不同剂量肾上腺素引起瞬时血压升高对血脑屏障开放的影响

目的：了解血压不同程度的瞬时升高对血脑屏障（ Ｂ Ｂ Ｂ）的影响。　方法：用不同剂量的肾上腺素（ Ａ Ｄ）对成年大鼠进行静脉注射，观察动脉血压的变化与 Ｂ Ｂ Ｂ开放程度之间的关系。结果：不同剂量 Ａ Ｄ 引起动脉压瞬时升高的幅度和变化时程与 Ｂ Ｂ Ｂ开放程度呈正相关趋势，当 ５ μｇ·ｋｇ－ １ Ａ Ｄ 注射后引起的动脉压在 ３６ ｓ 间一过性升高 ５０ｍ ｍ Ｈｇ 即可使 Ｂ Ｂ Ｂ轻度开放，而 ３μｇ·ｋｇ－ １ Ａ Ｄ 引起的血压升高则不能开放 Ｂ Ｂ Ｂ。　结论：一过性升高的动脉压在升幅和时程达到一定的阈值即可引起 Ｂ Ｂ Ｂ的开放。

Effect of Nilvadipine Treatments on Hemodynamic and Neurohormones ;in Elderly Hypertensives

Aim:To investigate the therapeutic effect of nivadipine on hypertensive patients. Methods:Hemodynamic and humoral respones to nilvadepine were assessed by Doppler echocardiography in 16 elderly hypertensives. A higher dose (8 mg/d) of nilvadipine reduced mean arterial pressure and increased cardiac output, whereas a lower dose (2 mg/d) of nilvadipine had no effect on mean arterial pressure or cardiac output. Both carotid and vertebral flows were increased irrespective of the doses of nilvadipine. There were no significant blood flow changes in celiac,superior mesenteric, renal,and terminal end segment of abdominal aortic blood vessels by either dose of nilvadipine. A lower dose of nilvadipine had no effect on any humoral factor,while a higher dose of nilvadipine increased plasma atrial natriuretic peptide and decreased plasma noradrenaline. Conclusion:Nivadipine 8 mg/d is a favorable dose for treatment of hypertension,it increased the cardial,carotid output and decreased blood norepinephrine.