ABSTRACT
The objective of the present study was to investigate the in vivo effect of a single and repeated doses of some organophosphorous insecticides, Viz. Gusathione A, Dimethoate and cyolaneond some pyrethroid insecticides, Viz permethvin and AC, 227-705 commonly used in Egypt, on the liver and kidney tryptophan metabolizing enzymes: Kynurenine hydrolase KH and kynurenine aminotransferase KATE. The present study indicated that the tested insecticides caused alterations in the kynurenine metabolism with marked difference observed in the response of liver and kidney enzymes. Since these insecticides either inhibit or activate the kynurenine metabolizing enzymes, therefore we expect that exposure to these insecticides might lead to the accumulation of some tryptophan metabolites which are suspected to act as carcinogens or cocarcinogens in the process of carcinogenes is occuring in these organs