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The effect of chronic hyperthyroidism and restored euthyroid state by methimazole therapy in rat small mesenteric arteries. Eur J Pharmacol 2013; 701:20-6. [DOI: 10.1016/j.ejphar.2012.12.021] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2012] [Revised: 12/14/2012] [Accepted: 12/19/2012] [Indexed: 11/20/2022]
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2
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Moezi L, Dehpour AR. Cardiovascular abnormalities in obstructive cholestasis: the possible mechanisms. Liver Int 2013; 33:7-15. [PMID: 22520558 DOI: 10.1111/j.1478-3231.2012.02803.x] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/03/2011] [Accepted: 03/12/2012] [Indexed: 02/13/2023]
Abstract
Cholestatic liver disease is associated with widespread derangements in the cardiovascular system, such as bradycardia, hypotension, QT prolongation and peripheral vasodilation; it is also associated with increased susceptibility to postoperative renal failure and haemorrhagic shock. A number of cellular signalling pathways have been shown to contribute to these abnormalities. In this article, we briefly review recent in vivo and in vitro findings in the field in an attempt to highlight the areas of agreement and areas of controversy. In this review, we will summarize pathogenic mechanisms underlying cardiac and vascular abnormalities in obstructive cholestasis. It seems that cardiovascular dysfunction is likely because of bile acids as one of the predominant factors. Other important factors which might play roles in these abnormalities are increased nitric oxide, endogenous opioids and endocannabinoids. These three factors interact with each other to exert vasodilation and impaired cardiovascular responses to sympathetic stimulation.
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Affiliation(s)
- Leila Moezi
- Department of Pharmacology, School of Medicine, Shiraz University of Medical Sciences, Shiraz, Iran
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3
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Heydari F, Mehr SE, Samini M. alpha(1)- and alpha(2)-Adrenoceptor hyporesponsiveness in isolated bisected vas deferens of bile duct-ligated rats. AUTONOMIC & AUTACOID PHARMACOLOGY 2010; 30:193-196. [PMID: 20345427 DOI: 10.1111/j.1474-8673.2010.00455.x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
It has been suggested that cholestasis accompanied with changes in autonomic balance and hyporesponsiveness in muscarinic and adrenergic receptors of some organs, e.g. cardiovascular system. Increased plasma levels of epinephrine and norepinephrine has been shown during cholestasis suggesting augmented activity of sympathetic nervous system. In this study we evaluate both alpha(1) and alpha(2) responsiveness in isolated rat vas deferens, as a tissue with rich adrenergic innervations. Epididymal and prostatic halves of vas deferens responsiveness have been studied to phenylephrine and clonidine respectively in three groups of un-operated, sham-operated (sham), and bile duct-ligated (BDL) rats. Our results indicate that in vas deferens of BDL animals, the concentration-response curve of both phenylephrine and clonidine shifted to rightward compared to control group, while the position of concentration-response curve of sham group did not change significantly (P > 0.05). EC(50) of phenylephrine and IC(50) of clonidine were increased showing a decreased responsiveness of tissue to phenylephrine (P < 0.05) and clonidine (P < 0.001) in BDL rats. In this study, both subtype of alpha-adrenoceptors (alpha(1) and alpha(2)) has been studied in cholestatic rat vas deference. Our results showed that cholestasis induce hyporesponsiveness to phenylephrine and clonidine. These results are consistent with previous reports, suggesting the hyporesponsiveness of alpha(1)-adrenoceptors in pulmonary artery and papillary muscle and mesenteric beds. Our conclusion is that the cholestasis induces hyporesponsiveness to phenylephrine and clonidine in epididymal (alpha(1)-adrenoceptors) and prostatic (alpha(2)-adrenoceptors) halves of rat vas deferens respectively. Although the logical explanation to this hyporesponsiveness is the down regulation but it has been suggested that it is not because of down regulation.
