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Conference Paper: Chronic treatment of vitamin D derivatives reduce endothelium-dependent contractions in the aorta of the spontaneously hypertensive rat

TitleChronic treatment of vitamin D derivatives reduce endothelium-dependent contractions in the aorta of the spontaneously hypertensive rat
Authors
KeywordsPharmacy and pharmacology environmental studies
Toxicology and environmental safety
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 (WorldPharma2010), Copenhagen, Denmark, 17-23 July 2010. In Basic & Clinical Pharmacology & Toxicology, 2010, v. 107, suppl. 1, p. 659 How to Cite?
AbstractThe available evidences suggest that vitamin D has cardiovascular effects besides regulating calcium homeostasis. Previous studies demonstrated that 1,25-dihydroxyvitamin D3, the major metabolite of vitamin D, acutely reduce endothelium-dependent contractions induced by acetylcholine. To examine the chronic effect of 1,25-dihydroxyvitamin D3, rats were treated with the vitamin D derivative for 6 weeks. The serum 1,25-dihydroxyvitamin D3 level was significantly higher than the control while the mean arterial blood pressure was significantly lower. Aortic rings with or without endothelium were used for organ bath experiments. The release of prostacyclin and thromboxnane A2 after acetylcholine or A23187 stimulation were measured. The cytosolic-free calcium concentration was measured by confocal microscopy with the fluorescent dyes Fluo-4. Real time PCR was used to compare the mRNA level of COX-1, prostacyclinsynthase, thromboxane synthase and eNOS between the control and treated groups. Both acetylcholine- and A23187-induced endothelium-dependent contractions were reduced significantly in the treated group. The acetylcholine- induced release of prostacyclin and the A23187-induced thromboxname A2 was reduced in the treated group. There was no significant difference in cytosolic free calcium concentration caused by acetylcholine or A23187 between control and treated groups. COX-1 mRNA level was significantly inhibited in the treated SHR. These results demonstrate that chronic treatment of 1,25-dihydroxyvitamin D3 modulates vascular tone by inhibiting the expression level of COX-1 mRNA which is a completely different mechanism as in the acute treatment. This chronic effect to EDCF may account for one of the factors that reducing the mean arterial blood pressure in the SHR rats.
DescriptionFocused Conference Group: P15 – Endotheliumin Health and Disease. Paper No. 1288
Persistent Identifierhttp://hdl.handle.net/10722/126869
ISSN
2015 Impact Factor: 3.097
2015 SCImago Journal Rankings: 0.539

 

DC FieldValueLanguage
dc.contributor.authorWong, MSKen_HK
dc.contributor.authorMan, RYKen_HK
dc.contributor.authorVanhoutte, PMen_HK
dc.date.accessioned2010-10-31T12:53:21Z-
dc.date.available2010-10-31T12:53:21Z-
dc.date.issued2010en_HK
dc.identifier.citationThe 16th World Congress on Basic and Clinical Pharmacology (WorldPharma2010), Copenhagen, Denmark, 17-23 July 2010. In Basic & Clinical Pharmacology & Toxicology, 2010, v. 107, suppl. 1, p. 659en_HK
dc.identifier.issn1742-7835-
dc.identifier.urihttp://hdl.handle.net/10722/126869-
dc.descriptionFocused Conference Group: P15 – Endotheliumin Health and Disease. Paper No. 1288-
dc.description.abstractThe available evidences suggest that vitamin D has cardiovascular effects besides regulating calcium homeostasis. Previous studies demonstrated that 1,25-dihydroxyvitamin D3, the major metabolite of vitamin D, acutely reduce endothelium-dependent contractions induced by acetylcholine. To examine the chronic effect of 1,25-dihydroxyvitamin D3, rats were treated with the vitamin D derivative for 6 weeks. The serum 1,25-dihydroxyvitamin D3 level was significantly higher than the control while the mean arterial blood pressure was significantly lower. Aortic rings with or without endothelium were used for organ bath experiments. The release of prostacyclin and thromboxnane A2 after acetylcholine or A23187 stimulation were measured. The cytosolic-free calcium concentration was measured by confocal microscopy with the fluorescent dyes Fluo-4. Real time PCR was used to compare the mRNA level of COX-1, prostacyclinsynthase, thromboxane synthase and eNOS between the control and treated groups. Both acetylcholine- and A23187-induced endothelium-dependent contractions were reduced significantly in the treated group. The acetylcholine- induced release of prostacyclin and the A23187-induced thromboxname A2 was reduced in the treated group. There was no significant difference in cytosolic free calcium concentration caused by acetylcholine or A23187 between control and treated groups. COX-1 mRNA level was significantly inhibited in the treated SHR. These results demonstrate that chronic treatment of 1,25-dihydroxyvitamin D3 modulates vascular tone by inhibiting the expression level of COX-1 mRNA which is a completely different mechanism as in the acute treatment. This chronic effect to EDCF may account for one of the factors that reducing the mean arterial blood pressure in the SHR rats.-
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 & Toxicologyen_HK
dc.rightsThe definitive version is available at www.blackwell-synergy.com-
dc.subjectPharmacy and pharmacology environmental studies-
dc.subjectToxicology and environmental safety-
dc.titleChronic treatment of vitamin D derivatives reduce endothelium-dependent contractions in the aorta of the spontaneously hypertensive raten_HK
dc.typeConference_Paperen_HK
dc.identifier.openurlhttp://library.hku.hk:4550/resserv?sid=HKU:IR&issn=1742-7835&volume=107, suppl. 1&spage=659&epage=&date=2010&atitle=Chronic+treatment+of+vitamin+D+derivatives+reduce+endothelium-dependent+contractions+in+the+aorta+of+the+spontaneously+hypertensive+rat-
dc.identifier.emailWong, MSK: mikwong@hkusua.hku.hken_HK
dc.identifier.emailMan, RYK: rykman@hkucc.hku.hken_HK
dc.identifier.emailVanhoutte, PM: vanhoutt@hku.hken_HK
dc.identifier.hkuros175338en_HK
dc.identifier.volume107, suppl. 1en_HK
dc.identifier.spage659en_HK
dc.identifier.epage659-
dc.description.otherThe 16th World Congress on Basic and Clinical Pharmacology (WorldPharma2010), Copenhagen, Denmark, 17-23 July 2010. In Basic & Clinical Pharmacology & Toxicology, 2010, v. 107, suppl. 1, p. 659-

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