ELECTROPHYSIOLOGICAL ACTIONS OF OXYTOCIN ON RABBIT MYOMETRIUM
ELECTROPHYSIOLOGICAL ACTIONS OF OXYTOCIN ON RABBIT MYOMETRIUM
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DOI：
10.1085/jgp.53.6.758
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发表时间：
1969-01-01
影响因子：
3.8
通讯作者：
KAO, CY
中科院分区：
文献类型：
--
作者：
KLEINHAUS, AL;KAO, CY
本文用蔗糖间隙和细胞内微电极记录技术研究了孕兔子宫肌层细胞的电活动。子宫肌层细胞的静息电位约为-50mV，不受妊娠时间和胎盘附着的影响。子宫肌层的动作电位，虽然依赖于外部Na+，并不总是再生型的，从nonparturient子宫的制剂往往主要产生小尖峰。平均峰电位振幅为35 μ m，以平均最大速率3 v/sec上升。催产素浓度低于500 μ U/ml时，可使平均峰电位幅值增至48 mV，平均最大上升速率增至7 V/sec，而不影响静息电位。膜电位和dV/dt的尖峰之间的关系是陡峭的催产素，这表明催产素增加了正常稀疏的钠门在子宫肌层膜的数量。通过这种作用，催产素被认为增加了成功再生尖峰的概率，从而在静止的准备中启动电活动，增加爆发放电的频率，每个爆发中的尖峰数量，以及单个细胞中尖峰的幅度。
The electrical activities of myometrial cells of the pregnant rabbit uterus have been studied by means of sucrose-gap and intracellular microelectrode recording techniques. The resting potential of the myometrial cell was about--50 my, and it is unaffected by the duration of pregnancy or placental attachment. Action potentials of the myometrium, although dependent on external Na+, were not always of the regenerative type; preparations from nonparturient uteri often produce mainly small spikes. The mean spike amplitude was 35 my, rising at a mean maximum rate of 3 v/see. Oxytocin, in concentrations less than 500/~ U/ml, increased the mean spike amplitude to 48 mv and the mean maximum rate of rise to 7 v/see, without affecting the resting potential. The relation between membrane potential and dV/dt of the spike was steepened by oxytoein, suggesting that oxytocin increased the number of normally sparse sodium gates in the myometrial membrane. By this action, oxytocin is believed to increase the probability of successful regenerative spikes and thereby initiate electrical activity in quiescent preparations, increase the frequency of burst discharges, the number of spikes in each burst, and the amplitude of spikes in individual cells.