[Changes in the supramolecular structure of chromatin and pepsinogen synthesis in the gastric mucosa of rats undergoing N-methyl-N'-nitro-N-nitrosoguanidine-induced carcinogenesis].

A model of gastric tumour induced by N-methyl-N'-nitro-N-nitrosoguanidine (MNNG) in rats made it possible to detect essential alterations of chromatin-DNA-protein complexes, that is a weakening of the DNA-protein linkage. The changes appear at early stages of carcinogenesis and persist in induced adenocarcinomas of the stomach. Simultaneously an inhibition was established in pepsinogen synthesis during MNNG carcinogenesis, which reflects a damage in expression of functionally important genetic information. This fact shows a molecular-genetic connection between the process of the gastric mucosa malignization and a disturbance of physiologically important tissue-specific gene functions.