We are investigating the transport of amino acids which are directly or indirectly incorporated into glutathione (G) and opthalmic acid (OA) in the ocular lens. Different systems of transport are involved for the substituent amino acids (ASC for cysteine and gamma- aminobutyrate, Gly for glycine, L for gluamine), though there is some overlap in affinities for the various transporters, and the A-system is also involved to a minor extent. Detailed studies are to be made of the incorporation of cysteine into G and of gamma-aminobutyrate into OA with the objectives of ascertaining the turnover of the tripeptides and learning whether the levels of these amino acids are rate-limiting in biosynthesis. Their competition for gamma-glutamylcysteine synthetase is to be evaluated. We intend to examine the effects of methionine sulfoximine and methionine sulfone on in vitro synthesis of G. If these inhibitors of the gamma-glutamyl synthetase are effective, analysis of catabolism of G will be facilitated. Acid filtrates of the lens are to be chromatographed on anion exchange columns in an attempt to achieve better resolution of the lenticular acidic amino acids and peptides which are of interest.