Stimulation of intestinal cytokinetics and mucin turnover in rats fed wheat bran or cellulose.
Rats were fed defined diets containing no fiber, 10% wheat bran or 10% cellulose, and intestinal morphology and cytokinetics were assessed by light microscopy and autoradiography, respectively. In bran-fed animals, there were no differences in morphological appearance of the jejunum, in the number of cells/villus column or in numbers of goblet cells compared to controls. Autoradiographic analysis, at one and 24 h after [3H]thymidine, however, suggested an increased turnover and villus transit of intestinal cells. There was also a 2.5 fold increase in incorporation of labeled sulfate, and a 2-fold increase in [3H]glucose incorporation into total intestinal glycoproteins and mucins. Similar, albeit less dramatic results were obtained in rats fed diets containing cellulose. These studies provide evidence that diets containing certain fiber derivatives can alter aspects of intestinal cell turnover, and support the earlier morphological observations suggesting increased goblet cell secretory activity in response to feeding these fiber derivatives.