Preventive effect of ascorbic acid against glucocorticoid-induced cataract formation of developing chick embryos.

Glucocorticoid administration to developing chick embryos is known to promote cataract formation with a decreasing level of glutathione in the lens. To gain further understanding of this process, the level of ascorbic acid, a biological antioxidant, in the lenses was measured during the course of glucocorticoid treatment. When 0.25 mumol of hydrocortisone hemisuccinate sodium (HC) were administered to 15-day-old chick embryos, the level of ascorbic acid in the lens began to decline after 30 hr and became around 40% of the control value at 48 hr after HC treatment. At this time about 90% of the lenses showed opacity in the nuclear region. However, the level of ascorbic acid in the cataractous lens recovered to the control level at 96 hr, a time when the lens has recovered from cataract formation. A triple application of ascorbic acid (20 mumol/egg) at 3, 10 and 20 hr after HC treatment significantly prevented lens opacification. The administration of ascorbic acid prevented the decline of ascorbic acid content and partially that of glutathione content in the lens caused by HC.