISTS

    OpenAIRE

    Y. A. Karpov; V. V. Buza

    2016-01-01

    The proofs of necessity of active arterial hypertension (AH) treatment in elderly patients are given. Peculiarities of pathogenesis of AH in elderly patients, connected predominantly with loss of big arteries elasticity and reasoning widely spread of isolated systolic AH in these patients, are discussed. Advantages of dihydropyridine calcium antagonists (DPCA) for AH treatment in elderly patients are proved, safety of treatment with DPCA is discussed. Data of clinical studies is analyzed. Ana...

  20. Affinity and selectivity of beta-adrenoceptor antagonists in vitro

    International Nuclear Information System (INIS)

    The potency order of the catecholamines (-)-isoprenaline (Iso), (-)-noradrenaline (NA), and (-)-adrenaline (Adr) in competition for radiolabelled sites is used for their pharmacological classification. It is shown that the radioligand 3H-CGP 12177 exclusively labels beta 1-adrenoceptors in rat salivary gland membranes (Iso greater than NA greater than Adr), and beta 2-adrenoceptors in rat reticulocytes (Iso greater than Adr greater than or equal to NA). These models are then used to derive the subtype-selectivity of the classical beta-adrenoceptor antagonists (+/-)-propranolol (prop; twofold beta 2-selective) and (+/-)-atenolol (aten; 35-fold beta 1-selective), as well as of the newer antagonists (+/-)-betaxolol and (+/-)-bisoprolol (betax and biso; 35-fold and 75-fold beta 1-selective, respectively). The ligand with the highest selectivity is ICI 118,551 (ICI), with a 300-fold beta 2-subtype selectivity. For comparison with antagonistic effects in humans at given plasma concentrations, the equilibrium dissociation constants of the ligands are measured in the presence of native human plasma and yield values for the relative selectively labelled subtype in the mean (Ki-values in nmol/l): prop: 20, aten: 250, biso: 24, betax: 23, and ICI: 2.5

  1. Multiple compound-related adverse properties contribute to liver injury caused by endothelin receptor antagonists.

    Science.gov (United States)

    Kenna, J Gerry; Stahl, Simone H; Eakins, Julie A; Foster, Alison J; Andersson, Linda C; Bergare, Jonas; Billger, Martin; Elebring, Marie; Elmore, Charles S; Thompson, Richard A

    2015-02-01

    Drug-induced liver injury has been observed in patients treated with the endothelin receptor antagonists sitaxentan and bosentan, but not following treatment with ambrisentan. The aim of our studies was to assess the possible role of multiple contributory mechanisms in this clinically relevant toxicity. Inhibition of the bile salt export pump (BSEP) and multidrug resistance-associated protein 2 was quantified using membrane vesicle assays. Inhibition of mitochondrial respiration in human liver-derived HuH-7 cells was determined using a Seahorse XF(e96) analyzer. Cytochrome P450 (P450)-independent and P450-mediated cell toxicity was assessed using transfected SV40-T-antigen-immortalized human liver epithelial (THLE) cell lines. Exposure-adjusted assay ratios were calculated by dividing the maximum human drug plasma concentrations by the IC50 or EC50 values obtained in vitro. Covalent binding (CVB) of radiolabeled drugs to human hepatocytes was quantified, and CVB body burdens were calculated by adjusting CVB values for fractional drug turnover in vitro and daily therapeutic dose. Sitaxentan exhibited positive exposure-adjusted signals in all five in vitro assays and a high CVB body burden. Bosentan exhibited a positive exposure-adjusted signal in one assay (BSEP inhibition) and a moderate CVB body burden. Ambrisentan exhibited no positive exposure-adjusted assay signals and a low CVB body burden. These data indicate that multiple mechanisms contribute to the rare, but potentially severe liver injury caused by sitaxentan in humans; provide a plausible rationale for the markedly lower propensity of bosentan to cause liver injury; and highlight the relative safety of ambrisentan. PMID:25467130

  2. Effects of VLA-4 antagonists in rat whole embryo culture.

    Science.gov (United States)

    Spence S; Vetter C; Hagmann WK; Van Riper G; Williams H; Mumford RA; Lanza TJ; Lin LS; Schmidt JA

    2002-01-01

    BACKGROUND: Pharmacological antagonism of VLA-4 (Very Late Antigen 4, alpha(4)beta(1) integrin) has become an attractive target for the treatment of predominantly eosinophil mediated disease states such as asthma, allergic rhinitis, multiple sclerosis, rheumatoid arthritis, diabetes, and inflammatory bowel disease. Gene knockouts of the alpha(4)-integrin subunit of VLA-4 or its cell surface ligand, VCAM-1, however, have been shown to result in embryo-lethality in homozygous null mice due to defects in chorio-allantoic or epi-myocardial fusion. Although gene knockout phenotypes are not always manifested by pharmacological antagonism, those studies suggested that VLA-4 antagonists might cause embryo-lethality or drug-induced malformations.METHODS: To test these concepts, early neurulating rat embryos were cultured by the methods of New ('78) after intra-coelomic microinjection of a VLA-4 blocking antibody or in the presence of small molecule VLA-4 antagonists.RESULTS: Defects in chorio-allantoic fusion were induced after microinjection of VLA4 blocking antibody and after continuous exposure to small molecule antagonists. In a minority of affected embryos chorio-allantoic fusion was completely blocked whereas the majority of affected embryos had only superficial chorio-allantoic fusion and the allantois was enlarged and edematous. Although the allantoic mesoderm covered the trophoblasts of the chorionic plate and contained blood vessels there was only minimal invasion of the trophoblasts by the allantoic mesoderm. The lowest observed effect level generally correlated with the IC(approximately 95), as determined in 90% plasma.DISCUSSION: Based on these data, VLA-4 antagonism might represent a significant risk to the developing embryo/fetus. In vitro exposure, however, is "constant" and does not take into account the elimination phase of these xenobiotics in vivo. Given the high concentrations required to elicit an effect, therapeutic blood levels in vivo may be several

  3. Antagonist effect of Interleukin 1 receptor on normal thymopoiesis and thymus toxicity of 5-azacytidine in mouse

    Science.gov (United States)

    Yu, Hongjing; Wu, Mingyuan; Wen, Bin; Sun, Ningyun; Xiang, Di; Zhang, Jing; Zhu, Shunying; Weng, Shunyan; Yu, Yan; Han, Wei

    2016-01-01

    Thymopoiesis is essential and significant for development and maintenance of the robust and healthy immune system. The acute suppression of thymopoiesis induced by 5-Azacytidine (5-Aza) is an intractable clinical problem complicating chemotherapy. Interleukin 1 receptor antagonist (IL-1Ra) is a cytokine that competitively blocks binding of interleukin 1 (IL-1) to its receptor. This study aims to investigate the effects of the IL-1Ra on the thymus toxicity of 5-Aza in mouse. In this study, we treated the mice with the 5-Aza (100 mg/kg per mouse). The GeneChip methodology developed by Affymetrix was used to monitor global gene expression during mouse thymus regeneration induced by a single injection of 5-Aza. The total thymocytes were counted using a hemocytometer. Cell cycle of samples were analyzed on a Becton Dickinson FACScan. Cells surfaces were labeled with anti-CD4, anti-CD8 and anti-CD45RA antibodies, and detected by flow cytometry. BrdU incorporation was detected by flow cytometry. The results indicated that administering exogenous IL-1Ra to normal mice inhibited cell cycle progress of thymocytes in a dosage-dependent manner. Proliferation of immature CD4-CD8- double negative (DN) and CD4+CD8+ double positive (DP) thymocytes were both inhibited. The pretreatment of normal mice with exogenous IL-1Ra reduced acute toxicity on thymus and immune suppression induced by 5-Aza. Furthermore, thymus reconstitution after 5-Aza treatment was accelerated by IL-1Ra. In conclusion, interleukin 1 receptor antagonist could inhibit normal thymopoiesis and reduce thymus toxicity of 5-azacytidine in mouse. Pretreatment with IL-1Ra would offer a new and promising strategy to alleviate immunotoxicity of chemotherapy in clinical. PMID:27158410

  4. Antagonist effect of Interleukin 1 receptor on normal thymopoiesis and thymus toxicity of 5-azacytidine in mouse.

    Science.gov (United States)

    Yu, Hongjing; Wu, Mingyuan; Wen, Bin; Sun, Ningyun; Xiang, Di; Zhang, Jing; Zhu, Shunying; Weng, Shunyan; Yu, Yan; Han, Wei

    2016-01-01

    Thymopoiesis is essential and significant for development and maintenance of the robust and healthy immune system. The acute suppression of thymopoiesis induced by 5-Azacytidine (5-Aza) is an intractable clinical problem complicating chemotherapy. Interleukin 1 receptor antagonist (IL-1Ra) is a cytokine that competitively blocks binding of interleukin 1 (IL-1) to its receptor. This study aims to investigate the effects of the IL-1Ra on the thymus toxicity of 5-Aza in mouse. In this study, we treated the mice with the 5-Aza (100 mg/kg per mouse). The GeneChip methodology developed by Affymetrix was used to monitor global gene expression during mouse thymus regeneration induced by a single injection of 5-Aza. The total thymocytes were counted using a hemocytometer. Cell cycle of samples were analyzed on a Becton Dickinson FACScan. Cells surfaces were labeled with anti-CD4, anti-CD8 and anti-CD45RA antibodies, and detected by flow cytometry. BrdU incorporation was detected by flow cytometry. The results indicated that administering exogenous IL-1Ra to normal mice inhibited cell cycle progress of thymocytes in a dosage-dependent manner. Proliferation of immature CD4(-)CD8(-) double negative (DN) and CD4(+)CD8(+) double positive (DP) thymocytes were both inhibited. The pretreatment of normal mice with exogenous IL-1Ra reduced acute toxicity on thymus and immune suppression induced by 5-Aza. Furthermore, thymus reconstitution after 5-Aza treatment was accelerated by IL-1Ra. In conclusion, interleukin 1 receptor antagonist could inhibit normal thymopoiesis and reduce thymus toxicity of 5-azacytidine in mouse. Pretreatment with IL-1Ra would offer a new and promising strategy to alleviate immunotoxicity of chemotherapy in clinical. PMID:27158410

  5. Dexmedetomidine inhibits vasoconstriction via activation of endothelial nitric oxide synthase

    Science.gov (United States)

    Nong, Lidan; Ma, Jue; Zhang, Guangyan; Deng, Chunyu; Mao, Songsong; Li, Haifeng

    2016-01-01

    Despite the complex vascular effects of dexmedetomidine (DEX), its actions on human pulmonary resistance arteries remain unknown. The present study tested the hypothesis that DEX inhibits vascular tension in human pulmonary arteries through the endothelial nitric oxide synthase (eNOS) mediated production of nitric oxide (NO). Pulmonary artery segments were obtained from 62 patients who underwent lung resection. The direct effects of DEX on human pulmonary artery tension and changes in vascular tension were determined by isometric force measurements recorded on a myograph. Arterial contractions caused by increasing concentrations of serotonin with DEX in the presence or absence of L-NAME (endothelial nitric oxide synthase inhibitor), yohimbine (α2-adrenoceptor antagonist) and indomethacin (cyclooxygenase inhibitor) as antagonists were also measured. DEX had no effect on endothelium-intact pulmonary arteries, whereas at concentrations of 10–8~10–6 mol/L, it elicited contractions in endothelium-denuded pulmonary arteries. DEX (0.3, 1, or 3×10–9 mmol/L) inhibited serotonin-induced contraction in arteries with intact endothelium in a dose-dependent manner. L-NAME and yohimbine abolished DEX-induced inhibition, whereas indomethacin had no effect. No inhibitory effect was observed in endothelium-denuded pulmonary arteries. DEX-induced inhibition of vasoconstriction in human pulmonary arteries is mediated by NO production induced by the activation of endothelial α2-adrenoceptor and nitric oxide synthase. PMID:27610030

  6. Insertion of an aspartic acid moiety into cyclic pseudopeptides: synthesis and biological characterization of potent antagonists for the human Tachykinin NK-2 receptor.

    Science.gov (United States)

    Fedi, Valentina; Altamura, Maria; Balacco, Giuseppe; Canfarini, Franca; Criscuoli, Marco; Giannotti, Danilo; Giolitti, Alessandro; Giuliani, Sandro; Guidi, Antonio; Harmat, Nicholas J S; Nannicini, Rossano; Pasqui, Franco; Patacchini, Riccardo; Perrotta, Enzo; Tramontana, Manuela; Triolo, Antonio; Maggi, Carlo Alberto

    2004-12-30

    A new series of monocyclic pseudopeptide tachykinin NK-2 receptor antagonists has been derived from the lead compound MEN11558. A synthesis for these molecules sharing the same intermediate was designed and performed. The replacement of the succinic moiety with an aspartic acid and the functionalization of its amino group with a wide variety of substituents led to very potent and selective NK-2 antagonists. Best results were obtained through the insertion in position 12 of an amino group with R configuration, linked by a short spacer to a saturated nitrogen heterocycle (morpholine, piperidine, or piperazine). The study led to compounds 54 and 57, endowed with high in vivo potency at very low doses and long duration of action in animal models of bronchoconstriction. In particular 54 and 57 completely inhibited NK-2 agonist induced bronchoconstriction in guinea pig after intratracheal administration at subnanomolar doses (ED(50) = 0.27 nmol/kg and 0.15 nmol/kg, respectively). PMID:15615542

  7. Alterations in locomotor activity after microinjections of GBR-12909, selective dopamine antagonists or neurotensin into the medial prefrontal cortex.

    Science.gov (United States)

    Radcliffe, R A; Erwin, V G

    1996-06-01

    It has been postulated that increased dopamine (DA) activity in the medial prefrontal cortex (mPFC) exerts an inhibitory influence over DA release in the nucleus accumbens and, thus, also over locomotor activity. Experiments were designed to examine the role of mPFC DA and neurotensin (NT), a neuropeptide which interacts with DA, in spontaneous locomotor activity. LS/IBG mice were injected bilaterally with either GBR-12909, a selective DA uptake blocker, the DA D1 receptor antagonist R-(+)-SCH-23390, the DA D2 receptor antagonist epidepride, NT or a combination of drugs. GBR-12909 produced a U-shaped dose-response curve with a maximum inhibition of 47% of control. Postmortem tissue levels of DA, 5-hydroxytryptamine, norepinephrine and their major metabolites were determined after microinjections of GBR-12909. Tissue levels of these compounds were not significantly affected by GBR-12909. However, the ratios of homovanilic acid/DA and homovanilic acid + 3,4-dihyroxyphenylacetic acid/DA were significantly decreased, whereas the 5-hydroxyindoleacetic acid/5-hydroxytryptamine ratio was not affected by GBR-12909, suggesting a selective effect on DAergic processes. By itself, R-(+)-SCH-23390 had no effect on locomotor activity except at a very high dose which caused locomotor inhibition (49% of control). Epidepride caused a dose-dependent inhibition of locomotor activity with a maximum inhibition of 49% of control. When coinjected with an inhibitory dose of GBR-12909, both epidepride and R-(+)-SCH-23390 attenuated the GBR-12909 effect in a dose-dependent manner. A broad range of doses of NT was found to have no consistent effect on locomotor activity. However, when coinjected with an inhibitory dose of GBR-12909, NT attenuated the GBR-12909-induced inhibition in a dose-dependent manner. The results suggest that stimulation of DA receptors in the mPFC, both DA D1 and DA D2 receptors mediates locomotor inhibition. Furthermore, stimulation of NT receptors appears to

  8. Transient Receptor Potential Vanilloid 4 Inhibits γ-Aminobutyric Acid-Activated Current in Hippocampal Pyramidal Neurons

    Science.gov (United States)

    Hong, Zhiwen; Tian, Yujing; Qi, Mengwen; Li, Yingchun; Du, Yimei; Chen, Lei; Liu, Wentao; Chen, Ling

    2016-01-01

    The balance between excitatory and inhibitory neurotransmitter systems is crucial for the modulation of neuronal excitability in the central nervous system (CNS). The activation of transient receptor potential vanilloid 4 (TRPV4) is reported to enhance the response of hippocampal glutamate receptors, but whether the inhibitory neurotransmitter system can be regulated by TRPV4 remains unknown. γ-aminobutyric acid (GABA) is the major inhibitory neurotransmitter in the CNS. Here, we show that application of transient receptor potential vanilloid 4 (TRPV4) synthetic (GSK1016790A or 4α-PDD) or endogenous agonist (5,6-EET) inhibited GABA-activated current (IGABA) in hippocampal CA1 pyramidal neurons, which was blocked by specific antagonists of TRPV4 and of GABAA receptors. GSK1016790A increased the phosphorylated AMP-activated protein kinase (p-AMPK) and decreased the phosphorylated protein kinase B (p-Akt) protein levels, which was attenuated by removing extracellular calcium or by a calcium/calmodulin-dependent protein kinase kinase-β antagonist. GSK1016790A-induced decrease of p-Akt protein level was sensitive to an AMPK antagonist. GSK1016790A-inhibited IGABA was blocked by an AMPK antagonist or a phosphatidyl inositol 3 kinase (PI3K) agonist. GSK1016790A-induced inhibition of IGABA was also significantly attenuated by a protein kinase C (PKC) antagonist but was unaffected by protein kinase A or calcium/calmodulin-dependent protein kinase II antagonist. We conclude that activation of TRPV4 inhibits GABAA receptor, which may be mediated by activation of AMPK and subsequent down-regulation of PI3K/Akt signaling and activation of PKC signaling. Inhibition of GABAA receptors may account for the neuronal hyperexcitability caused by TRPV4 activation.

  9. Isolation of bacteria producing chitinase and inhibiting growth of Rhizoctonia solani

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    @@ Five bacteria strains with higher chitinase activity were isolated by using a technique of enriched cell wall of R. solani. All of them showed inhibiting effect on the growth of R. solani. Being cultured 3 d, strain CH-1 showed higher chitinase activity on the chitin plate. The diameter of the transparent circle reached 8.7 mm (4 replications) . In the antagonistic test to R. solani in PDA plate, the circle was 18.1 mm. It was also observed that the antagonistic ability of some strains was not consistent with the chitinase activity (Table 1). It may be connected with the secretion of chitinase at different culture situations.

  10. The Screening and the Use of Antagonists for Biological Control of Anthracnose of Chilli at Pre-and Post-Harvesting

    International Nuclear Information System (INIS)

    A total of 301 of isolates of microorganism were isolated from pepper leaves and fruit skin, including fungi bacteria and yeast. They were tested inhibition of mycelia l growth of Colletotrichum gloeosporioides, a causal agent of anthracnose, on potato dextrose agar (PDA). The result showed that 145 isolate inhibited the growth of mycelia l by 45-70 %. The selected high efficiency antagonists were tested for potential reduce anthracnose lesion development on detected pepper fruit. The selected four isolate antagonists including Y18, YFm1, YFm2 and AC2-1 were finding suitable method test for control of anthracnose disease. The results show that application of antagonistic microorganism before inoculation of C. gloeosporiodes was superior in disease controlling than inoculation regardless the use of pathogen inoculation procedures. Antagonist Y18, YFm1 and YFm2 were test ability in greenhouse, in was found that three isolates have high efficiency for control anthracnose disease. Under field condition, spraying cell suspension of Y18, YFm2 and Yfm1 on pepper fruit before inoculation C. gloeosporioides and cover with plastic bag. 14 day after treatment it was found that Y18, YFm2, YFm1 and control had percentage of fruit disease by 33.33, 40.7, 73.4 and 100 % respectively. When study ability of three isolate in field at found anthracnose disease revealed that Y18 and YFm2 could control of C. gloesporiodides within 12 day after treatment. Addition, YFm2 could control of C. gloeosporidide in field at not found anthracnose high efficiency. The efficiency test of YFm2 for anthracnose controlling on chilli fruit for export were kept at 13 degree C for 18 days. YFm2 showed 100 % control of anthracnose with satisfactory firmness of chilli friut.

  11. In silico modelling of prostacyclin and other lipid mediators to nuclear receptors reveal novel thyroid hormone receptor antagonist properties.

    Science.gov (United States)

    Perez Diaz, Noelia; Zloh, Mire; Patel, Pryank; Mackenzie, Louise S

    2016-01-01

    Prostacyclin (PGI2) is a key mediator involved in cardiovascular homeostasis, acting predominantly on two receptor types; cell surface IP receptor and cytosolic peroxisome proliferator activated receptor (PPAR) β/δ. Having a very short half-life, direct methods to determine its long term effects on cells is difficult, and little is known of its interactions with nuclear receptors. Here we used computational chemistry methods to investigate the potential for PGI2, beraprost (IP receptor agonist), and GW0742 (PPARβ/δ agonist), to bind to nuclear receptors, confirmed with pharmacological methods. In silico screening predicted that PGI2, beraprost, and GW0742 have the potential to bind to different nuclear receptors, in particular thyroid hormone β receptor (TRβ) and thyroid hormone α receptor (TRα). Docking analysis predicts a binding profile to residues thought to have allosteric control on the TR ligand binding site. Luciferase reporter assays confirmed that beraprost and GW0742 display TRβ and TRα antagonistic properties; beraprost IC50 6.3×10(-5)mol/L and GW0742 IC50 4.9×10(-6)mol/L. Changes to triiodothyronine (T3) induced vasodilation of rat mesenteric arteries measured on the wire myograph were measured in the presence of the TR antagonist MLS000389544 (10(-5)mol/L), beraprost (10(-5)mol/L) and GW0742 (10(-5)mol/L); all significantly inhibited T3 induced vasodilation compared to controls. We have shown that both beraprost and GW0742 exhibit TRβ and TRα antagonist behaviour, and suggests that PGI2 has the ability to affect the long term function of cells through binding to and inactivating thyroid hormone receptors. PMID:26686607

  12. The design of orally bioavailable 2, 5-diketopiperazine oxytocin antagonists: from concept to clinical candidate for premature labor.

