细胞外ATP可增加培养的大鼠肾动脉平滑肌细胞的胞质钙浓度。

Extracellular ATP increases cytosolic calcium in cultured rat renal arterial smooth muscle cells.

Inscho E W, Belott T P, Mason M J, Smith J B, Navar L G

Department of Physiology, Tulane University School of Medicine, New Orleans, Louisiana 70112, USA.

Clin Exp Pharmacol Physiol. 1996 Jun-Jul;23(6-7):503-7. doi: 10.1111/j.1440-1681.1996.tb02769.x.

Abstract

Experiments were conducted on cultured renal arterial smooth muscle cells to determine the ability of extracellular ATP to alter cytosolic calcium concentration and to determine the mechanisms by which this effect occurs. 2. ATP (100 mumol/L) caused the fluorescence ratio of fura-2 to increase from a control value of 1.06 +/- 0.05 to 2.06 +/- 0.13 (P < 0.01) before stabilizing at a sustained level of 1.35 +/- 0.04 (n = 8; P < 0.05). 3. Removal of extracellular calcium from the bathing medium resulted in an attenuation of the initial response to 100 mumol/L ATP with cell fluorescence increasing from 1.16 +/- 0.18 to 1.44 +/- 0.18 ratio units (n = 5). Furthermore, the initial increase in fluorescence ratio rapidly declined to 1.02 +/- 0.06, indicating that an influx of extracellular calcium is required to sustain the increase in fura-2 fluorescence. 4. Depletion of intracellular calcium pools with thapsigargin prevented the increase in fura-2 fluorescence evoked by ATP. 5. These data suggest that ATP-mediated increases in cytosolic calcium in cultured renal arterial smooth muscle cells involve calcium release from the thapsigargin-sensitive, intracellular pool in conjunction with calcium influx from the extracellular medium.

摘要

对培养的肾动脉平滑肌细胞进行实验，以确定细胞外ATP改变胞质钙浓度的能力，并确定这种效应发生的机制。2. ATP（100μmol/L）使fura-2的荧光比率从对照值1.06±0.05增加到2.06±0.13（P<0.01），然后稳定在1.35±0.04的持续水平（n = 8；P<0.05）。3. 从浴液中去除细胞外钙导致对100μmol/L ATP的初始反应减弱，细胞荧光从1.16±0.18增加到1.44±0.18比率单位（n = 5）。此外，荧光比率的初始增加迅速下降到1.02±0.06，表明需要细胞外钙的流入来维持fura-2荧光的增加。4. 用毒胡萝卜素耗尽细胞内钙库可阻止ATP引起的fura-2荧光增加。5. 这些数据表明，培养的肾动脉平滑肌细胞中ATP介导的胞质钙增加涉及从毒胡萝卜素敏感的细胞内钙库释放钙并伴有细胞外介质中的钙流入。