Ouabain-resistant hyperpolarization induced by insulin in aggregates of embryonic heart cells.
Ouabain-resistant hyperpolarization induced by insulin in aggregates of embryonic heart cells.
复制标题
胚胎心脏细胞聚集体中胰岛素诱导的哇巴因抗性超极化。
DOI：
--
复制
发表时间：
1980
影响因子：
11.1
通讯作者：
R. Dehaan
中科院分区：
文献类型：
--
作者：
R. Lantz;L. Elsas;R. Dehaan
在旋转摇床上旋转48小时后，胰蛋白酶解离的14天胚鸡心脏形成球形聚集体。在1.3 mM K+平衡盐溶液中，细胞内记录的聚集体静息膜电位平均（+/- SD）为64 +/- 4 mV。在达到稳定电位后，加入1-100 nM牛胰岛素钠在4-5分钟后引起高达19 mV的缓慢超极化，随后，在某些情况下，进一步更快地转移到接近EK的电位。当胰岛素与10 mM瓦巴因同时加入时，观察到等效的超极化，表明Na+，K+泵活性的增强不是膜电位变化的原因。产生半最大超极化（2 nM）的胰岛素浓度对应于高亲和胰岛素受体的关联常数，表明与这类受体的结合导致了膜电位的变化。电流钳实验的稳态电流-电压曲线表明，胰岛素通过诱导表观电位为负至- 90mv的向外电流，在接近静止电位时产生斜率电导的增加。
Spheroidal aggregates formed from trypsin-dissociated 14-day embryonic chicken hearts after 48 hr of rotation on a gyratory shaker. Intracellularly recorded resting membrane potentials of aggregates bathed in 1.3 mM K+ balanced salt solution had a mean (+/- SD) of 64 +/- 4 mV. After a stable potential was achieved, addition of 1-100 nM sodium bovine insulin caused a slow hyperpolarization of up to 19 mV after 4-5 min, followed, in some cases, by a further, more rapid, shift to a potential near EK. Equivalent hyperpolarizations were observed when insulin was added in the presence of 10 mM ouabain, indicating that enhanced Na+,K+ pump activity was not responsible for the change in membrane potential. The concentration of insulin that produced half-maximal hyperpolarization (2 nM) corresponded to the association constant of a high-affinity insulin receptor, suggesting that binding to this class of receptors led to the change in membrane potential. Steady-state current-voltage curves from current clamp experiments suggested that insulin produced an increase in slope conductance at potentials near rest by inducing an outward current with an apparent potential negative to -90 mV.