Bhagat B, Sullivan J M, Fischer V W, Nadel E M, Dhalla N S
Recent Adv Stud Cardiac Struct Metab. 1976;12:465-70.
Isoproterenol-induced myocardial necrosis (ISO-MN) was obviated by the cardioselective beta-blocker, practolol, suggesting that ISO-MN is caused by specific activation of myocardial beta-adrenergic receptors. Because cAMP is the "second messenger" in such activation, enhanced activity of cAMP should aggravate ISO-MN. Pretreatment of rats with bretylium in various amounts, elicited no ill effects but enhanced the effects of ISO on the cAMP activity and also intensified the ISO-induced structural changes in the myocardium.
心脏选择性β受体阻滞剂心得宁可消除异丙肾上腺素诱导的心肌坏死(ISO-MN),这表明ISO-MN是由心肌β肾上腺素能受体的特异性激活所致。由于环磷酸腺苷(cAMP)在此类激活过程中作为“第二信使”,cAMP活性增强应会加重ISO-MN。用不同剂量的溴苄铵预处理大鼠,未产生不良影响,但增强了ISO对cAMP活性的作用,同时也加剧了ISO诱导的心肌结构变化。