Increase of .BETA.-glucuronidase activity in the serum of rats administered organophonphate and carbamate insecticides.

An approximately 50-fold increase in serum beta-glucuronidase activity appeared 2 hours after the administration of such organophosphate insecticides as dichlorvs, diazinon and disulfoton and of a carbamate insecticide, carbaryl. The activities of other acid hydrolases in the serum such as ribonuclease, acid phosphatase, hyaluronidase and N-acetylglucosaminidase did not change significantly after the insecticide treatment. The response was related to the dose level and was evident after a single intraperitoneal dose of diazinon as low as 1.6 mg/kg. This appearence of an increase in beta-glucuronidase was retarded by pretreatment with SKF 525A, an inhibitor of drug metabolizing enzyme. When beta-glucuronidase was elevated by a large dose of diazinon, full response to a second dose of diazinon did not occur until approximately one month after administration of the first dose.