HYPERPOLARIZATION IN MOUSE PARATHYROID CELLS BY LOW CALCIUM
HYPERPOLARIZATION IN MOUSE PARATHYROID CELLS BY LOW CALCIUM
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DOI：
10.1152/ajpcell.1979.236.1.c15
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发表时间：
1979-01-01
影响因子：
--
通讯作者：
ANDERSON, NC
中科院分区：
文献类型：
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作者：
BRUCE, BR;ANDERSON, NC
用细胞内微电极记录小鼠甲状旁腺细胞的静息膜电位。2.5mMCa的膜电位平均值为-20 mV。暴露于低钙溶液(1.5 mM)可引起快速超极化，平均值为-50 mV。细胞外钙与膜电位呈S形关系，细胞内高、低电位的转换发生在1.5~2.25 mMCa之间。镁、锰和镧可逆转低钙超极化。在1.5 mM钙溶液中，外源性K(~gt；10 mM)与膜电位的关系为46 mV/10倍。在2.5 mM钙溶液中，静息膜电位与外源性K浓度无关。小鼠甲状旁腺细胞静息膜电位对细胞外钙离子和类钙离子浓度高度敏感。在低钙分泌刺激下，超极化伴随着静息膜电位对细胞外钾水平的强烈依赖。
Intracellular microelectrodes were used to record the resting membrane potential of mouse parathyroid cells in vitro. The mean value of the membrane potential in 2.5 mM Ca was -20 mV. Exposure to low-Ca solutions (1.5 mM) caused rapid hyperpolarization to a mean value of -50 mV. The relationship between extracellular Ca and the membrane potential was sigmoid and the transition between high and low intracellular potentials occurred between 1.5 mM and 2.25 mM Ca. Mg, Mn, and La reversed the low-Ca hyperpolarization. In 1.5 mM Ca solutions, the relationship between external K (> 10 mM) and the membrane potential was 46 mV per 10-fold change in extracellular K. In 2.5 mM Ca solutions, the resting membrane potential was independent of the external K concentration. The resting membrane potential of mouse parathyroid cells is highly sensitive to the extracellular concentration of Ca and Ca-like ions. With the low-Ca secretory stimulus, hyperpolarization is accompanied by the development of strong dependence of the resting membrane potential on extracellular K levels.