Gardiner S M, Compton A M, Bennett T
Department of Physiology and Pharmacology, Medical School, Queen's Medical Centre, Nottingham, England.
J Cardiovasc Pharmacol. 1989;13 Suppl 5:S202-4. doi: 10.1097/00005344-198900135-00057.
Regional hemodynamic measurements were made in conscious, unrestrained, Wistar rats chronically instrumented with pulsed Doppler flow probes around left renal and superior mesenteric arteries and the distal abdominal aorta, or around left and right common carotid arteries. The cardiovascular changes with i.v. bolus doses (0.004 and 0.04 nmol) or a 20-min infusion (0.04 nmol/20 min of endothelin-1 (ET-1) were assessed. ET-1 at a dose of 0.004 nmol had no effect on mean arterial pressure (MAP), but caused reductions in renal and mesenteric blood flow accompanied by hindquarters hyperemia; there were no changes in carotid hemodynamics. The higher bolus dose (0.04 nmol) of ET-1 caused initial hypotension and tachycardia followed by hypertension and bradycardia; these changes were associated with sustained reductions in renal and mesenteric flows but a transient hindquarters hyperemia. There was an initial carotid hyperemia followed by a marked reduction in blood flow. Infusion of ET-1 caused progressive bradycardia and hypertension accompanied by reductions in renal and mesenteric flows, but no changes in hindquarters or carotid hemodynamics. These observations are consistent with the hyperemia in the latter vascular beds with high bolus doses of ET-1 due to release of an endogenous vasodilator substance(s).
对清醒、未受束缚且长期植入脉冲多普勒血流探头的Wistar大鼠进行区域血流动力学测量，探头分别置于左肾动脉、肠系膜上动脉和腹主动脉远端周围，或左右颈总动脉周围。评估静脉推注剂量（0.004和0.04 nmol）或20分钟输注（0.04 nmol/20分钟）内皮素-1（ET-1）后的心血管变化。剂量为0.004 nmol的ET-1对平均动脉压（MAP）无影响，但导致肾和肠系膜血流减少，同时伴有后肢充血；颈动脉血流动力学无变化。较高推注剂量（0.04 nmol）的ET-1引起初始低血压和心动过速，随后是高血压和心动过缓；这些变化与肾和肠系膜血流持续减少但后肢短暂充血有关。最初有颈动脉充血，随后血流显著减少。输注ET-1导致进行性心动过缓和高血压，同时伴有肾和肠系膜血流减少，但后肢或颈动脉血流动力学无变化。这些观察结果与高推注剂量ET-1导致后肢血管床充血一致，这是由于内源性血管扩张物质的释放所致。
