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Conference Paper: Inhibition of cyclooxygenase activity improves endothelium-dependent relaxation in mesenteric arteries of ovariectomized rats following chronic inhibition of nitric oxide synthase

TitleInhibition of cyclooxygenase activity improves endothelium-dependent relaxation in mesenteric arteries of ovariectomized rats following chronic inhibition of nitric oxide synthase
Authors
Issue Date2010
PublisherBlackwell Publishing Ltd. The Journal's web site is located at http://www.blackwellpublishing.com/journals/PTO
Citation
The 16th World Congress on Basic and Clinical Pharmacology (WorldPharma 2010), Copenhagen, Denmark, 17-23 July 2010. In Basic & Clinical Pharmacology & Toxicology, 2010, v. 107, suppl. 1, p. 409 How to Cite?
AbstractGender differences exist in the incidence and manifestation of vascular diseases, of which endothelial dysfunction is the underlying cause. Endothelial dysfunction is associated with a reducd bioavaliability of nitric oxide. In the present study, the effect of estrogen on endothelial function were examined in rats follwoing chronic inhibition of nitric oxide synthases. Female Sprague Dawley rats were ovariectomized at 12 weeks old, and they were supplemented with 17b-estradiol (25 lg/kg, intramuscularly) or its vehicle (olive oil). At 18 weeks old, they were administered daily with L-NAME (a nitric oxide synthase inhibitor, 60 mg/kg, by gavage) or its vehicle (drinking water) for 6 weeks. 17b-estradiol supplementation increased the plasma level of high density lipoprotein without affecting the low density lipoprotein level in ovariectomized rats. Chronic L-NAME treatment did not cause a signficant increase in blood pressure in all these rats [unlike in male rats of same ages; unpublished data]. In mesenteric artery contracted with phenylephrine, chronic L-NAME treatment impaired endothelium-dependent relaxation to A23187 (a calcium ionophore) in ovariectomized rats with or without 17b-estradiol supplement. This impairment was reversed in the presence of indomethacin (a cyclooxygenase inhibitor), which did not affect A23187-induced relaxation in mesenteric arteries of rats without L-NAME treatment. Therefore, the present finding suggests that ovariectomy enhances the impairment of endothelium-dependent relaxation in L-NAME-treated rats through activation of a cyclooxygenase-dependent signaling pathway, and that 17bestradiol may not be responsible for this detrimental effect of ovariectomy.
DescriptionPaper no. 2316 - Focused Conference Group: P15 - Endothelium in Health and Disease
Persistent Identifierhttp://hdl.handle.net/10722/126865
ISSN
2023 Impact Factor: 2.7
2023 SCImago Journal Rankings: 0.744

 

DC FieldValueLanguage
dc.contributor.authorLeung, SWSen_HK
dc.contributor.authorChan, MLYen_HK
dc.contributor.authorMan, GSKen_HK
dc.contributor.authorMan, RYKen_HK
dc.date.accessioned2010-10-31T12:53:07Z-
dc.date.available2010-10-31T12:53:07Z-
dc.date.issued2010en_HK
dc.identifier.citationThe 16th World Congress on Basic and Clinical Pharmacology (WorldPharma 2010), Copenhagen, Denmark, 17-23 July 2010. In Basic & Clinical Pharmacology & Toxicology, 2010, v. 107, suppl. 1, p. 409en_HK
dc.identifier.issn1742-7835-
dc.identifier.urihttp://hdl.handle.net/10722/126865-
dc.descriptionPaper no. 2316 - Focused Conference Group: P15 - Endothelium in Health and Disease-
dc.description.abstractGender differences exist in the incidence and manifestation of vascular diseases, of which endothelial dysfunction is the underlying cause. Endothelial dysfunction is associated with a reducd bioavaliability of nitric oxide. In the present study, the effect of estrogen on endothelial function were examined in rats follwoing chronic inhibition of nitric oxide synthases. Female Sprague Dawley rats were ovariectomized at 12 weeks old, and they were supplemented with 17b-estradiol (25 lg/kg, intramuscularly) or its vehicle (olive oil). At 18 weeks old, they were administered daily with L-NAME (a nitric oxide synthase inhibitor, 60 mg/kg, by gavage) or its vehicle (drinking water) for 6 weeks. 17b-estradiol supplementation increased the plasma level of high density lipoprotein without affecting the low density lipoprotein level in ovariectomized rats. Chronic L-NAME treatment did not cause a signficant increase in blood pressure in all these rats [unlike in male rats of same ages; unpublished data]. In mesenteric artery contracted with phenylephrine, chronic L-NAME treatment impaired endothelium-dependent relaxation to A23187 (a calcium ionophore) in ovariectomized rats with or without 17b-estradiol supplement. This impairment was reversed in the presence of indomethacin (a cyclooxygenase inhibitor), which did not affect A23187-induced relaxation in mesenteric arteries of rats without L-NAME treatment. Therefore, the present finding suggests that ovariectomy enhances the impairment of endothelium-dependent relaxation in L-NAME-treated rats through activation of a cyclooxygenase-dependent signaling pathway, and that 17bestradiol may not be responsible for this detrimental effect of ovariectomy.-
dc.languageengen_HK
dc.publisherBlackwell Publishing Ltd. The Journal's web site is located at http://www.blackwellpublishing.com/journals/PTO-
dc.relation.ispartofBasic & Clinical Pharmacology & Toxicology-
dc.rightsThe definitive version is available at www.blackwell-synergy.com-
dc.titleInhibition of cyclooxygenase activity improves endothelium-dependent relaxation in mesenteric arteries of ovariectomized rats following chronic inhibition of nitric oxide synthaseen_HK
dc.typeConference_Paperen_HK
dc.identifier.openurlhttp://library.hku.hk:4550/resserv?sid=HKU:IR&issn=1742-7835&volume=107, suppl. 1&spage=409&epage=&date=2010&atitle=Inhibition+of+cyclooxygenase+activity+improves+endothelium-dependent+relaxation+in+mesenteric+arteries+of+ovariectomized+rats+following+chronic+inhibition+of+nitric+oxide+synthase-
dc.identifier.emailLeung, SWS: swsleung@HKUCC.hku.hken_HK
dc.identifier.emailChan, MLY: matmat912@hotmail.comen_HK
dc.identifier.emailMan, GSK: gskman@HKUSUA.hku.hken_HK
dc.identifier.emailMan, RYK: rykman@hkucc.hku.hken_HK
dc.identifier.email409-
dc.identifier.hkuros172955en_HK
dc.identifier.volume107-
dc.identifier.issuesuppl. 1-
dc.identifier.spage409-
dc.identifier.issnl1742-7835-

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