[Effects of age and selected inductors of aromatic hydrocarbon hydroxylase (AHH) activity in the rat liver].

The effects of treatment with phenobarbital, beta-naphthoflavone and dexamethasone on 0,5, 1, 2, 4, 8, 12, 20 and 28 month old male Wistar rats was studied. The animals were treated intraperitoneally with phenobarbital (50 mg/kg; two times), beta-naphthoflavone (20 mg/kg; three times) or dexamethasone (10 mg/kg; three times). The rats were killed and Dallner method hepatic microsomes were isolated. In this fractions the protein by Lowry method and AHH activity according to Gelboin were determined. The AHH activity changes was not observed with age. In all studied animals (with 28 months old rats) phenobarbital inhibited AHH activity. The beta-naphthoflavone markedly increased the AHH activity; particularly in sex maturation and senescent. The dexamethasone injections also increased activity of the enzyme but in young rats only.