硫酸锌对心肌慢反应电活动和哇巴因引起振荡后电位的影响

INFLUENCE OF ZINC SULFATE ON MYOCARDIAL SLOW RESPONSE ELECTRICAL ACTIVITY AND OUABAIN INDUCED OSCILLATORY AFTERPOTENTIAL

摘要: 本文目的旨在观察硫酸锌对心肌慢反应电活动的影响,所得结果如下:(1) 0.1～0.3mmol硫酸锌能使高钾除极引起的豚鼠乳头肌慢反应动作电位APA和V_max降低,APD₅₀和APD₉₀)显著延长;(2) 0.1～0.3 mmol硫酸锌能抑制家兔离体窦房结细胞的自律性,使窦房结APA降低,APD₉₀延长,SP₀和SP₄减小;(3) 0.1 mmol硫酸锌可对抗0.4μmol哇巴因诱发的豚鼠心室肌振荡后电位,提高引起振荡后电位的哇巴因阈浓度。提示:锌抑制心肌慢反应电活动。

Abstract: The action of ZnSO₄ (0.1～0.3 mmol) on the slow response action potentials induced by high concentration K⁺ (25 mmol) was observed on isolated guinea pig papillary muscles. APA and V_max of the slow response action potentials were decreased. APD₅₀ and APD₉₀ were prolonged significantly. ZnSO₄ (0.1～0.3 mmol) inhibited the automaticity of the isolated rabbit sinoatrial node preparations. The sinus rate decreased (P<0.01). APA of the rabbit sinoatrial node was reduced, APD₉₀ prolonged, while SP₀ and SP₄ were decreased. Zinc sulfate (0.1 mmol) inhibited the guinea pig papillary muscle oscillatory afterpotential induced by ouabain (0.4 μmol). It increased the threshold concentration of ouabain necessary for inducing oscillatory afterpotential. The results suggest that ZnSO₄ inhibited myocardial slow response electrical activity.