Effect of feeding and lighting on the regulation of aryl hydrocarbon (benzo[a]pyrene) hydroxylase activity in the liver, small intestine, and lung of mice.
The effect of feeding and lighting on the regulation of aryl hydrocarbon hydroxylase activity in liver, small intestine, and lung from C3H/He, DBA/2, and Swiss albino mice was investigated. A circadian rhythm of aryl hydrocarbon hydroxylase activity in the liver from DBA/2 mice was observed under the controlled lighting conditions, showing higher activity at the end of the light period of a day and lower activity in the dark period. Contrasting to the change of the enzyme activity in mice fed freely in the continuous dark period, inconsistent and variable results of the enzyme activity and its induction by 3-methylcholanthrene were observed in the mice that were fed during the continuous light period, depending on the sex and strain of the mice used. Different responses in the induction of aryl hydrocarbon hydroxylase to different routes of 3-methylcholanthrene administration were found between the liver and small intestine of the mice, but not in the lung. The higher levels of the enzyme activity induced in the liver and small intestine were detected after the intraperitoneal and intragastric administration of 3-methylcholanthrene. The significance of controlled feeding schedules for obtaining reproducible experimental results in the regulation of aryl hydrocarbon hydroxylase activity in the mice was discussed.
D000818:Animals; D001189:Aryl Hydrocarbon Hydroxylases / Q000378:metabolism*; D002940:Circadian Rhythm; D004435:Eating; D004790:Enzyme Induction; D005260:Female; D007267:Injections; D007274:Injections, Intraperitoneal; D007421:Intestine, Small / Q000201:enzymology*; D008027:Light; D008099:Liver / Q000201:enzymology*; D008168:Lung / Q000201:enzymology*; D008297:Male; D008748:Methylcholanthrene / Q000008:administration & dosage / Q000494:pharmacology; D051379:Mice; D008815:Mice, Inbred Strains; D010634:Phenobarbital / Q000494:pharmacology; D012737:Sex Factors; D013045:Species Specificity; D013270:Stomach
D008748:Methylcholanthrene; D001189:Aryl Hydrocarbon Hydroxylases; D010634:Phenobarbital