[Changes in the epithelial permeability of the large intestine of mice in the process of carcinogenesis].

1,2-dimethylhydrazine (DMH), a colon carcinogen, being injected weekly to BALB/c mice, inhibits an active sodium transport, increases the transepithelial passive ion permeation and decreases ion selectivity in the descending colon. A single DMH injection leads to the same alterations, manifested for a month, followed by normalization of all the parameters to the control value. Distinctive, wavy changes in electrophysiological parameters were noted after a single injection of "non-colon" carcinogen 7,12-dimethyl-benz(alpha)antracen. It is supposed that the prolonged drop in active sodium transport, transepithelial resistance and ion selectivity are specific reactions of the colonic epithelium to carcinogenic treatment with DMH.