Decreased glutathione S-transferase activity in mice livers by acute treatment with lead, independent of alteration in glutathione content.

Glutathione S-transferase (GST) activity and glutathione content in livers of male mice were assayed after acute administration of lead acetate (100 mg/kg i.p.). Fall in GST activity of lead-treated mice followed the decrease in glutathione content with a delay of more than 1 day. In addition, L-methionine (250 mg/kg i.p.) pretreatment did not antagonize the fall in GST activity induced by lead. In contrast, diethyl maleate, a potent glutathione depletor, increased GST activity. Thus, lead administration reduced the ability of the phase II reaction of drug metabolism, although glutathione depletion was not necessarily a critical factor for impairmen of GST per se.