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Affiliation(s)
- F Heydari
- Department of Pharmacology, School of Pharmacy Islamic Azad University, Yakhchal, Shariati, Tehran, Iran
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4
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Dalton GD, Bass CE, Van Horn CG, Howlett AC. Signal transduction via cannabinoid receptors. CNS & NEUROLOGICAL DISORDERS DRUG TARGETS 2009; 8:422-31. [PMID: 19839935 PMCID: PMC3976677 DOI: 10.2174/187152709789824615] [Citation(s) in RCA: 77] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/13/2009] [Accepted: 10/09/2009] [Indexed: 01/20/2023]
Abstract
The endocannabinoids anandamide and 2-arachidonoylglycerol are lipid mediators that signal via CB(1) and CB(2) cannabinoid receptors and Gi/o-proteins to inhibit adenylyl cyclase and stimulate mitogen-activated protein kinase. In the brain, CB(1) receptors interact with opioid receptors in close proximity, and these receptors may share G-proteins and effector systems. In the striatum, CB(1) receptors function in coordination with D(1) and D(2) dopamine receptors, and combined stimulation of CB(1)-D(2) receptor heteromeric complexes promotes a unique interaction to stimulate cAMP production. CB(1) receptors also trigger growth factor receptor signaling cascades in cells by engaging in cross-talk or interreceptor signal transmission with the receptor tyrosine kinase (RTK) family. Mechanisms for CB(1) receptor-RTK transactivation can include stimulation of signal transduction pathways regulated by second messengers such as phospholipase C, metalloprotease cleavage of membrane-bound precursor proteins such as epidermal growth factor which activate RTKs, RTK autophosphorylation, and recruitment of non-receptor tyrosine kinases. CB(1) and CB(2) receptors are expressed in peripheral tissues including liver and adipose tissue, and are induced in pathological conditions. Novel signal transduction resulting from endocannabinoid regulation of AMP-regulated kinase and peroxisome proliferator-activated receptors have been discovered from studies of hepatocytes and adipocytes. It can be predicted that drug discovery of the future will be based upon these novel signal transduction mechanisms for endocannabinoid mediators.
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Affiliation(s)
- George D Dalton
- Department of Physiology and Pharmacology, Wake Forest University Health Sciences, Winston-Salem, NC 27157, USA
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Bahremand A, Nasrabady SE, Shafaroodi H, Ghasemi M, Dehpour AR. Involvement of nitrergic system in the anticonvulsant effect of the cannabinoid CB(1) agonist ACEA in the pentylenetetrazole-induced seizure in mice. Epilepsy Res 2009; 84:110-9. [PMID: 19223154 DOI: 10.1016/j.eplepsyres.2009.01.003] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2008] [Revised: 01/08/2009] [Accepted: 01/10/2009] [Indexed: 01/04/2023]
Abstract
Cannabinoid system plays a pivotal role in the seizure threshold modulation which is mainly mediated through activation of the cannabinoid CB(1) receptor. There is also several evidence of interaction between cannabinoid system and other neurotransmitters including nitric oxide (NO) system. Using model of clonic seizure induced by pentylenetetrazole (PTZ) in male NMRI mice, we investigated whether NO is involved in the effects of cannabinoids on the seizure threshold. Injection of the selective cannabinoid CB(1) agonist ACEA (2mg/kg, i.p.) significantly (P<0.01) increased the seizure threshold which was prevented (P<0.001) by pretreatment with the selective CB(1) antagonist AM251 (1mg/kg, i.p.). The NO precursor l-arginine (50 and 100mg/kg, i.p.) potentiated the anticonvulsant effects of the sub-effective dose of ACEA (1mg/kg, i.p.). Pretreatment with non-effective doses of the non-specific NOS inhibitor l-NAME (15 and 30mg/kg, i.p.) and the specific neuronal NOS inhibitor 7-NI (40 and 80mg/kg, i.p.) but not the inducible NOS inhibitor aminoguanidine (10, 50 and 100mg/kg, i.p.) prevented the anticonvulsant effect of ACEA (2mg/kg, i.p.). Co-administration of non-effective dose of AM251 (0.5mg/kg) with both low and per se non-effective doses of l-NAME (1mg/kg, i.p.) and 7-NI (10mg/kg, i.p.) had significant (P<0.01) effect in preventing the anticonvulsant effect of ACEA (2mg/kg, i.p.). Our findings demonstrated that central NO system could be involved in the anticonvulsant properties of the specific cannabinoid CB(1) agonist ACEA, emphasizing on the interaction between two systems in the seizure modulation.
