Influence of insecticide exposure on thein vivo andin vitro metabolic activity of rats

Abstract

Insecticides were administered to rats as single doses, oral and IP, at approximately 1/10 their acute oral LD₅₀ levels, or in the diet at concentrations where the daily intake was equivalent to the single doses. Carbofuran decreased the rate of urinary elimination of carbaryl-¹⁴C from rats whereas Ruelene tended to increase the rates. However, the changes were minor, 12% or less, and the nature of the carbaryl metabolites was not altered. Carbaryl and carbofuran caused a reduction in liver protein of rats injected with the carbamates for five days, but had no affect when fed in the diet for 40 days. DDT increased the liver protein when injected but not when fed in the diet. When administered in combination, by injection or in the diet, DDT and carbaryl did not modify the protein content of the liver. Liver and kidney microsomes of rats fed DDT in the diet, alone or with carbaryl, resulted in increased oxidase activity. Neither of the compounds affected microsomal glucuronidation of 1-naphthol. In a four-week feeding study, the rate of weight gain was 15% less in animals fed carbaryl plus Ruelene or coumaphos plus Ruelene than in the control rats. No significant difference from the controls was observed with carbaryl or carbaryl plus carbofuran. Feeding these compounds did not affect urine pH; but the urea content was increased by all treatments and the glucose content increased by all except treatment with coumaphos plus Ruelene.