Sex-dependent difference in aryl hydrocarbon hydroxylase activity in mouse liver.

Sex difference was observed in the aryl hydrocarbon hydroxylase (AHH) activity of liver in the C3H/He strain of mice. Treatment with estradiol showed an increase in AHH activity in gonadectomized female mice, but not in males. Testosterone, however, lowered AHH activity in both the gonadectomized male and female. Following treatment with either estradiol or testosterone in neonatal stages, AHH activity increased in males, but not in females. A sex difference was observed also in the activity of NADPH-cytochrome c reductase, which was higher in the female, but not in the levels of cytochrome P-450 and benzo[a]pyrene (BP)-induced spectral changes.