    Science.gov (United States)

    Borthwick, Alan D; Liddle, John

    2011-07-01

    A short, efficient and highly stereoselective synthesis has been developed for a series of 6-indanyl-3-alkyl-7-aryl/heterocyclic-(3R, 6R, 7R)-2, 5-diketopiperazine amides that are potent and selective oxytocin (OT) antagonists. Property-based design using an estimate of human oral absorption enabled focus to be directed to those templates with the greatest chance of delivering high bioavailability in humans. This led to the 2', 4'-difluorophenyl dimethylamide 40, a highly potent (pK(i) =9.2) and selective OT antagonist (>1,000-fold selectivity vs. the human vasopressin receptors V1a, V2, and V1b) with good oral bioavailability (>50%) in the rat and dog. Increased solubility and an improved Cyp450 profile was achieved with a range of 2'-substituted 7-(1',3'-oxazol-4'-yl)-(3R,6R,7R)-2,5-diketopiperazine amides and branching at the α-carbon of the 3-butyl group led to a superior rat pharmacokinetic profile that resulted in the discovery of the 2'-methyl-1',3'-oxazol-4'-yl morpholine amide derivative 74 GSK221149A (Retosiban), which had the best oral exposure and bioavailability in the rat. Retosiban has sub-nanomolar affinity (K(i) =0.65 nM) for the oxytocin receptor with >1400-fold selectivity over the closely related vasopressin receptors. It has good solubility, low protein binding and has a good Cyp450 profile with no significant inhibition IC(50) >100 µM. Retosiban is >15-fold more potent at the human oxytocin receptor than atosiban (a marketed i.v, peptide OT antagonist) and it has been shown to be an effective tocolytic by i.v. and by oral administration in rats, and was selected for progression as a potential clinical candidate for preterm labor. PMID:20027670

  13. Antiproliferative effect of growth hormone-releasing hormone (GHRH antagonist on ovarian cancer cells through the EGFR-Akt pathway

    Directory of Open Access Journals (Sweden)

    Varga Jozsef

    2010-05-01

    Full Text Available Abstract Background Antagonists of growth hormone-releasing hormone (GHRH are being developed for the treatment of various human cancers. Methods MTT assay was used to test the proliferation of SKOV3 and CaOV3. The splice variant expression of GHRH receptors was examined by RT-PCR. The expression of protein in signal pathway was examined by Western blotting. siRNA was used to block the effect of EGFR. Results In this study, we investigated the effects of a new GHRH antagonist JMR-132, in ovarian cancer cell lines SKOV3 and CaOV3 expressing splice variant (SV1 of GHRH receptors. MTT assay showed that JMR-132 had strong antiproliferative effects on SKOV3 and CaOV3 cells in both a time-dependent and dose-dependent fashion. JMR-132 also induced the activation and increased cleaved caspase3 in a time- and dose-dependent manner in both cell lines. In addition, JMR-132 treatments decreased significantly the epidermal growth factor receptor (EGFR level and the phosphorylation of Akt (p-Akt, suggesting that JMR-132 inhibits the EGFR-Akt pathway in ovarian cancer cells. More importantly, treatment of SKOV3 and CaOV3 cells with 100 nM JMR-132 attenuated proliferation and the antiapoptotic effect induced by EGF in both cell lines. After the knockdown of the expression of EGFR by siRNA, the antiproliferative effect of JMR-132 was abolished in SKOV3 and CaOV3 cells. Conclusions The present study demonstrates that the inhibitory effect of the GHRH antagonist JMR-132 on proliferation is due, in part, to an interference with the EGFR-Akt pathway in ovarian cancer cells.

  14. Renoprotective Effects of a Highly Selective A3 Adenosine Receptor Antagonist in a Mouse Model of Adriamycin-induced Nephropathy.

    Science.gov (United States)

    Min, Hye Sook; Cha, Jin Joo; Kim, Kitae; Kim, Jung Eun; Ghee, Jung Yeon; Kim, Hyunwook; Lee, Ji Eun; Han, Jee Young; Jeong, Lak Shin; Cha, Dae Ryong; Kang, Young Sun

    2016-09-01

    The concentration of adenosine in the normal kidney increases markedly during renal hypoxia, ischemia, and inflammation. A recent study reported that an A3 adenosine receptor (A3AR) antagonist attenuated the progression of renal fibrosis. The adriamycin (ADX)-induced nephropathy model induces podocyte injury, which results in severe proteinuria and progressive glomerulosclerosis. In this study, we investigated the preventive effect of a highly selective A3AR antagonist (LJ1888) in ADX-induced nephropathy. Three groups of six-week-old Balb/c mice were treated with ADX (11 mg/kg) for four weeks and LJ1888 (10 mg/kg) for two weeks as following: 1) control; 2) ADX; and 3) ADX + LJ1888. ADX treatment decreased body weight without a change in water and food intake, but this was ameliorated by LJ1888 treatment. Interestingly, LJ1888 lowered plasma creatinine level, proteinuria, and albuminuria, which had increased during ADX treatment. Furthermore, LJ1888 inhibited urinary nephrin excretion as a podocyte injury marker, and urine 8-isoprostane and kidney lipid peroxide concentration, which are markers of oxidative stress, increased after injection of ADX. ADX also induced the activation of proinflammatory and profibrotic molecules such as TGF-β1, MCP-1, PAI-1, type IV collagen, NF-κB, NOX4, TLR4, TNFα, IL-1β, and IFN-γ, but they were remarkably suppressed after LJ1888 treatment. In conclusion, our results suggest that LJ1888 has a renoprotective effect in ADX-induced nephropathy, which might be associated with podocyte injury through oxidative stress. Therefore, LJ1888, a selective A3AR antagonist, could be considered as a potential therapeutic agent in renal glomerular diseases which include podocyte injury and proteinuria. PMID:27510383

  15. The dopamine receptor antagonist levo-tetrahydropalmatine attenuates heroin self-administration and heroin-induced reinstatement in rats.

    Science.gov (United States)

    Yue, Kai; Ma, Baomiao; Ru, Qin; Chen, Lin; Gan, Yongping; Wang, Daisong; Jin, Guozhang; Li, Chaoying

    2012-07-01

    Opiate addiction is a chronic recrudescent disorder characterized by a high rate of relapse. Levo-tetrahydropalmatine (l-THP) is an alkaloid substance extracted from Corydalis and Stephania and is contained in a number of traditional Chinese herbal preparations. Compared to other dopamine receptor antagonists, l-THP has lower affinity for D2 receptors than for D1 receptors, and a recent study showed that l-THP also binds to D3 receptors, possibly functioning as an antagonist. The unique pharmacological profile of l-THP suggests that l-THP may be effective for the treatment of opiate addiction. In this study, we investigated the effects of l-THP on heroin self-administration and reinstatement triggered by a priming injection of heroin in abstinent rats trained to stably self-administer heroin under an extinction/reinstatement protocol, and found that l-THP (2.5 and 5 mg/kg, i.p.) decreased heroin self-administration on the fixed-ratio 1 schedule and dose-dependently (1.25, 2.5 and 5 mg/kg, i.p.) inhibited heroin-induced reinstatement of heroin-seeking behavior. Importantly, l-THP (1.25 and 2.5 mg/kg, i.p.) did not affect locomotion, indicating that the observed effects of l-THP on reinstatement do not appear to be due to motor impairments. The present results demonstrated that dopamine receptor antagonist l-THP attenuates heroin self-administration and heroin-induced reinstatement. PMID:22741173

  16. Influenza A virus does not encode a tetherin antagonist with Vpu-like activity and induces IFN-dependent tetherin expression in infected cells.

    Directory of Open Access Journals (Sweden)

    Michael Winkler

    Full Text Available The interferon-induced host cell factor tetherin inhibits release of human immunodeficiency virus (HIV from the plasma membrane of infected cells and is counteracted by the HIV-1 protein Vpu. Influenza A virus (FLUAV also buds from the plasma membrane and is not inhibited by tetherin. Here, we investigated if FLUAV encodes a functional equivalent of Vpu for tetherin antagonism. We found that expression of the FLUAV protein NS1, which antagonizes the interferon (IFN response, did not block the tetherin-mediated restriction of HIV release, which was rescued by Vpu. Similarly, tetherin-mediated inhibition of HIV release was not rescued by FLUAV infection. In contrast, FLUAV infection induced tetherin expression on target cells in an IFN-dependent manner. These results suggest that FLUAV escapes the antiviral effects of tetherin without encoding a tetherin antagonist with Vpu-like activity.

  17. A novel integrin α5β1 antagonistic peptide, A5-1, screened by Protein Chip system as a potent angiogenesis inhibitor

    International Nuclear Information System (INIS)

    Integrin α5β1 immobilized on a ProteoChip was used to screen new antagonistic peptides from multiple hexapeptide sub-libraries of the positional scanning synthetic peptide combinatorial library (PS-SPCL). The integrin α5β1-Fibronectin interaction was demonstrated on the chip. A novel peptide ligand, A5-1 (VILVLF), with high affinity to integrin α5β1 was identified from the hexapeptide libraries with this chip-based screening method on the basis of a competitive inhibition assay. A5-1 inhibits the integrin-fibronectin interaction in a dose-dependent manner (IC50; 1.56 ± 0.28 μM. In addition, it inhibits human umbilical vein endothelial cell proliferation, migration, adhesion, tubular network formation, and bFGF-induced neovascularization in a chick chorioallantoic membrane. These results suggest that A5-1 will be a potent inhibitor of neovascularization.

  18. Sexually antagonistic "zygotic drive" of the sex chromosomes.

    Directory of Open Access Journals (Sweden)

    William R Rice

    2008-12-01

    Full Text Available Genomic conflict is perplexing because it causes the fitness of a species to decline rather than improve. Many diverse forms of genomic conflict have been identified, but this extant tally may be incomplete. Here, we show that the unusual characteristics of the sex chromosomes can, in principle, lead to a previously unappreciated form of sexual genomic conflict. The phenomenon occurs because there is selection in the heterogametic sex for sex-linked mutations that harm the sex of offspring that does not carry them, whenever there is competition among siblings. This harmful phenotype can be expressed as an antagonistic green-beard effect that is mediated by epigenetic parental effects, parental investment, and/or interactions among siblings. We call this form of genomic conflict sexually antagonistic "zygotic drive", because it is functionally equivalent to meiotic drive, except that it operates during the zygotic and postzygotic stages of the life cycle rather than the meiotic and gametic stages. A combination of mathematical modeling and a survey of empirical studies is used to show that sexually antagonistic zygotic drive is feasible, likely to be widespread in nature, and that it can promote a genetic "arms race" between the homo- and heteromorphic sex chromosomes. This new category of genomic conflict has the potential to strongly influence other fundamental evolutionary processes, such as speciation and the degeneration of the Y and W sex chromosomes. It also fosters a new genetic hypothesis for the evolution of enigmatic fitness-reducing traits like the high frequency of spontaneous abortion, sterility, and homosexuality observed in humans.

  19. The role of oxytocin antagonists in repeated implantation failure

    OpenAIRE

    Decleer, W.; Osmanagaoglu, K.; Devroey, P.

    2012-01-01

    A prospective cohort study has been performed to find out if the administration of an oxytocin antagonist (Atosiban) at the occasion of embryo transfer has an effect on the pregnancy rate in patients with repeated failure of implantation. A total of 52 women with repeated failure of implantation after IVF/ICSI were included in this study. The ongoing pregnancy rate (OPR) in the total group of patients was 12 out of 52 (23.1%). Based on embryo quality all cases were categorized in two groups. ...

  20. The opiate antagonist, naltrexone, in the treatment of trichotillomania

    DEFF Research Database (Denmark)

    Grant, Jon E; Odlaug, Brian Lawrence; Schreiber, Liana R N;

    2014-01-01

    Trichotillomania (TTM) is characterized by repetitive hair pulling resulting in hair loss. Data on the pharmacological treatment of TTM are limited. This study examined the opioid antagonist, naltrexone, in adults with TTM who had urges to pull their hair. Fifty-one individuals with TTM were...... randomized to naltrexone or placebo in an 8-week, double-blind trial. Subjects were assessed with measures of TTM severity and selected cognitive tasks. Naltrexone failed to demonstrate significantly greater reductions in hair pulling compared to placebo. Cognitive flexibility, however, significantly...

  1. Synthesis of carbon-11 labelled calcium channel antagonists

    International Nuclear Information System (INIS)

    A useful synthetic approach to carbon-11 labelled 1,4-dihydropyridines is described. Carbon-11 labelled calcium channel antagonists 11C-Nifedipine, 11C-Nisoldipine, 11C-nitrendipine and 11C-CF3-Nifedipine were synthesized by a modified Hantzsch method using protected carboxy functions. Deprotection of the carboxylic acids by alkaline hydrolysis followed by conversion into the corresponding potassium salts and subsequent methylation with 11CH3I produced the labelled compounds in very good chemical and radiochemical yields (94%). (author)

  2. Interaction of palmitoyl carnitine with calcium antagonists in myocytes.

    OpenAIRE

    Patmore, L; Duncan, G. P.; Spedding, M.

    1989-01-01

    1. Beating of aggregates of embryonic chick myocytes, in primary culture, was quantified by use of a motion-detector and video-recorder technique. Interactions of palmitoyl carnitine, a putative endogenous ligand at Ca2+ channels, with calcium antagonists were investigated. 2. Bay K 8644 (1-100 nM) and palmitoyl carnitine (0.2-30 microM) increased edge movement of the aggregates; beats fused so that there was an increase in baseline 'tone'. The concentrations required to produce a 50% increas...

  3. Komplikationer til langtidsbehandling med vitamin K-antagonister

    DEFF Research Database (Denmark)

    May, O; Garne, E; Mickley, H

    1990-01-01

    Long-term treatment with vitamin K antagonists (vKA) frequently involves complications. The commonest complication is haemorrhage and cases of serious haemorrhage are stated in the literature to occur with a frequency per 1,000 treatment years of 12-108, of which 2-17 are fatal. The majority of...... deaths associated with haemorrhage are due to intracranial haemorrhage. Notifications of complications of vKA treatment in Denmark are considerably fewer than might be anticipated from the literature. The stability of anticoagulation treatment decreases with the number of drugs administered...

  4. ANTIHYPERTENSIVE TREATMENT IN ELDERLY PATIENTS WITH DIHYDROPYRIDINE CALCIUM ANTAGONISTS

    Directory of Open Access Journals (Sweden)

    Y. A. Karpov

    2016-01-01

    Full Text Available The proofs of necessity of active arterial hypertension (AH treatment in elderly patients are given. Peculiarities of pathogenesis of AH in elderly patients, connected predominantly with loss of big arteries elasticity and reasoning widely spread of isolated systolic AH in these patients, are discussed. Advantages of dihydropyridine calcium antagonists (DPCA for AH treatment in elderly patients are proved, safety of treatment with DPCA is discussed. Data of clinical studies is analyzed. Analysis of target levels of blood pressure for antihypertensive treatment in elderly hypertensive patients is made. As a conclusion DPCA are the medicines of choice for AH treatment in elderly patients.

  5. The Rotavirus Interferon Antagonist NSP1: Many Targets, Many Questions.

    Science.gov (United States)

    Arnold, Michelle M

    2016-06-01

    Rotavirus is a leading cause of death due to diarrhea among young children across the globe. Despite the limited coding capacity that is characteristic of RNA viruses, rotavirus dedicates substantial resources to avoiding the host innate immune response. Among these strategies is use of the interferon antagonist protein NSP1, which targets cellular proteins required for interferon production to be degraded by the proteasome. Although numerous cellular targets have been described, there remain many questions about the mechanism of NSP1 activity and its role in promoting replication in specific host species. PMID:27009959

  6. Expression of Interleukin 1 Receptor Antagonist in Human Cornea

    OpenAIRE

    Heur, Martin; Shyam S. Chaurasia; Wilson, Steven E.

    2008-01-01

    The purpose of this study was to confirm the expression of interleukin-1 receptor antagonist (IL-1 Ra) in the human cornea. Four samples of human ex vivo corneal epithelium were obtained from patients undergoing photorefractive keratectomy. RT-PCR was performed using mRNA isolated from the corneal epithelium and oligo-dT primers. PCR was performed on the cDNA products using primers specific for human IL-1Ra. The PCR products were subcloned and sequenced. Human cornea sections were prepared fr...

  7. Antagonist of prostaglandin E2 receptor 4 induces metabolic alterations in liver of mice.

    Science.gov (United States)

    Li, Ning; Zhang, Limin; An, Yanpeng; Zhang, Lulu; Song, Yipeng; Wang, Yulan; Tang, Huiru

    2015-03-01

    Prostaglandin E2 receptor 4 (EP4) is one of the receptors for prostaglandin E2 and plays important roles in various biological functions. EP4 antagonists have been used as anti-inflammatory drugs. To investigate the effects of an EP4 antagonist (L-161982) on the endogenous metabolism in a holistic manner, we employed a mouse model, and obtained metabolic and transcriptomic profiles of multiple biological matrixes, including serum, liver, and urine of mice with and without EP4 antagonist (L-161982) exposure. We found that this EP4 antagonist caused significant changes in fatty acid metabolism, choline metabolism, and nucleotide metabolism. EP4 antagonist exposure also induced oxidative stress to mice. Our research is the first of its kind to report information on the alteration of metabolism associated with an EP4 antagonist. This information could further our understanding of current and new biological functions of EP4. PMID:25669961

  8. [Influence of GABA(C)-Receptor Antagonist on Formation of Evoked Potentials in Columns of the Rat Somatosensory Cortex].

    Science.gov (United States)

    Matukhno, A E; Lysenko, L V; Andreeva, Y V; Sukhov, A G

    2015-01-01

    Microelectrode studies of evoked potentials (EP) in neuronal column of rats barrel cortex show activating action of selective GABA(C)-receptor antagonist 1,2,5,6-tetrahydropyridin-4-yl-methylphosphinic acid (TPMPA) mainly on secondary components of EP of supragranular afferent layers of column compared to the efferent infragranular layers. These data suggest localization of GABA(C)-receptors on pre- synaptic terminals of thalamo-cortical glutamatergic afferents and ascending apical dendrites of pyramidal cells. A blockade of GABA(C)-receptors with the selective antagonist TPM PA leads to dose-dependent afferent depolarization with development of presynaptic inhibition and suppression of primary components of EP GABA(C)-receptors blocker produces different effects on secondary components of EP in supragranular layers of the cortex caused by the development of neuronal after hyperpolarization followed by high-amplitude primary response and afterdepolarization followed by low-amplitude primary responses with subsequent activation of different voltage-gated channels and formation of different level of cortical direct current potential gradients. PMID:26841661

  9. Development of a new Ca2+/calmodulin antagonist and its anti-proliferative activity against colorectal cancer cells

    International Nuclear Information System (INIS)

    We previously identified a cellular target of a cell cycle inhibitor HBC as Ca2+/calmodulin (Ca2+/CaM) through chemical genetics approach. Using the mechanism-based drug design, we developed a new Ca2+/CaM antagonists based on the structure of HBC. The compound, (4-{3,5-bis-[2-(4-hydroxy-3-methoxy-phenyl)-vinyl]-4,5-dihydro-pyrazol-1-yl }-phenyl)-(4-methyl-piperazin-1-yl)-methanone (referred as HBCP), binds to Ca2+/CaM in vitro and inhibits the proliferation of HCT15 colon cancer cells. HBCP induced sustained phosphorylation of ERK1/2 and subsequently activated p21WAF1 expression in HCT15 cells. Moreover, HBCP reversibly induced the G0/G1 cell cycle arrest in the cells. These data demonstrate that HBCP is a new potent Ca2+/CaM antagonist and can be applied for CaM related therapeutic uses

  10. Kinetics of in vivo binding of antagonist to muscarinic cholinergic receptor in the human heart studied by Positron Emission Tomography

    Energy Technology Data Exchange (ETDEWEB)

    Syrota, A.; Paillotin, G.; Davy, J.M.; Aumont, M.C.

    1984-08-27

    Positron Emission Tomography (PET) was used to analyze in vivo antagonist binding to human myocardial muscarinic cholinergic receptor. The methiodide salt of the muscarinic antagonist, quinuclidinyl benzilate (MQNB), was labeled with the positron emitter, Carbon-11, and injected intravenously to 8 normal subjects. /sup 11/C-MQNB concentration was determined in vivo in the ventricular septum from 40 cross-sectional images acquired at the same transverse level over a period of 70 minutes. In 4 subjects, various amounts of unlabeled atropine were rapidly injected at 20 minutes to study whether atropine competitively inhibited MQNB. The kinetics of binding of /sup 11/C-MQNB were not the same in vivo and in vitro. The apparent dissociation rate of /sup 11/C-MQNB in vivo was much slower (by 1 to 2 orders of magnitude) than that observed in vitro with /sup 3/H-QNB. After atropine injection, /sup 11/C-MQNB dissociated from its binding sites at a rate that apparently depended on the amount of atropine present. /sup 11/C-MQNB kinetics were analyzed with a mathematical model which assumes the existence of a boundary layer containing free ligand in the vicinity of the binding sites. The dissociation rate of the radioligand depends on the probability of its rebinding to a free receptor site. 11 references, 1 table.

