鉄口 宗弘

本研究は,大阪府下のスポーツ系専門学校生女子5名を対象に,運動前に摂取した市販の分岐鎖アミノ酸を多量に含むアミノ酸飲料が,有酸素運動中の生体にどのような影響を及ぼすかについて検討することを目的にとした。その結果、運動中の酸素摂取量はアミノ酸飲料摂取により他の飲料に比べ開始から低い値を示した。また,アミノ酸飲料の運動前の飲水により運動直後の血中乳酸濃度の上昇率が抑えられることが認められた。さらに主観的運動強度は他の飲料に比べてアミノ酸飲料摂取でより低い値を示した。以上の結果より,運動前のアミノ酸飲料の摂取は運動効率の向上,血中乳酸濃度上昇抑制,疲労の軽減などの効果が期待できるものと示唆された。

L-Arabitolの生理効果をしらべるために,まず, Sprague-Dawley系雄ラット15匹を3群(1%L-arabitol, L-arabitol,5%L-arabitol)に分けて4週間飼育し,高用量では下痢になることを観察した.その結果に基づいて,本実験は2.5%のL-arabitolを含む飼料で4週間飼育し,対照群と比較検討した.対照群の飼料はレarabitolの代りにcelluloseを用いた.両群ラットの諸臓器重量を定したところ,L-arabitol群の脂肪組織が有意に小さく,一方,腎臓ならびに盲腸が有意に大きかった.また,盲腸と結腸の内容物も対照群に比べて意に多かった.これらの所見はL-arabitolが水溶性食繊維様の生理効果を有することを示唆している.

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.