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Affiliation(s)
- Arash Bahremand
- Department of Pharmacology, School of Medicine, Medical Sciences/University of Tehran, Tehran, Iran
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6
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Ebrahimkhani MR, Moezi L, Kiani S, Merat S, Dehpour AR. Opioid receptor blockade improves mesenteric responsiveness in biliary cirrhosis. Dig Dis Sci 2008; 53:3007-11. [PMID: 18465246 DOI: 10.1007/s10620-008-0261-7] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/30/2007] [Accepted: 03/26/2008] [Indexed: 12/09/2022]
Abstract
Arterial vasodilation with concomitant hyperdynamic circulation is a common finding in cirrhotic subjects. Elevated levels of plasma endogenous opioid peptides have been reported in cholestasis and cirrhosis. Increased opioid peptides contribute to different manifestations of chronic liver disease such as pruritus, ascitis, and hepatic encephalopathy. In this study the potential role of opioid system in cirrhosis-induced vascular hyporesponsiveness was investigated. Bile duct ligated and sham operated animals received daily subcutaneous administration of naltrexone, an opioid receptor antagonist (20 mg/kg/day), or saline for 28 days. After 4 weeks the superior mesenteric artery was cannulated and was perfused according to McGregor method and then phenylephrine vasoconstrictor response of mesenteric vessels (10(-10) to 10(-6 )mol) was examined. In order to evaluate the effects of acute opioid receptor blockade, additional groups of animals were treated by acute single intraperitoneal naltrexone injection (20 mg/kg). Plasma level of nitrite/nitrate as an indicator for nitric oxide production was measured. Biliary cirrhosis was accompanied with a decrease in baseline perfusion pressure in mesenteric vascular bed (P < 0.01). Chronic opioid receptor blockade significantly increased this parameter (P < 0.01). The maximum pressure response to phenylephrine was decreased significantly in cirrhosis while chronic naltrexone treatment completely improved it (P < 0.01). Acute single injection of naltrexone could not influence the understudied homodynamic parameters. Chronic opioid receptor blockade did not modulate the increased nitrite/nitrate levels following cholestasis. This study provided evidence on the contribution of endogenous opioid system to vascular hyporesponsiveness in cirrhosis which is not directly correlated to high plasma NO levels.
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Moezi L, Gaskari SA, Lee SS. Endocannabinoids and liver disease. V. endocannabinoids as mediators of vascular and cardiac abnormalities in cirrhosis. Am J Physiol Gastrointest Liver Physiol 2008; 295:G649-53. [PMID: 18703639 DOI: 10.1152/ajpgi.90352.2008] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Cirrhosis is associated with marked cardiovascular disturbances. These include hyperdynamic circulation characterized by reduced peripheral vascular resistance and mean arterial pressure and increased cardiac output. Despite the baseline increase in cardiac output, ventricular responsiveness to stimuli is blunted. A number of cellular signaling pathways have been shown to contribute to these abnormalities, including central nervous system cardiovascular dysregulation and humoral factors such as nitric oxide. Endogenous and exogenous cannabinoids have significant cardiovascular effects. Recent evidence suggests that increased activity of the endocannabinoid system at multiple levels contributes to development of both cardiac and vascular changes in cirrhosis. This brief review surveys recent in vivo and in vitro findings in an attempt to highlight the areas of agreement and areas of controversy in the field. The endocannabinoid system affects key cardiovascular regulators, including the autonomic nervous system, cardiac muscle, and vascular smooth muscle. The interplay among these modes of action further complicates interpretation of the in vivo findings. The broad range of cardiovascular actions of endocannabinoids provides ample opportunities for pharmacological manipulation. At the same time, it increases the possibility of undesirable side effects, which need to be carefully evaluated in long-term studies.
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Affiliation(s)
- Leila Moezi
- Department of Pharmacology, School of Medicine, Shiraz University of Medical Sciences, Shiraz, Iran
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Avraham Y, Magen I, Zolotarev O, Vorobiav L, Nachmias A, Pappo O, Ilan Y, Berry EM, Ackerman Z. 2-Arachidonoylglycerol, an endogenous cannabinoid receptor agonist, in various rat tissues during the evolution of experimental cholestatic liver disease. Prostaglandins Leukot Essent Fatty Acids 2008; 79:35-40. [PMID: 18771906 DOI: 10.1016/j.plefa.2008.07.003] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/21/2007] [Revised: 07/08/2008] [Accepted: 07/11/2008] [Indexed: 12/22/2022]
Abstract
BACKGROUND/AIM Changes in tissue levels of 2-arachidonoylglycerol (2-AG), an endocannabinoid, during the evolution of bile duct ligation (BDL) may indicate that endocannabinoids have a role in the hemodynamic changes that occur in this condition. METHODS 2-AG levels, in various organs and vascular beds of BDL rats, 2 and 4 weeks post surgery, were determined. Untouched and sham-operated (SO) rats were used as controls. RESULTS 2-AG content of a specific organ was not a static finding and depended on the rat's age, the time from the surgical procedure and the type of procedure. The most pronounced changes were observed in BDL rats 4 weeks post surgery. In these rats, hepatic, pulmonary, cardiac and renal medullary and papillary 2-AG levels were highest observed. No changes in splenic, aortic and renal cortical 2-AG levels were observed. In addition a stepwise increase in 2-AG levels from the cortex to the papilla was detected and was followed by a decrease in creatinine clearance. CONCLUSIONS 2-AG probably has a role in the pathophysiologic changes in the liver, heart, lung and kidney that follows BDL.
