Effect of methylazoxymethanol acetate on adenylate cyclase and 5'-nucleotidase in rat liver plasma membranes.

A single tumorigenic dose of methylazoxymethanol acetate increased adenylate cyclase activity in total liver homogenates 70-100% by the seventh day after treatment. The increased activity occurred in the plasma membranes rather than in the nuclei and was accompanied by a significant increase in 5'-nucleotidase activity. The data indicate that the carcinogen may alter the structure of the plasma membrane.