Effect of 1.1.1 trifluoro-N-(2-methyl-4-phenyl sulfonyl) methane sulfonamide (Destun 50WP) on rat hepatic microsomal enzymes, aniline hydroxylase and amino-pyrine N-demethylase.

Investigations have been carried out to determine the effects of the herbicide 1.1.1 trifluoro-N-(2-methyl-4-phenyl sulfonyl) methane sulfonamide (Destun) on some hepatic microsomal drug metabolizing enzymes in rat. Administration of 100 mg herbicide/kg rat (i.p. or oral) resulted in a stimulation of aniline hydroxylase and p-aminopyrene N-demethylase activities by 1.3 fold and 1.6 fold respectively. A dose-related increase in enzyme activities was observed with a maximum effect at about 100 mg Destun/kg rat. The increased microsomal protein content, liver weight: body weight ratio and decreased sleeping time in the herbicide-treated animals indicated the possibility of Destun being an "inducer". Results of investigations on the kinetic properties of aniline hydroxylase and p-aminopyrene-N-demethylase on administration of Destun suggests that in addition to its inducer effect, the herbicide could stimulate the enzyme activities by decreasing the affinity of these enzymes for their respective substrates.