Mixed function oxidase system in hepatic and extrahepatic tissues of developing chickens following various treatments.

Alterations in hepatic and extrahepatic protein content, activities of drug enzymes, lipid peroxidation and hydrogen peroxide formation and levels of microsomal electron transport components were examined in developing chickens during treatment with phenobarbital (PB), benzene and 1,1,1,-trichloro 2,2, bis (p-chlorophenyl) ethane (DDT) treated group of 4-8 weeks old chickens. Activities of hepatic and extrahepatic (kidney, lung, intestine) tissues enzymes were induced during PB treatment in all groups of chicken. However benzene and DDT treated group of chickens recorded decrease in activities of drug enzymes. Magnitude of increase due to PB administration was much more in liver as compared to kidney, lung and intestine. Hydrogen peroxide and lipid peroxide formation significantly increased in all tissues during treatments of benzene and DDT. Levels of cyto P-450, cyto b5 and cyto c-reductase, lipid peroxidation and hydrogen peroxide formation increased in all groups of chickens during various treatments. The results suggest that chicken liver contains more drug enzyme activities and electron transport components during development as compared to other tissues. Benzene and DDT administration resulted into decrease in the activities of drug enzymes.

Hepatic mixed function oxidase system and effect of phenobarbital, 3-methylcholanthrene and 1, 1, 1-trichloro-2, 2-bis(p-chlorophenyl)ethane in developing chickens.

Contents of hepatic microsomal protein, aminopyrine N-demethylase, acetanilide hydroxylase, aniline hydroxylase, hydrogen peroxide formation, cytochrome-c-reductase, cytochrome b5 and cytochrome P-450 were examined in control, phenobarbital (PB), 3-methylcholanthrene (3-MC) and 1, 1, 1-trichloro-2, 2-bis(p-chlorophenyl)ethane (DDT) treated group of 1-28 days old chickens. Increase in aminopyrine N-demethylase, acetanilide hydroxylase, aniline hydroxylase, cytochrome-c-reductase, cytochrome b5 and cytochrome P-450 was noticed at all stages of development during administration of PB and 3-MC. But these enzyme activities were not always paralleled by increase in age. Aminopyrine N-demethylase was increased in early stages only during DDT administration, which indicates that the form of cytochrome P-450, responsible for aminopyrine N-demethylation is present in early stages only. However, acetanilide hydroxylase was decreased in all stages of development, in postnatal development the basal activities of the enzymes for various substrates do not exhibit identical pattern, the degree of inducibility by inducers varied in relation to age of animal. Hydrogen peroxide formation increased in all stages of developing chickens due to the administration of PB and DDT. It however decreased due to 3-MC administration which may be due to induction of high spin cytochrome P-450.