AJP - Endocrinology and Metabolism, Vol 259, Issue 3 E443-E450, Copyright © 1990 by American Physiological Society

ARTICLES

Effect of bathocuproine disulfonate, a copper chelator, on cyst(e)ine metabolism by freshly isolated rat hepatocytes

R. M. Coloso, M. R. Drake and M. H. Stipanuk
Division of Nutritional Sciences, Cornell University, Ithaca, New York 14853.

The metabolism of L-cysteine was studied in freshly isolated rat hepatocytes. Because cysteine is rapidly oxidized in oxygenated incubation medium at neutral pH, the effect of bathocuproine disulfonate, a copper-specific chelator, was investigated. Addition of bathocuproine disulfonate resulted in a higher extracellular cysteine-to-half-cystine ratio in incubations of hepatocytes with cysteine. Bathocuproine disulfonate also increased the total uptake and metabolism of cysteine plus cystine [cyst(e)ine] by hepatocytes, which is consistent with the more efficient transport of cysteine than of cystine by freshly isolated rat hepatocytes. The partitioning of cysteine between cysteinesulfinate-dependent and cysteinesulfinate-independent pathways of catabolism was also altered by the addition of bathocuproine disulfonate; the percentage of total catabolic flux that resulted in taurine plus hypotaurine formation was greater, and the percentage of total catabolic flux that occurred by the beta-cleavage of cystine in a reaction catalyzed by gamma-cystathionase was less in incubations that contained bathocuproine disulfonate. Thus addition of bathocuproine disulfonate to maintain a higher extracellular thiol-to-disulfide ratio favored cysteinesulfinate-dependent catabolism of cysteine in rat hepatocytes.

This article has been cited by other articles:

				Y. H. Kwon and M. H. Stipanuk Cysteine regulates expression of cysteine dioxygenase and {gamma}-glutamylcysteine synthetase in cultured rat hepatocytes Am J Physiol Endocrinol Metab, May 1, 2001; 280(5): E804 - E815. [Abstract] [Full Text] [PDF]