Modulation by pH(o) and intracellular Ca2+ of Na+-H+ exchange in diabetic rat isolated ventricular myocytes
Modulation by pH(o) and intracellular Ca2+ of Na+-H+ exchange in diabetic rat isolated ventricular myocytes
复制标题
DOI：
10.1161/01.res.80.2.253
复制
发表时间：
1997-02-01
影响因子：
20.1
通讯作者：
Feuvray, D
中科院分区：
文献类型：
--
作者：
LePrigent, K;LagadicGossmann, D;Feuvray, D
我们以前已经表明，糖尿病与大鼠心脏乳头肌Na+-H+交换活性降低有关。目前的工作已经进行，以阐明这种变化的因素负责。因此，我们研究了pH（o）和细胞内Ca ~（2+）对从链脲佐菌素诱导的糖尿病大鼠心脏分离的心室肌细胞Na ~+-H ~+交换的影响。pH（i）使用羧基-萘酚或（SNARF-1）记录。NH 4+（10 mmol/L）预脉冲法用于诱导酸负荷以激活HEPES缓冲的台氏液中的Na+-H+交换。然而糖尿病并没有改变细胞内的缓冲能力，它显著降低了通过Na+-H+交换的酸流出量（pH（i）6.9时，酸流出量为4.32+/-0.4 [n=32，正常细胞] vs 2.5+/-0.2 [n=43，糖尿病细胞] meq/L/min;
We have previously shown that diabetes is associated with a decrease in Na+-H+ exchange activity in rat cardiac papillary muscle. The present work has been carried out in order to elucidate the factors responsible for such an alteration. Thus, we have studied the effects of pH(o) and intracellular Ca2+ on Na+-H+ exchange in ventricular myocytes isolated from streptozotocin-induced diabetic rat hearts. pH(i) was recorded using carboxy-seminaphthorhodafluor (SNARF-1). The NH4+ (10 mmol/L) prepulse method was used to induce an acid load in order to activate Na+-H+ exchange in HEPES-buffered Tyrode's solution. Whereas diabetes did not change intracellular buffering power, it significantly decreased acid efflux through Na+-H+ exchange (acid efflux, 4.32+/-0.4 [n=32, normal cells] versus 2.5+/-0.2 [n=43, diabetic cells] meq/L per minute at pH(i) 6.9; P