The potent heme oxygenase inducing action of arsenic and parasiticidal arsenicals.
Academic Article
Overview
abstract
The administration of trivalent arsenic, either as sodium arsenite or as the trypanocidal drug melarsoprol, to rats produced a profound induction of microsomal heme oxygenase (EC 1.14.99.3) in both liver and kidney and a concomitant decrease in cytochrome P-450 content. In addition, perturbations of delta-aminolevulinate synthase were observed which showed an initial decline followed by a rebound increase in the activity of this enzyme with arsenical treatment. Pentavalent arsenic did not induce hepatic heme oxygenase but did induce the enzyme in kidney, although to a lesser extent (50%) than trivalent arsenic. Treatment of isolated chick embryo liver cells in vitro with sodium arsenite or the parasiticidal drug melarsoprol also showed a potent induction of heme oxygenase. These findings describe a new and potent ability of arsenic and parasiticidal arsenicals to induce heme oxygenase resulting in enhanced degradation of cellular heme.