  11. Pyridyl-2,5-diketopiperazines as potent, selective, and orally bioavailable oxytocin antagonists: synthesis, pharmacokinetics, and in vivo potency.

    Science.gov (United States)

    Borthwick, Alan D; Liddle, John; Davies, Dave E; Exall, Anne M; Hamlett, Christopher; Hickey, Deirdre M; Mason, Andrew M; Smith, Ian E D; Nerozzi, Fabrizio; Peace, Simon; Pollard, Derek; Sollis, Steve L; Allen, Michael J; Woollard, Patrick M; Pullen, Mark A; Westfall, Timothy D; Stanislaus, Dinesh J

    2012-01-26

    A six-stage stereoselective synthesis of indanyl-7-(3'-pyridyl)-(3R,6R,7R)-2,5-diketopiperazines oxytocin antagonists from indene is described. SAR studies involving mono- and disubstitution in the 3'-pyridyl ring and variation of the 3-isobutyl group gave potent compounds (pK(i) > 9.0) with good aqueous solubility. Evaluation of the pharmacokinetic profile in the rat, dog, and cynomolgus monkey of those derivatives with low cynomolgus monkey and human intrinsic clearance gave 2',6'-dimethyl-3'-pyridyl R-sec-butyl morpholine amide Epelsiban (69), a highly potent oxytocin antagonist (pK(i) = 9.9) with >31000-fold selectivity over all three human vasopressin receptors hV1aR, hV2R, and hV1bR, with no significant P450 inhibition. Epelsiban has low levels of intrinsic clearance against the microsomes of four species, good bioavailability (55%) and comparable potency to atosiban in the rat, but is 100-fold more potent than the latter in vitro and was negative in the genotoxicity screens with a satisfactory oral safety profile in female rats. PMID:22239250

  12. The oxytocin receptor antagonist, Atosiban, activates pro-inflammatory pathways in human amnion via G(αi) signalling.

    Science.gov (United States)

    Kim, Sung Hye; MacIntyre, David A; Hanyaloglu, Aylin C; Blanks, Andrew M; Thornton, Steven; Bennett, Phillip R; Terzidou, Vasso

    2016-01-15

    Oxytocin (OT) plays an important role in the onset of human labour by stimulating uterine contractions and promoting prostaglandin/inflammatory cytokine synthesis in amnion via oxytocin receptor (OTR) coupling. The OTR-antagonist, Atosiban, is widely used as a tocolytic for the management of acute preterm labour. We found that in primary human amniocytes, Atosiban (10 μM) signals via PTX-sensitive Gαi to activate transcription factor NF-κB p65, ERK1/2, and p38 which subsequently drives upregulation of the prostaglandin synthesis enzymes, COX-2 and phospho-cPLA2 and excretion of prostaglandins (PGE2) (n = 6; p Atosiban treatment increased expression and excretion of the inflammatory cytokines, IL-6 and CCL5. We also showed that OT-simulated activation of NF-κB, ERK1/2, and p38 and subsequent prostaglandin and inflammatory cytokine synthesis is via Gαi-2 and Gαi-3 but not Gαq, and is not inhibited by Atosiban. Activation or exacerbation of inflammation is not a desirable effect of tocolytics. Therefore therapeutic modulation of the OT/OTR system for clinical management of term/preterm labour should consider the effects of differential G-protein coupling of the OTR and the role of OT or selective OTR agonists/antagonists in activating proinflammatory pathways. PMID:26586210

  13. Effects of oral cetirizine, a selective H1 antagonist, on allergen- and exercise-induced bronchoconstriction in subjects with asthma.

    LENUS (Irish Health Repository)

    Gong, H

    1990-03-01

    The protective efficacy of oral cetirizine, a selective and potent H1-receptor antagonist, against the immediate bronchoconstrictive response to allergen inhalation and exercise challenge was evaluated in 16 subjects with stable, predominantly mild asthma. The subjects underwent double-blind, crossover pretreatments in randomized order in two separate protocols with (1) three daily oral doses of 20 mg of cetirizine and placebo, followed by allergen inhalation, and (2) single oral doses of cetirizine (5, 10, and 20 mg), albuterol (4 mg), and placebo, followed by exercise with cold-air inhalation. Cetirizine failed to decrease bronchial sensitivity to inhaled allergen in eight of 10 subjects. Neither cetirizine nor albuterol uniformly inhibited exercise-induced bronchoconstriction. Serum concentrations of cetirizine were consistent with systemic H1-blocking activity. Modest bronchodilation occurred after administration of cetirizine and albuterol before exercise but not after the third dose of cetirizine in the allergen protocol. One subject developed moderate drowsiness during multiple dosing with cetirizine. Thus, cetirizine, in the doses studied, is not uniformly effective in preventing allergen- or exercise-induced bronchoconstriction. Histamine is one of many mediators participating in immediate asthmatic responses, and selective H1 antagonists do not completely block these airway events. However, cetirizine may still clinically benefit some patients with asthma, such as patients with allergic rhinitis or urticaria.

  14. P2X7 receptor antagonist activity of the anti-allergic agent oxatomide.

    Science.gov (United States)

    Yoshida, Kazuki; Ito, Masaaki; Matsuoka, Isao

    2015-11-15

    Activation of the P2X7 receptor by extracellular ATP is associated with various immune responses including allergic inflammation. Anti-allergic agents, such as H1-antihistamines, are known to inhibit the effects of different chemical mediators such as acetylcholine and platelet-activating factor. Therefore, we hypothesized that some anti-allergic agents might affect P2X7 receptor function. Using N18TG2 and J774 cells, which express functional P2X7 receptors, the effects of several anti-allergic agents on P2X7 receptor function were investigated by monitoring the ATP-induced increase in intracellular Ca(2+) concentrations ([Ca(2+)]i). Among the various agents tested, oxatomide significantly inhibited P2X7 receptor-mediated [Ca(2+)]i elevation in a concentration-dependent manner without affecting the P2Y2 receptor-mediated response in both N18TG2 and J774 cells. Consistently, oxatomide inhibited P2X7 receptor-mediated membrane current and downstream responses such as mitogen-activated protein kinase activation, inflammation-related gene induction, and cell death. In addition, oxatomide inhibited P2X7 receptor-mediated degranulation in mouse bone marrow-derived mast cells. Whole cell patch clamp analyses in HEK293 cells expressing human, mouse, and rat P2X7 receptors revealed that the inhibitory effect of oxatomide on ATP-induced current was most prominent for the human P2X7 receptor and almost non-existent for the rat P2X7 receptor. The potent inhibitory effects of oxatomide on human P2X7 receptor-mediated function were confirmed in RPMI8226 human B cell-like myeloma cells, which endogenously express the P2X7 receptor. Our results demonstrated that the antihistamine oxatomide also acts as a P2X7 receptor antagonist. Future studies should thus evaluate whether P2X7 receptor antagonism contributes to the anti-allergic effects of oxatomide. PMID:26463039

  15. Contributions of different modes of TRPV1 activation to TRPV1 antagonist-induced hyperthermia

    OpenAIRE

    Garami, Andras; Shimansky, Yury P.; Pakai, Eszter; Oliveira, Daniela L.; Gavva, Narender R.; Romanovsky, Andrej A

    2010-01-01

    Transient receptor potential vanilloid-1 (TRPV1) antagonists are widely viewed as next-generation pain therapeutics. However, these compounds cause hyperthermia, a serious side effect. TRPV1 antagonists differentially block three modes of TRPV1 activation: by heat, protons, and chemical ligands (e.g., capsaicin). We asked what combination of potencies in these three modes of TRPV1 activation corresponds to the lowest potency of a TRPV1 antagonist to cause hyperthermia. We studied hyperthermic...

  16. The kappa opioid receptor antagonist JDTic attenuates alcohol seeking and withdrawal anxiety

    OpenAIRE

    Schank, Jesse R.; Goldstein, Andrea L.; Rowe, Kelly E.; King, Courtney E.; Marusich, Julie A.; Wiley, Jenny L; Carroll, F. Ivy; Thorsell, Annika; Heilig, Markus

    2012-01-01

    The role of kappa-opioid receptors (KOR) in regulation of alcohol-related behaviors is not completely understood. For example, alcohol consumption has been reported to increase following treatment with KOR antagonists in rats, but was decreased in mice with genetic deletion of KOR. Recent studies have further suggested that KOR antagonists may selectively decrease alcohol self-administration in rats following a history of dependence. We assessed the effects of the KOR antagonist JDTic on alco...

  17. Antagonistic and synergistic effects of light irradiation on the effects of copper on Chlamydomonas reinhardtii

    Energy Technology Data Exchange (ETDEWEB)

    Cheloni, Giulia; Cosio, Claudia; Slaveykova, Vera I., E-mail: vera.slaveykova@unige.ch

    2014-10-15

    Highlights: • Light intensity and spectral composition affect Cu uptake and effects to C. reinhardtii. • High light (HL) reduced Cu effect on growth inhibition, oxidative stress and damage. • HL in combination with Cu up-regulated genes involved in the antioxidant responses. • HL with increased UVB radiation exacerbated Cu uptake and Cu-induced toxic effects. - Abstract: The present study showed the important role of light intensity and spectral composition on Cu uptake and effects on green alga Chlamydomonas reinhardtii. High-intenisty light (HL) increased cellular Cu concentrations, but mitigated the Cu-induced decrease in chlorophyll fluorescence, oxidative stress and lipid peroxidation at high Cu concentrations, indicating that Cu and HL interact in an antagonistic manner. HL up-regulated the transcription of genes involved in the antioxidant response in C. reinhardtii and thus reduced the oxidative stress upon exposure to Cu and HL. Combined exposure to Cu and UVBR resulted in an increase of cellular Cu contents and caused severe oxidative damage to the cells. The observed effects were higher than the sum of the effects corresponding to exposure to UVBR or Cu alone suggesting a synergistic interaction.

  18. A new potent calmodulin antagonist with arylalkylamine structure: crystallographic, spectroscopic and functional studies.

    Science.gov (United States)

    Harmat, V; Böcskei, Z; Náray-Szabó, G; Bata, I; Csutor, A S; Hermecz, I; Arányi, P; Szabó, B; Liliom, K; Vértessy, B G; Ovádi, J

    2000-03-31

    An arylalkylamine-type calmodulin antagonist, N-(3, 3-diphenylpropyl)-N'-[1-R-(3, 4-bis-butoxyphenyl)ethyl]-propylene-diamine (AAA) is presented and its complexes with calmodulin are characterized in solution and in the crystal. Near-UV circular dichroism spectra show that AAA binds to calmodulin with 2:1 stoichiometry in a Ca(2+)-dependent manner. The crystal structure with 2:1 stoichiometry is determined to 2.64 A resolution. The binding of AAA causes domain closure of calmodulin similar to that obtained with trifluoperazine. Solution and crystal data indicate that each of the two AAA molecules anchors in the hydrophobic pockets of calmodulin, overlapping with two trifluoperazine sites, i.e. at a hydrophobic pocket and an interdomain site. The two AAA molecules also interact with each other by hydrophobic forces. A competition enzymatic assay has revealed that AAA inhibits calmodulin-activated phosphodiesterase activity at two orders of magnitude lower concentration than trifluoperazine. The apparent dissociation constant of AAA to calmodulin is 18 nM, which is commensurable with that of target peptides. On the basis of the crystal structure, we propose that the high-affinity binding is mainly due to a favorable entropy term, as the AAA molecule makes multiple contacts in its complex with calmodulin. PMID:10731425

  19. Antagonistic and synergistic effects of light irradiation on the effects of copper on Chlamydomonas reinhardtii

    International Nuclear Information System (INIS)

    Highlights: • Light intensity and spectral composition affect Cu uptake and effects to C. reinhardtii. • High light (HL) reduced Cu effect on growth inhibition, oxidative stress and damage. • HL in combination with Cu up-regulated genes involved in the antioxidant responses. • HL with increased UVB radiation exacerbated Cu uptake and Cu-induced toxic effects. - Abstract: The present study showed the important role of light intensity and spectral composition on Cu uptake and effects on green alga Chlamydomonas reinhardtii. High-intenisty light (HL) increased cellular Cu concentrations, but mitigated the Cu-induced decrease in chlorophyll fluorescence, oxidative stress and lipid peroxidation at high Cu concentrations, indicating that Cu and HL interact in an antagonistic manner. HL up-regulated the transcription of genes involved in the antioxidant response in C. reinhardtii and thus reduced the oxidative stress upon exposure to Cu and HL. Combined exposure to Cu and UVBR resulted in an increase of cellular Cu contents and caused severe oxidative damage to the cells. The observed effects were higher than the sum of the effects corresponding to exposure to UVBR or Cu alone suggesting a synergistic interaction

  20. Antagonistic activity of fungi of Olea europaea L. against Colletotrichum acutatum.

    Science.gov (United States)

    Landum, Miguel C; Félix, Maria do Rosário; Alho, Joana; Garcia, Raquel; Cabrita, Maria João; Rei, Fernando; Varanda, Carla M R

    2016-02-01

    Fungi naturally present in olive trees were identified and tested for their antagonistic potential against Colletotrichum acutatum. A total of 14 isolates were identified, 12 belonged to genera Alternaria, Epicoccum, Fusarium, Aspergillus, Anthrinium, Chaetomium, Diaporthe, Nigrospora, one to family Xylariaceae and one was unclassified. All fungal isolates showed some inhibitory action over the growth of C. acutatum during dual culture growth, however, when agar-diffusible tests were performed only five fungal isolates caused C. acutatum growth inhibition: Alternaria sp. isolate 2 (26.8%), the fungus from Xylariaceae family (14.3%), Alternaria sp. isolate 1 (10.7%); Diaporthe sp. (10.7%), Nigrospora oryzae (3.5%). Volatile substances produced by these isolates were identified through gas-chromatography techniques, as phenylethyl alcohol, 4-methylquinazoline, benzothiazole, benzyl alcohol, lilial, galaxolide, among others. These inhibitory volatiles could play a significant role in reduction of C. acutatum expansion in olive and their study as potential biocontrol agents should be further explored. PMID:26805623

  1. Antagonistic interactions between garden yeasts and microfungal garden pathogens of leaf-cutting ants.

    Science.gov (United States)

    Rodrigues, Andre; Cable, Rachel N; Mueller, Ulrich G; Bacci, Maurício; Pagnocca, Fernando C

    2009-10-01

    We investigate the diversity of yeasts isolated in gardens of the leafcutter ant Atta texana. Repeated sampling of gardens from four nests over a 1-year time period showed that gardens contain a diverse assemblage of yeasts. The yeast community in gardens consisted mostly of yeasts associated with plants or soil, but community composition changed between sampling periods. In order to understand the potential disease-suppressing roles of the garden yeasts, we screened isolates for antagonistic effects against known microfungal garden contaminants. In vitro assays revealed that yeasts inhibited the mycelial growth of two strains of Escovopsis (a specialized attine garden parasite), Syncephalastrum racemosum (a fungus often growing in gardens of leafcutter lab nests), and the insect pathogen Beauveria bassiana. These garden yeasts add to the growing list of disease-suppressing microbes in attine nests that may contribute synergistically, together with actinomycetes and Burkholderia bacteria, to protect the gardens and the ants against diseases. Additionally, we suggest that garden immunity against problem fungi may therefore derive not only from the presence of disease-suppressing Pseudonocardia actinomycetes, but from an enrichment of multiple disease-suppressing microorganisms in the garden matrix. PMID:19449210

  2. Emerging role of orexin antagonists in insomnia therapeutics: An update on SORAs and DORAs.

    Science.gov (United States)

    Kumar, Anil; Chanana, Priyanka; Choudhary, Supriti

    2016-04-01

    The pharmacological management of insomnia has lately become a challenge for researchers worldwide. As per the third International Classification of Sleep disorders (ICSD-3) insomnia can be defined as a state with repeated difficulty in sleep initiation, duration, consolidation, or quality that occurs despite adequate opportunity and circumstances for sleep, and results in some form of daytime impairment. The conventional treatments approved for management of insomnia were benzodiazepines (BZDs) (estazolam, quazepam, triazolam, flurazepam and temazepam) and non-BZDs, also known as z-drugs (zaleplon, zolpidem, and eszopiclone), tricyclic antidepressant (TCA) doxepin as well as melatonin agonists, e.g. ramelteon. But the potential of these agents to address sleep problems has been limited due to substantial side effects associated with them like hangover, dependence and tolerance, rebound insomnia, muscular atonia, inhibition of respiratory system, cognitive dysfunctions, and increased anxiety. Recently, orexin neuropeptides have been identified as regulators of transition between wakefulness and sleep and documented to aid an initial transitory effect towards wakefulness by activating cholinergic/monoaminergic neural pathways of the ascending arousal system. This has led to the development of orexin peptides and receptors, as possible therapeutic targets for the treatment of sleep disorders with the advantage of having lesser side effects as compared to conventional treatments. The present review focuses on the orexin peptides and receptors signifying their physiological profile as well as the development of orexin receptor antagonists as novel strategies in sleep medicine. PMID:26922522

  3. Cyclic lipopeptide profile of three Bacillus subtilis strains; antagonists of Fusarium head blight.

    Science.gov (United States)

    Dunlap, Christopher A; Schisler, David A; Price, Neil P; Vaughn, Steven F

    2011-08-01

    The objective of the study was to identify the lipopetides associated with three Bacillus subtilis strains. The strains are antagonists of Gibberella zeae, and have been shown to be effective in reducing Fusarium head blight in wheat. The lipopeptide profile of three B. subtilis strains (AS43.3, AS43.4, and OH131.1) was determined using mass spectroscopy. Strains AS43.3 and AS43.4 produced the anti-fungal lipopeptides from the iturin and fengycin family during the stationary growth phase. All three strains produced the lipopeptide surfactin at different growth times. Strain OH131.1 only produced surfactin under these conditions. The antifungal activity of the culture supernatant and individual lipopeptides was determined by the inhibition of G. zeae. Cell-free supernatant from strains AS43.3 and AS43.4 demonstrated strong antibiosis of G. zeae, while strain OH131.1 had no antibiosis activity. These results suggest a different mechanism of antagonism for strain OH131.1, relative to AS43.3 and AS43.4. PMID:21887643

  4. CXCR4-antagonist Peptide R-liposomes for combined therapy against lung metastasis.

    Science.gov (United States)

    Ieranò, Caterina; Portella, Luigi; Lusa, Sara; Salzano, Giuseppina; D'Alterio, Crescenzo; Napolitano, Maria; Buoncervello, Maria; Macchia, Daniele; Spada, Massimo; Barbieri, Antonio; Luciano, Antonio; Barone, Maria Vittoria; Gabriele, Lucia; Caraglia, Michele; Arra, Claudio; De Rosa, Giuseppe; Scala, Stefania

    2016-03-31

    The chemokine CXCL12 activates CXCR4, initiating multiple pathways that control immune cell trafficking, angiogenesis and embryogenesis; CXCR4 is also overexpressed in multiple tumors affecting metastatic dissemination. While there has been great enthusiasm for exploiting the CXCR4-CXCL12 axis as a target in cancer therapy, to date the promise has yet to be fulfilled. A new class of CXCR4-antagonist cyclic peptides was recently developed and the compound named Peptide R was identified as the most active. With the intent to improve the efficacy and biodistribution of Peptide R, stealth liposomes decorated with Peptide R were developed (PL-Peptide R). In vitro PL-Peptide R efficiently inhibited CXCR4-dependent migration and in vivo it significantly reduced lung metastases and increased overall survival in B16-CXCR4 injected C57BL/6 mice. To evaluate if PL-Peptide R could also be a drug delivery system for CXCR4 expressing tumors, the PL-Peptide R was loaded with doxorubicin (DOX) (PL-Peptide R-DOX). PL-Peptide R-DOX efficiently delivered DOX to CXCR4 expressing cell lines with a consequent decrease in the DOX IC50 efficient dose. In vivo, B16-CXCR4 injected C57BL/6 mice treated with PL-Peptide R-DOX developed fewer lung metastases compared to PL-DOX treated mice. This work provides the proof-of-concept to prevent metastasis by using combined nanomedicine. PMID:26983756

  5. LSD1 and HY5 Antagonistically Regulate Red Light induced-Programmed Cell Death in Arabidopsis

    Directory of Open Access Journals (Sweden)

    Tingting eChai

    2015-05-01

    Full Text Available Programmed cell death (PCD in plant is triggered by abiotic and biotic stress. Light-dependent PCD is unique to plants. Light-induced PCD also requires reactive oxygen species (ROS and salicylic acid (SA. In this study, lesion simulating disease1 (LSD1 and elongated hypocotyl 5 (HY5 perform opposite roles to regulate excess red light (RL-triggered PCD associated with ROS and SA production. Under RL, the lsd1 mutant released more ROS and SA and displayed a stronger cell death rate than the hy5 mutant. It was shown that active LSD1 converted into inactive form by changing the redox status of the plastoquinone pool, and HY5 interacted with phytochrome B (phyB to promote PCD in response to RL. LSD1 inhibited the enhanced disease susceptibility 1 (EDS1 expression by upregulating SR1, whereas HY5 enhanced the enhanced EDS1 expression by binding to the G-box of the EDS1 promoter. This study suggested that LSD1 and HY5 antagonistically modulated EDS1-dependent ROS and SA signaling; thus, PCD was mediated in response to RL.

