B. Reddy, K. Watanabe, J. Weisburger
Sep 1, 1977
Citations
1
Influential Citations
459
Citations
Quality indicators
Journal
Cancer research
Abstract
The promoting effect of sodium cholate or sodium chenodeoxycholate on colon carcinogenesis was studied in female F344 germ-free and conventional rats. Both germ-free and conventional rats received intrarectal instillations of N -methyl- N ′-nitro- N -nitrosoguanidine (MNNG) for 2 weeks (total dose, 8 mg/rat) and then intrarectal doses of sodium cholate or sodium chenodeoxycholate (20 mg/rat/dose) three times a week for 46 weeks; other groups received MNNG for 2 weeks and vehicle thereafter for 46 weeks or bile acids alone for 48 weeks. Sodium cholate or sodium chenodeoxycholate increased MNNG-induced adenocarcinomas and adenomas in germ-free rats, whereas in conventional rats these bile acids induced more adenomas. Conventional rats treated with MNNG + sodium cholate or MNNG + sodium chenodeoxycholate had a higher incidence ( p 0.05) frequency of colon tumors than did those given MNNG alone. No tumors were detected in the colons of germ-free and conventional rats given sodium cholate or sodium chenodeoxycholate alone. It is concluded that sodium cholate or sodium chenodeoxycholate had a promoting effect in colon carcinogenesis in rats evoked by MNNG.