ArticleReim M, Luthe P.
Albrecht Von Graefes Arch Klin Exp Ophthalmol. 1977 Oct 28;204(2):135-40.
In bovine corneal epithelium, stroma, and aqueous humor the levels of ascorbic acid (ASC) and dehydroascorbic acid (DHA) were investigated. Two methods were used, the photometric assay with 2,6-dichlorophenolindophenol and the formation of osazone by 2,4-dinitrophenylhydrazine. The ASC levels in the corneal epithelium and aqueous humor were found to be in the millimolar range, the ASC/DHA ratio being about 10. The stromal ASC and DHA levels were much lower, with a ratio of 0.7. ASC and DHA had similar levels and ratios to those of reduced and oxidized glutathione (GSH/GSSG) reported in the literature. In the corneal epithelium the redox ratio of glutathione was higher than that of ascorbic acid. Therefore, glutathione was supposed to reduce dehydroascorbic acid.