내피세포를 제거한 흰쥐 대동맥에서 Phenylephrine이 일으킨 수축반응에 대한 alpha-수용체 길항제의 영향

• 영문명: Effects of alpha-Adrenoceptor Antagonists on Phenylephrine-induced Contraction in the Endothelium-denuded Rat Aorta
• 발행기관: 대한약학회
• 저자명: 홍승철(Sung Cheul Hong) 강맹희(Maeng Hee Kang) 박상일(Sang Il Park) 박미선(Mi Sun Park) 최수경(Su Kyung Choi) 정준기(Joon Ki Chung) 서석수(Suk Soo Suh)
• 간행물 정보: 『약학회지』제35권 제5호 (1991년), 416~426쪽, 전체 11쪽
• 주제분류: 의약학 > 기타의약학
• 파일형태: PDF
• 발행일자: 1991.10.30

영문 초록

The effects of an irreversible or a reversible alpha1-adrenoceptor antagonist (dibenamine or prazosin) on alpha1-adrenoceptor-mediated vasoconstrictions were studied in the endothelium-denuded rat aorta. In these experiments, the mobilization of intracelluler calcium and translocation of extracellular calcium were also studied. To exclude the modulation of endothelium releasing EDRF and EDCF, the endothelium was removed in all rat aortas. Contraction induced by phenylephrine (a full alpha1-adrenoceptor agonist) was separated into a fast phasic component of the response due to the release of intracellular calcium and a slow tonic one due to the influx of extracellular calcium. Pretreatments with increasing doses of reversible alpha1-adrenoceptor antagonist prazosin, as well as irreversible alpha1-adrenoceptor antagonist dibenamine, inhibited the phasic component of phenylephrine-induced contraction more effectively than the tonic one. Pretreatment of dibenamine (0.2 mcM) or prazosin (10 nM) to the rat aorta abolished phasic response but remained tonic one about 41% and 51%, respectively. These results suggest that as the efficiency of phenylephrine was progressively reduced by pretreatments with increasing doses of an irreversible or a reversible alpha1-adrenoceptor antagonist (dibenamine or prazosin), the contraction induced by phenylephrine became progressively more dependent on the influx of extracellular calcium.

키워드

Endothelium-denuded rat aorta phenylephrine phasic and tonic vasoconstriction α1-adrenoceptor antagonists efficiency.