Preliminary Study On Microsomal Cytochrome P450 Enzymes In Chickens

The biochemical determinations of hepatic microsomal enzymes in vitro and the metablism of a probe drug in vivo were conducted to evaluate the activities of microsomal cytochrome P450 enzymes in chickens. Induction of Phenobarbital and dexamethasone on hepatic microsomal cytochrome P450 in chickens was investigated in this paper. The results were summarized as follows:1 Study on methodology for the determination of activities of hepatic microsomal cytochrome P450 enzymes in chickensTwelve 60-day-old cocks were sacrificed by cutting off jugular vein. Liver microsome was distilled by different velocity centrifugation. The Bradford method was used to measure the concentration of protein in hepatic microsome. The activities of Cytochrome P450 were measured by spectrophotometer analysis. The results showed that the concertration of protein in hepatic microsome was 11.32±1.43 mg·g^-1, the content of cytochrome P450 was 0.71±0.08 nmol·mg^-1, NADPH -Cytochrome C reductase activity was 3.01±0.26 nmol·mg^-1·min^-1, aminopyrine-N-demethylase activity was 2.36±0.18 nmol·mg^-1·min^-1, erythromycin-N-demethylase activity was 1.21±0.11 nmol·mg^-1 ·min^-1, and aniline-4-hydroxylase activity was 0.25±0.03nmol·mg^-1·min^-1. The results suggested that the established methodology for determing the content and activities of hepatic microsomal cytochrome P450 enzymes in chickens was sensitive and credible.2 Study on pharmacokinetics of antipyrine probe after intravenous administration in chickensPharmacokinetics of antipyrine probe was studied in twelve healthy chickens after intravenous administration at a single dose of 20 mg·kg^-1. Antipyrine concentration in plasma was determined by a reversed phase high performance liquid chromatography method. The results showed that excellent line relationship was obtained in the range of 0.1 to 30μg·mL^-1 with a correlation coefficient of 0.9995. The lowest detection limit of antipyrine was 0.1μg·mL^-1. The mean recovery rate at the quantitative concentrations of 0.5,1.0,20μg·mL^-1 was 93.44%, 95.88% and 97.21%, respectively. The intra-day and inter-day RSD were both less than 5%. The concentration-time data of antipyrine were fitted to a two-compartment open model. The main parmacokinetic parameters were as...