Zhao Z Q, Zang Y M, Wang F Z, Li Z J, Yang M F, Ma S Y
Sheng Li Xue Bao. 1989 Feb;41(1):30-9.
Experiments were performed on 54 anesthetized, open-chest dogs to observe the effect of cardiac sympathetic nerves and alpha- and beta-adrenoceptor blockades on changes of platelet function during the early phase of myocardial ischemia. It was shown that contents of TXB2 and 6-keto-PGF1 alpha after coronary occlusion were markedly increased, and the platelet count was reduced in the coronary venous blood of ischemic myocardium. It was found that the changes in parameters of platelet function after coronary occlusion were significantly relieved by topical application of lignocaine-soaked gauze pads to the ischemic area of the heart or by bilateral stellectomy for blocking impulse of afferent and efferent of cardiac sympathetic nerves, compared with changes in parameters of control group, P less than 0.01. On the other hand, changes in parameters of the control group could be restored by intravenous infusion of noradrenaline to dogs which bilateral stellectomy was performed on, but not by infusion of normal saline. Different effects of alpha- and beta-adrenoceptor blockades on the changes in aforementioned parameters were found. The changing degrees in elevation of TXB2 and 6-keto-PGF1 alpha and in decrease of platelet count were significantly relieved by intravenous infusion of yohimbine (an alpha 2-blocker), phentolamine (a nonselective alpha-blocker), and propranolol (a beta-blocker), but not by infusion of prazosin (an alpha 1-blocker). Results were compared with the control group, P less than 0.01. These results suggest that cardiac sympathetic nerves play an important role for the changes of platelet function during the early phase of myocardial ischemia and that, yohimbine and phentolamine may exert an improving effect by blocking alpha 2-receptors on the platelet membrane, and propranolol may directly contribute to stabilization of the platelet membrane.
对54只麻醉开胸犬进行实验，观察心脏交感神经以及α和β肾上腺素能受体阻断对心肌缺血早期血小板功能变化的影响。结果显示，冠状动脉闭塞后血栓素B2（TXB2）和6-酮-前列腺素F1α（6-keto-PGF1α）含量显著升高，缺血心肌的冠状静脉血中血小板计数降低。发现与对照组相比，用利多卡因浸泡的纱布垫局部敷于心缺血区或进行双侧星状神经节切除术以阻断心脏交感神经的传入和传出冲动，可显著减轻冠状动脉闭塞后血小板功能参数的变化，P<0.01。另一方面，对进行双侧星状神经节切除术的犬静脉输注去甲肾上腺素可恢复对照组的参数变化，而输注生理盐水则不能。发现α和β肾上腺素能受体阻断对上述参数变化有不同影响。静脉输注育亨宾（一种α2受体阻滞剂）、酚妥拉明（一种非选择性α受体阻滞剂）和普萘洛尔（一种β受体阻滞剂）可显著减轻TXB2和6-keto-PGF1α升高及血小板计数降低的程度，而输注哌唑嗪（一种α1受体阻滞剂）则不能。结果与对照组比较，P<0.01。这些结果提示，心脏交感神经在心肌缺血早期血小板功能变化中起重要作用，育亨宾和酚妥拉明可能通过阻断血小板膜上的α2受体发挥改善作用，普萘洛尔可能直接有助于稳定血小板膜。
