摘要
静脉注射 APⅢ5μg,可使大鼠平均动脉压降低12％(p<0.01),此时心脏活动明显减弱。每搏指数、心指数、左室压、左室压上升最大速率和左室压下降最大速率均显著降低,T值显著增大,而此时心率和总外周阻力指数无明显变化。APⅢ的上述作用不能被阿托品阻断,但切断双侧迷走神经可使 APⅢ的降压作用减弱。预先用6-羟多巴胺化学切割交感神经后,可使APⅢ对心脏活动的抑制作用明显减弱。结果表明,APⅢ具有心脏抑制作用,植物神经,特别是交感神经可能参与这一活动。APⅢ使心输出量降低,是其降压作用的重要原因。
The effects of synthetic rat atriopeptin III(APⅢ)on cardiac fun- ction were studied in aneasthetized rats.Intravenous injection of APⅢ 5 μg caused the mean blood pressure decreased by 12% (P<0.01),associated with cardiac activities inhibited.Stroke volume index,cardiac index,left ventricular pressure,+LV(dp/dt)max,-LV(dp/dt)max all decreased significantly,and T value increased.Meanwhile the heart rate and total peripheral resistance index remained unchanged.The above effects could not be blocked by pre-atropiniza- tion;Bilateral vagotomy attenuated the hypotensive effect of APⅢ;Chemical sympathectomy by 6-HYdroxydopamine attenuated the hypotensive and cardiosu- ppressive effects markedly.The results demonstrated that APⅢ possesses card- iosuppressive effect,and autonomic nerves,especially sympathetic nerves might be involved in the effect.The cardiosuppression,thus decreasing cardiac output is an important mechanism in hypotensive effect of APⅢ.
基金
本研究得到国家自然科学基金(生85-432)和第四军医大学青年科学基金的资助
