Mayhan W G, Heistad D D
J Pharmacol Exp Ther. 1985 Oct;235(1):92-7.
The goal of this study was to determine effects of flordipine (REV 2609), a calcium channel blocker, on blood flow to brain and other organs. Blood flow was measured with microspheres during i.v. infusion of 0.5 to 2.0 mg/kg of flordipine in anesthetized and awake rabbits. In anesthetized rabbits, flordipine (0.5 mg/kg) increased cerebral blood flow by 50%, despite a small decrease in arterial pressure, with no increase in blood flow to skeletal muscle, bowel or kidney. Higher doses of flordipine produced 2- to 3-fold increases in cerebral and myocardial blood flow, marked increases in flow to skeletal muscle, but no increase in blood flow to bowel or kidney. Blood flow remained elevated 1 hr after stopping infusion of flordipine. The increase in cerebral blood flow was not associated with an increase in cerebral oxygen consumption. In awake rabbits, flordipine also produced a dose-related increase in cerebral, myocardial and skeletal muscle flood flow, with no increase in flow to bowel or kidney. Thus, flordipine produces a relatively selective increase in cerebral and myocardial blood flow. The increase in cerebral blood flow is the result of a direct vasodilator effect of flordipine and is not secondary to an increase in cerebral metabolism.
本研究的目的是确定钙通道阻滞剂氟桂利嗪（REV 2609）对脑及其他器官血流的影响。在麻醉和清醒的兔子静脉输注0.5至2.0mg/kg氟桂利嗪期间，用微球测量血流。在麻醉的兔子中，尽管动脉压略有下降，但氟桂利嗪（0.5mg/kg）使脑血流量增加了50%，而骨骼肌、肠道或肾脏的血流量没有增加。更高剂量的氟桂利嗪使脑和心肌血流量增加了2至3倍，骨骼肌血流量显著增加，但肠道或肾脏的血流量没有增加。停止输注氟桂利嗪1小时后，血流量仍保持升高。脑血流量的增加与脑氧耗量的增加无关。在清醒的兔子中，氟桂利嗪也使脑、心肌和骨骼肌血流量产生剂量相关的增加，而肠道或肾脏的血流量没有增加。因此，氟桂利嗪使脑和心肌血流量相对选择性增加。脑血流量的增加是氟桂利嗪直接血管舒张作用的结果，而非继发于脑代谢的增加。