  6. Antagonistic action of Bacillus subtilis strain SG6 on Fusarium graminearum.

    Directory of Open Access Journals (Sweden)

    Yueju Zhao

    Full Text Available Fusarium graminearum causes Fusarium head blight (FHB, a devastating disease that leads to extensive yield and quality loss of wheat and barley. Bacteria isolated from wheat kernels and plant anthers were screened for antagonistic activity against F. graminearum. Based on its in vitro effectiveness, strain SG6 was selected for characterization and identified as Bacillus subtilis. B. subtilis SG6 exhibited a high antifungal effect on the mycelium growth, sporulation and DON production of F. graminearum with the inhibition rate of 87.9%, 95.6% and 100%, respectively. In order to gain insight into biological control effect in situ, we applied B. subtilis SG6 at anthesis through the soft dough stage of kernel development in field test. It was revealed that B. subtilis SG6 significantly reduced disease incidence (DI, FHB index and DON (P ≤ 0.05. Further, ultrastructural examination shows that B. subtilis SG6 strain induced stripping of F. graminearum hyphal surface by destroying the cellular structure. When hypha cell wall was damaged, the organelles and cytoplasm inside cell would exude, leading to cell death. The antifungal activity of SG6 could be associated with the coproduction of chitinase, fengycins and surfactins.

  7. Induction of reproductive function in anestrous mares using a dopamine antagonist.

    Science.gov (United States)

    Besognet, B; Hansen, B S; Daels, P F

    1997-01-15

    We investigated the role of dopamine in the regulation of seasonal reproductive activity in mares. Nine seasonal anestrous mares, maintained under a natural photoperiod, were treated daily with a dopamine D2 antagonist, [-]-sulpiride (200 mg/mare, im), beginning February 5 (day of year = 36) until the first ovulation of the year or for a maximum of 58. Nine untreated anestrous mares were maintained under the same conditions. The ovaries were examined by ultrasonography twice a week, and blood was collected three times a week for progesterone, LH, FSH and prolactin determinations. Mean day of first ovulation was significantly advanced for [-]-sulpiride-treated mares than control mares (mean day of year +/- SEM = 77.3 +/- 7.9 and 110.0 +/- 6.8, respectively; P mares ovulated during [-]-sulpiride treatment while one mare failed to ovulate. Ovulation occurred 91 d after the start of treatment or on Day 127. All mares continued to have normal estrous cycles after the first ovulation. First cycle length and luteal progesterone concentrations did not differ between [-]-sulpiride-treated and control mares. Plasma prolactin concentrations were significantly increased at 2 and 9 h after [-]-sulpiride administration (P mares than in control mares (P mares and exerts a tonic inhibition on reproductive activity during the anovulatory season. PMID:16727999

  8. DREAM (downstream regulatory element antagonist modulator) contributes to synaptic depression and contextual fear memory.

    Science.gov (United States)

    Wu, Long-Jun; Mellström, Britt; Wang, Hansen; Ren, Ming; Domingo, Sofia; Kim, Susan S; Li, Xiang-Yao; Chen, Tao; Naranjo, Jose R; Zhuo, Min

    2010-01-01

    The downstream regulatory element antagonist modulator (DREAM), a multifunctional Ca2+-binding protein, binds specifically to DNA and several nucleoproteins regulating gene expression and with proteins outside the nucleus to regulate membrane excitability or calcium homeostasis. DREAM is highly expressed in the central nervous system including the hippocampus and cortex; however, the roles of DREAM in hippocampal synaptic transmission and plasticity have not been investigated. Taking advantage of transgenic mice overexpressing a Ca2+-insensitive DREAM mutant (TgDREAM), we used integrative methods including electrophysiology, biochemistry, immunostaining, and behavior tests to study the function of DREAM in synaptic transmission, long-term plasticity and fear memory in hippocampal CA1 region. We found that NMDA receptor but not AMPA receptor-mediated current was decreased in TgDREAM mice. Moreover, synaptic plasticity, such as long-term depression (LTD) but not long-term potentiation (LTP), was impaired in TgDREAM mice. Biochemical experiments found that DREAM interacts with PSD-95 and may inhibit NMDA receptor function through this interaction. Contextual fear memory was significantly impaired in TgDREAM mice. By contrast, sensory responses to noxious stimuli were not affected. Our results demonstrate that DREAM plays a novel role in postsynaptic modulation of the NMDA receptor, and contributes to synaptic plasticity and behavioral memory. PMID:20205763

  9. DREAM (Downstream Regulatory Element Antagonist Modulator contributes to synaptic depression and contextual fear memory

    Directory of Open Access Journals (Sweden)

    Wu Long-Jun

    2010-01-01

    Full Text Available Abstract The downstream regulatory element antagonist modulator (DREAM, a multifunctional Ca2+-binding protein, binds specifically to DNA and several nucleoproteins regulating gene expression and with proteins outside the nucleus to regulate membrane excitability or calcium homeostasis. DREAM is highly expressed in the central nervous system including the hippocampus and cortex; however, the roles of DREAM in hippocampal synaptic transmission and plasticity have not been investigated. Taking advantage of transgenic mice overexpressing a Ca2+-insensitive DREAM mutant (TgDREAM, we used integrative methods including electrophysiology, biochemistry, immunostaining, and behavior tests to study the function of DREAM in synaptic transmission, long-term plasticity and fear memory in hippocampal CA1 region. We found that NMDA receptor but not AMPA receptor-mediated current was decreased in TgDREAM mice. Moreover, synaptic plasticity, such as long-term depression (LTD but not long-term potentiation (LTP, was impaired in TgDREAM mice. Biochemical experiments found that DREAM interacts with PSD-95 and may inhibit NMDA receptor function through this interaction. Contextual fear memory was significantly impaired in TgDREAM mice. By contrast, sensory responses to noxious stimuli were not affected. Our results demonstrate that DREAM plays a novel role in postsynaptic modulation of the NMDA receptor, and contributes to synaptic plasticity and behavioral memory.

  10. Antagonistic interactions between honey bee bacterial symbionts and implications for disease

    Directory of Open Access Journals (Sweden)

    Armstrong Tamieka-Nicole

    2006-03-01

    Full Text Available Abstract Background Honey bees, Apis mellifera, face many parasites and pathogens and consequently rely on a diverse set of individual and group-level defenses to prevent disease. One route by which honey bees and other insects might combat disease is through the shielding effects of their microbial symbionts. Bees carry a diverse assemblage of bacteria, very few of which appear to be pathogenic. Here we explore the inhibitory effects of these resident bacteria against the primary bacterial pathogen of honey bees, Paenibacillus larvae. Results Here we isolate, culture, and describe by 16S rRNA and protein-coding gene sequences 61 bacterial isolates from honey bee larvae, reflecting a total of 43 distinct bacterial taxa. We culture these bacteria alongside the primary larval pathogen of honey bees, Paenibacillus larvae, and show that many of these isolates severely inhibit the growth of this pathogen. Accordingly, symbiotic bacteria including those described here are plausible natural antagonists toward this widespread pathogen. Conclusion The results suggest a tradeoff in social insect colonies between the maintenance of potentially beneficial bacterial symbionts and deterrence at the individual and colony level of pathogenic species. They also provide a novel mechanism for recently described social components behind disease resistance in insect colonies, and point toward a potential control strategy for an important bee disease.

  11. Role of periostin and its antagonist PNDA-3 in gastric cancer metastasis.

    Science.gov (United States)

    Liu, Guo-Xiao; Xi, Hong-Qing; Sun, Xiao-Yan; Wei, Bo

    2015-03-01

    The extracellular matrix component periostin is a secreted protein that functions as both a cell attachment protein and an autocrine or paracrine factor that signals through the cell adhesion molecule integrins αvβ3 and αvβ5. Periostin participates in normal physiological activities such as cardiac development, but is also involved in pathophysiological processes in vascular diseases, wound repair, bone formation, and tumor development. It is of increasing interest in tumor biology because it is frequently overexpressed in a variety of epithelial carcinomas and is functionally involved in multiple steps of metastasis progression. These include the maintenance of stemness, niche formation, EMT, the survival of tumor cells, and angiogenesis, all of which are indispensable for gastric cancer metastasis. Periostin has been reported to activate the PI-3K/AKT, Wnt, and FAK-mediated signaling pathways to promote metastasis. Therefore, periostin represents a potentially promising candidate for the inhibition of metastasis. In this review article, we summarize recent advances in knowledge concerning periostin, its antagonist PNDA-3, and their influence on such key processes in cancer metastasis as maintenance of stemness, niche formation, epithelial-to-mesenchymal transition, tumor cell survival, and angiogenesis. In particular, we focus our attention on the role of periostin in gastric cancer metastasis, speculate as to the usefulness of periostin as a therapeutic and diagnostic target for gastric cancer metastasis, and consider potential avenues for future research. PMID:25759527

  12. Galanin antagonist increases insulin resistance by reducing glucose transporter 4 effect in adipocytes of rats.

    Science.gov (United States)

    Guo, Lili; Shi, Mingyi; Zhang, Ling; Li, Guangzhi; Zhang, Lingxiang; Shao, Hu; Fang, Penghua; Ma, Yingping; Li, Jian; Shi, Qiaojia; Sui, Yumei

    2011-08-01

    Seeing that galanin increases animal body weight on the conditions of inhibiting insulin secretion and animals with metabolic disorder of galanin easily suffer from diabetes, we postulate that endogenous galanin is necessary to reduce insulin resistance in adipocytes. To test this hypothesis, we compared four groups of rats to examine whether an increase in galanin secretion stimulated by swimming may reduce insulin resistance. The rats from sedentary and trained drug groups were injected by M35, a galanin antagonist. The rats from trained control and trained drug groups swam after each injection for four weeks. We found that exercise significantly elevated plasma galanin contents and glucose transporter 4 (GLUT4) mRNA levels in adipocytes. Meanwhile, M35 treatment reduced GLUT4 and GLUT4 mRNA levels, and glucose infusing rates in euglycemic-hyperinsulinemic clamp tests. The ratios of GLUT4 concentrations at plasma membranes to total cell membranes in both drug groups were lower compared with each control group, respectively. These observations suggest that endogenous galanin reduces insulin resistance by increasing GLUT4 contents and promoting GLUT4 transportation from intracellular membranes to plasma membranes in adipocytes. Galanin is an important hormone to reduce insulin resistance in rats. PMID:21664358

  13. Identification of VDR Antagonists among Nuclear Receptor Ligands Using Virtual Screening

    Directory of Open Access Journals (Sweden)

    Kelly Teske

    2014-04-01

    Full Text Available Herein, we described the development of two virtual screens to identify new vitamin D receptor (VDR antagonists among nuclear receptor (NR ligands. Therefore, a database of 14330 nuclear receptor ligands and their NR affinities was assembled using the online available “Binding Database.” Two different virtual screens were carried out in conjunction with a reported VDR crystal structure applying a stringent and less stringent pharmacophore model to filter docked NR ligand conformations. The pharmacophore models were based on the spatial orientation of the hydroxyl functionalities of VDR's natural ligands 1,25(OH2D3 and 25(OH2D3. The first virtual screen identified 32 NR ligands with a calculated free energy of VDR binding of more than -6.0 kJ/mol. All but nordihydroguaiaretic acid (NDGA are VDR ligands, which inhibited the interaction between VDR and coactivator peptide SRC2-3 with an IC50 value of 15.8 μM. The second screen identified 162 NR ligands with a calculated free energy of VDR binding of more than -6.0 kJ/mol. More than half of these ligands were developed to bind VDR followed by ERα/β ligands (26%, TRα/β ligands (7%, and LxRα/β ligands (7%. The binding between VDR and ERα ligand H6036 as well as TRα/β ligand triiodothyronine and a homoserine analog thereof was confirmed by fluorescence polarization.

  14. Intronic microRNAs support their host genes by mediating synergistic and antagonistic regulatory effects

    Directory of Open Access Journals (Sweden)

    Krumsiek Jan

    2010-04-01

    Full Text Available Abstract Background MicroRNA-mediated control of gene expression via translational inhibition has substantial impact on cellular regulatory mechanisms. About 37% of mammalian microRNAs appear to be located within introns of protein coding genes, linking their expression to the promoter-driven regulation of the host gene. In our study we investigate this linkage towards a relationship beyond transcriptional co-regulation. Results Using measures based on both annotation and experimental data, we show that intronic microRNAs tend to support their host genes by regulation of target gene expression with significantly correlated expression patterns. We used expression data of three differentiating cell types and compared gene expression profiles of host and target genes. Many microRNA target genes show expression patterns significantly correlated with the expressions of the microRNA host genes. By calculating functional similarities between host and predicted microRNA target genes based on GO annotations, we confirm that many microRNAs link host and target gene activity in an either synergistic or antagonistic manner. Conclusions These two regulatory effects may result from fine tuning of target gene expression functionally related to the host or knock-down of remaining opponent target gene expression. This finding allows to extend the common practice of mapping large scale gene expression data to protein associated genes with functionality of co-expressed intronic microRNAs.

  15. Roles of ERα during mouse trophectoderm lineage differentiation: revealed by antagonist and agonist of ERα.

    Science.gov (United States)

    Cheng, Xiaoxiang; Xu, Songhua; Song, Chanchan; He, Lin; Lian, Xiuli; Liu, Yue; Wei, Jianen; Pang, Lili; Wang, Shie

    2016-04-01

    During mouse early embryogenesis, blastomeres increase in number by the morula stage. Among them, the outer cells are polarized and differentiated into trophectoderm (TE), while the inner cells remain unpolarized and give rise to inner cell mass (ICM). TE provides an important liquid environment for ICM development. In spite of extensive research, the molecular mechanisms underlying TE formation are still obscure. In order to investigate the roles of estrogen receptor α (ERα) in this course, mouse 8-cell embryos were collected and cultured in media containing ERα specific antagonist MPP and/or agonist PPT. The results indicated that MPP treatment inhibits blastocyst formation in a dose-dependent manner, while PPT, at proper concentration, promotes the cavitation ratio of mouse embryos. Immunofluorescence staining results showed that MPP significantly decreased the nuclear expression of CDX2 in morula, but no significant changes of OCT4 were observed. Moreover, after MPP treatment, the expression levels of the genes related to TE specification, Tead4, Gata3 and Cdx2, were significantly reduced. Overall, these results indicated that ERα might affect mouse embryo cavitation by regulating TE lineage differentiation. PMID:27037955

  16. The neuromedin B receptor antagonist, BIM-23127, is a potent antagonist at human and rat urotensin-II receptors

    OpenAIRE

    Herold, Christopher L; Behm, David J.; Buckley, Peter T.; Foley, James J; William E Wixted; Sarau, Henry M; Douglas, Stephen A

    2003-01-01

    The functional activity of the peptidic neuromedin B receptor antagonist BIM-23127 was investigated at recombinant and native urotensin-II receptors (UT receptors). Human urotensin-II (hU-II) promoted intracellular calcium mobilization in HEK293 cells expressing the human UT (hUT) or rat UT (rUT) receptors with pEC50 values of 9.80±0.34 (n=6) and 9.06±0.32 (n=4), respectively. While BIM-23127 alone had no effect on calcium responses in either cell line, it was a potent and competitive antagon...

  17. Glutamate Receptor Agonists and Glutamate Transporter Antagonists Regulate Differentiation of Osteoblast Lineage Cells.

    Science.gov (United States)

    Xie, Wenjie; Dolder, Silvia; Siegrist, Mark; Wetterwald, Antoinette; Hofstetter, Willy

    2016-08-01

    Development and function of osteoblast lineage cells are regulated by a complex microenvironment consisting of the bone extracellular matrix, cells, systemic hormones and cytokines, autocrine and paracrine factors, and mechanical load. Apart from receptors that transduce extracellular signals into the cell, molecular transporters play a crucial role in the cellular response to the microenvironment. Transporter molecules are responsible for cellular uptake of nutritional components, elimination of metabolites, ion transport, and cell-cell communication. In this report, the expression of molecular transporters in osteoblast lineage cells was investigated to assess their roles in cell development and activity. Low-density arrays, covering membrane and vesicular transport molecules, were used to assess gene expression in osteoblasts representing early and late differentiation states. Receptors and transporters for the amino acid glutamate were found to be differentially expressed during osteoblast development. Glutamate is a neurotransmitter in the central nervous system, and the mechanisms of its release, signal transduction, and cellular reabsorption in the synaptic cleft are well understood. Less clear, however, is the control of equivalent processes in peripheral tissues. In primary osteoblasts, inhibition of glutamate transporters with nonselective inhibitors leads to an increase in the concentration of extracellular glutamate. This change was accompanied by a decrease in osteoblast proliferation, stimulation of alkaline phosphatase, and the expression of transcripts encoding osteocalcin. Enzymatic removal of extracellular glutamate abolished these pro-differentiation effects, as did the inhibition of PKC- and Erk1/2-signaling pathways. These findings demonstrate that glutamate signaling promotes differentiation and activation of osteoblast lineage cells. Consequently, the glutamate system may represent a putative therapeutic target to induce an anabolic response

  18. Effects of the estrogen receptor antagonist fulvestrant on F344 rat prolactinoma models.

    Science.gov (United States)

    Cao, Lei; Gao, Hua; Gui, Songbai; Bai, Giwei; Lu, Runchun; Wang, Fei; Zhang, Yazhuo

    2014-02-01

    The relationship between estrogen and prolactinoma is well documented. But the anti-tumor effects of a pure estrogen receptor antagonist fulvestrant on prolactinomas, especially in vivo, and the possible mechanisms are still unclear. Therefore, the aim of this study was to evaluate the effects of fulvestrant and the involvement of the Wnt signaling pathway on rat prolactinoma models. Forty female F344 rat prolactinoma models were established by subcutaneous administration of 10 mg 17β-estradiol for 6 weeks. Rats were intramuscularly injected with fulvestrant (0, 0.5, 3, 20, 40 mg/kg), and tumor size, weight and serum prolactin (PRL) levels were evaluated before and after fulvestrant treatment at 3, 7 and 14 days. Expression of estrogen receptor α (ERα), β-catenin and Wnt inhibitory factor-1 (WIF-1) in prolactinomas was measured using quantitative PCR and western blotting, and methylation of the WIF-1 promoter was investigated using pyrosequencing. Tumor size, weight and serum PRL levels were inhibited in dose-dependent and time-dependent manners after fulvestrant treatments. β-catenin expression was downregulated but WIF-1 expression was upregulated following fulvestrant treatment. The methylation of the CpG site of the WIF-1 promoter was negatively correlated to the expression of WIF-1. In addition, the anti-cell proliferation of fulvestrant on GH3 cells was partly disrupted by Wnt signaling pathway agonist SB 216763. In conclusion, fulvestrant inhibited tumor proliferation and PRL secretion of prolactinomas via ERα, and the Wnt signaling pathway was involved in this anti-tumor effect. Therefore, fulvestrant may be a potential new drug for prolactinomas. PMID:24407733

  19. Human homosexuality: a paradigmatic arena for sexually antagonistic selection?

    Science.gov (United States)

    Camperio Ciani, Andrea; Battaglia, Umberto; Zanzotto, Giovanni

    2015-04-01

    Sexual conflict likely plays a crucial role in the origin and maintenance of homosexuality in our species. Although environmental factors are known to affect human homosexual (HS) preference, sibling concordances and population patterns related to HS indicate that genetic components are also influencing this trait in humans. We argue that multilocus, partially X-linked genetic factors undergoing sexually antagonistic selection that promote maternal female fecundity at the cost of occasional male offspring homosexuality are the best candidates capable of explaining the frequency, familial clustering, and pedigree asymmetries observed in HS male proband families. This establishes male HS as a paradigmatic example of sexual conflict in human biology. HS in females, on the other hand, is currently a more elusive phenomenon from both the empirical and theoretical standpoints because of its fluidity and marked environmental influence. Genetic and epigenetic mechanisms, the latter involving sexually antagonistic components, have been hypothesized for the propagation and maintenance of female HS in the population. However, further data are needed to truly clarify the evolutionary dynamics of this trait. PMID:25635045

  20. Scaffold Optimisation of Tetravalent Antagonists of the Mannose Binding Lectin.

    Science.gov (United States)

    Goti, Giulio; Palmioli, Alessandro; Stravalaci, Matteo; Sattin, Sara; De Simoni, Maria-Grazia; Gobbi, Marco; Bernardi, Anna

    2016-03-01

    Antagonists of mannose binding lectin (MBL) have shown a protective role against brain reperfusion damage after acute ischemic stroke. Here we describe the design and streamlined synthesis of glycomimetic MBL antagonists based on a new tetravalent dendron scaffold. The dendron was developed by optimisation of a known polyester structure previously demonstrated to be very efficient for ligand presentation to MBL. Replacement of a labile succinyl ester bond with a more robust amide functionality, use of a longer and more hydrophilic linker, fast modular synthesis and orthogonal functionalisation at the focal point are the main features of the new scaffold. The glycoconjugate constructs become stable to silica gel chromatography and to water solutions at physiological pH, while preserving water solubility and activity in an SPR assay against the murine MBL-C isoform. Higher-order constructs were easily assembled, as demonstrated by the synthesis of a 16-valent dendrimer, which leads to two orders of magnitude increase in activity over the tetravalent version against MBL-C. PMID:26696414

  1. Rogue sperm indicate sexually antagonistic coevolution in nematodes.

    Directory of Open Access Journals (Sweden)

    Ronald E Ellis

    2014-07-01

    Full Text Available Intense reproductive competition often continues long after animals finish mating. In many species, sperm from one male compete with those from others to find and fertilize oocytes. Since this competition occurs inside the female reproductive tract, she often influences the outcome through physical or chemical factors, leading to cryptic female choice. Finally, traits that help males compete with each other are sometimes harmful to females, and female countermeasures may thwart the interests of males, which can lead to an arms race between the sexes known as sexually antagonistic coevolution. New studies from Caenorhabditis nematodes suggest that males compete with each other by producing sperm that migrate aggressively and that these sperm may be more likely to win access to oocytes. However, one byproduct of this competition appears to be an increased probability that these sperm will go astray, invading the ovary, prematurely activating oocytes, and sometimes crossing basement membranes and leaving the gonad altogether. These harmful effects are sometimes observed in crosses between animals of the same species but are most easily detected in interspecies crosses, leading to dramatically lowered fitness, presumably because the competitiveness of the sperm and the associated female countermeasures are not precisely matched. This mismatch is most obvious in crosses involving individuals from androdioecious species (which have both hermaphrodites and males, as predicted by the lower levels of sperm competition these species experience. These results suggest a striking example of sexually antagonistic coevolution and dramatically expand the value of nematodes as a laboratory system for studying postcopulatory interactions.

