视网膜视杆细胞光转导的信号机制。

Signal mechanisms of phototransduction in retinal rod.

作者信息

Korenbrot J I

出版信息

CRC Crit Rev Biochem. 1985;17(3):223-56. doi: 10.3109/10409238509113605.

Abstract

The levels of intracellular molecules are modulated by illumination of rod photoreceptor cells in the vertebrate retina. Among these are Ca ions, cyclic nucleotides (cGMP in particular), and phosphate nucleotides (ATP and GTP). It is presumed now that at least two of these molecules, Ca and cGMP, may function as chemical linkers between the absorption of light by rhodopsin and the ionic channels of the plasma membrane of the rod outer segment that close when the rod is illuminated. The manuscript will review the physiology of the rod cell, the evidence in support of light-dependent changes in the intracellular levels of various small molecules, and the role of these changes in coupling rhodopsin excitation to the control of the light-sensitive membrane channels in the rod.

摘要

在脊椎动物视网膜中，视杆光感受器细胞受光照会调节细胞内分子的水平。其中包括钙离子、环核苷酸（尤其是cGMP）和磷酸核苷酸（ATP和GTP）。现在推测，这些分子中至少有两种，即钙和cGMP，可能作为化学连接物，在视紫红质吸收光与视杆外段质膜离子通道之间起作用，视杆受光照时这些离子通道会关闭。本文将综述视杆细胞的生理学、支持各种小分子细胞内水平光依赖性变化的证据，以及这些变化在将视紫红质激发与视杆中光敏感膜通道的控制相偶联中的作用。