Butyrate and the colonocyte : effect on cellular events and role in protection against colon cancer /
Colon cancer is a common and deadly human disease that is
| Main Author: | |
|---|---|
| Format: | Thesis Book |
| Language: | English |
| Published: |
[Place of publication not identified] :
[publisher not identified] ;
1997.
|
| Subjects: | |
| Online Access: | http://proxy.library.tamu.edu/login?url=http://proquest.umi.com/pqdweb?did=736824771&sid=1&Fmt=2&clientId=2945&RQT=309&VName=PQD |
| Summary: | Colon cancer is a common and deadly human disease that is strongly linked to dietary and environmental factors, both in initiation and progression of tumorigenesis. Dietary fibers and one of their byproducts, butyrate, are alternately linked to prevention or promotion of tumor development. Poorly fermented dietary fibers, such as wheat bran or cellulose, are believed to be protective. Conversely, highly fermented fibers, such as pectin or oat bran, may not be protective. Butyrate production by fiber fermentation may be an important part of its protective effects, because of the apparently different effects butyrate has on normal versus transformed colonocytes. Thus, this investigation was undertaken to study the effects of two different fibers, wheat bran and oat bran, and their fermentation by-product, butyrate on luminal pH, intracellular pH, cell cycle indices and apoptosis in freshly isolated colonocytes and on the development of tumors in a rodent model of colon cancer. The results of this investigation have addressed several major issues relating to colon cancer development and dietary fiber supplementation. Rats consuming oat bran diets produced the largest concentrations of butyrate, yet developed significantly more and larger tumors than rats consuming wheat bran diets. Oat bran rats also had lower luminal pH values, which was predicted to be protective, but was not correlated with decreased tumor incidence. Intracellular pH was more alkaline in carcinogen injected rats fed wheat bran diets, while in saline rats there was no difference in intracellular pH between diets. Thus, reduction of intracellular pH, presumably by the presence of increased SCFA was not protective. Finally, neither diet nor carcinogen treatment had a significant effect on cell cycle position (e.g. percentage of S phase cells) or apoptosis. In conclusion, these data show that while diets containing wheat bran fiber bran fiber are not, it is not luminal butyrate concentrations that are of primary importance to this effect. |
|---|---|
| Item Description: | Vita. "Major Subject: Nutrition". |
| Physical Description: | xiv, 227 leaves : illustrations ; 28 cm. Issued also on microfiche from University Microfilms Inc. |
| Bibliography: | Includes bibliographical references: pages 149-180. |