Prevention by steroids of cerium hepatotoxicity.

In female rats, the lethality and hepatotoxicity of cerous chloride (CeCl3) were significantly altered by pretreatment with steroidal and nonsteroidal compounds (pregnenolone-16alpha-carbonitrile "PCN", dexamethasone, spironolactone, phenobarbital) that stimulate hepatic drug-metabolizine enzyme activity and by estradiol. PCN, estradiol, and dexamethasone considerably decreased hepatic triglycerides, but the latter steroid also greatly sensitized the animals to CeCl3 lethality. Spironolactone and phenobarbital similarly lowered the triglyceride level but not significantly. Light and electron microscopy indicated that the hepatocytic damage elicited by CeCl3 was decreased significantly by PCN, estradiol, and dexamethasone. The steroids may have altered the distribution and binding of the metal to the endoplasmic reticulum (er) thus protecting these membranes against the effect of cerium.