Cellular accumulation of L-lysine in rat kidney cortex in vivo.

Abstract

A B S T R A C T Cellular accumulation of L-cystine in rat kidney cortex in vivo has been studied using L-[¶S] cystine. The L-[US]cystine radioactivity in plasma decreases to less than 10% of the initially calculated value by 15 min. Four 'S-containing intracellular products of L-cystine metabolism were identified including cystine, cysteine, reduced glutathione, and an as yet unidentified compound. The latter is probably taurine, cysteinesulphinate, or cysteic acid. Cellular accumulation of these products was found to be more rapid in vivo than in vitro. Cellular accumulation of the products of Lcystine metabolism was found to be essentially unchanged in the presence of ureter ligation. Unlabeled L-lysine administered simultaneously with L-[S]cystine, in both the presence and absence or ureter ligation, enhanced the cellular accumulation of intracellular metabolic products of L-[S]cystine. Simultaneous 'S cellular accumulation and L-cystine clearance studies were performed both in the presence and absence of L-lysine. L-Lysine enhanced cellular accumulation of S-products despite an accompanying increase in L-cystine clearance. The results are interpreted as evidence for a dissociation