EFFECT OF GLUCOSE-CYSTEINE ADDUCT AS A CYSTEINE PRODRUG IN RATS

Effect of intraperitoneal administration (5 mmol/kg of body weight) of glucose-cysteine adduct (glc-cys) as a cysteine prodrug in rat tissue s was studied. Cysteine levels in liver and kidney increased to 1.08 a nd 1.98 mu mol per g or mi, respectively, at 2 h after the administrat ion. GSH levels did not change substantially. However, when glc-cys wa s injected to rats treated with diethyl maleate, a GSH-depleting agent , the decreased GSH levels were restored rapidly. The recoveries in li ver and kidney were 72% at 1 h and 66% at 2 h, respectively, after glc -cys administration. Metabolism of glc-cys was assessed by urinary exc retion of glc-cys, sulfate and taurine. Average excretion of glc-cys w as 2.86 mmol/kg/24 h after glc-cys administration. Increased excretion s of sulfate and taurine were 0.77 and 0.14 mmol/kg/24 h, respectively . Data show that, although glc-cys excretion was relatively rapid, glc -cys was effectively utilized for GSH synthesis in GSH-depleted tissue s.