Trials to evaluate the biotransformation activity of the liver in calves using a simplified paracetamol test.

摘要

The aim of this investigation is to examine the use of paracetamol (as a model drug) test for calves. We examined if a precise determination of the pharmacokinetics of paracetamol (indirectly the activity of enzymes catalyzing the reaction of phase II of hepatic biotransformation) was possible using a simplified paracetamol test. The experiment was carried out on 15 healthy calves of BW (Black-and-White) breed. Paracetamol (5 mg/kg bw.) was administered per os on the tenth, twentieth and fourteenth days of the calves' lives. The concentration of a model drug in plasma was determined by the spectrophotometric method in 10, as well as 3 and 4 samples. Pharmacokinetic parameters were estimated using a non-compartmental method, via the TopFit computer program. The values of pharmacokinetic parameters of paracetamol estimated in "simplified variants" significantly correlated (r=0.874-0.985) with data obtained in a full test. The highest coefficients of the correlation was observed when the concentration of paracetamol was determined at 3, 4, 6 and 8 hours after the model drug administration. Summing up, it was determined that it is possible to evaluate precisely and indirectly the biotransformation activity in calves (activity of UDP-glucuronyltransferase and sulfonyltransferase) using a simplified variant of paracetamol test, based on the determination of the concentration of the model drug in 3-4 blood samples..