Protective Effect Of Saturated Hydrogen Saline Against Blue Light-induced Retinal Damage In Rats

Purpose:Light-induced retinal damage associated to the accumulation of reactive oxygen species (ROS) is the important pathogenesy of several retinal diseases such as ARMD, RP. H2has selective antioxidant properties, and hydrogen-rich saline can selectively reduced·OH and ONOO-, the most cytotoxic of reactive oxygen species (ROS). In this study, we explore the effect of saturated hydrogen saline on blue light-induced retinal damage in rats.Methods:One hundred healthy female rats weighing160g-180g were randomly assigned to the following four groups. They were maintained in12h:12h light:dark cycle of1101ux and free access to food and water ad libitum. Group1included30rats received light exposure without any other treatment. Group2included30rats received light exposure with intraperitoneal injection of normal saline. Group3included30rats received light exposure with intraperitoneal injection of saturated hydrogen saline. And Group4included the other10rats which did not receive any treatment. The retinal damage of rats was induced by blue light exposure for6hours and examined8h,16h and24h after the exposure. Specimens were collected and processed by H-E staining, ultrastructure observation, biochemical measurement to observe the damage of the retina and the effect of saturated hydrogen saline. Results:By H-E staining, although the structure of retina in Group1and Group2was injured heavily, the injury in Group3was mild. The differences between Group1and Group2were not significant. Compared with the rats in Group1and Group2, the ones in Group3had more clearly demarcated retina structure and more ordered cells by light microscope and TEM observation. The ONL thicknesses (400times) of four groups at each time point except between Group1and Group2were significantly different (P<0.05). The thicknesses of the ONL in Group1at three time points were30.41±4.04μm,26.11±2.82μm and20.63±1.06μm, in Group2were31.62±4.54μm,25.08±3.63μm and19.07±3.86μm, in Group3were29.75±3.62μm,28.83±1.97μm and27.61±1.83μm. In Group4the mean of the thickness was37.35±1.37μm. As time went by, the damage grew more severely. At24h point, the differences were most significant. Compared with Group4, the thickness was46.23%thinner in Group1,50.29%thinner in Group2and28.04%thinner in Group3. The stack structures of membranous disc in Group3were injured slightly, but in Group1and Group2the damage was more obvious by TEM. Compared with Group4at each time point, the content of MDA in Group1was higher (P<0.05). The content of MDA in Group3was significantly lower than those of Group1(P<0.05) and Group2(P<0.05). Between the Group1and Group2, the MDA concentration at each time point was no significant difference (P>0.05).Conclusions:Our results showed that saturated hydrogen saline had protective effects against the retina from light-induced damage by attenuating oxidative stress. This finding makes hydrogen potentially useful for treating a variety of retinal diseases of oxidative stress associated with reactive oxygen species inclusive of ARMD.