  2. Effects of tiflucarbine as a dual protein kinase C/calmodulin antagonist on proliferation of human keratinocytes and release of reactive oxygen species from human leukocytes.

    Science.gov (United States)

    Hegemann, L; Fruchtmann, R; Bonnekoh, B; Schmidt, B H; Traber, J; Mahrle, G; Müller-Peddinghaus, R; van Rooijen, L A

    1991-01-01

    Various studies have suggested that calmodulin (CaM) is involved in the pathophysiology of psoriasis. Protein kinase C (PKC) is also accepted as playing a regulatory role in cell proliferation as well as in inflammatory processes. Therefore, we investigated the effects of the known CaM antagonist tiflucarbine (BAY/TVX P 4495) on two cellular systems related to the major clinical symptoms of psoriasis: proliferation of cultured human keratinocytes (HaCa T cell line) and release of reactive oxygen species (ROS) from human polymorphonuclear leukocytes (PMNL). Tiflucarbine inhibited both cellular responses in a dose dependent manner. Furthermore, tiflucarbine directly affected PKC, and may thus be considered to be a dual PKC/CaM antagonist with putative antipsoriatic activity. The effects of tiflucarbine on the different parameters were compared with those of the structurally unrelated dual PKC/CaM inhibitor W-7 and those of the potent PKC inhibitor staurosporine. The potencies of all three compounds were found to be in the same range as their PKC-inhibiting potency. Our data indicate that PKC, rather than CaM, may play a regulatory role in the release of ROS as well as in keratinocyte proliferation. Therefore, inhibition of PKC in general might have a therapeutic benefit in psoriasis. PMID:1801655

  3. Role of platelet-activating factor (PAF) in the ovoimplantation in the rat: effect of the specific PAF-acether antagonist, BN 52021.

    Science.gov (United States)

    Acker, G; Hecquet, F; Etienne, A; Braquet, P; Mencia-Huerta, J M

    1988-02-01

    The role of PAF (platelet-activating factor) in early pregnancy has been recently postulated. Indeed, platelet count is markedly reduced immediately prior to and returns to normal following ovoimplantation. Using a pharmacological approach, we therefore further investigated the possible involvement of PAF in ovoimplantation. BN 52021 (10 nmol), a PAF antagonist, was administered after fecondation in the lumen of the left uterine horn. A group of animals was injected with the vehicle alone. The animals were sacrificed 1 week latter and the number of implanted embryos in the treated horn and in the untreated contralateral one was assessed. When injected on day 4 of pregnancy, the PAF antagonist, BN 52021, inhibited in a dose-dependent fashion ovoimplantation suggesting a role for this lipid mediator in this process. Total inhibition of ovoimplantation was observed in the horns treated with indomethacin, NDGA or BW 755 C. In addition, a significant inhibition of ovoimplantation was also produced by the lipoxygenase inhibitor, EP 10045 (10nmol). Since both PAF and leukotrienes trigger the generation of prostaglandins in various tissues, our results indicate that these two lipid mediators may be implicated in early stages of the inflammatory reaction accompanying ovoimplantation and may contribute to the local generation of cyclooxygenase metabolites. PMID:3129758

  4. Corrosion inhibiting organic coatings

    Energy Technology Data Exchange (ETDEWEB)

    Sasson, E.

    1984-10-16

    A corrosion inhibiting coating comprises a mixture of waxes, petroleum jelly, a hardener and a solvent. In particular, a corrosion inhibiting coating comprises candelilla wax, carnauba wax, microcrystalline waxes, white petrolatum, an oleoresin, lanolin and a solvent.

  5. Hedgehog signaling antagonist promotes regression of both liver fibrosis and hepatocellular carcinoma in a murine model of primary liver cancer.

    Directory of Open Access Journals (Sweden)

    George M Philips

    Full Text Available OBJECTIVE: Chronic fibrosing liver injury is a major risk factor for hepatocarcinogenesis in humans. Mice with targeted deletion of Mdr2 (the murine ortholog of MDR3 develop chronic fibrosing liver injury. Hepatocellular carcinoma (HCC emerges spontaneously in such mice by 50-60 weeks of age, providing a model of fibrosis-associated hepatocarcinogenesis. We used Mdr2(-/- mice to investigate the hypothesis that activation of the hedgehog (Hh signaling pathway promotes development of both liver fibrosis and HCC. METHODS: Hepatic injury and fibrosis, Hh pathway activation, and liver progenitor populations were compared in Mdr2(-/- mice and age-matched wild type controls. A dose finding experiment with the Hh signaling antagonist GDC-0449 was performed to optimize Hh pathway inhibition. Mice were then treated with GDC-0449 or vehicle for 9 days, and effects on liver fibrosis and tumor burden were assessed by immunohistochemistry, qRT-PCR, Western blot, and magnetic resonance imaging. RESULTS: Unlike controls, Mdr2(-/- mice consistently expressed Hh ligands and progressively accumulated Hh-responsive liver myofibroblasts and progenitors with age. Treatment of aged Mdr2-deficient mice with GDC-0449 significantly inhibited hepatic Hh activity, decreased liver myofibroblasts and progenitors, reduced liver fibrosis, promoted regression of intra-hepatic HCCs, and decreased the number of metastatic HCC without increasing mortality. CONCLUSIONS: Hh pathway activation promotes liver fibrosis and hepatocarcinogenesis, and inhibiting Hh signaling safely reverses both processes even when fibrosis and HCC are advanced.

  6. Identification of a group of brominated flame retardants as novel androgen receptor antagonists and potential neuronal and endocrine disrupters.

    Science.gov (United States)

    Kharlyngdoh, Joubert Banjop; Pradhan, Ajay; Asnake, Solomon; Walstad, Anders; Ivarsson, Per; Olsson, Per-Erik

    2015-01-01

    Brominated flame-retardants (BFRs) are used in industrial products to reduce the risk of fire. However, their continuous release into the environment is a concern as they are often persistent, bioaccumulating and toxic. Information on the impact these compounds have on human health and wildlife is limited and only a few of them have been identified to disrupt hormone receptor functions. In the present study we used in silico modeling to determine the interactions of selected BFRs with the human androgen receptor (AR). Three compounds were found to dock into the ligand-binding domain of the human AR and these were further tested using in vitro analysis. Allyl 2,4,6-tribromophenyl ether (ATE), 2-bromoallyl 2,4,6-tribromophenyl ether (BATE) and 2,3-dibromopropyl-2,4,6-tribromophenyl ether (DPTE) were observed to act as AR antagonists. These BFRs have recently been detected in the environment, in house dust and in aquatic animals. The compounds have been detected at high concentrations in both blubber and brain of seals and we therefore also assessed their impact on the expression of L-type amino acid transporter system (LAT) genes, that are needed for amino acid uptake across the blood-brain barrier, as disruption of LAT gene function has been implicated in several brain disorders. The three BFRs down-regulated the expression of AR target genes that encode for prostate specific antigen (PSA), 5α-reductases and β-microseminoprotein. The potency of PSA inhibition was of the same magnitude as the common prostate cancer drugs, demonstrating that these compounds are strong AR antagonists. Western blot analysis of AR protein showed that ATE, BATE and DPTE decreased the 5α-dihydrotestosterone-induced AR protein levels, further confirming that these BFRs act as AR antagonists. The transcription of the LAT genes was altered by the three BFRs, indicating an effect on amino-acid uptake across cellular membranes and blood-brain barrier. This study demonstrated that ATE, BATE

  7. Cysteinyl Leukotriene Receptor 1/2 Antagonists Nonselectively Modulate Organic Anion Transport by Multidrug Resistance Proteins (MRP1-4).

    Science.gov (United States)

    Csandl, Mark A; Conseil, Gwenaëlle; Cole, Susan P C

    2016-06-01

    Active efflux of both drugs and organic anion metabolites is mediated by the multidrug resistance proteins (MRPs). MRP1 (ABCC1), MRP2 (ABCC2), MRP3 (ABCC3), and MRP4 (ABCC4) have partially overlapping substrate specificities and all transport 17β-estradiol 17-(β-d-glucuronide) (E217βG). The cysteinyl leukotriene receptor 1 (CysLT1R) antagonist MK-571 inhibits all four MRP homologs, but little is known about the modulatory effects of newer leukotriene modifiers (LTMs). Here we examined the effects of seven CysLT1R- and CysLT2R-selective LTMs on E217βG uptake into MRP1-4-enriched inside-out membrane vesicles. Their effects on uptake of an additional physiologic solute were also measured for MRP1 [leukotriene C4 (LTC4)] and MRP4 [prostaglandin E2 (PGE2)]. The two CysLT2R-selective LTMs studied were generally more potent inhibitors than CysLT1R-selective LTMs, but neither class of antagonists showed any MRP selectivity. For E217βG uptake, LTM IC50s ranged from 1.2 to 26.9 μM and were most comparable for MRP1 and MRP4. The LTM rank order inhibitory potencies for E217βG versus LTC4 uptake by MRP1, and E217βG versus PGE2 uptake by MRP4, were also similar. Three of four CysLT1R-selective LTMs also stimulated MRP2 (but not MRP3) transport and thus exerted a concentration-dependent biphasic effect on MRP2. The fourth CysLT1R antagonist, LY171883, only stimulated MRP2 (and MRP3) transport but none of the MRPs were stimulated by either CysLT2R-selective LTM. We conclude that, in contrast to their CysLTR selectivity, CysLTR antagonists show no MRP homolog selectivity, and data should be interpreted cautiously if obtained from LTMs in systems in which more than one MRP is present. PMID:27068271

  8. Effects of histamine and its antagonists on murine T-cells and bone marrow-derived dendritic cells

    Directory of Open Access Journals (Sweden)

    Hu XF

    2015-08-01

    Full Text Available Xiufen Hu,1,* Mohammad Ishraq Zafar,2,* Feng Gao2 1Department of Paediatrics, Tongji Hospital, 2Department of Endocrinology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, People’s Republic of China *These authors contributed equally to this work Abstract: We determined the effects of histamine and its antagonists on the surface marker expression of dendritic cells (DCs and the influence of lipopolysaccharide (LPS, histamine, and histamine receptor antagonists on DCs and T-cells. The bone marrow was extracted from the femurs and tibiae of 6- to 8-week-old female Balb/c mice and cultured in medium containing penicillin, streptomycin, L-glutamine, fetal calf serum, or granulocyte macrophage colony-stimulating factor (GM-CSF alone or with interleukin (IL-4. The cells received three different doses of LPS and histamine, plus three different doses of descarboethoxyloratadine (DCL. We assayed the supernatant for various cytokines. The spleen cells of DO11.10 mice were examined by flow cytometry, which included labeling and sorting CD4+ T-cells, as well as coculture of DCs and T-cells with ovalbumin (OVA323–339 peptide. Histamine or histamine plus DCL did not affect the expression of major histocompatibility complex class II, CD11c, CD11b, CD86, and CD80. However, GM-CSF increased the expression of all markers except CD80. Histamine increased interferon-γ production in GM-CSF + IL-4-cultured cells; it also enhanced IL-10 production, but suppressed IL-12 production in LPS-stimulated DCs with no DCL. Cimetidine inhibited IL-10 production and restored IL-12 secretion in LPS-treated DCs. LPS increased IL-10 and decreased IL-12 levels. GM-CSF + IL-4-generated DCs had a stronger stimulatory effect on DO11.10 T-cell proliferation than GM-CSF-generated DCs. Inducible costimulator ligand expression was higher in GM-CSF + IL-4- than in GM-CSF-generated DC groups after 2 days of coculture, but decreased 4 days

  9. Misoprostol inhibits gastric mucosal release of endogenous prostaglandin E2 and thromboxane B2 in healthy volunteers

    DEFF Research Database (Denmark)

    Mertz-Nielsen, A; Eskerod, O; Bukhave, K; Rask-Madsen, J

    1995-01-01

    antagonists in preventing ulcer relapse. It could be that prostaglandin analogues inhibit gastric mucosal synthesis or release of endogenous eicosanoids, thereby abrogating their own effects. This study, therefore, examined how a single therapeutic dose (200 micrograms) of misoprostol, a synthetic analogue of...... performance in ulcer healing and prevention....

  10. The effect of Pseudomonas fluorescens strain q2-87 in pathogen inhibition and growth promotion of slash pine seedlings

    Science.gov (United States)

    Pseudomonas fluorescens strain Q2-87 showed significant antagonistic activity against the damping-off pathogens of slash pine (Pinus elliottii), including Rhizoctonia solani, Alternaria alternata and Fusarium oxysporum. In vitro assays showed that strain Q2-87, which has an inhibition index higher t...

  11. Naloxone-insensitive inhibition of acetylcholine release from parasympathetic nerves innervating guinea-pig trachea by the novel opioid, nociceptin

    OpenAIRE

    Patel, Hema J; Giembycz, Mark A; Spicuzza, Lucia; Barnes, Peter J; Belvisi, Maria G

    1997-01-01

    The novel peptide, nociceptin and the μ-opioid agonist [D-Ala2, N-Me-Phe4, Gly5-ol]-enkephalin (DAMGO) produced a concentration-dependent inhibition of electrical field stimulation (EFS)-evoked release of acetylcholine (ACh) from cholinergic nerves innervating guinea-pig trachea. The non-selective opioid receptor antagonist, naloxone, did not antagonize the inhibitory action of nociceptin under conditions where the inhibition of ACh release evoked by DAMGO was completely reversed. It is sugge...

  12. D1 Antagonists and D2 Agonists Have Opposite Effects on the Metabolism of Dopamine in the Rat Striatum.

    Science.gov (United States)

    Avila-Luna, Alberto; Prieto-Leyva, Jacqueline; Gálvez-Rosas, Arturo; Alfaro-Rodriguez, Alfonso; Gonzalez-Pina, Rigoberto; Bueno-Nava, Antonio

    2015-07-01

    The striatum is known to possess high levels of D1-like and D2-like receptors (D1Rs and D2Rs, respectively). We have previously shown that selective inhibition of D1Rs increases the dopaminergic metabolic response and proposed that this effect is associated with the concomitant activation of postsynaptic D2Rs by endogenous dopamine (DA). Here, we examined whether activation of D2Rs modulates the metabolism and synthesis of DA in the striatum. We used male Wistar rats to evaluate the effects of the systemic administration of a D2R agonist (bromocriptine), a D1R antagonist (SCH-23390), and the co-administration of these compounds with pargyline on the inhibition of monoamine oxidase. DA and L-3,4-dihidroxyphenylacetic acid (DOPAC) levels and 3,4-dihydroxy-L-phenylalanine (L-DOPA) content were measured using high performance liquid chromatography. The systemic administration of SCH-23390 alone, at 0.25, 0.5, 1 or 2 mg/kg, significantly (P DOPAC levels and the DOPAC/DA ratio. At 2, 4 and 8 mg/kg, the administration of bromocriptine alone significantly (P DOPAC levels, L-DOPA content and the DOPAC/DA ratio, whereas at 2 mg/kg, it decreased DA levels. In both groups, co-administration of either SCH-23390 or bromocriptine with pargyline decreased DOPAC levels and the DOPAC/DA ratio by approximately 70 % compared to the levels observed in the control groups. In conclusion, administration of the D2R agonist bromocriptine decreased dopaminergic synthesis and metabolism in the striatum; in contrast, administration of the D1R antagonist SCH-23390 induced the opposite effects. PMID:25981954

  13. Meta-diamide insecticides acting on distinct sites of RDL GABA receptor from those for conventional noncompetitive antagonists.

    Science.gov (United States)

    Nakao, Toshifumi; Banba, Shinich; Nomura, Michikazu; Hirase, Kangetsu

    2013-04-01

    The RDL GABA receptor is an attractive target of insecticides. Here we demonstrate that meta-diamides [3-benzamido-N-(4-(perfluoropropan-2-yl)phenyl)benzamides] are a distinct class of RDL GABA receptor antagonists showing high insecticidal activity against Spodoptera litura. We also suggest that the mode of action of the meta-diamides is distinct from that of conventional noncompetitive antagonists (NCAs), such as fipronil, picrotoxin, lindane, dieldrin, and α-endosulfan. Using a membrane potential assay, we examined the effects of the meta-diamide 3-benzamido-N-(2-bromo-4-(perfluoropropan-2-yl)-6-(trifluoromethyl)phenyl)-2-fluorobenzamide (meta-diamide 7) and NCAs on mutant Drosophila RDL GABA receptors expressed in Drosophila Mel-2 cells. NCAs had little or no inhibitory activity against at least one of the three mutant receptors (A2'S, A2'G, and A2'N), which were reported to confer resistance to NCAs. In contrast, meta-diamide 7 inhibited all three A2' mutant receptors, at levels comparable to its activity with the wild-type receptor. Furthermore, the A2'S·T6'V mutation almost abolished the inhibitory effects of all NCAs. However, meta-diamide 7 inhibited the A2'S・T6'S mutant receptor at the same level as its activity with the wild-type receptor. In contrast, a G336M mutation in the third transmembrane domain of the RDL GABA receptor abolished the inhibitory activities of meta-diamide 7, although the G336M mutation had little effect on the inhibitory activities of conventional NCAs. Molecular modeling studies also suggested that the binding site of meta-diamides was different from those of NCAs. Meta-diamide insecticides are expected to be prominent insecticides effective against A2' mutant RDL GABA receptors with a different mode of action. PMID:23416568

  14. Systemic EP4 Inhibition Increases Adhesion Formation in a Murine Model of Flexor Tendon Repair.

    Science.gov (United States)

    Geary, Michael B; Orner, Caitlin A; Bawany, Fatima; Awad, Hani A; Hammert, Warren C; O'Keefe, Regis J; Loiselle, Alayna E

    2015-01-01

    Flexor tendon injuries are a common clinical problem, and repairs are frequently complicated by post-operative adhesions forming between the tendon and surrounding soft tissue. Prostaglandin E2 and the EP4 receptor have been implicated in this process following tendon injury; thus, we hypothesized that inhibiting EP4 after tendon injury would attenuate adhesion formation. A model of flexor tendon laceration and repair was utilized in C57BL/6J female mice to evaluate the effects of EP4 inhibition on adhesion formation and matrix deposition during flexor tendon repair. Systemic EP4 antagonist or vehicle control was given by intraperitoneal injection during the late proliferative phase of healing, and outcomes were analyzed for range of motion, biomechanics, histology, and genetic changes. Repairs treated with an EP4 antagonist demonstrated significant decreases in range of motion with increased resistance to gliding within the first three weeks after injury, suggesting greater adhesion formation. Histologic analysis of the repair site revealed a more robust granulation zone in the EP4 antagonist treated repairs, with early polarization for type III collagen by picrosirius red staining, findings consistent with functional outcomes. RT-PCR analysis demonstrated accelerated peaks in F4/80 and type III collagen (Col3a1) expression in the antagonist group, along with decreases in type I collagen (Col1a1). Mmp9 expression was significantly increased after discontinuing the antagonist, consistent with its role in mediating adhesion formation. Mmp2, which contributes to repair site remodeling, increases steadily between 10 and 28 days post-repair in the EP4 antagonist group, consistent with the increased matrix and granulation zones requiring remodeling in these repairs. These findings suggest that systemic EP4 antagonism leads to increased adhesion formation and matrix deposition during flexor tendon healing. Counter to our hypothesis that EP4 antagonism would improve the

  15. Enhancement of Glutamate Release by l-Fucose Changes Effects of Glutamate Receptor Antagonists on Long-Term Potentiation in the Rat Hippocampus

    OpenAIRE

    Matthies, Henry; Schroeder, Helmut; Smalla, Karl-Heinz; Krug, Manfred

    2000-01-01

    In previous studies l-fucose has been shown to facilitate long-term memory formation and to enhance and prolong long-term potentiation (LTP). To search for possible presynaptic or postsynaptic mechanisms that are affected by l-fucose, we examined the effect of l-fucose on (1) inhibition of LTP induction via glutamate receptors by antagonists, (2) paired-pulse facilitation, and (3) presynaptic transmitter release. Coapplication of 0.2 mm l-fucose with the competitive N-methyl-d-aspartate (NMDA...

