Abstract:AIM: To investigate the relationship between development of blood-retinal barrier and formation of selenite nuclear cataract in rat.
METHODS: Activity of GPx, MDA level in lens and selenium content in the eyeballs of different ages rats were determined. Besides, lanthanum hydroxide \〖La(OH)3\〗 tracer method was used to detect development status of blood-retina barrier at different ages.
RESULTS: The result showed that the enzyme activity of GPx was highest in young rats before open eyes, but then decreased gradually with age. Distribution of La(OH)3 in retinal pigment epithelial layer of 20-day-old rats was significantly less than 11-day-old rats. Injecting sodium selenite to 9-day-old rats, lanthanum hydroxide increased obviously and extended to the inner layers of the retina after 48h, and the retinal pigment epithelial layer was damaged seriously; while injecting sodium selenite to 18-day-old rats with the same dose, number of lanthanum hydroxide decreased significantly and did not extend to the inner layer after 48h.Before opening eyes, the content of MDA in the lens of rats was the highest, and decreased significantly after opening eyes. The Se group was 5 times as that of the control group. Besides, in these groups of rats, selenium content in the eyeballs and MDA level in the lens were in agreement with the change of La(OH)3 distribution.
CONCLUSION: These results indicated that antioxidant capacity in the eyelid unopened rats is not the main reason for selenite induced cataract formation. The real reason is that blood-retina barrier development is not mature in the eyelid unopened rats.
