Figure 1: Age-related differences in specific activities of biotransformation enzymes with oxidizing activity in rat liver. The white column represents young (6-week-old) rats, and the hatched column indicates old (21-month-old) rats. The activities of individual CYP isoforms were normalized to the total CYP content. Data of each age group represent the mean ± SD (six animals per age group) (*data with , Student’s t-test). CYP = cytochrome P450; FMO = flavine monooxygenase.