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Affiliation(s)
- Yosefa Avraham
- Department of Human Nutrition and Metabolism, Braun School of Public Health, Hadassah-Hebrew University Medical School, Jerusalem, Israel
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9
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Yang YY, Lin HC, Huang YT, Lee TY, Hou MC, Wang YW, Lee FY, Lee SD. Role of Ca2+-dependent potassium channels in in vitro anandamide-mediated mesenteric vasorelaxation in rats with biliary cirrhosis. Liver Int 2007; 27:1045-55. [PMID: 17845532 DOI: 10.1111/j.1478-3231.2007.01551.x] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
BACKGROUND/AIM Anandamide can activate potassium (K(+)) channels to induce an endothelium-dependent vasorelaxation in normal rat mesenteric arteries. Cannabinoids contribute partly to the splanchnic vasodilation in cirrhosis. This study investigated the roles of vascular K(+) channels in anandamide-induced mesenteric vasorelaxation in isolated rat cirrhotic vessels. METHODS The effects of the pretreatment of AM251, a specific CB(1) receptor antagonist, were assessed on the vascular reactivity to phenylephrine (PE), potassium chloride (KCl), acetylcholine (ACh) and sodium nitroprusside (SNP). Additionally, cannabinoid (CB(1) and CB(2)) receptors' protein expression and the effects of different K(+) channel blockers on vascular reactivity to anandamide were also studied. RESULTS Cirrhotic mesenteric arteries showed an overexpression of CB(1) receptor associated with hyporeactivity to PE and KCl, and hyper-response to ACh, SNP and anandamide. Pretreatment with AM251 significantly improved the hyporeactivity to KCl and ameliorated the hyper-response to ACh in cirrhotic vessels. Increased relaxation response to anandamide was suppressed by combinations of vascular Ca(2+)-dependent K(+) channel blockers (including apamin+charybdotoxin+iberiotoxin or apamin+TRAM-34+iberiotoxin) (TRAM-34, 1-[(2-chlorophenyl)diphenylmethyl]-1H-pyrazole). CONCLUSIONS In cirrhotic mesenteric arteries, vascular CB(1) receptor and anandamide contribute to the in vitro hyporeactivity to KCl. In addition, hyper-response to ACh may probably act through the modulation of vascular Ca(2+)-dependent K(+) channels.
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MESH Headings
- Acetylcholine/pharmacology
- Animals
- Apamin/pharmacology
- Arachidonic Acids/metabolism
- Cannabinoid Receptor Modulators/metabolism
- Charybdotoxin/pharmacology
- Common Bile Duct/surgery
- Dose-Response Relationship, Drug
- Endocannabinoids
- Glyburide/pharmacology
- Ligation
- Liver Cirrhosis, Biliary/metabolism
- Liver Cirrhosis, Biliary/physiopathology
- Liver Cirrhosis, Experimental/metabolism
- Liver Cirrhosis, Experimental/physiopathology
- Male
- Mesenteric Artery, Superior/drug effects
- Mesenteric Artery, Superior/metabolism
- Mesenteric Artery, Superior/physiopathology
- Nitroprusside/pharmacology
- Peptides/pharmacology
- Phenylephrine/pharmacology
- Piperidines/pharmacology
- Polyunsaturated Alkamides/metabolism
- Potassium/metabolism
- Potassium Channel Blockers/pharmacology
- Potassium Channels, Calcium-Activated/antagonists & inhibitors
- Potassium Channels, Calcium-Activated/metabolism
- Potassium Chloride/pharmacology
- Pyrazoles/pharmacology
- Rats
- Rats, Sprague-Dawley
- Receptor, Cannabinoid, CB1/antagonists & inhibitors
- Receptor, Cannabinoid, CB1/metabolism
- Receptor, Cannabinoid, CB2/metabolism
- Vasoconstrictor Agents/pharmacology
- Vasodilation/drug effects
- Vasodilator Agents/pharmacology
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Affiliation(s)
- Ying-Ying Yang
- Institute of Clinical Medicine, National Yang-Ming University School of Medicine, Taipei, Taiwan
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10
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Ghasemi M, Sadeghipour H, Shafaroodi H, Nezami BG, Gholipour T, Hajrasouliha AR, Tavakoli S, Nobakht M, Moore KP, Mani AR, Dehpour AR. Role of the nitric oxide pathway and the endocannabinoid system in neurogenic relaxation of corpus cavernosum from biliary cirrhotic rats. Br J Pharmacol 2007; 151:591-601. [PMID: 17486141 PMCID: PMC2013996 DOI: 10.1038/sj.bjp.0707279] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
BACKGROUND AND PURPOSE Relaxation of corpus cavernosum, which is mediated by nitric oxide (NO) released from non-adrenergic non-cholinergic (NANC) neurotransmission, is critical for inducing penile erection and can be affected by many pathophysiological conditions. However, the peripheral effect of liver cirrhosis on erectile function is as yet unknown. The aim of the present study was to investigate the effect of biliary cirrhosis on NANC-mediated relaxation of rat corpus cavernosum and the possible roles of endocannabinoid and nitric oxide systems in this model. EXPERIMENTAL APPROACH Cirrhosis was induced by bile duct ligation. Controls underwent sham operation. Four weeks later, strips of corpus cavernosum were mounted in a standard organ bath and NANC-mediated relaxations were obtained by applying electrical field stimulation. KEY RESULTS The NANC-mediated relaxation was enhanced in corporal strips from cirrhotic animals. Anandamide potentiated the relaxations in both groups. Either AM251 (CB(1) antagonist) or capsazepine (vanilloid VR(1) antagonist), but not AM630 (CB(2) antagonist), prevented the enhanced relaxations of cirrhotic strips. Either the non-selective NOS inhibitor L-NAME or the selective neuronal NOS inhibitor L-NPA inhibited relaxations in both groups, but cirrhotic groups were more resistant to the inhibitory effects of these agents. Relaxations to sodium nitroprusside (NO donor) were similar in tissues from the two groups. CONCLUSIONS AND IMPLICATIONS Cirrhosis potentiates the neurogenic relaxation of rat corpus cavernosum probably via the NO pathway and involving cannabinoid CB(1) and vanilloid VR(1) receptors.
