Effects of various bile acids and their sodium salts on development of pepsinogen-altered pyloric glands in rats.

Effects of dietary bile acids and their sodium salts on the development of pepsinogen-altered pyloric glands (PAPG) were examined in male WKY/N Crj rats initially given a single dose of 160 mg/kg body weight of N-methyl-N'-nitro-N-nitrosoguanidine (MNNG) by gastric intubation. From week 3 the animals were administered basal diet containing 0.5% supplements of cholic acid (CA), deoxycholic acid (DCA), chenodeoxycholic acid (CDCA) or their sodium salts (Na-C, Na-DC and Na-CDC), or 5% ascorbic acid (ASA) or its salt (Na-AS) for 18 weeks. The concentration of DCA and Na-DC was reduced to 0.3% from week 12. At week 20, animals were killed and the numbers of immunohistochemically-demonstrated PAPG were determined. Values were significantly higher with Na-C and Na-CDC than with the corresponding parent acids, and in the Na-C case PAPG development was greater than with MNNG alone. In addition, Na-CDC itself induced the numbers of PAPG significantly. These results suggest that bile salts are possible intrinsic promoters of gastric carcinogenesis. They were without effect, however, on forestomach lesions.