Influence of diet or intrarectal bile acid injections on colon epithelial cell proliferation in rats previously injected with 1,2-dimethylhydrazine.
The effects of varying colon bile acid concentrations on rat colon epithelial cell proliferation were studied. Bile acid concentrations were altered by intrarectally injecting either deoxycholic or lithocholic acid for 4 weeks or by increasing the dietary fat or fiber (wheat bran, agar, or carrageenan) intake for 4 weeks. 1,2-Dimethylhydrazine (DMH) was s.c. injected into half of the rats 1 week before treatments began. Colon epithelial cell proliferation was measured by [3H]thymidine autoradiography of colon crypts. Rats injected with DMH had more DNA-synthesizing cells per crypt. Neither bile acid injection nor any of the diets altered the number of DNA-synthesizing cells per crypt. DMH injections, deoxycholic and lithocholic acid intrarectal injections, and dietary agar and wheat bran all increased the total number of cells per crypt. High fat diets and dietary carrageenan did not affect cell number. All diets containing fiber lowered total fecal bile acid concentrations, but increasing the fat content of the diet did not affect them. These results indicate that the bile acid injections and dietary agar and wheat bran induce a slight hyperplasia in the colon.
D000818:Animals; D001345:Autoradiography; D001647:Bile Acids and Salts / Q000008:administration & dosage / Q000032:analysis / Q000494:pharmacology*; D002455:Cell Division / Q000187:drug effects; D003106:Colon / Q000166:cytology* / Q000187:drug effects; D003840:Deoxycholic Acid / Q000008:administration & dosage / Q000494:pharmacology; D004032:Diet; D004041:Dietary Fats / Q000008:administration & dosage; D004043:Dietary Fiber / Q000008:administration & dosage; D004127:Dimethylhydrazines / Q000008:administration & dosage*; D004847:Epithelial Cells; D004848:Epithelium / Q000187:drug effects; D005243:Feces / Q000032:analysis; D007279:Injections, Subcutaneous; D008095:Lithocholic Acid / Q000008:administration & dosage / Q000494:pharmacology; D008297:Male; D008763:Methylhydrazines / Q000008:administration & dosage*; D051381:Rats; D011919:Rats, Inbred Strains; D012007:Rectum; D013936:Thymidine; D014316:Tritium
D001647:Bile Acids and Salts; D004041:Dietary Fats; D004043:Dietary Fiber; D004127:Dimethylhydrazines; D008763:Methylhydrazines; D003840:Deoxycholic Acid; D014316:Tritium; D008095:Lithocholic Acid; D013936:Thymidine