N-ACETYLCYSTEINE AND SODIUM 2-MERCAPTOETHANE SULFONATE AS SOURCES OF URINARY THIOL-GROUPS IN THE RAT

Abstract

Increasing the urinary output of free thiol groups protects against cyclophosphamide-induced bladder toxicity. Intact rats, isolated perfused kidneys and freshly isolated cells from various rat organs were used to compare the efficacy of N-acetylcysteine and sodium 2-mercaptoethane sulfonate (mesna) as sources of urinary thiols. In intact rats given a single i.v. dose of mesna, urinary thiol output was .apprx. 10-fold higher than in rats given an equimolar dose of N-acetylcysteine. This is partly due to the fact that N-acetylcysteine is rapidly absorbed by various types of cells, whereas mesna is transported selectively to the kidney, and partly to different renal handling of the 2 compounds. Mesna evidently is a more favorable drug than N-acetylcysteine for increasing urinary thiol excretion.