【摘要】 本文观察了硫酸锌对猪心浦肯野氏纤维及心室肌动作电位（AP）的影响,观察了硫酸锌对豚鼠心肌电活动和收缩力的作用。实验结果表明:（1）50μM硫酸锌可降低仔猪浦肯野氏纤维及心室肌动作电位振幅（APA）和动作电位零相最大上升速率(V_max),可显著延长动作电位时程（APD）和有效不应期（ERP）。累积给药,发现以上参数变化为剂量依赖性。（2）0.1mM硫酸锌可使豚鼠离体心乳头肌APA和V_max降低,APD₂₀,APD₅₀,APD₉₀及ERP延长。并可抑制心肌收缩力。（3）50μM硫酸锌可拮抗乙酰胆碱对心房肌APD的缩短作用。提示锌的心肌电生理作用可能与阻滞Na⁺,K⁺,Ca²⁺离子流有关。更多还原

【Abstract】 The effects of ZnSO₄ on the action potential of purkinjefibers and ven- tricular muscles in pigs, and its effects on the electrical activity and contraction of papillary muscles in guinea pigs were observed. The results indicated that: （1） In pigs, ZnSO₄（50 μM） decreased the action potential amplitude （APA） and the maximum velocity of O phase (V_max), and it increased the repolarization duration of the action potential （APD）, as well as the effective refractory period （ERP） of purkinje fibers and ventricular muscles. The effects were concentration dependent. （2） In guinea pigs, ZnSO₄ （100 μM） also decreased the APA and V_max, increased the repolarization duration of the action potential of 20% ( APD₂₀), APD₅₀,APD₉₀ and ERP, and in addition depressed the myocardial contraction force of papillary muscles. （3） Finally, ZnSO₄ （50 μM ） has been shown to inhibit the action induced by Ach which shortens auricular muscle action potential duration. The results suggest that the electrophysiological effects of ZnSO₄ may be related to a blockage of the cation currents of Na⁺, K⁺and Ca²⁺.更多还原