Nutritional significance of intestinal sucrase activity in rats.

Abstract

A certain amount of evidence suggesting that the intestinal sucrase activity in rats plays an important role in the digestion and absorption of dietary sucrose has been obtained from many investigations (1-6). Little, however, indicates the physiological role of this enzyme activity in the nutritional condition at the level of the whole body. The present study was conducted to observe the effect of tris(hydroxymethyl)aminomethane (IRIS), an inhibitor of intestinal disaccharidase activity (7), added to a diet on changes in body weight, food consumption, fecal consistency and intestinal sucrase activity, and the effect of TRIS on digestive enzyme activities localized in the brush border membrane of the small intestine (8) in vitro. And from these experimental results the nutritional significance of intestinal sucrase activity in rats was discussed.Male rats of the Wistar strain were used, and the basal diet was a 20% casein high-sucrose diet (SCD) described in the previous study (9). Rats were fed on the basal diet ad libitum before initiation of the experiments. Thereafter they were fasted for 2 days, being refed on the experimental diet for 3 days. The experimental diets were SCD, the 20% casein high-starch diet (STD), and the 20% casein high-glucose diet (GD), the sucrose in SCD being replaced by a-starch and glucose respectively. The enzyme activities were determined in the manner described in the previous study (10). Statistical analysis was done by taking the least significant difference calculated according to the method of Snedecor and Cochran (11).In the preliminary experiments, the addition of TRIS at levels of 1 and more to SCD caused significant growth retardation, reduction in food consumption and diarrhea. As shown in Table 1, in experiment 1 the addition of TRIS at the 2% level to SCD produced significant reduction in body weight gain and food consumption, and diarrhea, whereas the addition of TRIS at the same level to STD did not produce any adverse effect, although changes in body weight and food consumption 485

Mechanisms of toxicities of some detergents added to a diet and of the ameliorating effect of dietary fiber in the rat.

“…These experimental results supported the suggestion that the primary cause of the adverse effects in rats fed on the diet containing these detergents was the exfoliating or releasing effect thereof on the brush border membrane, together with the inhibitory effect of some of these detergents on intestinal disaccharidase activities (4,14), and that the ameliorating effect of GDF on the adverse effects of Tween 20 and Tween 60 was produced by the physicochemical affinity of GDF with the brush border membrane, which exceeded the exfoliating or releasing effect of these detergents.…”

Mechanisms of adverse effect of amaranth feeding in the rat.

“…In consideration of these findings, the primary cause of the toxicity of amaranth feeding is suggested to be a moderate degree of exfoliating or solubilizing effects of dietary amaranth on the brush border membrane. On the other hand, inhibition of intestinal sucrase activity caused by Tris feeding, which was not accompanied with a significant exfoliation or solubilization of the brush border membrane, brought about severe gastrointestinal disturbance (10). These findings lent further support to the sugges tion that intestinal sucrase played an important role in nutritional significance .…”

“…The release of sucrase with amaranth-RBS perfusion was not so significant as compared with that of sucrase with sodium taurocholate and sodium deoxycholate-RBS perfusion (6), but was more remarkable than that of sucrase with Tween 20 and Tween 60-RBS perfusion (6). Figure 4 shows the release of alkaline phosphatase activity with Tris-RBS perfusion at the 0.25% level, at which the sucrase activity in vitro was completely inhibited by Tris (10). The release of alkaline phosphatase as well as sucrase with RBS perfusion shown in Fig.…”

“…The control group was perfused with RBS, and the experimental group was perfused with RBS for 60min, being followed with RBS containing 1% amaranth or 0.25% Tris. The concentrations of amaranth or Tris added into RBS were one-fifth of the toxic levels of these chemicals added to a high sucrose diet (3,10), since these chemicals in the diet were diluted one-half to one tenth in the lumen of the small intestine with drinking water and secreting water (4). Intestinal sucrase or alkaline phosphatase activities in the resulting perfusate were adopted as the criteria for exfoliation or solubilization of the brush border membrane.…”

Effect of feeding of raw winged bean seeds on gastrointestinal functions in rats.

“…And a significant reduction or inhibition of intestinal sucrase activity induced gastrointestinal disorders following nutritional disorders throughout the whole body (17)(18)(19)(20). The segmental alkaline phosphatase and leucine aminopeptidase activities, however, are known to be affected not only by quality but also the quantity of the diet consumed (13,14,17).…”