A nuclear component interacting with a retinoic acid re-sponse element (RARE-β) derived from the all-trans-retinoic acid recep-tor β (RARβ) gene promoter was detected in the rat liver by gel-shift assay. Competition experiments using the competitors of the other retinoid response elements and non-specific sequences upon the binding of this hepatic component (HBC) to the RARE-β revealed that the binding of the HBC to the RARE-β was competed only by the self competitor, but not the other elements, suggesting that the HBC is specific for the RARE-β. Moreover, although the specific monoclonal antibodies for RARα, RARβ, and RARγ reacted and shifted up the DNA complexes of endogenous as well as recombinant RARs, the DNA complex with HBC was not subjected to the immunoreaction with the antibodies. Thus, newly identified HBC, which is distinct from the characterized retinoid receptors, may modulate retinoid signaling through its direct binding upon the RARE-β.

抄録全体を表示

To determine the vitamin B₂ supply, 62 athletes in various types of sports and 16 non-athletes were examined, using a weighed food record (7-day), α-EGR determination, microbiological blood, and HPLC urinary measurements. If the guidelines of 1.5 or 1.7mg/day vitamin B₂ or 0.6 mg/4, 184 kJ (GRDA) are defined for adequate status, all sports groups (M±SEM) are above this level. The vitamin B₂ blood concentra-tions show a range (mean) from 303-372 nmol/liter, which indicates that more than 90% of the athletes are above the reference value of 327 nmol/liter (mean). There is a correlation of r=0.49 between the vitamin B₂ intake (mean over 7 days) and the vitamin B₂ blood level. Determina-tion of vitamin B₂ blood concentration is characterized by good precision (C. V.±3.2%) and recovery (95.7%). The enzyme activation measure-ment (α-EGR) shows that all of the athletes are below the α-EGR reference value of < 1.50 (good supply). No significant correlations could be determined between α-EGR and vitamin B₂ intake, blood concentrations, and urinary excretion. The measurement also shows high precision (C. V. 1.7%). The Vitamin B₂ excretion in urine (μmol/g Cr.) was higher than the reference values for non-athletes in more than 90% of the athletes. There is a correlation of r=0.89 between the vitamin B₂ intake on the last day (Day 7) of the food record and the riboflavin excretion, and between vitamin B₂ in blood and urinary excretion of r=0.52. The C. V. of vitamin B₂ urinary measurement using HPLC is 2.5%, with recovery of 98.2%. Combined measurement of vitamin B₂ intake, blood concentration, and urine excretion appears to be a suitable proce-dure for determining the vitamin B₂ status. Most of the performance athletes were sufficiently supplied with vitamin B₂, compared to the reference values for non-athletes.

抄録全体を表示

We examined whether a modification of a starch into an α-amylase resistant form can lead to a reduction of postprandial glucose and insulin responses, and consequently to a change of lipid metabolism in liver and adipose tissue. For this purpose, a processed starch was prepared using a cornstarch (70% amylose and 30% amylopectin) and monoacylglycerol (monostearate; MS), forming monostearate-starch complex (MS-treated cornstarch). When we determined in vitro hydroly-sis of MS-treated cornstarch using α-amylase and intestinal microvillar α-glucosidases, the glucose production rate of the MS-treated cornstarch was slower than the non-treated cornstarch. Measurement of a trans-mural potential difference (ΔPD) evoked by the MS-treated cornstarch in everted rat jejunum showed that the absorption rate of glucose released from the MS-treated cornstarch was also remarkably slower than that from the non-treated cornstarch. The postprandial plasma insulin re-sponse to the MS-treated cornstarch was reduced, although plasma glu-cose response was unchanged. In a feeding study, two groups of five or six male Wistar-strain rats were fed defined diets containing 61.1% MS-treated cornstarch or 58.2% non-treated cornstarch ad libitum for 14 days. Food intakes during the period were similar between the two groups. Feeding the MS-treated cornstarch resulted in a significantly lower maltase activity in upper jejunum than did the non-treated corn-starch feeding. The activities of lipogenic enzymes-fatty acid synthetase (FAS), malic enzyme (ME), and glucose-6-phosphate dehydrogenase (G-6-PDH)-significantly decreased in epididymal adipose tissue of rats fed the MS-treated cornstarch. In the liver, FAS activity was lower in the MS-treated cornstarch group. The results indicated that MS-treated cornstarch was digested less rapidly, and lowered blood insulin response, consequently leading to a declined lipogenesis of adipose tissue and liver. This study suggests that the rate of intestinal hydrolysis of starch is an important determinant of metabolic responses such as glycemic and lipogenic responses to diets.

