光照对大鼠视网膜的影响及其机制研究.

Objective To study the effect of strong visible light on the structure and function of the rat retina and its mechanism. Methods Self-made light box. Adult Sprague-Dawley (SD) rats were randomly divided into normal control and experimental groups. Normal control group rats were raised in a normal environment of 12 h light / 12 h dark cycle. Rats in the experimental group were first darkly adapted for 24 h, then were irradiated with 5 000 lx strong visible light for 48 h, followed by a dark adaption of another 24 h. All the rats were anesthetized for about 30 minutes. Firstly, the retinal function of the rats were detected by retinal electrophysiology (ERG); Secondly, rats' eyeballs were removed and fixed in fixative solution or 4% polyoxymethylene before paraffin or frozen sections were made for HE staining and TUNEL staining respectively. Paraffin sections with HE staining were used to observe the change of retinal tissue structures under light microscope, and frozen sections with TUNEL staining were observed under confocol microscope. qRT-PCR and Western blot (WB) were used to detect tumor necrosis factor-α (TNF-α) content in the photo damaged retinas. Results HE staining showed that retinal outer nuclear layer was significantly thinner than normal after light exposure, and the temporal side was more severely damaged than the nasal side; TUNEL staining showed that the number of retinal apoptotic cells increased significantly after photo damage; qRT-PCR and WB revealed that TNF-α increased in the photo damaged retinas；and ERG demonstrated that the retinal function of photo damaged rats was significantly reduced. All the results above were statistically different（P<0.05）. Conclusions The damage of outer nuclear layer (ONL) after light exposure is one of the reasons for the impairment of retinal function, and the retinal damage may be related to the increased expression of TNF-α. [ABSTRACT FROM AUTHOR]