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Affiliation(s)
- M Ghasemi
- Department of Pharmacology, School of Medicine, Medical Sciences/University of Tehran Tehran, Iran
- The UCL Institute of Hepatology, Department of Medicine, Royal Free and University College Medical School, UCL London, UK
| | - H Sadeghipour
- Department of Pharmacology, School of Medicine, Medical Sciences/University of Tehran Tehran, Iran
| | - H Shafaroodi
- Department of Pharmacology, Tehran Medical Unit, Islamic Azad University of Medical Sciences Tehran, Iran
| | - B G Nezami
- Department of Pharmacology, School of Medicine, Medical Sciences/University of Tehran Tehran, Iran
| | - T Gholipour
- Department of Pharmacology, School of Medicine, Medical Sciences/University of Tehran Tehran, Iran
| | - A R Hajrasouliha
- Department of Pharmacology, School of Medicine, Medical Sciences/University of Tehran Tehran, Iran
| | - S Tavakoli
- Department of Pharmacology, School of Medicine, Medical Sciences/University of Tehran Tehran, Iran
| | - M Nobakht
- Department of Histology, Medical School, Iran University of Medical Sciences Tehran, Iran
| | - K P Moore
- The UCL Institute of Hepatology, Department of Medicine, Royal Free and University College Medical School, UCL London, UK
| | - A R Mani
- The UCL Institute of Hepatology, Department of Medicine, Royal Free and University College Medical School, UCL London, UK
| | - A R Dehpour
- Department of Pharmacology, School of Medicine, Medical Sciences/University of Tehran Tehran, Iran
- Author for correspondence:
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Orliac ML, Peroni RN, Abramoff T, Neuman I, Podesta EJ, Adler-Graschinsky E. Increases in vanilloid TRPV1 receptor protein and CGRP content during endotoxemia in rats. Eur J Pharmacol 2007; 566:145-52. [PMID: 17482593 DOI: 10.1016/j.ejphar.2007.03.032] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2006] [Revised: 02/26/2007] [Accepted: 03/13/2007] [Indexed: 02/08/2023]
Abstract
The aim of the present study was to determine whether the transient receptor potential vanilloid (TRPV1) receptor protein as well as the calcitonin gene-related peptide (CGRP) content could be enhanced after the i.p. administration of 5 mg/kg lipopolysaccharide (LPS) to Sprague-Dawley rats. In tongue tissue, used as a representative model of TRPV1 receptors expression, there was a significant increase in the abundance of TRPV1 receptor protein 6 h after LPS administration. In mesenteric arteries, the density of the CGRP-positive nerves as well as the release of CGRP induced by 10 microM anandamide was also significantly increased 6 h after LPS administration. The relaxant responses induced by anandamide in mesenteric beds isolated from either untreated or LPS-treated rats were abolished after a 2 h exposure to 10 microM capsaicin. Moreover, anandamide-induced relaxations of untreated mesenteries were potentiated by the protein kinase C (PKC) activator phorbol 12-myristate 13-acetate (PMA, 0.1 microM), but not by its inactive analogue 4alpha-phorbol (0.1 microM). The potentiation of anandamide effects caused by the PKC activator was accompanied by a significant increase in the overflow of CGRP induced by anandamide in the untreated rats. It is proposed that the overexpression of the TRPV1 receptors and the increased content of CGRP could contribute to the enhancement of anandamide effects during the endotoxemic shock. An eventual phosphorylation event linked to the overflow of CGRP could also participate in the enhanced relaxation caused by anandamide in endotoxemia.
