Homma S, Miyauchi T, Goto K, Sugishita Y, Sato M, Ohshima N
Department of Internal Medicine, University of Tsukuba, Ibaraki, Japan.
J Cardiovasc Pharmacol. 1991;17 Suppl 7:S276-8. doi: 10.1097/00005344-199100177-00078.
An intravital fluorescence videomicroscope system was used to investigate the pharmacological effects of endothelin-1 (ET-1) on the coronary microcirculation in isolated beating hearts of rats. The heart was perfused by retrograde aortic steady flow with an oxygenated Krebs-Ringer solution containing FITC-dextran. Cumulative injections of ET-1 (1-30 pmol) elicited a dose-dependent increase in perfusion pressure from 52 +/- 15 mm Hg (mean +/- SEM; n = 6) before the ET-1 injection to 104 +/- 23 mm Hg at the ET-1 dose of 30 pmol. A dose-dependent narrowing of microvessels was also observed on a monitor screen. This diffuse vasoconstriction was especially prominent in small arterioles; the maximum vasoconstriction of the smaller arterioles was significantly higher than that of the larger arterioles. These findings suggest that ET-1 may have an important role in governing the coronary resistance and regulating the capillary flow in myocardium.
采用活体荧光视频显微镜系统，研究内皮素-1（ET-1）对大鼠离体跳动心脏冠脉微循环的药理作用。心脏通过逆行主动脉稳流，用含异硫氰酸荧光素标记葡聚糖的氧合Krebs-Ringer溶液灌注。累积注射ET-1（1-30 pmol）可使灌注压呈剂量依赖性升高，从注射ET-1前的52±15 mmHg（均值±标准误；n = 6）升高至ET-1剂量为30 pmol时的104±23 mmHg。在监视器屏幕上也观察到微血管呈剂量依赖性狭窄。这种弥漫性血管收缩在小动脉中尤为明显；较小动脉的最大血管收缩明显高于较大动脉。这些发现表明，ET-1可能在控制冠脉阻力和调节心肌毛细血管血流方面发挥重要作用。
