离子和药物对妊娠大鼠子宫肌层环形肌高原电位的影响。

Effect of ions and drugs on the plateau potential in the circular muscle of pregnant rat myometrium.

作者信息

Osa T, Kawarabayashi T

出版信息

Jpn J Physiol. 1977;27(1):111-21. doi: 10.2170/jjphysiol.27.111.

DOI:10.2170/jjphysiol.27.111

Abstract

Effect of Na, Ca, anions and isoprenaline on the plateau potential in circular muscle of 11- to 13-day pregnant rat myometrium were investigated using the double sucrose gap method. During the plateau potential, which amounted about 15-20 mV and lasted for 10-20 sec, the membrane conductance increased initially, then decreased. The amplitude and duration of the plateau potential increased by raising the external Ca concentration to between 0.3 and 3 mM, and decreased when the concentration was increased more. The plateau was prolonged in low Na solutin (54 mM). When 154 mM Cl was replaced with Br the plateau was prolonged, however, the plateau was nearly suppressed when Cl was replaced with benzene sulphonate or isethionate. Isoprenaline increased membrane conductance and depressed the plateau. It was concluded that a decrease in K conductance was largely responsible for the plateau potential, and an inward Ca current may have contributed to its formation.

摘要

采用双蔗糖间隙法研究了钠、钙、阴离子和异丙肾上腺素对11至13天妊娠大鼠子宫肌层环行肌平台电位的影响。在约15 - 20 mV且持续10 - 20秒的平台电位期间，膜电导先增加，然后降低。将细胞外钙浓度提高到0.3至3 mM时，平台电位的幅度和持续时间增加，而当浓度进一步增加时则降低。在低钠溶液（54 mM）中平台期延长。当154 mM的Cl被Br取代时平台期延长，然而，当Cl被苯磺酸盐或羟乙磺酸盐取代时平台期几乎被抑制。异丙肾上腺素增加膜电导并降低平台电位。得出的结论是，钾电导的降低在很大程度上导致了平台电位，内向钙电流可能对其形成有贡献。