Effect of vitamin E on glutathione content in red blood cells, aqueous humor and lens of humans and other species.

High doses of orally administered vitamin E have been given to humans, rabbits and rats. Placebo has been given to control groups. At the end of the treatment period, enhanced levels of reduced glutathione (GSH) were found in the red blood cells (humans and rabbits), aqueous humor (humans and rabbits) and lens (rabbits and rats) of treated subjects and animals. The percentage of GSH converted to oxidized glutathione (GSSG) was the same in both vitamin E-supplied and control groups. The GSSG--GSH ratio remained unchanged. The plasma levels of vitamin E were significantly higher in treated than in control subjects and animals. At the end of the study, the levels of vitamin E in aqueous humor and lens of rabbit were the same in animals which received vitamin E and in animals which received placebo. Lastly, vitamin E administration did not influence ascorbic-acid levels in plasma (humans and rabbits), aqueous humor, lens and vitreous body (rabbits).