抄録全体を表示

The effects of water exercise, as a form of daily physical activity (water exercise in a warm water pool), on bone loss in healthy Japanese postmenopausal women have been cross-sectionally and longi-tudinally investigated from the viewpoint of preventing osteoporosis. In the cross-sectional study, the bone mineral density (BMD) of the lumbar spine (Z-score (%)) in the Veterans group (N=27), who had been exercising for 35.2 months on average, was significantly higher than that in the Newcomers (N=40), who had only begun to exercise 3 or 4 weeks before, and that in the Non-exercisers (N=30), serving as a control group. The rate of change in the BMD of the lumbar spine was -0.92%/ year in the Non-exercisers (N=30), +1.55%/year in the Veterans (N=20), and +2.16%/year in the Newcomers (N=15), based on BMD Z-scores. In the Exercisers groups, it was found that the rate of change in the BMD showed a slight increase rather than a decrease irrespective of the duration of menopause. On the other hand, in the Non-exercisers group, the rate of change in the BMD decreased slightly. The results of questionnaires showed that the subjects' general awareness of health and fitness in daily life was enhanced after starting the water exercise pro-gram. These results suggest that consistently participating in water exercise is an important factor in preventing bone loss, and moreover, appears not only to indirectly improve awareness of daily physical activity but also to promote health and improve daily life.

抄録全体を表示

Wistar rats (4-week-old) were administered with streptozo-tocin (45mg/kg) through tail veins. After 3 months, diabetic rats were divided into 2 groups. One group (EPA group, n=16) was fed a lipid-free diet (90%, w/w) plus lard (8%) and 90% pure eicosapentaenoic acid ethyl ester (2%) for 6 months. The other group (control group, n=16) was fed in the same way except that eicosapentaenoic acid ethyl ester was replaced by safflower oil. Twenty-four-hour urine was collected just before starting the experimental diets and during the 6-month experimen-tal period at monthly intervals. There were no differences in food intake and body weight between the two groups throughout the experiment. The mean microalbuminuria of the EPA group became significantly lower than that of the control group after 4 months on the diets through the end of the study (6 months). The mean microalbuminuria levels at the end of the study were 1.38mg/day in the EPA group (n=9) and 5.19mg/day in the control group (n=6) (p<0.01). Eicosapentaenoic acid administra-tion might retard the progression of diabetic nephropathy by reducing microalbuminuria.

抄録全体を表示

Porcine small intestine evolved a specific offensive odor only 0.5 to 1 day after storage at 20°C. We investigated the effects of Houttuyniae cordata (dokudami), refinery final molasses (RFM), green tea, and brown sugar on the evolution of methylmercaptan and ethanol, which were the main components of the volatiles which evolved from porcine small intestine in storage. Furthermore, we determined their antibacterial effect and deodorant activity against methylmercaptan, as possible factors in reducing the offensive odor. Addition of those materi-als reduced the offensive odor during storage. In particular, dokudami, green tea, and RFM markedly suppressed the evolution of methylmer-captan. RFM was most effective in suppressing the growth of bacteria. Dokudami had the highest deodorant activity, comparable to that of perilla leaves. However, the retardation of methylmercaptan evolution in situ cannot be simply explained by either of deodorant or antibacterial effect. It seems likely that the combined action of both effects affects the evolution of methylmercaptan in situ.

抄録全体を表示

We improved the analytical method for the detection of ascorbic acid in plasma by high-performance liquid chromatography (HPLC) with an electrochemical detector (ECD) to be more selective and rapid than the protocol previously used. Main improvements are as follows. Applied potential of ECD to obtain the maximal response for ascorbic acid was +450mV versus Ag/AgCl, but it was reduced to+ 350mV. In that condition, uric acid did not respond to ECD, and only ascorbic acid was detected. EDTA contained in sample extrac-tion/stabilizing solution gave the peak after the ascorbic acid. The addition of EDTA (0.2mM) to the mobile phase eliminated the EDTA peak. These two improvements gave the chromatogram in which the peak that appeared from the plasma sample was only ascorbic acid, and shorten the sample run time. Ascorbic acid in plasma was unstable even though the plasma was treated with methanol/EDTA: it decreased from 1.5 h at 4°C. However, the treated sample, which was placed at -14°C until the analysis was performed, gave the reliable ascorbic acid value at least up to 6 h. The data obtained from the HPLC-ECD method was consistent with those from the hydrazine method.

抄録全体を表示