Repeated partial hepatectomy as a promoting stimulus for carcinogenic response of liver to nitrosamines in rats

Abstract

Partial hepatectomy 24 h before a single i.p. dose of dimethylnitrosamine, diethylnitrosamine or ethylmethylnitrosamine increased the carcinogenic response in the liver of rats as determined by the number of tumors and the number of focal proliferations produced. In rats given a single i.p. dose of diethylnitrosamine, 3 partial hepatectomies 5, 10 and 15 wk after dosing the animals increased the carcinogenic response in the liver. The stimulus of repeated partial hepatectomy appears to act as a promoting agent for liver carcinogenesis, i.e., if the single dose of diethylnitrosamine is regarded as an initiating agent in terms of the 2-stage hypothesis.