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Affiliation(s)
- María Luz Orliac
- Instituto de Investigaciones Farmacológicas (ININFA-CONICET), Junín 956, 5 piso C1113AAD Buenos Aires, Argentina
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12
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Kiarostami V, Samini L, Ghazi-Khansari M. Protective effect of melatonin against multistress condition induced lipid peroxidation via measurement of gastric mucosal lesion and plasma malondialdehyde levels in rats. World J Gastroenterol 2007; 12:7527-31. [PMID: 17167845 PMCID: PMC4087602 DOI: 10.3748/wjg.v12.i46.7572] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
AIM To study the protective effect of a natural antioxidant, melatonin, against multistress condition induced lipid peroxidation via determination of gastric damage and plasma malondialdehyde (MDA) level by high performance liquid chromatography in rats. METHODS We compared indomethacin-induced gastric damage and MDA plasma level in three groups of rats: unoperated, bile duct ligated and sham-operated and evaluated the role of the melatonin on gastric damage and plasma MDA level. Indomethacin and melatonin were injected intraperitoneally in doses of 50 mg/kg and 20 mg/kg, respectively. Animals were killed 4 h after indomethacin injection. RESULTS Indomethacin induced more severe gastric damage and plasma MDA level in bile duct ligated animals was significantly higher (3.1 +/- 0.04 micromol/L) than sham (2.8 +/- 0.04 micromol/L) and unoperated animals (1.4 +/- 0.08 micromol/L). Pretreatment with melatonin reduced indomethacin-induced gastric damage and plasma MDA level. CONCLUSION Considering the results of this study, we suggest that in multistress conditions the intensity of gastric damage and the plasma MDA level are great and melatonin reduces the negative effect of lipid peroxidation and cell damage by oxidative stress in multistress conditions due to its antioxidizing activity.
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Affiliation(s)
- V Kiarostami
- Faculty of Chemistry, Islamic Azad University, North Tehran Branch, Tehran, Iran
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13
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Romano MR, Lograno MD. Cannabinoid agonists induce relaxation in the bovine ophthalmic artery: evidences for CB1 receptors, nitric oxide and potassium channels. Br J Pharmacol 2007; 147:917-25. [PMID: 16474412 PMCID: PMC1760716 DOI: 10.1038/sj.bjp.0706687] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Glaucoma pathophysiology appears to involve vascular deficits, which may contribute to initiation and progression of the disease. Anandamide, the endogenous cannabinoid ligand, and WIN55212-2, a synthetic cannabinoid agonist, are able to evoke concentration-dependent relaxations in bovine ophthalmic artery rings, precontracted with 5-hydroxytryptamine (5-HT) (1 microM). Endothelium removal reduces cannabinoid agonist potency and efficacy. The selective cannabinoid 1 (CB1) receptor antagonists SR141716A (100 nM) and AM251 (100 nM) cause a shift to the right in the concentration-response curves to anandamide and WIN55212-2 in arterial rings both in the presence and in the absence of endothelium. In endothelium-intact arteries, the nitric oxide synthase inhibitor, N(G)-monomethyl-L-arginine (L-NMMA, 300 microM), completely blocked the anandamide- and WIN55212-2-relaxant responses; by contrast, the nitric oxide donor S-nitroso-N-acetylpenicillamine (SNAP, 100 microM) induced an increase in vasorelaxant responses to cannabinoid agonists. Relaxations to anandamide and WIN55212-2 were inhibited by iberiotoxin (IbTX, 200 nM), a blocker of large conductance, Ca2+-activated K+ channel (BK(Ca)), and by 4-aminopyridine (4-AP; 1 mM), a blocker of delayed rectifier K+ channel, whereas the blockade of K(ATP) channels by glibenclamide (5 microM) and of small conductance Ca2+-activated K+ channels (SK(Ca)) by apamin (100 nM) did not produce any effects. These data suggest that anandamide and WIN55212-2 relax the bovine ophthalmic artery by involving CB1 the cannabinoid receptor-sensitive pathway. In endothelium-intact arteries, relaxation occurs through activation of nitric oxide synthase cyclic GMP and Ca2+-activated K+ channels. They also cause endothelium-independent relaxation by involving potassium channel opening.