  16. Impairment of GABA transporter GAT-1 terminates cortical recurrent network activity via enhanced phasic inhibition

    Directory of Open Access Journals (Sweden)

    David Johannes Hawellek

    2013-09-01

    Full Text Available In the central nervous system, GABA transporters (GATs very efficiently clear synaptically released GABA from the extracellular space, and thus exert a tight control on GABAergic inhibition. In neocortex, GABAergic inhibition is heavily recruited during recurrent phases of spontaneous action potential activity which alternate with neuronally quiet periods. Therefore, such activity should be quite sensitive to minute alterations of GAT function. Here, we explored the effects of a gradual impairment of GAT-1 and GAT-2/3 on spontaneous recurrent network activity – termed network bursts and silent periods – in organotypic slice cultures of rat neocortex. The GAT-1 specific antagonist NO-711 depressed activity already at nanomolar concentrations (IC50 for depression of spontaneous multiunit firing rate of 42 nM, reaching a level of 80% at 500-1000 nM. By contrast, the GAT-2/3 preferring antagonist SNAP-5114 had weaker and less consistent effects. Several lines of evidence pointed towards an enhancement of phasic GABAergic inhibition as the dominant activity-depressing mechanism: network bursts were drastically shortened, phasic GABAergic currents decayed slower, and neuronal excitability during ongoing activity was diminished. In silent periods, NO-711 had little effect on neuronal excitability or membrane resistance, quite in contrast to the effects of muscimol, a GABA mimetic which activates GABAA receptors tonically. Our results suggest that an enhancement of phasic GABAergic inhibition efficiently curtails cortical recurrent activity and may mediate antiepileptic effects of therapeutically relevant concentrations of GAT-1 antagonists.

  17. Antagonistic effect of Lactobacillus strains against gas-producing coliforms isolated from colicky infants

    Directory of Open Access Journals (Sweden)

    Oggero Roberto

    2011-06-01

    Full Text Available Abstract Background Infantile colic is a common disturb within the first 3 months of life, nevertheless the pathogenesis is incompletely understood and treatment remains an open issue. Intestinal gas production is thought to be one of the causes of abdominal discomfort in infants suffering from colic. However, data about the role of the amount of gas produced by infants' colonic microbiota and the correlation with the onset of colic symptoms are scanty. The benefit of supplementation with lactobacilli been recently reported but the mechanisms by which they exert their effects have not yet been fully defined. This study was performed to evaluate the interaction between Lactobacillus spp. strains and gas-forming coliforms isolated from stools of colicky infants. Results Strains of coliforms were isolated from stools of 45 colicky and 42 control breastfed infants in McConkey Agar and identified using PCR with species-specific primers, and the BBL™ Enterotube™ II system for Enterobacteriaceae. Gas-forming capability of coliforms was assessed in liquid cultures containing lactose as sole carbon source. The average count of total coliforms in colicky infants was significantly higher than controls: 5.98 (2.00-8.76 log10 vs 3.90 (2.50-7.10 CFU/g of faeces (p = 0.015. The following strains were identified: Escherichia coli, Klebsiella pneumoniae, Klebsiella oxytoca, Enterobacter aerogenes, Enterobacter cloacae and Enterococcus faecalis. Then, 27 Lactobacillus strains were tested for their antagonistic effect against coliforms both by halo-forming method and in liquid co-cultures. Lactobacillus delbrueckii subsp.delbrueckii DSM 20074 and L. plantarum MB 456 were able to inhibit all coliforms strains (halo-forming method, also in liquid co-cultures, thus demonstrating an antagonistic activity. Conclusions This study shows that two out of 27 strains of Lactobacillus examined possess an antimicrobial effect against six species of gas-forming coliforms

  18. SB 242084, a selective and brain penetrant 5-HT2C receptor antagonist.

    Science.gov (United States)

    Kennett, G A; Wood, M D; Bright, F; Trail, B; Riley, G; Holland, V; Avenell, K Y; Stean, T; Upton, N; Bromidge, S; Forbes, I T; Brown, A M; Middlemiss, D N; Blackburn, T P

    1997-01-01

    SB 242084 has a high affinity (pKi 9.0) for the cloned human 5-HT2C receptor and 100- and 158-fold selectivity over the closely related cloned human 5-HT2B and 5-HT2A subtypes respectively. SB 242084 had over 100-fold selectivity over a range of other 5-HT, dopamine and adrenergic receptors. In studies of 5-HT-stimulated phosphatidylinositol hydrolysis using SH-SY5Y cells stably expressing the cloned human 5-HT2C receptor, SB 242084 acted as an antagonist with a pKb of 9.3, which closely resembled its corresponding receptor binding affinity. SB 242084 potently inhibited m-chlorophenylpiperazine (mCPP, 7 mgkg i.p. 20 min pre-test)-induced hypolocomotion in rats, a model of in vivo central 5-HT2C receptor function, with an ID50 of 0.11 mg/kg i.p., and 2.0 mg/kg p.o. SB 242084 (0.1-1 mg/kg i.p.) exhibited an anxiolytic-like profile in the rat social interaction test, increasing time spent in social interaction, but having no effect on locomotion. SB 242084 (0.1-1 mg/kg i.p.) also markedly increased punished responding in a rat Geller-Seifter conflict test of anxiety, but had no consistent effect on unpunished responding. A large acute dose of SB 242084 (30 mg/kg p.o.) had no effect on seizure susceptibility in the rat maximal electroshock seizure threshold test. Also, while SB 242084 (2 and 6 mg/kg p.o. 1 hr pre-test) antagonized the hypophagic response to mCPP, neither acute nor subchronic administration of the drug, for 5 days at 2 or 6 mg/kg p.o. twice daily, affected food intake or weight gain. The results suggest that SB 242084 is the first reported selective potent and brain penetrant 5-HT2C receptor antagonist and has anxiolytic-like activity, but does not possess either proconvulsant or hyperphagic properties which are characteristic of mutant mice lacking the 5-HT2C receptor. PMID:9225286

  19. Characterization of the binding of a novel nonxanthine adenosine antagonist radioligand, ( sup 3 H)CGS 15943, to multiple affinity states of the adenosine A1 receptor in the rat cortex

    Energy Technology Data Exchange (ETDEWEB)

    Jarvis, M.F.; Williams, M.; Do, U.H.; Sills, M.A. (CIBA-GEIGY Corp., Summit, NJ (USA))

    1991-01-01

    The triazoloquinazoline CGS 15943 is the first reported nonxanthine adenosine antagonist that has high affinity for brain adenosine receptors. In the present study, the binding of (3H) CGS 15943 to recognition sites in rat cortical membranes was characterized. Saturation experiments revealed that (3H)CGS 15943 labeled a single class of recognition sites with high affinity and limited capacity. Competition studies revealed that the binding of (3H)CGS 15943 was consistent with the labeling of brain adenosine A1 receptors. Adenosine agonists inhibited 1 nM (3H)CGS 15943 binding with the following order of activity N6-cyclopentyladenosine (IC50 = 15 nM) greater than 2-chloroadenosine greater than (R)-N6-phenylisopropyladenosine greater than 5'-N6-ethylcarboxamidoadenosine greater than (S)N6-phenylisopropyladenosine greater than CGS 21680 greater than CV 1808 (IC50 greater than 10,000 nM). The potency order for adenosine antagonists was CGS 15943 (IC50 = 5 nM) greater than 8-phenyltheophylline greater than 1,3-dipropyl-8-(4-amino-2-chloro)phenylxanthine greater than 1,3-diethyl-8-phenylxanthine greater than theophylline = caffeine (IC50 greater than 10,000 nM). Antagonist inhibition curves were steep and best described by a one-site binding model. In contrast, adenosine A1 agonist competition curves were shallow, as indicated by Hill coefficients less than unity. Computer analysis revealed that these inhibition curves were best described by a two-site binding model. Agonist competition curves generated in the presence of 1 mM GTP resulted in a rightward shift and steepening of the inhibition-concentration curves, whereas antagonist binding was not altered in the presence of GTP. The complex binding interactions found with adenosine agonists indicate that (3H)CGS 15943 labels both high and low affinity components of the adenosine A1 receptor in the rat cortex.

  20. Bronchoprotection with a leukotriene receptor antagonist in asthmatic preschool children

    DEFF Research Database (Denmark)

    Bisgaard, H; Nielsen, K G

    2000-01-01

    We hypothesized that a leukotriene receptor antagonist (LTRA) could provide bronchoprotection against the cold, dry air-induced response in asthmatic preschool children. In a randomized, double-blind, placebo-controlled crossover study, we examined the effect of the specific LTRA montelukast at 5...... repeatability of the bronchoprotection was examined by repeating the placebo-controlled study in six of the 13 children. sRaw increased by an average of 46% (95% confidence interval [CI]: 30 to 63%) after placebo treatment and 17% (95% CI: 3 to 31%) after montelukast (p < 0.01). Eight of the children were...... receiving regular treatment with budesonide delivered by an inhaler with a spacer in a mean daily dose of 350 microg, but the bronchoprotection provided by montelukast was independent of concurrent steroid treatment. There was no convincing evidence of failure to respond, and the protective effect of...

  1. Identification of Bexarotene as a PPARγ Antagonist with HDX

    Directory of Open Access Journals (Sweden)

    David P. Marciano

    2015-01-01

    Full Text Available The retinoid x receptors (RXRs are the pharmacological target of Bexarotene, an antineoplastic agent indicated for the treatment of cutaneous T cell lymphoma (CTCL. The RXRs form heterodimers with several nuclear receptors (NRs, including peroxisome proliferator-activated receptor gamma (PPARγ, to regulate target gene expression through cooperative recruitment of transcriptional machinery. Here we have applied hydrogen/deuterium exchange (HDX mass spectrometry to characterize the effects of Bexarotene on the conformational plasticity of the intact RXRα:PPARγ heterodimer. Interestingly, addition of Bexarotene to PPARγ in the absence of RXRα induced protection from solvent exchange, suggesting direct receptor binding. This observation was confirmed using a competitive binding assay. Furthermore, Bexarotene functioned as a PPARγ antagonist able to alter rosiglitazone induced transactivation in a cell based promoter:reporter transactivation assay. Together these results highlight the complex polypharmacology of lipophilic NR targeted small molecules and the utility of HDX for identifying and characterizing these interactions.

  2. Effect of diseases on response to vitamin K antagonists.

    Science.gov (United States)

    Self, Timothy H; Owens, Ryan E; Sakaan, Sami A; Wallace, Jessica L; Sands, Christopher W; Howard-Thompson, Amanda

    2016-04-01

    Introduction The purpose of this review article is to summarize the literature on diseases that are documented to have an effect on response to warfarin and other VKAs. Methods We searched the English literature from 1946 to September 2015 via PubMed, EMBASE, and Scopus for the effect of diseases on response vitamin K antagonists including warfarin, acenocoumarol, phenprocoumon, and fluindione. Discussion Among many factors modifying response to VKAs, several disease states are clinically relevant. Liver disease, hyperthyroidism, and CKD are well documented to increase response to VKAs. Decompensated heart failure, fever, and diarrhea may also elevate response to VKAs, but more study is needed. Hypothyroidism is associated with decreased effect of VKAs, and obese patients will likely require higher initial doses of VKAs. Conclusion In order to minimize risks with VKAs while ensuring efficacy, clinicians must be aware of the effect of disease states when prescribing these oral anticoagulants. PMID:26695107

  3. Research progress of antagonistic interactions among root canal irrigations disease

    Directory of Open Access Journals (Sweden)

    Chen QU

    2013-07-01

    Full Text Available Root canal therapy is the most effective way to treat various pulposis and periapical disease. Simple mechanical apparatus can not clean root canal thoroughly, but may affect tight filling instead. It can achieve a satisfactory cleansing effect only when it is combined with a chemical solution. Irrigation fluid for root canal should possess the properties of tissue dissolution, antimicrobial, lubrication, and removal of smear layer. So far, no solution is able to fulfill all these functions. Therefore, a combined use of multiple irrigation solutions is suggested. It can not only achieve good effect in cleaning and disinfection, also it can lower the concentration of different solutions, thus reducing the side effects. Nevertheless, some experiments proved that antagonism existed among the chemicals used for irrigations. The purpose of present article is to review the antagonistic effect among the chemicals used for irrigation when they are used together for root canal treatment.

  4. Defining the role of GLP-1 in the enteroinsulinar axis in type 2 diabetes using DPP-4 inhibition and GLP-1 receptor blockade

    DEFF Research Database (Denmark)

    Aulinger, Benedikt A; Bedorf, Anne; Kutscherauer, Gabriele;

    2014-01-01

    ) inhibition and its glucose-lowering actions were tested after an oral glucose tolerance test (OGTT). The contribution of GLP-1 was examined by infusion of the GLP-1 receptor (GLP-1r) antagonist exendin-9. DPP-4 inhibition reduced glycemia and enhanced insulin levels and the incretin effect (IE). Glucagon was...... suppressed, and gastric emptying (GE) was decelerated. Exendin-9 increased glucose levels and glucagon secretion, attenuated insulinemia and the IE, and accelerated GE. With the GLP-1r antagonist, the glucose-lowering effects of DPP-4 inhibition were reduced by ∼ 50%. However, a significant effect on insulin...... secretion remained during GLP-1r blockade, whereas the inhibitory effects of DPP-4 inhibition on glucagon and GE were abolished. Thus, in this cohort of T2D patients with a substantial IE, GLP-1 contributed ∼ 50% to the insulin excursion after an OGTT with and without DPP-4 inhibition. Thus, a significant...

  5. Alpha antagonists and intraoperative floppy iris syndrome: A spectrum

    Directory of Open Access Journals (Sweden)

    Sharif A Issa

    2008-07-01

    Full Text Available Sharif A Issa, Omar H Hadid, Oliver Baylis, Margaret DayanDepartment of Ophthalmology, Royal Victoria Infirmary, Newcastle upon Tyne, UKBackground: To determine occurrence of features of intraoperative floppy iris syndrome (IFIS during cataract surgery in patients taking systemic alpha-antagonists (AA.Methods: We prospectively studied patients on AA and who underwent phacoemulsification. The following were recorded: pupil diameter preoperatively, iris flaccidity, iris prolapse and peroperative miosis.Results: We studied 40 eyes of 31 subjects. Mean age was 78 years. Overall, 14 eyes (13 patients showed signs of IFIS: 9/13 (69% eyes of patients on tamsulosin, 1/18 (6% eyes in the doxazosin group, 2/2 prazosin patients, 1/4 eyes in the indoramin group, and 1/2 eyes in two patients on a combination of doxazosin and tamsulosin. Most cases (92% had only one or two signs of IFIS. Bilateral cataract surgery was undertaken in 9 patients but only one patient (on tamsulosin had features of IFIS in both eyes, while 4 patients (2 on tamsulosin and 2 on other AA showed signs of IFIS in one eye only, and 4 patients did not show IFIS in either eye.Conclusion: Most AA were associated with IFIS, but it tends to present as a spectrum of signs rather than full triad originally described. Tamsulosin was most likely to be associated with IFIS; however, its intake does not necessarily mean that IFIS will occur. For patients on AA, the behavior of the iris intraoperatively in one eye is a poor predictor of the other eye. Surgeons should anticipate the occurrence of IFIS in any patient on AA.Keywords: alpha blocker, alpha antagonist, cataract surgery, intraoperative floppy iris syndrome, tamsulosin.

  6. Isolation, characterization, and formulation of antagonistic bacteria for the management of seedlings damping-off and root rot disease of cucumber.

    Science.gov (United States)

    Khabbaz, Salah Eddin; Abbasi, Pervaiz A

    2014-01-01

    Antagonistic bacteria are common soil inhabitants with potential to be developed into biofungicides for the management of seedling damping-off, root rot, and other soil-borne diseases of various crops. In this study, antagonistic bacteria were isolated from a commercial potato field and screened for their growth inhibition of fungal and oomycete pathogens in laboratory tests. The biocontrol potential of the 3 most effective antagonistic bacteria from the in vitro tests was evaluated against seedling damping-off and root rot of cucumber caused by Pythium ultimum. Based on phenotypic characteristics, biochemical tests, and sequence analysis of 16S-23S rDNA gene, the 3 antagonistic bacteria were identified as Pseudomonas fluorescens (isolate 9A-14), Pseudomonas sp. (isolate 8D-45), and Bacillus subtilis (isolate 8B-1). All 3 bacteria promoted plant growth and suppressed Pythium damping-off and root rot of cucumber seedlings in growth-room assays. Both pre- and post-planting application of these bacteria to an infested peat mix significantly increased plant fresh masses by 113%-184% and percentage of healthy seedlings by 100%-290%, and decreased damping-off and root rot severity by 27%-50%. The peat and talc formulations of these antagonistic bacteria applied as seed or amendment treatments to the infested peat mix effectively controlled Pythium damping-off and root rot of cucumber seedlings and enhanced plant growth. The survival of all 3 antagonistic bacteria in peat and talc formulations decreased over time at room temperature, but the populations remained above 10(8) CFU/g during the 180-day storage period. The peat formulation of a mixture of 3 bacteria was the best seed treatment, significantly increasing the plant fresh masses by 245% as compared with the Pythium control, and by 61.4% as compared with the noninfested control. This study suggests that the indigenous bacteria from agricultural soils can be developed and formulated as biofungicides for minimizing

  7. Fermentation of lignocellulosic hydrolysates: Inhibition and detoxification

    Energy Technology Data Exchange (ETDEWEB)

    Palmqvist, E.

    1998-02-01

    The ethanol yield and productivity obtained during fermentation of lignocellulosic hydrolysates is decreased due to the presence of inhibiting compounds, such as weak acids, furans and phenolic compounds produced during hydrolysis. Evaluation of the effect of various biological, physical and chemical detoxification treatments by fermentation assays using Saccharomyces cerevisiae was used to characterise inhibitors. Inhibition of fermentation was decreased after removal of the non-volatile compounds, pre-fermentation by the filamentous fungus Trichoderma reesei, treatment with the lignolytic enzyme laccase, extraction with ether, and treatment with alkali. Yeast growth in lignocellulosic hydrolysates was inhibited below a certain fermentation pH, most likely due to high concentrations of undissociated weak acids. The effect of individual compounds were studied in model fermentations. Furfural is reduced to furfuryl alcohol by yeast dehydrogenases, thereby affecting the intracellular redox balance. As a result, acetaldehyde accumulated during furfural reduction, which most likely contributed to inhibition of growth. Acetic acid (10 g 1{sup -1}) and furfural (3 g 1{sup -1}) interacted antagonistically causing decreased specific growth rate, whereas no significant individual or interaction effects were detected by the lignin-derived compound 4-hydroxybenzoic acid (2 g 1{sup -1}). By maintaining a high cell mass density in the fermentor, the process was less sensitive to inhibitors affecting growth and to fluctuations in fermentation pH, and in addition the depletion rate of bioconvertible inhibitors was increased. A theoretical ethanol yield and high productivity was obtained in continuous fermentation of spruce hydrolysate when the cell mass concentration was maintained at a high level by applying cell recirculation 164 refs, 16 figs, 5 tabs

  8. Hotspots of damage by antagonists shape the spatial structure of plant-pollinator interactions.

    Science.gov (United States)

    Rodríguez-Rodríguez, María C; Jordano, Pedro; Valido, Alfredo

    2015-08-01

    The balance between mutualistic and antagonistic plant-animal interactions and their spatial variation results in a highly dynamic mosaic of reproductive success within plant populations. Yet, the ecological drivers of this small-scale heterogeneity of interaction patterns and their outcomes remain virtually unexplored. We analyzed spatial structure in the frequency and intensity of interactions that vertebrate pollinators (birds and lizards) and invertebrate antagonists (florivores, nectar larcenists, and seed predators) had when interacting with the insular plant Isoplexis canariensis, and their effect on plant fitness. Spatially autocorrelated variation in plant reproductive success (fruit and viable seed set) emerged from the combined action of mutualists and antagonists, rather than reflecting the spatial pattern of any specific animal group. However, the influence of antagonists on plant fitness was stronger primarily due to the florivores' action on earlier reproductive stages, consuming and damaging floral structures before the arrival of pollinators. Our results indicate that the early action of antagonists creates hotspots of increased plant damage, where the effects of later acting mutualists are not translated into increased reproductive benefits. We foresee the potential for antagonists to shape the intra-population mosaics of plant fitness in situations where antagonists outnumber mutualists, when their interactions occur before those of mutualists, and when mutualists can detect and avoid damaged plants while foraging. Severely damaged plants in antagonistic hotspots might be excluded from the mating network and render a limited production of viable seeds, reducing both the growth rate of the plant population and the effective population size. PMID:26405743

  9. Folic acid sensitive birth defects in association with intrauterine exposure to folic acid antagonists

    NARCIS (Netherlands)

    Meijer, W.M.; Walle, H.E.K.de; Kerstjens-Frederikse, W.S; de Jong-van den Berg, Lolkje Theodora Wilhelmina

    2005-01-01

    Since the protective effect of folic acid (FA) on birth defects is well known, it is reasonable to assume intrauterine exposure to FA antagonists increases the risk on these defects. We have therefore performed case-control analyses to investigate the risk of intrauterine exposure to FA antagonists,

  10. Anti-inflammatory properties of a novel peptide interleukin 1 receptor antagonist

    DEFF Research Database (Denmark)

    Klementiev, Boris; Li, Shizhong; Korshunova, Irina; Dmytriyeva, Oksana; Pankratova, Stanislava; Walmod, Peter S; Kjær, Laura K; Dahllöf, Mattias S; Lundh, Morten; Christensen, Dan P; Mandrup-Poulsen, Thomas; Bock, Elisabeth; Berezin, Vladimir

    2014-01-01

    Interleukin 1 (IL-1) is implicated in neuroinflammation, an essential component of neurodegeneration. We evaluated the potential anti-inflammatory effect of a novel peptide antagonist of IL-1 signaling, Ilantide.......Interleukin 1 (IL-1) is implicated in neuroinflammation, an essential component of neurodegeneration. We evaluated the potential anti-inflammatory effect of a novel peptide antagonist of IL-1 signaling, Ilantide....

