Effect of several chemicals added to a diet on intestinal enzyme activities of rats.

Abstract

The effects of anionic surface-active agents or of a laxative agent and dietary fiber added to a 20% casein high sucrose diet on changes in body weight, food consumption and gastrointestinal functions of rats were studied and compared with those of polyethyleneglycol 4000(PEG) and polyoxyethylene sorbitan monolaurate (Tween 20) reported in the previous study by Kimura, T., Furuta, H., Matsumoto, Y:, and Yoshida, A. (J. Nutr., 110, 513(1980)). And the effects of these chemicals on intestinal enzyme activities, localized in the brush border membrane of the small intestine, in vitro were investigated. The effects of sodium laurylbenzenesulfonate(LBS) added to the diet on changes in the body weight, food consumption, feces and intestinal sucrase and alkaline phosphatase activities were more adverse than those of PEG or Tween 20, and the adverse effects of the former were not prevented with the concurrent feeding of Gobo dietary fiber(GDF) or soybean dietary fiber(Okara), although those of the latter two were prevented with the concurrent feeding of these dietary fibers. The massive addition of sodium stearate or sodium oleate to the diet did not produce any adverse effects on changes in the body weight, food consumption, feces and intestinal enzyme activities. The addition of magnesium sulfate, a laxative agent, to the diet induced diarrhea without significant changes in the body weight, food consumption and intestinal enzyme activities, and the induced diarrhea was not prevented with the concurrent feeding of GDF. Intestinal alkaline phosphatase activity in vitro was not affected by PEG, Tween 20, LBS or magnesium sulfate, but intestinal leucine aminopeptidase activity in vitro was inhibited by PEG, Tween 20, LBS or sodium oleate. Although intestinal sucrase and maltase activities were inhibited by LBS alone, the inhibition-effect of LBS on the sucrase activity was more severe than that of LBS on the maltase activity. From the experimental results, the mechanism by which these chemicals and dietary fiber exerted their effects on physiological functions was discussed.