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Affiliation(s)
- Maria Rosaria Romano
- Department of Pharmacobiology, Section of Pharmacology, University of Bari, Via Orabona 4, 70125 Bari, Italy
| | - Marcello D Lograno
- Department of Pharmacobiology, Section of Pharmacology, University of Bari, Via Orabona 4, 70125 Bari, Italy
- Author for correspondence:
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14
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Yang YY, Lin HC, Huang YT, Lee TY, Hou MC, Wang YW, Lee FY, Lee SD. Roles of anandamide in the hepatic microcirculation in cirrhotic rats. Am J Physiol Gastrointest Liver Physiol 2006; 290:G328-34. [PMID: 16407591 DOI: 10.1152/ajpgi.00367.2005] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Cannabinoids have been reported to participate in the pathogenesis of peripheral vasodilatation in cirrhosis. However, their roles in increased intrahepatic resistance (IHR) in cirrhotic livers are unknown. We aimed to investigate the effects of cannabinoids in the hepatic microcirculation of cirrhotic rats produced by bile duct ligation. In isolated liver perfusion, portal perfusion pressure (PPP) and the production of eicosanoids in the perfusate were measured. In addition, various hepatic protein levels [cyclooxygenase (COX) isoform and 5-lipoxygenase (5-LOX)] were also determined. Finally, concentration-response curves for PPP and the corresponding production of eicosanoids in response to anandamide (1.44 x 10(-10)-1.44 x 10(-3) M) after indomethacin (COX inhibitor), piriprost (5-LOX inhibitor), or furegrelate (thromboxane A(2) synthase inhibitor) preincubation were obtained. The study showed that cirrhotic livers had significantly higher levels of PPP, COX-2 and 5-LOX protein expression, and production of thromboxane B(2) (TXB(2)) and cysteinyl leukotrienes (Cys-LTs) than normal livers. Anandamide induced a dose-dependent increase in PPP in both normal and cirrhotic livers. The anandamide-induced increase in PPP was found concomitantly with a significant increase in TXB(2) and Cys-LT production in the perfusate. In response to anandamide administration, cirrhotic livers exhibited a significantly greater increase in IHR and production of TXB(2) and Cys-LTs than normal livers. Indomethacin and furegrelate, but not piriprost, significantly ameliorated the anandamide-induced increase in IHR in cirrhotic livers. In conclusion, anandamide plays, in part, an important role in increased IHR of cirrhotic livers. The anandamide-induced increase in IHR in cirrhotic livers may be mediated by increased COX-derived eicosanoid (mainly thromboxane A(2)) production.
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Affiliation(s)
- Ying-Ying Yang
- Institute of Clinical Medicine, National Yang-Ming University School of Medicine, Taipei Veterans General Hospital, Taipei 11217, Taiwan
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15
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Abstract
This paper is the 27th consecutive installment of the annual review of research concerning the endogenous opioid system, now spanning over 30 years of research. It summarizes papers published during 2004 that studied the behavioral effects of molecular, pharmacological and genetic manipulation of opioid peptides, opioid receptors, opioid agonists and opioid antagonists. The particular topics that continue to be covered include the molecular-biochemical effects and neurochemical localization studies of endogenous opioids and their receptors related to behavior, and the roles of these opioid peptides and receptors in pain and analgesia; stress and social status; tolerance and dependence; learning and memory; eating and drinking; alcohol and drugs of abuse; sexual activity and hormones, pregnancy, development and endocrinology; mental illness and mood; seizures and neurologic disorders; electrical-related activity and neurophysiology; general activity and locomotion; gastrointestinal, renal and hepatic functions; cardiovascular responses; respiration and thermoregulation; and immunological responses.
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Affiliation(s)
- Richard J Bodnar
- Department of Psychology and Neuropsychology Doctoral Sub-Program, Queens College, City University of New York, Flushing, NY 11367, USA.