  11. Control of blue mold of apple by combining controlled atmosphere, antagonist mixtures and sodium bicarbonate

    Science.gov (United States)

    'Golden Delicious' apples were wound-inoculated with Penicillium expansum, treated with various combinations of sodium bicarbonate and two antagonists, and stored in air or controlled atmosphere (1.4% O2, 3% CO2). The fruit were stored for 2 or 4 months at 1°C. The antagonists survived and their p...

  12. Discovery and mapping of an intracellular antagonist binding site at the chemokine receptor CCR2

    DEFF Research Database (Denmark)

    Zweemer, Annelien J M; Bunnik, Julia; Veenhuizen, Margo; Miraglia, Fabiana; Lenselink, Eelke B; Vilums, Maris; de Vries, Henk; Gibert, Arthur; Thiele, Stefanie; Rosenkilde, Mette M; IJzerman, Adriaan P; Heitman, Laura H

    2014-01-01

    The chemokine receptor CCR2 is a G protein-coupled receptor that is involved in many diseases characterized by chronic inflammation, and therefore a large variety of CCR2 small molecule antagonists has been developed. On the basis of their chemical structures these antagonists can roughly be divi...

  13. Beta-adrenoceptor antagonists enhance white blood cell aggregation in patients with ischaemic heart disease.

    OpenAIRE

    Bridges, A B; Pringle, T. H.; McNeill, G P; Tavendale, R; Belch, J J

    1992-01-01

    The effects of beta-adrenoceptor antagonists, calcium channel blockers and long acting nitrates on white blood cell (WBC) aggregation were studied in patients with ischaemic heart disease. WBC aggregation was significantly increased by beta-adrenoceptor antagonists (P = 0.011) but was unaffected by either calcium channel blockers or long acting nitrates. Enhanced WBC aggregation promotes microvascular occlusion and damage.

  14. Modeling tandem AAG8-MEK inhibition in melanoma cells

    International Nuclear Information System (INIS)

    Drug resistance presents a challenge to the treatment of cancer patients, especially for melanomas, most of which are caused by the hyperactivation of MAPK signaling pathway. Innate or acquired drug-resistant relapse calls for the investigation of the resistant mechanisms and new anti-cancer drugs to provide implications for the ultimate goal of curative therapy. Aging-associated gene 8 (AAG8, encoded by the SIGMAR1 gene) is a chaperone protein profoundly elaborated in neurology. However, roles of AAG8 in carcinogenesis remain unclear. Herein, we discover AAG8 antagonists as new MEK inhibitors in melanoma cells and propose a novel drug combination strategy for melanoma therapy by presenting the experimental evidences. We report that specific antagonism of AAG8, efficiently suppresses melanoma cell growth and migration through, at least in part, the inactivation of the RAS-CRAF-MEK signaling pathway. We further demonstrate that melanoma cells that are resistant to AAG8 antagonist harbor refractory CRAF-MEK activity. MEK acts as a central mediator for anti-cancer effects and also for the resistance mechanism, leading to our proposal of tandem AAG8-MEK inhibition in melanoma cells. Combination of AAG8 antagonist and very low concentration of a MEK inhibitor synergistically restricts the growth of drug-resistant cells. These data collectively pinpoint AAG8 as a potential target and delineate a promising drug combination strategy for melanoma therapy

  15. Dopamine inhibits somatolactin gene expression in tilapia pituitary cells through the dopamine D2 receptors.

    Science.gov (United States)

    Jiang, Quan; Lian, Anji; He, Qi

    2016-07-01

    Dopamine (DA) is an important neurotransmitter in the central nervous system of vertebrates and possesses key hypophysiotropic functions. Early studies have shown that DA has a potent inhibitory effect on somatolactin (SL) release in fish. However, the mechanisms responsible for DA inhibition of SL gene expression are largely unknown. To this end, tilapia DA type-1 (D1) and type-2 (D2) receptor transcripts were examined in the neurointermediate lobe (NIL) of the tilapia pituitary by real-time PCR. In tilapia, DA not only was effective in inhibiting SL mRNA levels in vivo and in vitro, but also could abolish pituitary adenylate cyclase-activating polypeptide (PACAP)- and salmon gonadotropin-releasing hormone (sGnRH)-stimulated SL gene expression at the pituitary level. In parallel studies, the specific D2 receptor agonists quinpirole and bromocriptine could mimic the DA-inhibited SL gene expression. Furthermore, the D2 receptor antagonists domperidone and (-)-sulpiride could abolish the SL response to DA or the D2 agonist quinpirole, whereas D1 receptor antagonists SCH23390 and SKF83566 were not effective in this respect. In primary cultures of tilapia NIL cells, D2 agonist quinpirole-inhibited cAMP production could be blocked by co-treatment with the D2 antagonist domperidone and the ability of forskolin to increase cAMP production was also inhibited by quinpirole. Using a pharmacological approach, the AC/cAMP pathway was shown to be involved in quinpirole-inhibited SL mRNA expression. These results provide evidence that DA can directly inhibit SL gene expression at the tilapia pituitary level via D2 receptor through the AC/cAMP-dependent mechanism. PMID:26970582

  16. Design and synthesis of substituted 2-naphthyloxyethylamines as potential 5-HT 1A antagonists

    Directory of Open Access Journals (Sweden)

    Joshi Urmila

    2007-01-01

    Full Text Available Although 5-HT 1A antagonists are known to be useful in the treatment of depression, no specific 5-HT 1A antagonist is available clinically. Propranolol is one of the important ligands acting at the presynaptic 5-HT 1A receptor. This article deals with the design of 5-HT 1A antagonists based on propranolol using the pharmacophoric requirements of the receptor and the other SAR data, synthesis of these compounds and their preliminary evaluation for the 5-HT 1A antagonistic activity against a specific partial agonist. This was done by measuring the reversal of agonist-induced hypothermia in mice. The synthesized compounds showed a promising 5-HT 1A antagonistic activity.

  17. Antagonistic activity of autosimbionts А. viridans, B. subtilis and their probiotic association to conditionally microflora

    Directory of Open Access Journals (Sweden)

    Stepansky D.A.

    2015-03-01

    Full Text Available In this research the data on examination of antagonist qualities of bioassotiantes A. viridans and strain B. subtilis 3 towards pathogenic and opportunistic pathogenic microflora isolated from oropharynx and nasopharynx of children who were in contact with patients with pulmonary tuberculosis (MBT + are submitted. The expressed antagonist activity of autosimbionts A. viridans towards pathogenic and opportunistic pathogenic microflora was shown. Common antagonist activity of A. viridans (k N 1 and B. subtilis 3 towards diverse strains of test-cultures is 1,5-2 times higher, than separate antagonist activity of A. viridans (k №1 and B. subtilis 3. Received research data showed the possibility of continuing work on development of probiotic associations, that contain representatives of normal microflora - bioassociants A. viridans and probiotic strains B. subtilis 3 with broadspectrum of antagonistic activity in relation to the various groups of bacterium.

  18. Inhibition in multiclass classification

    OpenAIRE

    Huerta, Ramón; Vembu, Shankar; Amigó, José M.; Nowotny, Thomas; Elkan, Charles

    2012-01-01

    The role of inhibition is investigated in a multiclass support vector machine formalism inspired by the brain structure of insects. The so-called mushroom bodies have a set of output neurons, or classification functions, that compete with each other to encode a particular input. Strongly active output neurons depress or inhibit the remaining outputs without knowing which is correct or incorrect. Accordingly, we propose to use a classification function that embodies unselective inhibition and ...

  19. Fluoxetine-induced inhibition of synaptosomal [3H]5-HT release: Possible Ca2+-channel inhibition

    International Nuclear Information System (INIS)

    Fluoxetine, a selective 5-Ht uptake inhibitor, inhibited 15 mM K+-induced [3H]5-HT release from rat spinal cord and cortical synaptosomes at concentrations > 0.5 uM. This effect reflected a property shared by another selective 5-HT uptake inhibitor paroxetine but not by less selective uptake inhibitors such as amitriptyline, desipramine, imipramine or nortriptyline. Inhibition of release by fluoxetine was inversely related to both the concentration of K+ used to depolarize the synaptosomes and the concentration of external Ca2+. Experiments aimed at determining a mechanism of action revealed that fluoxetine did not inhibit voltage-independent release of [3H]5-HT release induced by the Ca2+-ionophore A 23187 or Ca2+-independent release induced by fenfluramine. Moreover the 5-HT autoreceptor antagonist methiothepin did not reverse the inhibitory actions of fluoxetine on K+-induced release. Further studies examined the effects of fluoxetine on voltage-dependent Ca2+ channels and Ca2+ entry

  20. Growth inhibiting effects of terazosin on androgen-independent prostate cancer cell lines

    Institute of Scientific and Technical Information of China (English)

    许克新; 王向红; 凌明达; 王云川

    2003-01-01

    Objective To study the effects of an α1-adrenoceptor antagonist, terazosin on the androgen-independent prostate cancer cell lines PC-3 and DU145.Methods Two androgen independent cell lines, PC-3 and DU145, were used to determine cell viability, colony-forming ability, as well as cell cycle distribution, after exposure to terazosin. Western blot analysis was used to determine the expression of p21WAF1 and p27KIP1.Results This study shows that terazosin inhibits not only prostate cancer cell growth but also its colony forming ability, both of which are main targets of clinical treatment. In addition, terazosin is shown to inhibit cell growth through G1 phase cell cycle arrest and the up-regulation of p27KIP1.Conclusion This study provides evidence that the α1-adrenoceptor antagonist terazosin may have therapeutic potential in the treatment of advanced hormone refractory prostate cancer.

  1. Group I mGluR antagonist rescues the deficit of D1-induced LTP in a mouse model of fragile X syndrome

    Directory of Open Access Journals (Sweden)

    Xu Zhao-Hui

    2012-05-01

    Full Text Available Abstract Background Fragile X syndrome (FXS is caused by the absence of the mRNA-binding protein Fragile X mental retardation protein (FMRP, encoded by the Fmr1 gene. Overactive signaling by group 1 metabotropic glutamate receptor (Grp1 mGluR could contribute to slowed synaptic development and other symptoms of FXS. Our previous study has identified that facilitation of synaptic long-term potentiation (LTP by D1 receptor is impaired in Fmr1 knockout (KO mice. However, the contribution of Grp1 mGluR to the facilitation of synaptic plasticity by D1 receptor stimulation in the prefrontal cortex has been less extensively studied. Results Here we demonstrated that DL-AP3, a Grp1 mGluR antagonist, rescued LTP facilitation by D1 receptor agonist SKF81297 in Fmr1KO mice. Grp1 mGluR inhibition restored the GluR1-subtype AMPA receptors surface insertion by D1 activation in the cultured Fmr1KO neurons. Simultaneous treatment of Grp1 mGluR antagonist with D1 agonist recovered the D1 receptor signaling by reversing the subcellular redistribution of G protein-coupled receptor kinase 2 (GRK2 in the Fmr1KO neurons. Treatment of SKF81297 alone failed to increase the phosphorylation of NR2B-containing N-methyl D-aspartate receptors (NMDARs at Tyr-1472 (p-NR2B-Tyr1472 in the cultures from KO mice. However, simultaneous treatment of DL-AP3 could rescue the level of p-NR2B-Tyr1472 by SKF81297 in the cultures from KO mice. Furthermore, behavioral tests indicated that simultaneous treatment of Grp1 mGluR antagonist with D1 agonist inhibited hyperactivity and improved the learning ability in the Fmr1KO mice. Conclusion The findings demonstrate that mGluR1 inhibition is a useful strategy to recover D1 receptor signaling in the Fmr1KO mice, and combination of Grp1 mGluR antagonist and D1 agonist is a potential drug therapy for the FXS.

  2. Platelet-Activating Factor (PAF Antagonistic Activity of a New Biflavonoid from Garcinia nervosa var. pubescens King

    Directory of Open Access Journals (Sweden)

    Azura Abdul Ghani

    2012-09-01

    Full Text Available The methanol extract of the leaves of Garcinia nervosa var. pubescens King, which showed strong inhibitory effects on platelet-activating factor (PAF receptor binding, was subjected to bioassay-guided isolation to obtain a new biflavonoid, II-3,I-5, II-5,II-7,I-4',II-4'-hexahydroxy-(I-3,II-8-flavonylflavanonol together with two known flavonoids, 6-methyl-4'-methoxyflavone and acacetin. The structures of the compounds were elucidated by spectroscopic methods. The compounds were evaluated for their ability to inhibit PAF receptor binding to rabbit platelets using 3H-PAF as a ligand. The biflavonoid and acacetin showed strong inhibition with IC50 values of 28.0 and 20.4 µM, respectively. The results suggest that these compounds could be responsible for the strong PAF antagonistic activity of the plant.

  3. Streptomyces sanglieri which colonised and enhanced the growth of Elaeis guineensis Jacq. seedlings was antagonistic to Ganoderma boninense in in vitro studies.

    Science.gov (United States)

    Nur Azura, A B; Yusoff, M; Tan, G Y A; Jegadeesh, R; Appleton, D R; Vikineswary, S

    2016-04-01

    Actinomycete strain AUM 00500 was 99.5 % similar to Streptomyces sanglieri NBRC 100784(T) and was evaluated for antagonistic activity towards Ganoderma boninense, the causative fungus of basal stem rot of oil palm. The strain showed strong antifungal activity towards G. boninense in in vitro and SEM analysis showed various modes of inhibition of the fungus. Ethyl acetate extracts of single culture and inhibition zone of cross-plug culture by HPLC indicated that strain AUM 00500 produced two different antibiotics of the glutarimide group namely cycloheximide and actiphenol. In greenhouse trials, oil palm seed treated with spores of S. sanglieri strain AUM 00500 at 10(9) cfu/ml showed significant (P < 0.05) increase in oil palm seedlings growth when compared to the control. Streptomyces sanglieri strain AUM 00500 successfully colonised the epidermal surface of the roots of treated oil palm seedlings and it was recovered from root fragments plated on starch casein agar. PMID:26721619

  4. Cheiradone: a vascular endothelial cell growth factor receptor antagonist

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    Ahmed Nessar

    2008-01-01

    Full Text Available Abstract Background Angiogenesis, the growth of new blood vessels from the pre-existing vasculature is associated with physiological (for example wound healing and pathological conditions (tumour development. Vascular endothelial growth factor (VEGF, fibroblast growth factor-2 (FGF-2 and epidermal growth factor (EGF are the major angiogenic regulators. We have identified a natural product (cheiradone isolated from a Euphorbia species which inhibited in vivo and in vitro VEGF- stimulated angiogenesis but had no effect on FGF-2 or EGF activity. Two primary cultures, bovine aortic and human dermal endothelial cells were used in in vitro (proliferation, wound healing, invasion in Matrigel and tube formation and in vivo (the chick chorioallantoic membrane models of angiogenesis in the presence of growth factors and cheiradone. In all cases, the concentration of cheiradone which caused 50% inhibition (IC50 was determined. The effect of cheiradone on the binding of growth factors to their receptors was also investigated. Results Cheiradone inhibited all stages of VEGF-induced angiogenesis with IC50 values in the range 5.20–7.50 μM but did not inhibit FGF-2 or EGF-induced angiogenesis. It also inhibited VEGF binding to VEGF receptor-1 and 2 with IC50 values of 2.9 and 0.61 μM respectively. Conclusion Cheiradone inhibited VEGF-induced angiogenesis by binding to VEGF receptors -1 and -2 and may be a useful investigative tool to study the specific contribution of VEGF to angiogenesis and may have therapeutic potential.

  5. Effects of casoxin 4 on morphine inhibition of small animal intestinal contractility and gut transit in the mouse

    Directory of Open Access Journals (Sweden)

    Glen S Patten

    2011-02-01

    Full Text Available Glen S Patten1,2, Richard J Head1, Mahinda Y Abeywardena1,21CSIRO Preventative Health National Research Flagship, Adelaide, Australia; 2CSIRO Food and Nutritional Sciences, Adelaide, AustraliaBackground and aims: Chronic opioid analgesia has the debilitating side-effect of constipation in human patients. The major aims of this study were to: 1 characterize the opioid-specific antagonism of morphine-induced inhibition of electrically driven contraction of the small intestine of mice, rats, and guinea pigs; and 2 test if the oral delivery of small milk-derived opioid antagonist peptides could block morphine-induced inhibition of intestinal transit in mice.Methods: Mouse, rat, and guinea pig intact ileal sections were electrically stimulated to contract and inhibited with morphine in vitro. Morphine inhibition was then blocked by opioid subtype antagonists in the mouse and guinea pig. Using a polymeric dye, Poly R-478, the opioid antagonists casoxin 4 and lactoferroxin A were tested orally for blocking activity of morphine inhibition of gut transit in vivo by single or double gavage techniques.Results: The guinea pig tissue was more sensitive to morphine inhibition compared with the mouse or the rat (IC50 [half maximal inhibitory concentration] values as nmol/L ± SEM were 34 ± 3, 230 ± 13, and 310 ± 14 respectively (P < 0.01. The inhibitory influence of opioid agonists (IC50 in electrically driven ileal mouse preparations were DADLE ([D-Ala2, D-Leu5]-enkephalin ≥ met-enkephalin ≥ dynorphin A ≥ DAMGO ([D-Ala2, N-Me-Phe4, Gly-ol5]-enkephalin > morphine > morphiceptin as nmol/L 13.9, 17.3, 19.5, 23.3, 230, and 403 respectively. The mouse demonstrated predominantly Κ- and δ-opioid receptor activity with a smaller µ-opioid receptor component. Both mouse and guinea pig tissue were sensitive to casoxin 4 antagonism of morphine inhibition of contraction. In contrast to naloxone, relatively high oral doses of the µ-opioid receptor antagonists

  6. Vascular endothelial growth factor antagonist therapy for retinopathy of prematurity.

    Science.gov (United States)

    Hartnett, M Elizabeth

    2014-12-01

    In this article, the growing problem of retinopathy of prematurity (ROP) worldwide, treatments for severe ROP including standard-of-care laser treatment, and the need for new treatments are discussed. Also discussed are the reasons to consider inhibiting the vascular endothelial growth factor (VEGF) signaling pathway in severe ROP and the concerns about broad VEGF inhibition. Finally, the potential role of VEGF in ROP based on studies in animal models of oxygen-induced retinopathy, the effects of anti-VEGF based on basic research data, and the clinical relevance of these data are covered. PMID:25459781

  7. Blockade of Wnt signaling inhibits angiogenesis and tumor growth in hepatocellular carcinoma

    OpenAIRE

    J. Hu; Dong, A.; Fernandez-Ruiz, V. (Verónica); Shan, J.; Kawa, M. (Milosz); Martinez-Anso, E. (Eduardo); J. Prieto; Qian, C

    2009-01-01

    Aberrant activation of Wnt signaling plays an important role in hepatocarcinogenesis. In addition to direct effects on tumor cells, Wnt signaling might be involved in the organization of tumor microenvironment. In this study, we have explored whether Wnt signaling blockade by exogenous expression of Wnt antagonists could inhibit tumor angiogenesis and control tumor growth. Human Wnt inhibitory factor 1 (WIF1) and secreted frizzled-related protein 1 (sFRP1) were each fused with Fc fragment of ...

  8. Dkk-1 Inhibits Intestinal Epithelial Cell Migration by Attenuating Directional Polarization of Leading Edge Cells

    OpenAIRE

    Koch, Stefan; Capaldo, Christopher T.; Samarin, Stanislav; Nava, Porfirio; Neumaier, Irmgard; Skerra, Arne; Sacks, David B; Parkos, Charles A.; Nusrat, Asma

    2009-01-01

    Wnt signaling pathways regulate proliferation, motility, and survival in a variety of human cell types. Dickkopf-1 (Dkk-1) is a secreted Wnt antagonist that has been proposed to regulate tissue homeostasis in the intestine. In this report, we show that Dkk-1 is secreted by intestinal epithelial cells after wounding and that it inhibits cell migration by attenuating the directional orientation of migrating epithelial cells. Dkk-1 exposure induced mislocalized activation of Cdc42 in migrating c...

