ATP depletion causes a reversible decrease in Na+ pump density in cultured ventricular myocytes.
ATP depletion causes a reversible decrease in Na+ pump density in cultured ventricular myocytes.
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ATP 耗竭导致培养的心室肌细胞中 Na 泵密度可逆性降低。
DOI：
10.1152/ajpheart.1993.264.4.h1208
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发表时间：
1993
期刊：
影响因子：
--
通讯作者：
Barry,WH
中科院分区：
文献类型：
--
作者：
Ikenouchi,H;Zhao,L;McMillan,M;Hammond,EM;Barry,WH
为了检查由长期但亚致死的 ATP 消耗引起的 K+ 稳态受损的因素，我们用 20 mM 2-脱氧-D-葡萄糖加 1 mM NaCN 对培养的鸡心室肌细胞进行代谢抑制 2 小时，然后让肌细胞在含有 6% 胎牛血清 (FCS) 的培养基或补充激素的无血清培养基中恢复 5 天。我们测量了自发收缩（使用视频运动探测器）、K+ 含量、K+ 摄取、膜电位和 Na+ 泵密度（[3H]哇巴因结合）。暴露于代谢抑制 2 小时导致 Na+ 泵位点密度急剧下降 [8.2 +/- 1.1 至 3.8 +/- 0.8 (SE) pmol/mg 蛋白质； n = 9，P < 0.02]。与对照细胞（无代谢抑制，在无血清培养基中培养5天）相比，在无血清培养基中从代谢抑制恢复的细胞中Na+泵密度仍然降低（3.0+/-0.7pmol/mg），这与持续降低的K+摄取（对照的54%）、K+含量（对照的67%）和膜去极化（-19+/-2mV）、细胞数量显着减少（对照的79%）相关。以及无法恢复自发收缩。将抑制细胞 2 小时的细胞暴露于含有 6% FCS 的培养基中，导致 Na+ 泵位点密度在 5 天后恢复到正常水平，这与 K+ 摄取和 K+ 含量的恢复、细胞数量的保存以及收缩的恢复有关。（摘要截断为 250 字）
To examine factors contributing to impaired K+ homeostasis induced by prolonged but sublethal ATP depletion, we subjected cultured chick ventricular myocytes to metabolic inhibition with 20 mM 2-deoxy-D-glucose plus 1 mM NaCN for 2 h and then allowed myocytes to recover for 5 days in medium containing 6% fetal calf serum (FCS) or in hormone-supplemented serum-free medium. We measured spontaneous contractions (with a video motion detector), K+ content, K+ uptake, membrane potential, and Na+ pump density ([3H]ouabain binding). Exposure to metabolic inhibition for 2 h caused an acute decrease in Na+ pump site density [8.2 +/- 1.1 to 3.8 +/- 0.8 (SE) pmol/mg protein; n = 9, P < 0.02]. Compared with control cells (no metabolic inhibition, cultured for 5 days in serum-free medium), Na+ pump density remained depressed in cells recovered from metabolic inhibition in serum-free medium (3.0 +/- 0.7 pmol/mg), and this was associated with persistently depressed K+ uptake (54% of control), K+ content (67% of control), and membrane depolarization (-19 +/- 2 mV), a significant decrease in cell number (79% of control), and failure to resume spontaneous contractions. Exposure of cells inhibited for 2 h to culture medium containing 6% FCS resulted in a return of Na+ pump site density toward normal levels by 5 days, associated with recovery of K+ uptake and K+ content, preservation of cell number, and resumption of contraction.(ABSTRACT TRUNCATED AT 250 WORDS)