[Effect of the type of nutrition on the dynamics and stages of morphological changes in the liver during experimental N-nitrosodiethylamine carcinogenesis].

The time course of the development of morphological changes was studied in the liver of rats given intraperitoneal injections of nitrosodiethylamine (NDEA) in a dose of 130 mg/kg, weekly, during 9 weeks, in the presence of full value hypocalorific (70% calorific value of the ration received by the control group), and hypercalorific (130% calorific value) nutrition. Four stages were distinguished in the development of the pathologic process under a chronic action of NDEA: I-alternative, II-alternative-proliferative, III--proliferative-tumorigenic, and IV--the stage of malignant growth. No matter what character of nutrition was, continuous NDEA administration induced the development of neoplasms in the liver 120 days after the commencement of the injections. The frequency of tumorigenesis rose significantly when NDEA was injected in the presence of hypo- or hypercalorific rations.