[Effect of age on the activity of hepatic mixed function oxidases in female rats].

Female Wistar rats aged 5, 10, 15, 30, 60 and 540 days were tested. The rough and smooth microsomes fraction of the liver were tested for protein, cytochromes P-450 and b5 contents as well as for NADPH-cytochrome c reductase, NADH-cytochrome b5 reductase and two monooxygenases activity. Cytochrome P-450 and b5 contents and NADH-cytochrome b5 reductase activity were increasing up to the age of 60 but aniline hydroxylase--up to the age of 15 days. NADPH-cytochrome c reductase activity exhibited a gradual decreasing trend with age. In senescent animals (540 days) the contents of cytochromes and monooxygenases activity were lower but NADPH-cytochrome c reductase activity was higher, as compared to young rats.