- 作者: Nilce Mitiko Matsuda; Paul J Pearson; Hartzell V Schaff; Carlos E Piccinato; Alfredo J Rodrigues; Paulo Roberto Barbosa Evora
- 作者服務機構: Department of Surgery and Anatomy, Ribeirao Preto Faculty of Medicine, University of Sao Paulo, Ribeirao Preto, Sao Paulo, Brazil
- 中文摘要: --
- 英文摘要:
Segments of the canine internal mammary artery (35 mm in length)
were suspended in vitro in an organ chamber containing physiological salt
solution (95% O2/5% CO2, pH= 7.4, 370 C). Segments were individually
cannulated and perfused at 5 ml/minute using a roller pump. Vasorelaxant
activity of the effluent from the perfused internal mammary arteries was
bioassayed by measuring the decrease in tension induced by the effluent of
the coronary artery endothelium-free ring which had been contracted with
prostaglandin F2α (2 x 10-6 M). Intraluminal perfusion of adenosine
diphosphate (10-5 M) induced significant increase in relaxant activity in the
effluent from the perfused blood vessel. However, when adenosine
diphosphate (10-5 M) was added extraluminally to the internal mammary
artery, no change in relaxant activity in the effluent was noted. In contrast,
acetylcholine produced significant increase in the relaxant activity of the
effluent of the perfused internal mammary artery with both intraluminal and
extraluminal perfusion. The intraluminal and extraluminal release of
endothelium-derived relaxing factor (EDRF) by acetylcholine (10-5 M) can
be inhibited by site-specific administration of atropine (10-5 M). These
experiments indicate that certain agonists can induce the release of EDRF
only by binding to intravascular receptors while other agonists can induce
endothelium-dependent vasodilatation by acting on neural side receptors. - 中文關鍵字: --
- 英文關鍵字: --