Stimulation of the mouse hepatic microsomal aniline p-hydroxylases by acetone and polyamines

The effects of acetone +/- spermine on the high (AH-I) and low (AH-II) affinity forms of aniline hydroxylases in the mouse hepatic microsomes were investigated under in vitro conditions. The addition of either acetone or spermine alone stimulated both AH-I and AH-II activities at low concentration while some decline in stimulation was noted at higher concentrations. In the presence of both the modifiers the observed monoxygenation rates were greater than those produced by any one enhancer alone for AH-I and more than additive for AH-II. The results suggest that the enhancement of aniline p-hydroxylation by the acetone and spermine in the mouse hepatic microsomes involves at least two separate and possibly interdependent mechanisms.