A measurable reduction of sr Ca content follows spontaneous Ca release in rat ventricular myocytes
A measurable reduction of sr Ca content follows spontaneous Ca release in rat ventricular myocytes
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DOI：
10.1007/s004240050475
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发表时间：
1997-11-01
影响因子：
4.5
通讯作者：
Eisner, DA
中科院分区：
文献类型：
--
作者：
Diaz, ME;Trafford, AW;Eisner, DA
利用咖啡因释放肌浆网钙含量引起的Na-Ca交换电流积分，测定了电压箝位大鼠心室肌细胞肌浆网钙含量。随着钙从s.r中自发释放，s.r中的钙含量降低。这种减少的幅度等于直接测量到的钙在自发释放过程中被泵出细胞的量。自发释放后，s.r Ca含量线性恢复。这些结果被证明与自发释放频率的假设是一致的，这是由细胞和s.r.在自发释放期间重新积累泵出细胞的Ca2+离子所花费的时间决定的。
The Ca content of the sarcoplasmic reticulum (s.r.) was measured in voltage-clamped rat ventricular myocytes from the integral of the Na-Ca exchange current evoked by applying caffeine to release the s.r. Ca content. Following spontaneous release of Ca from the s.r., the s.r. Ca content was decreased. The magnitude of this decrease was equal to that of the amount of calcium directly measured to have been pumped out of the cell during the spontaneous release. Following a spontaneous release, the s.r. Ca content recovered linearly. These results are shown to be consistent with the hypothesis that the frequency of spontaneous release is determined by the time taken for the cell and s.r. to reaccumulate the Ca2+ ions pumped out of the cell during spontaneous release.