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Role of the endothelium on the response to adrenoceptor agonists of rabbit aorta during cooling
Author(s) -
Ataik Esra K.,
Şahin Ayşe S.,
Kiliç Mehmet,
Doğan Necdet
Publication year - 2000
Publication title -
fundamental and clinical pharmacology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.655
H-Index - 73
eISSN - 1472-8206
pISSN - 0767-3981
DOI - 10.1111/j.1472-8206.2000.tb00390.x
Subject(s) - methoxamine , phenylephrine , endothelium , endocrinology , medicine , aorta , chemistry , nitric oxide , clonidine , agonist , receptor , blood pressure
— The role of the endothelium in the effects of cooling on the response to α 1 ‐ and α 2 ‐adrenoceptor agonists of rabbit aorta was studied. The contractions induced by clonidine (10 −9 ‐ 3 × 10 −4 M) and xylazine (10 −7 ‐ 10 −3 M) but not phenylephrine (10 −9 ‐ 3 × 10 −4 M) and methoxamine (10 −9 ‐ 3 × 10 −4 M) were enhanced in endothelium‐denuded or N G ‐nitro‐L arginine methyl esther ( l ‐NAME) (10 −5 M) pretreated rabbit aorta. The senstivily, but not the maximal response, of both α 1 ‐ and α 2 ‐adrenoceptor agonists was significantly lower at 28 °C (cooling) than at 37 °C. Endothelium removal did not affect the action of cooling. These results were taken as evidence for the specificity of α 2 ‐adrenoceptor agonists on the production and release of nitric oxide from vascular endothelium. The results suggest that the endothelium seems to have no role in the cooling‐induced responses of both α 1 ‐ and α 2 ‐adrenoceptors.