title: Seasonal change and sex difference in drug-metabolizing activity in frog liver microsomes.
abstract: The drug-metabolizing activities (aminopyrine N-demethylase and p-nitroanisole O-demethylase activities) have been measured at monthly intervals throughout the year in liver microsomes of male and female Japanese bullfrogs, Rana catesbeiana. The aminopyrine N-demethylase activity based on cytochrome P-450 of both sexes was significantly higher in May-July (spring-summer) than in August-October (summer-autumn). On the contrary, the p-nitroanisole O-demethylase activity based on cytochrome P-450 of males was significantly higher in July-October (summer-autumn) than in May-June (spring). However, there was no seasonal changes in the O-demethylase activity in females. There were significant differences between males and females in the N-demethylase activity in August-October and in the O-demethylase activity in May-June (or July-October).
mesh_terms: D000064:Acclimatization; D000633:Aminopyrine N-Demethylase / Q000378:metabolism*; D000818:Animals; D003577:Cytochrome P-450 Enzyme System / Q000378:metabolism*; D005260:Female; D008297:Male; D008862:Microsomes, Liver / Q000201:enzymology*; D009575:Nitroanisole O-Demethylase / Q000378:metabolism*; D010088:Oxidoreductases / Q000378:metabolism*; D011892:Rana catesbeiana; D012621:Seasons; D012737:Sex Factors
chemical_list: D003577:Cytochrome P-450 Enzyme System; D009575:Nitroanisole O-Demethylase; D010088:Oxidoreductases; D000633:Aminopyrine N-Demethylase