Sodium transport in a mouse model of colonic carcinogenesis.

Following 4 weeks of s.c. injections of 1,2-dimethylhydrazine, a carcinogen that produces colon cancer in CF1 mice, an increase in the unidirectional mucosal to serosal flux and net absorption of sodium was observed in the distal colon. This increase in sodium transport was amiloride sensitive. 1,2-Dimethylhydrazine treatment had no effect on sodium transport in the distal colon of DBA/2 mice, a strain which does not develop colonic malignant transformation. Although stimulation of sodium transport has been observed in cultured cell systems exposed to growth factors, similar changes in sodium transport have not previously been demonstrated in an intact epithelium at an early stage of carcinogenesis. The present study in mouse distal colon demonstrates that sodium transport is altered in 1,2-dimethylhydrazine-induced malignant transformation of the large bowel.