心交感神经对缺血心肌区血液中TXB_2和6-酮-PGF_(1α)浓度变化的影响  

EFFECT OF CARDIAC SYMPATHETIC NERVES ON CHANGES OF TXB_2 AND 6--KETO--PGF_(1α) IN VENOUS BLOOD OF ISCHEMIC MYOCARDIUM

作　　者：赵志青[1] 臧益民[1] 王复周[1] 李振甲[2] 杨梅芳[2] 马三元[2] 

机构地区：[1]第四军医大学生理教研室 [2]中国人民解放军301医院中心实验室

出　　处：《生理学报》1989年第1期30-39,共10页Acta Physiologica Sinica

摘　　要：本实验在54只麻醉开胸犬,分别观察了心交感神经和α、β受体阻断剂对心肌缺血早期血小板功能变化的影响。结果表明,阻断冠脉后,心肌缺血区血液中TXB_2和6-酮-PGF_(1α)含量明显升高,血小板计数减少,随缺血时间延长,变化程度也增大。缺血心肌局部外敷2％利多卡因湿沙条或切除双侧星状神经节,分别阻断心交感神经的传入和传出效应,发现阻断冠脉后各参数变化程度明显减轻,与单纯阻断冠脉后各参数变化相比,有显著差异,P<0.01。切除星状神经节并由静脉输注去甲肾上腺素后再阻断冠脉,可重新恢复单纯阻断冠脉后的各参数变化,但输注生理盐水无影响。α和β受体阻断剂对上述参数的影响途径不同。α_2受体阻断剂育亨宾和非选择性α受体阻断剂酚妥拉明,可明显减轻TXB_2和6-酮-PGF_(1α)升高及血小板计数降低的程度,与单纯阻断冠脉后的各参数变化程度相比,有显著差异,P<0.01。但α_1受体阻滞剂哌唑嗪无此作用。和α_2受体阻断剂一样,β受体阻断剂心得安对缺血后上述参数的变化也具有明显改善效应。这些结果提示,心交感神经在血小板功能变化中具有重要作用;育亨宾和酚妥拉明是通过阻断血小板膜α_2受体发挥作用的;在输注心得安而未阻断血小板膜α_2受体时所看到对缺血后血小板功能参数的改善效应。Experiments were perfomed on 54 anesthetized,open-chest dogs to observethe effect of cardiac sympathetic nerves and alpha-and beta-adrenoceptor blockadeson changes of platelet function during the early phase of myocardial ischemia.It was shown that contents of TXB_2 and 6-keto-PGF_(1a) after coronary occlusionwere markedly increased,and the platelet count was reduced in the coronary venousblood of ischemic myocardium.It was found that the changes in parameters ofplatelet function after coronary occlusion were significantly relieved by topicalapplication of lignocaine-soaked gauze pads to the ischemic area of the heart orby bilateral stellectomy for blocking impulse of afferent and efferent of cardiacsympathetic nerves,compared with changes in parameters of control group,P<0.01.On the other hand,changes In parameters of the control group could be restoredby Intravenous infusion of noradrenaline to dogs which bilateral stellectomy wasperformed on,but not by infusion of normal saline.Different effects of alpha-and beta-adrenoceptor blockades on the changes in aforementioned parameterswere found.The changing degrees in elevation of TXB_2 and 6-keto-PGF_(1a) andin decrease of platelet count were significantly relieved by intravenous infusionof yohimbine(anα_2-blocker).phentolamine(a nonselective α-blocker),andpropranolol(aβ-blocker),but not by infusion of prazosin(an α_1-blooker).Resultswere compared with the control group,P<0.01. These results suggest that cardiac sympathetic nerves play an important rolefor the changes of platelet function during the early phase of myocardial ischemiaand that,yohimbine and phentolamine may exert an improving effect by blockingα_2-receptors on the platelet membuane,and propranolol may directly contributeto stabilization of the platelet membrane.

关 键 词：心肌缺血 心交感神经 前列环素 

分 类 号：R331.143[医药卫生—人体生理学]