Takata Y, Koga T, Kobayashi K, Takishita S, Fujishima M
Second Department of Internal Medicine, Faculty of Medicine, Kyushu University, Fukuoka, Japan.
Jpn Circ J. 1990 Feb;54(2):183-91. doi: 10.1253/jcj.54.183.
Endothelium-dependent and independent hypotension, vasodilation and relaxation were examined comparatively, in vivo and in vitro, in spontaneously hypertensive (SHR) and normotensive Wistar-Kyoto rats (WKY). In conscious and unrestrained animals, the dose-dependent hypotensive responses to both acetylcholine and adenosine triphosphate (ATP) were attenuated in SHR, compared to findings in the WKY, while sodium nitroprusside lowered mean arterial pressure (MAP), to a similar degree in SHR and WKY. Acetylcholine, ATP and nitroprusside increased the heart rate of SHR and WKY, in a dose-related manner. Mesenteric and femoral blood flow was altered by acetylcholine, ATP and nitroprusside, in a similar manner in the SHR and WKY anesthetized with urethane. However, an ATP-induced reduction in renal blood flow was greater in the SHR than in the WKY. Acetylcholine and nitroprusside led to a concentration-dependent relaxation in the isolated mesenteric artery, to a similar extent in both strains of rats. The relaxation response to acetylcholine was nearly abolished by mechanical removal of the endothelium, but the nitroprusside-induced relaxation was not altered by this denudation. ATP did not influence contraction of the mesentric artery but did produce endothelium-dependent relaxation of aorta, in a dose-dependent manner. All these events suggest that suppression of the endothelium dependent relaxation of resistant arterioles relates to the maintenance of hypertension, in the SHR.
在体内和体外，对自发性高血压大鼠（SHR）和血压正常的Wistar-Kyoto大鼠（WKY）的内皮依赖性和非依赖性低血压、血管舒张和松弛进行了比较研究。在清醒且不受束缚的动物中，与WKY相比，SHR对乙酰胆碱和三磷酸腺苷（ATP）的剂量依赖性降压反应减弱，而硝普钠降低平均动脉压（MAP）的程度在SHR和WKY中相似。乙酰胆碱、ATP和硝普钠以剂量相关的方式增加SHR和WKY的心率。在用乌拉坦麻醉的SHR和WKY中，乙酰胆碱、ATP和硝普钠以相似的方式改变肠系膜和股血流量。然而，ATP诱导的肾血流量减少在SHR中比在WKY中更明显。乙酰胆碱和硝普钠导致离体肠系膜动脉浓度依赖性舒张，在两种品系大鼠中程度相似。通过机械去除内皮，乙酰胆碱的舒张反应几乎消失，但硝普钠诱导的舒张不受这种剥脱的影响。ATP不影响肠系膜动脉的收缩，但确实以剂量依赖的方式产生主动脉的内皮依赖性舒张。所有这些情况表明，在SHR中，对阻力小动脉内皮依赖性舒张的抑制与高血压的维持有关。
