Mixed-function amine oxidase of the rat hepatocyte nuclear envelope. Demonstration and effects of phenobarbital and 3-methylcholanthrene.
Mixed-function amine oxidase (EC 1.14.13.8) has been demonstrated in highly purified rat hepatocyte nuclear envelope . The enzyme was present in the nuclear envelope at a level 20 percent of that observed in microsomes. Induction studies indicated that nuclear envelope amine oxidase as well as its microsomal counterpart were refractory to the effects of phenobarbital and 3-methylcholanthrene. Phenobarbital administration increased the specific activity of the microsomal N, N-dimethylaniline N-demethylase and benzo[a]pyrene hydroxylase by 600 and 190 percent, respectively, but decreased the specific activity of the nuclear enzymes by 30-50 percent. In contrast, 3-methylcholanthrene increased the specific activity of benzo[a]pyrene hydroxylase in nuclear envelope and microsomes by 42- and 11-fold, respectively. The hydrocarbon also increased the microsomal and nuclear N, N-dimethylaniline N-demethylase by 40 and 60 percent, respectively, but the specific activity of microsomal and nuclear aniline 4-hydroxylase was decreased by 50 percent. Demonstration of amine oxidase in rat hepatocyte nuclear envelope implicates this enzyme in the toxicity and carcinogenicity of certain drugs and chemicals.
D000818:Animals; D004789:Enzyme Activation / Q000187:drug effects; D007425:Intracellular Membranes / Q000201:enzymology; D008099:Liver / Q000201:enzymology*; D008297:Male; D008748:Methylcholanthrene / Q000494:pharmacology*; D008862:Microsomes, Liver / Q000201:enzymology; D009685:Nuclear Envelope / Q000201:enzymology; D000587:Oxidoreductases Acting on CH-NH Group Donors / Q000032:analysis* / Q000378:metabolism; D010634:Phenobarbital / Q000494:pharmacology*; D051381:Rats; D011919:Rats, Inbred Strains
D008748:Methylcholanthrene; D000587:Oxidoreductases Acting on CH-NH Group Donors; C019668:amine oxidase, mixed function; D010634:Phenobarbital