  9. CXCR4-antagonist Peptide R-liposomes for combined therapy against lung metastasis

    Science.gov (United States)

    Ieranò, Caterina; Portella, Luigi; Lusa, Sara; Salzano, Giuseppina; D'Alterio, Crescenzo; Napolitano, Maria; Buoncervello, Maria; Macchia, Daniele; Spada, Massimo; Barbieri, Antonio; Luciano, Antonio; Barone, Maria Vittoria; Gabriele, Lucia; Caraglia, Michele; Arra, Claudio; De Rosa, Giuseppe; Scala, Stefania

    2016-03-01

    The chemokine CXCL12 activates CXCR4, initiating multiple pathways that control immune cell trafficking, angiogenesis and embryogenesis; CXCR4 is also overexpressed in multiple tumors affecting metastatic dissemination. While there has been great enthusiasm for exploiting the CXCR4-CXCL12 axis as a target in cancer therapy, to date the promise has yet to be fulfilled. A new class of CXCR4-antagonist cyclic peptides was recently developed and the compound named Peptide R was identified as the most active. With the intent to improve the efficacy and biodistribution of Peptide R, stealth liposomes decorated with Peptide R were developed (PL-Peptide R). In vitro PL-Peptide R efficiently inhibited CXCR4-dependent migration and in vivo it significantly reduced lung metastases and increased overall survival in B16-CXCR4 injected C57BL/6 mice. To evaluate if PL-Peptide R could also be a drug delivery system for CXCR4 expressing tumors, the PL-Peptide R was loaded with doxorubicin (DOX) (PL-Peptide R-DOX). PL-Peptide R-DOX efficiently delivered DOX to CXCR4 expressing cell lines with a consequent decrease in the DOX IC50 efficient dose. In vivo, B16-CXCR4 injected C57BL/6 mice treated with PL-Peptide R-DOX developed fewer lung metastases compared to PL-DOX treated mice. This work provides the proof-of-concept to prevent metastasis by using combined nanomedicine.The chemokine CXCL12 activates CXCR4, initiating multiple pathways that control immune cell trafficking, angiogenesis and embryogenesis; CXCR4 is also overexpressed in multiple tumors affecting metastatic dissemination. While there has been great enthusiasm for exploiting the CXCR4-CXCL12 axis as a target in cancer therapy, to date the promise has yet to be fulfilled. A new class of CXCR4-antagonist cyclic peptides was recently developed and the compound named Peptide R was identified as the most active. With the intent to improve the efficacy and biodistribution of Peptide R, stealth liposomes decorated with Peptide

  10. Antagonistic effect of disulfide-rich peptide aptamers selected by cDNA display on interleukin-6-dependent cell proliferation

    Energy Technology Data Exchange (ETDEWEB)

    Nemoto, Naoto, E-mail: nemoto@fms.saitama-u.ac.jp [Graduate School of Science and Engineering, Saitama University, 255 Shimo-Okubo, Sakura-ku, Saitama 338-8570 (Japan); Innovation Center for Startups, National Institute of Advanced Industrial Science and Technology, 2-2-2 Marunouchi, Chiyoda-ku, Tokyo 100-0005 (Japan); Janusys Corporation, 508, Saitama Industrial Technology Center, Skip City, 3-12-18 Kami-Aoki, Kawaguchi, Saitama 333-0844 (Japan); Tsutsui, Chihiro [Graduate School of Science and Engineering, Saitama University, 255 Shimo-Okubo, Sakura-ku, Saitama 338-8570 (Japan); Yamaguchi, Junichi [Innovation Center for Startups, National Institute of Advanced Industrial Science and Technology, 2-2-2 Marunouchi, Chiyoda-ku, Tokyo 100-0005 (Japan); Applied Gene Technology, Institute for Biological Resources and Functions, National Institute of Advanced Industrial Science and Technology, Central 6, 1-1-1 Higashi, Tsukuba, Ibaraki 305-8566 (Japan); Ueno, Shingo [Graduate School of Science and Engineering, Saitama University, 255 Shimo-Okubo, Sakura-ku, Saitama 338-8570 (Japan); Machida, Masayuki [Applied Gene Technology, Institute for Biological Resources and Functions, National Institute of Advanced Industrial Science and Technology, Central 6, 1-1-1 Higashi, Tsukuba, Ibaraki 305-8566 (Japan); Kobayashi, Toshikatsu [Innovation Center for Startups, National Institute of Advanced Industrial Science and Technology, 2-2-2 Marunouchi, Chiyoda-ku, Tokyo 100-0005 (Japan); Janusys Corporation, 508, Saitama Industrial Technology Center, Skip City, 3-12-18 Kami-Aoki, Kawaguchi, Saitama 333-0844 (Japan); Sakai, Takafumi [Graduate School of Science and Engineering, Saitama University, 255 Shimo-Okubo, Sakura-ku, Saitama 338-8570 (Japan)

    2012-04-27

    Highlights: Black-Right-Pointing-Pointer Disulfide-rich peptide aptamer inhibits IL-6-dependent cell proliferation. Black-Right-Pointing-Pointer Disulfide bond of peptide aptamer is essential for its affinity to IL-6R. Black-Right-Pointing-Pointer Inhibitory effect of peptide depends on number and pattern of its disulfide bonds. -- Abstract: Several engineered protein scaffolds have been developed recently to circumvent particular disadvantages of antibodies such as their large size and complex composition, low stability, and high production costs. We previously identified peptide aptamers containing one or two disulfide-bonds as an alternative ligand to the interleukin-6 receptor (IL-6R). Peptide aptamers (32 amino acids in length) were screened from a random peptide library by in vitro peptide selection using the evolutionary molecular engineering method 'cDNA display'. In this report, the antagonistic activity of the peptide aptamers were examined by an in vitro competition enzyme-linked immunosorbent assay (ELISA) and an IL-6-dependent cell proliferation assay. The results revealed that a disulfide-rich peptide aptamer inhibited IL-6-dependent cell proliferation with similar efficacy to an anti-IL-6R monoclonal antibody.

  11. The Potential Role of GnRH Agonists and Antagonists in Inducing Thyroid Physiopathological Changes During IVF.

    Science.gov (United States)

    Gizzo, Salvatore; Noventa, Marco; Quaranta, Michela; Vitagliano, Amerigo; Esposito, Federica; Andrisani, Alessandra; Venturella, Roberta; Alviggi, Carlo; Plebani, Mario; Gangemi, Michele; Nardelli, Giovanni Battista; D'Antona, Donato

    2016-04-01

    We conducted an observational cohort study to evaluate whether drugs used for hypothalamic inhibition may impact thyroid function of infertile women scheduled for fresh nondonor in vitro fertilization/intracytoplasmic sperm injection treatment. We considered eligible for inclusion in the study only women with normal thyroid function (serum thyroid-stimulating hormone [TSH] range: 0.2-4.0 mIU/L, serum thyroxin values: 9-22 pmol/L) and negative personal history for previous thyroid disorders. According to which protocols were implemented to gain hypothalamic inhibition, patients were assigned to group A (70 women treated by long gonadotropin-releasing hormone [GnRH] agonist protocol) or to group B (86 women treated by flexible GnRH antagonist protocol). Before initiating controlled ovarian stimulation (COS), both groups were further stratified into 4 subgroups: A1 (46 of the 70 women) and B1 (61 of the 86 women) in women with a baseline TSH value negative antibodies), we reported a 20.7% clinical pregnancy rate and a 54.5% ongoing pregnancy rate. Our preliminary data, despite requiring further confirmation, seem to suggest that the various drugs used for gaining hypothalamic control during COS could interfere through different mechanisms with physiological function of thyroid axis, potentially affecting its regulation. PMID:26445999

  12. Effects of dopamine D1 and D2 receptor agonists and antagonists on bombesin-induced behaviors.

    Science.gov (United States)

    Merali, Z; Piggins, H

    1990-12-01

    Central administration of bombesin elicits excessive grooming and locomotor activity in rats. This grooming activity is one characterised by vigorous scratching of the face, nape and body flanks. Pretreatment with the D1 receptor antagonist SCH 23390 inhibited the expression of bombesin-induced activity with grooming being more inhibited than locomotion. Blockade of D2 receptors with eticlopride significantly attenuated the behavioral responses to bombesin. When SCH 23390 and eticlopride were administered concurrently, it was apparent that D1 blockade had a greater effect on grooming and D2 blockade a larger effect on locomotion. Stimulation of D1 receptors by SKF 38393 elicited non-stereotyped locomotor activity and a form of grooming behavior characterised by vigorous washing of the face and ventral body surfaces. Co-administration of bombesin and SKF 38393 resulted in a form of grooming which resembled that elicited by SKF 38393 alone. The specific D2 agonist PPHT elicited a form of locomotion characterised by a downward oriented head posture and slow ambulatory activity around the cage perimeter. Co-administration of PPHT and bombesin resulted in a complete suppression of bombesin-induced behaviors and was largely indistinguishable from activity observed under PPHT alone conditions. These data implicate both D1 and D2 receptor based mechanisms in the modulation/mediation of the behavioral effects of bombesin. Part of the bombesin-induced behavioral effects may be explained by (indirect) activation of (a) dopamine system(s). PMID:2086245

  13. The glucosinolate breakdown product indole-3-carbinol acts as an auxin antagonist in roots of Arabidopsis thaliana.

    Science.gov (United States)

    Katz, Ella; Nisani, Sophia; Yadav, Brijesh S; Woldemariam, Melkamu G; Shai, Ben; Obolski, Uri; Ehrlich, Marcelo; Shani, Eilon; Jander, Georg; Chamovitz, Daniel A

    2015-05-01

    The glucosinolate breakdown product indole-3-carbinol functions in cruciferous vegetables as a protective agent against foraging insects. While the toxic and deterrent effects of glucosinolate breakdown on herbivores and pathogens have been studied extensively, the secondary responses that are induced in the plant by indole-3-carbinol remain relatively uninvestigated. Here we examined the hypothesis that indole-3-carbinol plays a role in influencing plant growth and development by manipulating auxin signaling. We show that indole-3-carbinol rapidly and reversibly inhibits root elongation in a dose-dependent manner, and that this inhibition is accompanied by a loss of auxin activity in the root meristem. A direct interaction between indole-3-carbinol and the auxin perception machinery was suggested, as application of indole-3-carbinol rescues auxin-induced root phenotypes. In vitro and yeast-based protein interaction studies showed that indole-3-carbinol perturbs the auxin-dependent interaction of Transport Inhibitor Response (TIR1) with auxin/3-indoleacetic acid (Aux/IAAs) proteins, further supporting the possibility that indole-3-carbinol acts as an auxin antagonist. The results indicate that chemicals whose production is induced by herbivory, such as indole-3-carbinol, function not only to repel herbivores, but also as signaling molecules that directly compete with auxin to fine tune plant growth and development. PMID:25758811

  14. Kinesin-14 and kinesin-5 antagonistically regulate microtubule nucleation by γ-TuRC in yeast and human cells.

    Science.gov (United States)

    Olmsted, Zachary T; Colliver, Andrew G; Riehlman, Timothy D; Paluh, Janet L

    2014-01-01

    Bipolar spindle assembly is a critical control point for initiation of mitosis through nucleation and organization of spindle microtubules and is regulated by kinesin-like proteins. In fission yeast, the kinesin-14 Pkl1 binds the γ-tubulin ring complex (γ-TuRC) microtubule-organizing centre at spindle poles and can alter its structure and function. Here we show that kinesin-14 blocks microtubule nucleation in yeast and reveal that this inhibition is countered by the kinesin-5 protein, Cut7. Furthermore, we demonstrate that Cut7 binding to γ-TuRC and the Cut7 BimC domain are both required for inhibition of Pkl1. We also demonstrate that a yeast kinesin-14 peptide blocks microtubule nucleation in two human breast cancer cell lines, suggesting that this mechanism is evolutionarily conserved. In conclusion, using genetic, biochemical and cell biology approaches we uncover antagonistic control of microtubule nucleation at γ-TuRC by two kinesin-like proteins, which may represent an attractive anti-mitotic target for cancer therapies. PMID:25348260

  15. Interleukin expression after injury and the effects of interleukin-1 receptor antagonist.

    Directory of Open Access Journals (Sweden)

    Connie S Chamberlain

    Full Text Available Ligament healing follows a series of complex coordinated events involving various cell types, cytokines, as well as other factors, producing a mechanically inferior tissue more scar-like than native tissue. Macrophages provide an ongoing source of cytokines to modulate inflammatory cell adhesion and migration as well as fibroblast proliferation. Studying interleukins inherent to ligament healing during peak macrophage activation and angiogenesis may elucidate inflammatory mediators involved in subsequent scar formation. Herein, we used a rat healing model assayed after surgical transection of their medial collateral ligaments (MCLs. On days 3 and 7 post-injury, ligaments were collected and used for microarray analysis. Of the 12 significantly modified interleukins, components of the interleukin-1 family were significantly up-regulated. We therefore examined the influence of interleukin-1 receptor antagonist (IL-1Ra on MCL healing. Transected rat MCLs received PBS or IL-1Ra at the time of surgery. Inhibition of IL-1 activation decreased pro-inflammatory cytokines (IL-1α, IL-1β, IL-12, IL-2, and IFN-γ, myofibroblasts, and proliferating cells, as well as increased anti-inflammatory cytokines (IL-10, endothelial cells/blood vessel lumen, M2 macrophages, and granulation tissue size without compromising the mechanical properties. These results support the concept that IL-1Ra modulates MCL-localized granulation tissue components and cytokine production to create a transient environment that is less inflammatory. Overall, IL-1Ra may have therapeutic potential early in the healing cascade by stimulating the M2 macrophages and altering the granulation tissue components. However, the single dose of IL-1Ra used in this study was insufficient to maintain the more regenerative early response. Due to the transient influence on most of the healing components tested, IL-1Ra may have greater therapeutic potential with sustained delivery.

  16. SNX-325, a novel calcium antagonist from the spider Segestria florentina.

    Science.gov (United States)

    Newcomb, R; Palma, A; Fox, J; Gaur, S; Lau, K; Chung, D; Cong, R; Bell, J R; Horne, B; Nadasdi, L

    1995-07-01

    A novel selective calcium channel antagonist peptide, SNX-325, has been isolated from the venom of the spider Segestria florentina. The peptide was isolated using as bioassays the displacement of radioiodinated omega-conopeptide SNX-230 (MVIIC) from rat brain synaptosomal membranes, as well as the inhibition of the barium current through cloned expressed calcium channels in oocytes. The primary sequence of SNX-325 is GSCIESGKSCTHSRSMKNGLCCPKSRCNCRQIQHRHDYLGKRKYSCRCS, which is a novel amino acid sequence. Solid-phase synthesis resulted in a peptide that is chromatographically identical with the native peptide and which has the same configuration of cysteine residues as the spider venom peptide omega-Aga-IVa [Mintz, I. M., et al., (1992) Nature 355, 827-829]. At micromolar concentrations, SNX-325 is an inhibitor of most calcium, but not sodium or potassium, currents. At nanomolar concentrations, SNX-325 is a selective blocker of the cloned expressed class B (N-type), but not class C (cardiac L), A, or E, calcium channels. SNX-325 is approximately equipotent with the N-channel selective omega-conopeptides (GVIA and MVIIA as well as closely related synthetic derivatives) in blocking the potassium induced release of tritiated norepinephrine from hippocampal slices (IC50s, 0.1-0.5 nM) and in blocking the barium current through cloned expressed N-channels in oocytes (IC50s 3-30 nM). By contrast, SNX-325 is 4-5 orders of magnitude less potent than is SNX-111 (synthetic MVIIA) at displacing radioiodinated SNX-111 from rat brain synaptosomal membranes. SNX-325 will be a useful comparative tool in further defining the function and pharmacology of the N- and possibly other types of high-voltage activated calcium channels. PMID:7541240

  17. The effects of angiotensin II receptor antagonist (candesartan on rat renal vascular resistance

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    Supatraviwat, J

    2004-05-01

    Full Text Available The present study aimed to investigate the action of angiotensin II (AII on renal perfusion pressure and renal vascular resistance using noncompetitive AT1-receptor antagonist (candesartan or CV 11974. Experiments were performed in isolated kidney of adult male Wistar rats. Kreb's Henseleit solution was perfused into the renal artery at the rate of 3.5 ml/min. This flow rate was designed in order to maintain renal perfusion pressure between 80-120 mm Hg. Dose-response relationship between perfusion flow rate and AII concentration were studied. Renal perfusion pressure in response to 1, 10 and 100 nM AII were increased from basal perfusion pressure of 94±8 mm Hg to 127±6, 157±12 and 190±16 mm Hg, respectively. Administration of perfusate containing 11.4 μM candesartan for 30 min had no effect on the basal perfusion pressure. However, this significantly reduced renal perfusion pressure in the presence of AII (1, 10 and 100 nM by 39%, 47% and 61%, (n=7, P<0.05 respectively. At the basal perfusion pressure, calculated renal vascular resistance was 27±2 mm Hg · min · ml-1. However, the vascular resistance were found to be 41±1, 45±2 and 47±2 mm Hg · min · ml-1 when 1, 10 and 100 nM AII were added. Moreover, this dose of candesartan also showed a significant decrease in renal vascular resistance at the corresponding doses of AII by 38%, 48% and 43%, (n=7, P<0.05 respectively. The higher dose of candesartan (22.7 μM completely inhibited the action of 1, 10 and 100 nM AII on renal vasoconstriction. These results may indicate that the action of AII on renal vascular resistance is via AT1-receptor, at least in rat isolated perfusion kidney.

  18. Multifaceted defense against antagonistic microbes in developing offspring of the parasitoid wasp Ampulex compressa (Hymenoptera, Ampulicidae.

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    Katharina Weiss

    Full Text Available Effective antimicrobial strategies are essential adaptations of insects to protect themselves, their offspring, and their foods from microbial pathogens and decomposers. Larvae of the emerald cockroach wasp, Ampulex compressa, sanitize their cockroach hosts, Periplaneta americana, with a cocktail of nine antimicrobials comprising mainly (R-(--mellein and micromolide. The blend of these antimicrobials has broad-spectrum antimicrobial activity. Here we explore the spatio-temporal pattern of deployment of antimicrobials during the development from egg to adult as well as their physico-chemical properties to assess how these aspects may contribute to the success of the antimicrobial strategy. Using gas chromatography/mass spectrometry (GC/MS we show that larvae start sanitizing their food as soon as they have entered their host to feed on its tissue. Subsequently, they impregnate the cockroach carcass with antimicrobials to create a hygienic substrate for cocoon spinning inside the host. Finally, the antimicrobials are incorporated into the cocoon. The antimicrobial profiles on cockroach and wasp cocoon differed markedly. While micromolide persisted on the cockroaches until emergence of the wasps, solid-phase microextraction sampling and GC/MS analysis revealed that (R-(--mellein vaporized from the cockroaches and accumulated in the enclosed nest. In microbial challenge assays (R-(--mellein in the headspace of parasitized cockroaches inhibited growth of entomopathogenic and opportunistic microbes (Serratia marcescens, Aspergillus sydowii, Metarhizium brunneum. We conclude that, in addition to food sanitation, A. compressa larvae enclose themselves in two defensive walls by impregnating the cocoon and the cockroach cuticle with antimicrobials. On top of that, they use vaporous (R-(--mellein to sanitize the nest by fumigation. This multifaceted antimicrobial defense strategy involving the spatially and temporally coordinated deployment of several

  19. In vivo mucosal delivery of bioactive human interleukin 1 receptor antagonist produced by Streptococcus gordonii

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    Tagliabue Aldo

    2003-09-01

    Full Text Available Abstract Background Interleukin-1 (IL-1 is a cytokine involved in the initiation and amplification of the defence response in infectious and inflammatory diseases. IL-1 receptor antagonist (IL-1ra is an inactive member of the IL-1 family and represents one of the most potent mechanisms for controlling IL-1-dependent inflammation. IL-1ra has proven effective in the therapy of acute and chronic inflammatory diseases in experimental animal models and also in preliminary clinical trials. However, optimisation of therapeutic schedules is still needed. For instance, the use of drug delivery systems targeting specific mucosal sites may be useful to improve topical bioavailability and avoid side effects associated with systemic administration. Results In order to develop systems for the delivery of IL-1ra to mucosal target sites, a Streptococcus gordonii strain secreting human IL-1ra was constructed. The recombinant IL-1ra produced by S. gordonii was composed of the four amino acid residues RVFP of the fusion partner at the N-terminus, followed by the mature human IL-1ra protein. RFVP/IL-1ra displayed full biological activity in vitro in assays of inhibition of IL-1β-induced lymphocyte proliferation and was released by recombinant S. gordonii in vivo both at the vaginal and the gastrointestinal mucosa of mice. RFVP/IL-1ra appeared beneficial in the model of ulcerative colitis represented by IL-2-/- mice (knock-out for the interleukin-2 gene, as shown by the body weight increase of IL-2-/- mice locally treated with S. gordonii producing RFVP/IL-1ra. Conclusions These results indicate that recombinant S. gordonii can be successfully used as a delivery system for the selective targeting of mucosal surfaces with therapeutic proteins.

  20. Antagonistic Activity of Nocardia brasiliensis PTCC 1422 Against Isolated Enterobacteriaceae from Urinary Tract Infections.

    Science.gov (United States)

    Jalali, Hossnieh Kafshdar; Salamatzadeh, Abdolreza; Jalali, Arezou Kafshdar; Kashani, Hamed Haddad; Asbchin, Salman Ahmadi; Issazadeh, Khosro

    2016-03-01

    The main drawback of current antibiotic therapies is the emergence and rapid increase in antibiotic resistance. Nocardiae are aerobic, Gram-positive, catalase-positive, non-motile actinomycetes. Nocardia brasiliensis was reported as antibiotic producer. The purpose of the study was to determine antibacterial activity of N. brasiliensis PTCC 1422 against isolated Enterobacteriaceae from urinary tract infections (UTIs). The common bacteria from UTIs were isolated from hospital samples. Antimicrobial susceptibility test was performed for the isolated pathogens using Kirby-Bauer disk diffusion method according to clinical and Laboratory Standards Institute guideline. Antagonistic activity of N. brasiliensis PTCC 1422 was examined with well diffusion methods. Supernatant of N. brasiliensis PTCC 1422 by submerged culture was analyzed with gas chromatography-mass spectrometry. Isolated strains included Escherichia coli, Klebsiella pneumoniae, Serratia marcescens and Proteus mirabilis. The most common pathogen isolated was E. coli (72.5 %). Bacterial isolates revealed the presence of high levels of antimicrobial resistances to ceftriaxone and low levels of resistance to cephalexin. Supernatant of N. brasiliensis PTCC 1422 showed antibacterial activity against all of the isolated microorganisms in well diffusion method. The antibiotic resistance among the uropathogens is an evolving process, so a routine surveillance to monitor the etiologic agents of UTI and the resistance pattern should be carried out timely to choose the most effective empirical treatment by the physicians. Our present investigation indicates that the substances present in the N. brasiliensis PTCC 1422 could be used to inhibit the growth of human pathogen. Antibacterial resistance among bacterial uropathogen is an evolving process. Therefore, in the field on the need of re-evaluation of empirical treatment of UTIs, our present. The study has demonstrated that N. brasiliensis PTCC 1422 has a high