The effects of a novel enzymatic hydrolysate of guar gum (GSF) on postprandial blood glucose level and intestinal transport were studied in mice and rats. GSF was obtained by partial hydrolysis of guar gum with β-mannanase from the alkalophilic bacterium, Bacillus sp. AM-001. GSF dosedependently inhibited the increase in the blood glucose level after sucrose- and starch-loading but not after glucose-loading. Unhydrolyzed guar gum inhibited the increase of blood glucose after both sucroseand glucose-loading and significantly retarded the gastric emptying ratio, whereas no effect on the gastric emptying ratio was observed in the GSF-administered mice. GSF stimulated intestinal transport in normal mice and rats and in mice with atropine-induced constipation, whereas unhydrolyzed guar gum had little or no effect. The fecal volume and moisture content of mice and rats increased when they were fed GSF. These results suggest that GSF may exert a beneficial effect on carbohydrate metabolism and gastrointestinal function in rats and mice, and that GSF differs from unhydrolyzed guar gum in some respects.

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Recently, Japan has become an aging society, increasing the importance of preventing postmenopausal osteoporosis. The present study was undertaken to determine the effect of voluntary exercise on bone metabolism in a rat model of postmenopausal osteoporosis. Eight-month-old Wistar-strain female rats were ovariectomized or given a sham operation. Thereafter, each rat group was further divided into non-exercise (control) and voluntary exercise (running) sub-groups. All rats were fed on a solid diet (1.2% Ca, 0.96% P) ad libitum for 170 days. The results obtained were as follows: Ia voluntary exercise groups within the ovariectomized and sham groups, the decrease of Ca absorption was alleviated for six months, the breaking force and Ca content of the femur increased and the ash weight of the femur were significantly higher than those in the control group. These results suggest that voluntary exercise could be effective for prevention of disturbances of bone metabolism in estrogen deficiency.

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Four-week-old male Wistar rats were fed a vitamin E (VE) -deficient diet for 8 weeks, followed by intraperitoneal injection of DL-buthionine- [S, R] -sulfoximine (BSO), an inhibitor of γ-glutamylcysteine synthetase, at l mmol/kg body weight. Rats in a glutathione (GSH) treatment group were intraperitoneally injected three times with GSH monoisopropyl ester at 1.7 mmol/kg body weight in addition to BSO administration. The TBA (2-thiobarbituric acid) value, GSH content, lipofuscin content and enzyme activities in the kidneys of rats, and BUN (blood urea nitrogen) content, creatinine content and LDH (lactate dehydrogenase) activity in their sera were measured. GSH depletion by BSO administration was accompanied by a decrease in the renal TBA value and a marked increase in the renal lipofuscin content. This increase in the renal lipofuscin content was prevented by GSH treatment. The increase in serum creatinine and the decrease in renal enzyme activities of rats administered BSO were inhibited by GSH treatment. GSH treatment did not completely prevent necrosis of the proximal renal tubule epithelia but such degeneration in rats treated with GSH was observed only in a narrow zone of the S₃ segment near the descending thin limb of Henle's loop. It seems that lipid peroxides produced by VE deficiency may cause the accumulation of lipofuscin in the presence of renal GSH depletion, followed by necrosis of the proximal renal tubule epithelia. These results suggest that GSH has an important role in preventing the production of lipofuscin by reaction of lipid peroxides with amino acids.

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The effect of vitamin E (VE, DL-α-tocopheryl acetate) on the development of hypertension was evaluated in two experiments using DOCA-salt hypertensive rats. ln the first experiment (Exp. 1), rats were fed on a commercial labaratory chow (CE-2), and VE (26 mg/rat) was administered orally every other day. In the second experiment (Exp. 2), rats were fed on purified AIN-76 diets; a low-VE diet (-VE), a basal VE diet (+4.5mg% VE) and a high-VE diet (+45mg% VE). Development of hypertension in DOCA-salt-treated rats was rapid in Exp. 1, but mild in Exp. 2. VE administration attenuated the increase in blood pressure only during the initial phase in Exp. 1. In contrast, the high-VE diet attenuated the increase in blood pressure throughout the experimental period in Exp. 2. The development of hypertension in rats given the low-VE diet was comparable to th at in rats given the basal VE diet. These results suggest that excess VE intake tends to attenuate the development of hypertension in DOCA-salt hypertensive rats, and that the effect is not necessarily attributable to its antioxidant effect.

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Browning of onion juice by heating was investigated. Raising of the temperature and pH (range: pH 3-8) enhanced the browning reaction. Addition of Fe³⁺ and Cu²⁺ to the onion juice enhanced the browning reaction, whereas Mn²⁺ and Zn²⁺ retarded it. Several components assumed to be involved in the browning reaction of onion juice were determined. Total free sugar, total free amino acid, and ascorbic acid contents were decreased, whereas reducing sugar, reductone, and 3-deoxyglucosone contents were increased in the course of heating. These results suggest that the heat-induced browning reaction of onion juice is not ascribable to an enzymic reaction, but to a nonenzymic reaction, i. e. degradation of sugars and/or reaction between sugars and amino acids.

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Water-soluble dietary fiber (SDF) and insoluble dietary fiber (IDF) isolated from apple pomace powder (AF) were prepared by the modified Asp method. The hypocholesterolemic effects of these materials were examined in rats fed hypercholesterolemic diets containing 1% cholesterol and 0.25% sodium cholate. Cellulose powder (CP) and AF were added to the diet at a level of 5% total dietary fiber. SDF and IDF were added to the diet at levels of 1.27% and 3.73% respectively. The diets were given to rats for 10 days. CP, AF, and IDF did not suppress the elevation of serum cholesterol levels, but SDF suppressed the elevation of serum cholesterol levels. SDF also tended to depress liver cholesterol accumulation and facilitated the excretion of neutral steroid. These results indicate that the mechanism of the hypocholesterolemic effect of SDF is prevention of dietary cholesterol absorption from the small intestine.

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Lipids, carotenoids and chlorophylls of the Iateral flower buds of six varieties of field-grown broccoli were investigated. The weight of the edible portion of the lateral flower buds of the broccoli ranged from 19g to 31g, the highest value being found in the Ryokuyo cultivar. The ranges of contents of total lipids and fatty acids per 100g fresh weight in different varieties of broccoli were 830-1051mg and 375-509mg respectively, the highest values being found in the Ryokurei cultivar. The values for carotenoids and chlorophylls were 3.43-8.66mg and 52.7-75.3mg, respectively, the highest values being found in the Chuseimidori cultivar. The proportion of n-3 essential fatty acids (18: 3) was relatively high, ranging from 59% to 63%. The contents of the fat-soluble components and the sizes of edible portions thus displayed characteristic variation among the varieties of broc- Coli.

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In a previous study, we observed that the growth of intestinal Bifidobacterium was selectively premoted by administration of 8g galactooligosaccharide per day. To determine the dosage of galactooligosaccharide (CUP OLIGO P, COP) necessary for the proliferation of fecal Bifidobacterium, fecal microflora, fecal moisture and pH were studied in eleven healty adult men (aged 25-60 years) given COP containing 2g galactooligosaccharide daily for 20 days. Total bacterial counts and percentages of Bifidebacterium spp. (p<0.01) were significantly increased during COP intake, whereas percentages of Bacteroidaceae were decreased.

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