Abstract: | It has been established for the first time that in extracts of the regenerating and preneoplastic (4 months after the beginning of carcinogen introduction) intestine as well as in the peritumor tissue the content of EPR-similar polypeptides and insulin raises, whereas in tumours it remains not high. Proteins with molecular weight greater than 120 kD able to compete with 125I-EPR for the binding with the receptors of EPR and being, evidently, the precursors of EPP are found in case of carcinogenesis. Besides, the content of insulin receptors rises, this process being most typical of the large intestine. |