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16
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Ebrahimi F, Tavakoli S, Hajrasouliha AR, Shafaroodi H, Sadeghipour H, Riazi K, Borhani AA, Houshmand G, Ahmadi SH, Dehpour AR. Contribution of endogenous opioids and nitric oxide to papillary muscle contractile impairment in cholestatic rats. Eur J Pharmacol 2005; 523:93-100. [PMID: 16226248 DOI: 10.1016/j.ejphar.2005.08.057] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2005] [Accepted: 08/31/2005] [Indexed: 11/24/2022]
Abstract
Attenuated responsiveness to adrenoceptor stimulation has been proposed as an important factor underlying cardiovascular complications of cholestasis. We examined isolated papillary muscle responsiveness to alpha (phenylephrine) and beta-adrenoceptor (isoproterenol) agonists in 7-day bile duct-ligated rats. We investigated the role of nitric oxide (NO) and endogenous opioids in papillary muscle hyporesponsiveness to isoproterenol stimulation. In order to evaluate the effect of NO and endogenous opioids, animals were treated with chronic subcutaneous injections of N(omega)-nitro-L-arginine methyl ester (L-NAME, 10 mg/kg/day) or naltrexone (20 mg/kg/day), or isolated papillary muscles were exposed acutely to the same drugs (10(-4) and 10(-6) M, respectively) in an organ bath. The basal contractile force of papillary muscle, +dT/dtmax and -dT/dtmax, was significantly decreased in bile duct-ligated rats compared to sham-operated ones (P<0.05, for each value). The concentration-response curve for phenylephrine and isoproterenol demonstrated a reduced maximum effect in bile duct-ligated rats compared to the sham-operated group (P<0.01 and 0.05, respectively). Basal contractile abnormalities of bile duct-ligated rats were corrected by L-NAME or naltrexone treatment, either acute or chronic. While chronic L-NAME treatment resulted in a left-ward shift (P<0.05), it had no effect on the maximum effect in bile duct-ligated rats. Acute L-NAME treatment did not influence isoproterenol responsiveness. Acute and chronic naltrexone treatment resulted in partial and complete correction of the hyporesponsiveness of bile duct-ligated rats, respectively (P<0.05). This investigation demonstrates that the papillary muscles of 7-day bile duct ligated-rats have an impaired basal contractility and hyporesponsiveness to both alpha and beta-adrenoceptor stimulation. It also provides evidence for the involvement of increased opioidergic tone and NO overproduction in cholestasis-induced cardiac impairment.
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Affiliation(s)
- Farzad Ebrahimi
- Department of Pharmacology, School of Medicine, Tehran University of Medical Sciences, P.O. Box 13145-784, Tehran, Iran
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17
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Borhani AA, Houshmand G, Samini M, Namiranian K, Hajrasouliha AR, Tavakoli S, Ebrahimi F, Dehpour AR. α2-Adrenoceptor subsensitivity in mesenteric vascular bed of cholestatic rats: The role of nitric oxide and endogenous opioids. Eur J Pharmacol 2005; 514:183-9. [PMID: 15910805 DOI: 10.1016/j.ejphar.2005.03.015] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2004] [Revised: 03/15/2005] [Accepted: 03/18/2005] [Indexed: 11/23/2022]
Abstract
Cholestasis is associated with vascular changes and in previous studies decreased response of visceral vessels of cholestatic animals to phenylephrine and acetylcholine has been shown. In the present study, the response of mesenteric vascular bed of cholestatic rats to clonidine (an alpha2-adrenoceptor agonist) was investigated and we also examined the role of endogenous opioids and nitric oxide (NO). Seven-day ligation of bile duct was used as the model to study cholestasis. Six groups of rats, each of which divided into two subgroups (bile duct-ligated and sham-operated), were examined. Three groups of animals were chronically treated with either normal saline, naltrexone (an opioid receptor antagonist, 20 mg/kg/day, s.c.) or aminoguanidine (a selective inducible nitric oxide synthase inhibitor, 150 mg/kg/day, s.c.) for 7 days. After 7 days the response of the mesenteric vascular bed to subsequent doses of clonidine was studied. In other two groups, 7 days after the operation, the response of the mesenteric vascular bed to clonidine in the presence of either yuhimbine, an alpha2-adrenoceptor antagonist, or N(omega)-nitro-L-arginine methyl ester (L-NAME), a non-selective nitric oxide synthase inhibitor, was studied. In the last group, vasodilation response to sodium nitroprusside (an endothelium-independent vasorelaxant) was evaluated. Clonidine caused vasodilation in a dose-dependent manner by acting on endothelial alpha2-adrenoceptors since its effect was antagonized by yohimbine, and this vasodilation was through the L-arginine pathway since there was no response in the presence of L-NAME in the perfusate. Compared to sham-operated rats, there was a significant right shift in the clonidine concentration curves of cholestatic animals. Maximum response in cholestatic rats was significantly lower comparing to the sham group (P<0.01) and the dose of clonidine that causes 50% of maximum response (ED50) was significantly higher in cholestatic rats (P<0.05). Vasodilation response to sodium nitroprusside was the same in cholestatic and sham-operated rats. Seven-day treatment with aminoguanidine recovered the effect of cholestasis. Seven-day treatment with naltrexone caused an increase in maximum response (P<0.01) and a decrease in ED50 (P<0.05) in cholestatic rats, while this treatment in sham-operated rats caused a decrease in the maximum response (P<0.01) and an increase in ED50 (P<0.05). This study showed that cholestasis is associated with decreased responsiveness of mesenteric vascular bed to clonidine and the cholestasis-associated NO overproduction and increased level of endogenous opioids may contribute to this process.
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Affiliation(s)
- Amir Ali Borhani
- Department of Pharmacology, School of Medicine, Tehran University of Medical Sciences, P.O. Box 13145-784, Tehran, Iran
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