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目的和方法 :用双微电极电压钳技术 ,观察腺苷 (adenosine ,Ad)对绵羊心室浦肯野纤维起搏离子流 1f 的影响。结果 :在正常台氏液中加入 10 -5mol/LAd灌流 15min和 30min后 ,在 - 70～ - 12 0mV所有膜电位 ,If 离子流幅值均降低 (n =12 ,P <0 0 5～ 0 0 1) ,引起激活曲线向超极化方向移位 ,但If 稳态激活时间无明显改变。“缺血”15min和 30min后 ,在 - 70～ - 12 0mV所有膜电位If 离子流幅值均降低 (n =13,P <0 0 5 ) ,稳态激活时间延长 ,导致激活曲线向超极化方向移位 ;“缺血”30min基础上再加 10 -5mol/lAd灌流 15min和 30min ,If 幅值进一步显著减小 (n =13 ,vs“缺血”P <0 0 5 )。结论 :缺血代谢产物Ad对心室的正常自律活动具有抑制作用 ,在“缺血”条件下 ,它能使已受抑制的自律活动进一步受抑
PURPOSE AND METHODS: The effects of adenosine (Ad) on pf flow 1f in sheep’s ventricular Purkinje fiber were observed using a dual-electrode voltage-clamp technique. Results: After 10 min and 10 min perfusion with 10 -5 mol / L Ad in normal Tyrode’s solution, the amplitude of If ion currents decreased at all membrane potential of -70 ~ -12 0 mV (n = 12, P <0 05 ~ 0 0 1), causing the activation curve to shift towards hyperpolarization, but there was no significant change in the activation time of If. After 15 min and 30 min of “ischemia”, the amplitude of If currents in all membrane potentials at -70 ~ -12 0 mV decreased (n = 13, P <0 05) and the activation time prolonged, (N = 13, vs “ischemia”, P <0 05) after 15 min and 30 min perfusion with 10 -5 mol / l Ad on the basis of “ischemia” for 30 min. CONCLUSION: Ischemic metabolic product Ad has an inhibitory effect on the normal autonomic activity of the ventricle. Under “ischemic” conditions, it can further inhibit the already suppressed autonomic activity