Dysproteinuria induced in rats by O,O,S-trimethyl phosphorothioate

Administration of a single oral dose of 60 mg/kg O,O,S-trimethyl phosphorothioate (OOS-Me), a malathion impurity, resulted in a substantial increase in the amounts of amino acids along with a change in the nature of proteins excreted in the urine of treated rats. In contrast to control rats, a small increase in albumin and a small decrease in alpha 1-globulin were observed. However, alpha2-, beta- and gamma 1-globulin, which were not detected in the urine of control rats, were found in substantial amounts in the urine of OOS-Me-treated rats. These findings, coupled with observed increases in urinary glucose levels and consistent specific gravity readings of 1.01 even though treated rats were experiencing oliguria, provide evidence for OOS-Me-induced kidney tubule damage.