Ionic currents of cultured horizontal cells isolated from white perch retina.
Ionic currents of cultured horizontal cells isolated from white perch retina.
复制标题
从白鲈视网膜中分离出的培养水平细胞的离子电流。
DOI：
10.1152/jn.1986.55.3.499
复制
发表时间：
1986
影响因子：
2.5
通讯作者：
Lasater,EM
中科院分区：
文献类型：
--
作者：
Lasater,EM
从白色鲈鱼视网膜分离水平细胞，并保持在细胞培养3天至3周。四种形态上不同类型的水平细胞可以在培养中识别，并标记为H1，H2，H3和H4型。全细胞膜片钳技术被用来研究在四种细胞类型中存在的离子电流。在所有细胞中，阈值以上的去极化命令引起了一个快速内向电流，然后是外向电流。河豚毒素（TTX）或0 Na+ Ringer's可阻断快内向电流，表明该电流由Na+携带。在H1、H2和H3细胞中，由K+携带的外向电流由两部分组成：瞬时电流（IA），可被4-氨基吡啶（4-AP）、四乙基铵（TEA）或细胞内铯阻断;持续电流，可被TEA阻断。H4细胞只有持续电流。在四种细胞类型中观察到内向整流K+电流（异常整流）。该电流对细胞外K+浓度敏感。它的激活表现出两个组成部分：一个瞬时的组成部分和一个缓慢的组成部分。随着超极化的增加，慢分量变得更快。四种细胞类型具有一个小的，持续的钙电流，在正常条件下，被掩盖的内向钠电流和外向钾电流。
Horizontal cells from the retinas of white perch were isolated and maintained in cell culture for 3 days to 3 wk. Four morphologically distinct types of horizontal cells could be identified in culture and were labeled types H1, H2, H3, and H4. Whole-cell patch-clamp techniques were used to study the ionic currents present in the four cell types. In all cells, depolarizing commands above threshold elicited a fast-inward current followed by an outward current. The fast-inward current was abolished by tetrodotoxin (TTX) or 0 Na+ Ringer's, indicating the current was carried by Na+. In H1, H2, and H3 cells, the outward current, carried by K+, consisted of two components: a transient current (IA), blockable with 4-aminopyridine (4-AP), tetraethylammonium (TEA), or intracellular cesium and a sustained current that could be blocked with TEA. The H4 cell had only the sustained current. An inward rectifying K+ current (anomalous rectifier) was observed in the four cell types. The current was sensitive to the extracellular K+ concentration. Its activation showed two components: an instantaneous component and a slower component. The slow component becomes faster with greater hyperpolarizations. The four cell types possessed a small, sustained Ca2+ current that, under normal conditions, was masked by the inward Na+ current and outward K+ currents.