β-Glucuronidase activity in the serum and liver of rats treated with parathion

Abstract

Rats of either sex were administered 0.25, 0.50, or 1.0 mg/kg parathion daily for 4, 10, or 15 days. Twenty-four hours after the last administered dose, serum β-glucuronidase (β-Glu) activity in the females was increased above control activity at each time period and at each parathion dose, with the greatest increase after 15-day administration. In the males, activity was increased only after 15-day treatment. There was decreased β-Glu activity in liver at all timeperiods; the decrease was approximately the same for both sexes and was not dose-related. Serum cholinesterase in the females was inhibited after 4, 10, and 15 days of parathion administration; in the males the enzyme was significantly inhibited only after 10 and 15 days. In both sexes, the amount of inhibition was dose-related. Liver sections from these rats were examined histochemically for β-Glu activity with 6-bromo-2-naphthyl-β- d-glucopyruronoside as substrate. The β-Glu staining was less in all the sections from parathion-treated rats at each dose and each time period than in the sections from control livers. Paraoxon, Banol, and Mobam in concentrations of 4 × 10 −4 to 4 × 10 −6 m were used in studies of the in vitro β-Glu activity of rat serum and of liver homogenates. No changes in activity were noted.