Ichikawa K
Foundation Research Lab., Fuji Xerox Co. Ltd., Kanagawa, Japan.
Neurosci Res. 1994 Mar;19(2):201-12. doi: 10.1016/0168-0102(94)90144-9.
The chemical reactions of retinal rod outer segments (ROS) were modeled aimed at finding the critical process for the reconstruction of the photocurrent to flash stimuli. The differential equations, which were derived from the chemical reactions, were numerically integrated. According to the present model, it was found that the most critical process for the recovery of the photocurrent was the synthesis of cGMP by guanylate cyclase in the [Ca2+]i-dependent manner. The other recovery processes, such as rhodopsin phosphorylation, transducin and phosphodiesterase inactivation seemed not to be involved in the recovery of the photocurrent to flash stimuli. Finally, a recently proposed scheme in which transducin remained bound to phosphodiesterase after its activation was examined. The simulation for this scheme showed that the ROS sensitivity was greatly reduced because of the limited amplification in the transduction cascades.
对视网膜视杆细胞外段（ROS）的化学反应进行建模，旨在找出光电流对闪光刺激进行重建的关键过程。从化学反应推导得出的微分方程进行了数值积分。根据当前模型发现，光电流恢复的最关键过程是以依赖细胞内钙离子浓度（[Ca2+]i）的方式由鸟苷酸环化酶合成环鸟苷酸（cGMP）。其他恢复过程，如视紫红质磷酸化、转导素和磷酸二酯酶失活，似乎与光电流对闪光刺激的恢复无关。最后，对最近提出的一种转导素激活后仍与磷酸二酯酶结合的方案进行了研究。该方案的模拟结果表明，由于转导级联反应中的放大作用有限，ROS的敏感性大大降低。
