氨酰心安的心脏选择性作用

CARDIOSELECTIVITY OF ATENOLOL

近年来肾上腺素乙受体(β受体)阻断剂的研究在适应症、品种以及作用原理等方面进展很快。目前在常用的乙受体阻断剂中仍以心得安居于首位,但它的缺点之一是对心脏乙受体作用的选择性不高,在对心脏发挥治疗作用的同时,也会阻断乙受体,从而兴奋支气管平滑肌,故禁用于哮喘病人。

Effects of atenolol on isolated rabbit right atria and guinea-pig tracheal stripe were studied in comparision with propranolol and practolol.The results showed that atenolol,as propranolol and practolol,could cause a parallel shift of the cumulative dose-response curves of isoprenaline to the right.pA2 values of atenolol,practolol and propranolol on rabbit atria were 7.48,7.22 and 8.67,while those on guineapig tracheal strips were 5.49,6.33 and 8.76 respectively.Thus,the cardioselectivity index of atenolol was calculated as 1.99,and that of praotolol was 0.89;i.e.,the effect of atenolol onβ1 adrenoceptors was about 100 times as potent as that onβ2 adrenoceptors,and that of practolol onβ1 adrenoceptors was only 8 times as that onβ2 adrenoceptors.Our results were consistent with the idea that the cardioselectivity of atenolol is higher than that of practolol,and that atenolol could be used clinically in place of practolol.