[Changes in rat liver enzymatic activity induced by CT 1341 (althesin) administration]

Six enzyme activities with different intracellular localization were selected for a study of the metabolic effects caused by CT 1341 (Althesin). Glucose-6-phosphato-phosphatasic, ATP-asic and aryl-4-hydroxylasic (hydroxylasic aniline) activities are in fact localised in the microsomial fraction whereas glucose-6-phosphato-dehydrogenasic, 6-phosphogluconic dehydrogenasic and UDP-glucoso-dehydrogenasic activities are to be found in the soluble fraction. The Althesin doses used varied between 0.75 and 6 mg/kg body weight, but only the latter dose is capable of triggering significant variations. With the exception of glucose-6-phosphato-phosphatase, which falls markedly, and ATPase which behaves discontinuously, the other enzyme activities increase to reach their maximum between the 15th and 30th minute after treatment. The diminution in glucose-6-phosphato-phosphatasic activity is attributable to a drug-induced change in the microsomial membranes. The increase in other activities, on the other hand, is connected with drug metabolisation. On a par with other steroid compounds, CT 1341 to be eliminated, must go through a hydroxylation reaction requiring higher production of NADPH. Its elimination also requires a higher concentration of UDP-glucuronic. The data obtained with separate injection of the active principles making up the drug did not give results in agreement with those obtained with the commercial product and, for the present, no final conclusions can be drawn.