Munehiro Tetsuguchi

The purpose of this study was to investigate the effects of amino acid drink which contains so much the branch chain amino acid on physical activity during aerobic exercise in college students. As a results, the amount of maximum oxygen uptake during exercise showed the low value compared with other drinks by amino acid drink ingestion. It was admitted that the increasing rate of the blood lactic acid concentration immediately after movement was stopped with the drinking of an amino acid drink before exercise. The rate of perceptive exertion showed the lower value by amino acid drink ingestion compared with other drinks. In conclusion, it was suggested that amino acid drink ingestion before the exercise was expected effects such as improvement in movement efficiency, control of" blood lactate acid concentration and mitigation of fatigue.

Physiological effect of L-arabitol was investigated by feeding Sprague-Dawley male rats for four weeks with a diet containing 2.5% L-arabitol in comparison with the control diet, containing cellulose. The weights of kidney and cecum increased, while adipose tissue decreased significantly in spite of no difference in their body weights.

We intended to know how the partially hydrolyzed guar gum affects the morphological fine structure of intestinal mucosa in rat. The Sprague-Dawley male rats were fed a diet containing 5% partially hydrolyzed guar gum (experimental diet) for 4 weeks; a significant increment in the weight of the cecum and in its contents, and a significant decrement in the fecal weight were observed in comparing with those fed a 5% cellulose diet (control diet). The transit time of gastrointestinal tract was extended by the partially hydrolyzed guar gum supplementation. The surface structures of ileal and cecal mucosa changed markedly to the abnormal in the rats fed the experimental diet; their microvilli of experimental diet group were more tightly packed than those of the control, and more intestinal contents adhered to the tops of the microvilli in the experimental diet group. When rats were fed a diet containing 1% partially hydrolyzed guar gum together with 4% cellulose, the effects of the partially hydrolyzed guar gum were reduced, significantly. In conclusion, excess of a partially hydrolyzed guar gum exerted effects on the ileal and cecal mucosal surface structure.

We reported in the previous paper that rats fed a curdlan diet showed significant increases in the weight of the cecum and its contents, a decrease in fecal wet weight, a retardation in the transit time of the gastrointestinal tract, and morphological changes of the ileal and cecal mucosal surface when compared with the rats fed a cellulose diet. In the present study, we intended to learn if the curdlan effects on the morphological structure of intestinal mucosa were reversible. When rats were fed on the curdlan diet for 2 weeks followed by a cellulose diet for another 2 weeks, the cecum and cecal contents were not different from those of the cellulose group. The transit time of the gastrointestinal tract of the curdlan-followed-by-cellulose group was shorter than that of the curdlan group, whereas it was longer than that of the cellulose group. In scanning electron micrographs, the ileal villi of the curdlan-followed-by-cellulose group were normal, as in the cellulose group. However, their ileal and cecal microvilli were similar to those of the curdlan group, that is, the microvilli were crowded and more tightly packed, and some appeared to have been squeezed out. From these results, it was concluded that the effects of the curdlan feeding were only partially reversible, but the effects on the surface structure of intestinal mucosa were still sustained even after curdlan feeding of 2 weeks was discontinued. This might result from response to the high viscosity of the intestinal contents remaining after discontinuation of the curdian.

The effects of curdlan and gellan gum on the gastrointestinal function were studied, and the morphological structure of the intestinal mucosal surface was observed by scanning electron microscopy of rats fed curdlan and gellan gum diets for four weeks. The rats fed the curdlan diet showed a significant increase in the weight of the cecum and its contents and a decrease in fecal weight as compared to the rats fed a cellulose diet. On the other hand, the rats fed the gellan gum diet showed a weight loss in cecal contents and weight gain in colonic contents. The transit time of the gastrointestinal tract was extended by curdlan supplementation whereas it was shortened by gellan gum supplementation. The surface structures of the ileal and cecal mucosa were markedly abnormal in the rats fed the curdlan diet: the microvilli were tightly packed and had fallen out at places. In the gellan gum-fed rats, the tops of the ileal and cecal microvilli adhered to one another and were covered with their contents. There was no difference in the surface structure of colonic mucosa among the cellulose, curdlan and gellan gum diet groups.