Protective effect of 16,16-dimethyl prostaglandin E2 on the hepatotoxicity of bromobenzene in mice.

It has been suggested that 16,16-dimethyl prostaglandin E2 may have a cytoprotective effect in the liver. To assess this hypothesis, we determined the effects of this prostaglandin on the metabolism and toxicity of bromobenzene in mice. Administration of 16,16-dimethyl prostaglandin E2 (50 micrograms/kg s.c., 30 min before, and every 6 hr after, the administration of bromobenzene) did not modify the disappearance curves of unchanged bromobenzene from plasma and liver, and did not modify the amount of bromobenzene metabolites covalently bound to hepatic proteins 1-24 hr after the administration of a toxic dose of bromobenzene (0.36 ml/kg i.p.). The prostaglandin, however, markedly reduced serum alanine aminotransferase activity, the extent of liver cell necrosis, the depletion of glutathione, and the disappearance of cytochrome P-450 after administration of this toxic dose of bromobenzene (0.36 ml/kg i.p.). It also markedly reduced mortality after administration of a lethal dose of bromobenzene (0.43 ml/kg i.p.). We conclude that 16,16-dimethyl prostaglandin E2 can prevent hepatic necrosis without decreasing the covalent binding of bromobenzene metabolites to hepatic proteins. The mechanism for this dissociation between covalent binding and toxicity remains unknown.