[The modification of the toxic effects of phenyl mercury by the adaptive reactions of the rat kidney. 1. Timely development of adaptation].

Doses of 0.5 mg/kg body weight, 1.5 mg/kg, 3.0 mg/kg, 7.5 mg/kg, and 15.0 mg/kg of phenylmercury acetate (PMA), as a model substance, were administered to Ico:WIST rats, over periods of 1, 5, 20, and 40 days, for the purpose of studying time-dependent and dose-related buildup of adaptive alterations in kidney. Substance-related damage to kidneys was assessed with reference to functional and morphological parameters. Application of organic PMA resulted exclusively in accumulation in kidneys of inorganic Hg, as had been shown by determination of residues. One single application of a toxic dose of phenylmercury acetate caused severe structural and functional necrobiotic damage. Repetitive applications caused renal damage in response to lower daily doses but caused also adaptation of kidneys to effect of higher doses. Adaptation was characterised by unambiguous reduction in necrosis, increase in regenerative cells in tubular epithelium, limited enzyme excretion in urine as well as restitution of impaired functional parameters and proteinuria. These findings are discussed in some detail, with reference being made to effects of other Hg compounds and possible mechanisms of adaptation.