阴离子替代和阴离子通道阻断剂对大鼠心率和心室收缩的影响

Effects of Cl^-substitution and Cl^- channel blockers on rat heart rate and contraction

目的 :探讨 Cl-通道对大鼠离体心脏的心率和心室收缩的影响。方法 :采用离体心脏 Langendorff法灌流 ,监测心率和左心室内压的变化。结果 :通透性较弱的阴离子替代细胞外液中的 Cl-后 ,心率减慢和心室收缩减弱 ,Cl-通道阻断剂产生相似的结果。用高渗液灌流细胞后可以使室内压明显降低 ,但对心率的影响不明显。结论

AIM: To explore the role of Cl - channels in the mechanical activities of perfusing isolated rat hearts. METHODS: The hearts was retrogradely perfused in a Langendorff apparatus under constant pressure. The left ventricular pressure (LVP) and ECG were recorded. RESULTS: Replacement of extracellular Cl - with glutamate or gluconate significantly decreased the heart rate and suppressed the development of LVP. Comparable effects were observed by using putative Cl - channel blocker 5 nitro 2 (3 phenylpropylamino)benzoic acid (NPPB) and niflumic acid. Perfusion of the heart with hypertonic solution also induced inhibition of cardiac ventricular contraction but did not produced markedly influence on heart rate. CONCLUSION: Cl - channels play an important role in the cardiac mechanical activities.