On the appearance of polyadenylate polymerase activity in blood serum of animals exposed to a short-term influence by N,N'-ethylenethiourea, a well known hepatic carcinogen: a preliminary report.

Daily intragastric administration of a carcinogen N,N'-ethylenethiourea (ETU) (85 mg/kg body wt, congruent to 0.1 DL50) leads to significant polyadenylate polymerase (PAP) activity in rat blood serum by the 10th day of experiment. A similar course of N,N'-ethyleneurea (EU) fails to affect this enzyme activity in the blood. Also, PAP activity is not registered in the blood serum of intact rats.