The distribution of 3-hydroxy-3-methylglutaryl coenzyme A reductase in the small intestine of rats fed raw or gelatinized starch as a carbohydrate source.

Abstract

SummaryThe effect of gelatinization of dietary starch (wheat, corn and potato) on the distribution of 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase along the small intestine of rats was studied in villus and crypt cell populations isolated by graduated scraping. Gelatinized starch preferentially stimulated jejunal reductase activity in both villus and crypt cells and consequently retained the ileojejunal gradient for the reductase activity which is characteristic for rats fed on a sucrose or glucose-enriched semi-purified diet. The distribution of the reductase in rats fed the raw starches, however, depended on the degree of gelatinization of the preparations; raw wheat starch maintained the ileojejunal gradient, whereas the corn or potato starch eliminated the gradient, and with the latter in particular, the reductase activity tended to be higher in the ileum than in the jejunum. The digestibility of dietary starches seems to be closely related to the intertissue distribution of the intestinal HMG-CoA reductase activity.

Comparative Effects of Non-Gelatinized Corn and Rice Starches on the Life-Span of ICR Mice

“…15,16,20) It has also been demonstrated that the gelatinization of dietary starches affected the glycemic response 21) and intestinal enzyme activity in rats. 22) Given these observations, it is necessary to compare the effects of starches of various origins on the various physiological processes to understand the mechanism behind the divergent effects of corn and rice starches on the life-span of mice. It is also required to examine the effect of the degree of starch gelatinization on the life-span and on various physiological parameters, inasmuch as humans consume starches as cooked meals.…”