尼群地平单用及其与美多洛尔合用对大鼠血压和胸主动脉环收缩的影响

Effects of nitrendipine alone and in combination with metoprolol on blood pressure and aortic-ring contractions in rats

近年来,在高血压病的治疗中,钙拮抗剂(如硝苯啶)与β受体阻断剂(如醋丁洛尔)的合用已引起关注.尼群地平(nitrendIpine,Nit)是一种较新的二氢吡啶类钙通道阻滞剂,美多洛尔(metoprolol,Met)是一种选择性β_1受体阻断剂.该二药的合用尚未见研究报道.

Nitrendipine iv 0.01 mg·kg-1 lowered markedly the blood pressure. Metoprolol slightly increased the blood pressure at smaller doses (0.03-0.75 mg·kg-1) and a hypotensive effect was observed at doses ≥3.75 mg·kg-1. The hypotensive effect of nitrendipine was potentiated by metoprolol. In the isolated aortic rings, metoprolol increased thevasodilator action of nitrendipine. These results suggest that the increase in nitrendipine-induced hypotension by metoprolol occurs possibly in part at the vascular smooth muscle level.