关键词: 酸中毒;钙通道;大鼠;心肌细胞

    摘 要:目的 观察酸中毒对心肌细胞L型钙通道电流(ICa·L )的影响. 方法 采用全细胞膜片箝技术记录ICa·L .用酸液灌流造成细胞外和细胞内酸中毒，NH4 Cl洗脱造成单纯细胞内酸中毒. 结果 细胞外酸中毒可明显抑制ICa·L ，在1～2min内，pH6.5及pH7.0的灌流液对ICa·L 的峰值抑制分别达正常的(41.7±7.5)%和(65.6±6.3)%(n=5，P<0.01)，NH4 Cl洗脱引起单纯细胞内酸中毒后，ICa·L 被抑制到正常幅度的(69.4±5.8)%(n=5，P<0.01). 结论 酸中毒对心肌细胞L型钙通道具有明显的抑制作用，细胞内酸中毒参与该作用.

    Effects of acidosis on the L┐type calcium current of rat ventricular myocytes

    GAO Zhan，ZHU Miao-Zhang，ZHOU Jing-Jun，WANG Yue-Min，LIANG Tao，ZHANG Mei-Fang

    1 Department of Physiology，Faculty of Preclinical Medicine，Fourth Military Medical University，Xi'an710033，China，2 Department of Pharmacolo-gy，Nanjing Chinese Medicine Pharmanceutics Uni-versity，3 Cardiovascular Laboratory，Second Affili-ated Hospital of Zhejiang University

    Keywords:acidosis;calcium channel;rat;cardiomyocyte

    Abstract:AIM To explore the effects of acidosis on the L-type Ca

    2+ current(I

    Ca·L )of rat ventricular myocytes.METHODS ICa·L was recorded using whole-cell patch clamp technique.Acidosis was produced either by superfusing the cells with acid solution(intracellular and extracellular acido-sis)or by NH4 Cl withdrawal(intracellular acidosis).RESULTS Both types of acidosis inhibited ICa·L markedly.In the presence of acid solution(pH6.5and pH7.0) ......