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用浮置微电极技术观察了高血钙时兔心室肌细胞跨膜电位(TMP)的变化,以及刺激迷走神经对这些变化的影响。结果表明,高血钙可使心室肌细胞动作电位时程(APD)缩短,O相上升速率([dv/dt]_(max))减慢,刺激迷走神经可消除高血钙引起的[dv/dt]_(mac)的改变,在用氯化四乙基胺(TEA)阻断K通道后,这些作用仍部分出现,并且APD_(30)及APD_(50)缩短。上述结果提示,迷走神经对心室肌细胞跨膜电位的影响,不仅能提高膜对K~+的通透性,而且还可能抑制钙内流。
Floating microelectrode technique was used to observe the changes of transmembrane potential (TMP) of rabbit ventricular myocytes during hypercalcemia and the effects of vagus nerve stimulation on these changes. The results showed that hypercalcemia can shorten the action potential duration (APD) and increase the rate of O phase ([dv / dt] _ (max)), and stimulate the vagus nerve to eliminate hypervolemic [dv / dt] _ (mac), these effects were still partially observed after blockade of K channels with tetraethylammonium chloride (TEA), and APD_ (30) and APD_ (50) were shortened. These results suggest that the vagus nerve on the transmembrane potential of ventricular myocytes, not only can improve the membrane permeability of K ~ +, but also may inhibit calcium influx.