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Volume 43 (1997)
- Issue 6 Pages 601-
- Issue 5 Pages 491-
- Issue 4 Pages 425-
- Issue 3 Pages 271-
- Issue 2 Pages 167-
- Issue 1 Pages 1-
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Volume 43, Issue 5
Displaying 1-11 of 11 articles from this issue
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Emiko SUZUKI, Tadao KURATA, Miho SHIBATA, Miki MORI, Nobuhiko ARAKAWA1997 Volume 43 Issue 5 Pages 491-496
Published: 1997
Released on J-STAGE: April 28, 2009
JOURNAL FREE ACCESSL-Xyloascorbic acid (L-xylo-ASA) and its three stereoiso-mers, D-xyloascorbic acid (D-xylo-AsA), L-araboascorbic acid (L-arabo-AsA) and D-araboascorbic acid (D-arabo-AsA), have been considered to show some differences in vitamin C activity. In this paper the effect of L-xylo-AsA, D-xylo-AsA, L-arabo-AsA and D-arabo-AsA on the activity of dopamine β-hydroxylase was studied to clarify whether or not the struc-tural specificities of these stereoisomers have different effects on enzyme activity. The maximum velocity (Vmax) of the hydroxylation and Km for ascorbic acid were calculated using double-reciprocal plotting. Vmax for L-xylo-AsA was estimated to be 201 nmol/min/mg protein and those of D-xylo-AsA, L-arabo-AsA and D-arabo-AsA were 157 nmol/min/mg pro-tein, 112 nmol/min/mg protein and 194 nmol/min/mg protein, respectively. Km for L-xylo-AsA was 1.5 mM and those for D-xylo-AsA, L-arabo-AsA and D-arabo-AsA were 2.3 mM, 2.7 mM and 1.4 mM, respectively. The effect of D-arabo-AsA on the activity of dopamine β-hydroxylase was almost the same as that of L-xylo-AsA, while D-xylo-AsA and L-arabo-AsA showed smaller effects. Our results suggest that the configuration at carbon 4 might be more important than that of the hydroxyl group at carbon 5 for the development of the activity as a cofactor for dopamine β-hydroxylase reaction.View full abstractDownload PDF (604K) -
Akihiko MATSUDA, Mieko KIMURA, Yoshinori ITOKAWA1997 Volume 43 Issue 5 Pages 497-504
Published: 1997
Released on J-STAGE: June 15, 2009
JOURNAL FREE ACCESSThe purpose of this study was to determine both the seleni-um (Se) level and glutathione peroxidase (GSH-Px) activity in plasma, erythrocytes and platelets from 51 healthy Japanese individuals. The Se levels (mean±SD) of plasma, erythrocytes and platelets were 117.4±15.7 μg/L, 0.954±0.159 μg/g hemoglobin, and 4.93±1.52 μg/mg protein, respectively, and GSH-Px activity was 318±50 U/L, 18.0±5.0 U/g he-moglobin, and 0.142 ±0.035 U/mg protein, respectively. There was a negative correlation between age and the platelet Se level in men (γ=-0.761, p<0.001), and a positive correlation between the plasma and platelet GSH-Px activities in women (γ=0.663, p<0.001).View full abstractDownload PDF (816K) -
Yasuhiro KIDO, Takayoshi TSUKAHARA, Kazuhito ROKUTAN, Kyoichi KISHI1997 Volume 43 Issue 5 Pages 505-514
Published: 1997
Released on J-STAGE: April 28, 2009
JOURNAL FREE ACCESSIn a previous study, we reported that protein intake at the level of dietary protein allowance for Japanese adults, i.e. 1.08g/kg per day, was enough for recommended daily exercise. However, whether or not recommended daily exercise increases the protein requirement for young adults has not been examined. In this study, we investigated the effect of recommended daily exercise on the protein requirement under an isoenergetic state by a nitrogen balance method. After an adaptation period of 3 days, 12 healthy college students exercised for 10 days with a non-exercise control period of 10 days before or after the exercise period. They were given a maintenance level of energy and 0.64g/kg per day of high-quality mixed proteins, estimated as the average protein requirement for adults by the Ministry of Health and Welfare of Japan, throughout the experimental period. They performed treadmill running during the exercise period at about 65% of VO2 max for 25 or 40 min/d, which expended 200 or 300 kcal of extra energy, respectively. Although the exercise increased the dermal nitrogen loss, a compensatory decrease in urinary nitrogen excretion was observed. Consequently, the exercises (200 and 300 kcal/d) did not significantly affect the nitrogen balance. These findings indicate that the recommended amount of daily exercise does not change the protein requirement.View full abstractDownload PDF (1151K) -
Munehiro TETSUGUCHI, Shouko NOMURA, Masayuki KATAYAMA, Yohko SUGAWA-KA ...1997 Volume 43 Issue 5 Pages 515-527
Published: 1997
Released on J-STAGE: April 28, 2009
JOURNAL FREE ACCESSThe 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.View full abstractDownload PDF (2815K) -
Hiroko N MATSUMOTO, Asako YAMAMOTO, Tadahiro IIMURA, Shinichiro OIDA, ...1997 Volume 43 Issue 5 Pages 529-539
Published: 1997
Released on J-STAGE: April 28, 2009
JOURNAL FREE ACCESSThe aim of this study was to investigate the effects of ovariectomy (OVX) on intestinal alkaline phosphatase (ALP) activity in rats. The calcium (Ca) and phosphorus (P) contents and the mechanical strength of bone were decreased significantly by OVX. Two kinds of mRNAs of rat intestinal ALP (RTIN-1 and RTIN-2) were detected by reverse transcription-polymerase chain reaction (RT-PCR). In OVX rats, the level of RTIN-2 mRNA was lowered significantly, while that of RTIN-1 mRNA did not change. This result was compatible with the results of enzymatic activity. This finding suggests the possibility that OVX affects bone metabolism not only directly but also in an indirect way through an intestinal Ca and/or P metabolism via regulation of intestinal RTIN-2 ALP expression.View full abstractDownload PDF (1818K) -
Angela GARCÍA, Carmen PANTIGA, Serafina FERNÁNDEZ, Angel ...1997 Volume 43 Issue 5 Pages 541-551
Published: 1997
Released on J-STAGE: June 15, 2009
JOURNAL FREE ACCESSMonoamine synthesis and release depend on the availability of their precursors. Thus some individual behaviors and aptitudes can be controlled by changing the dietary supply of such amino acids. In order to determine the effects of diet on skills for a correct driving attitude, such as sleep latency, attention level, arousal and differences between sexes, we designed a crossover, double-blind trial with 50 volunteers from both sexes, aged 21-30, who ingested a protein enriched product or one composed only of carbohydrates. After 3 h, psychotechnical computerized tests were performed to assess ability to calculate speed, manual skills and vision coordination and concentration capability. No differences were seen in the performance of the tests after the ingestion of both products; thus, diet does not seem to influence behaviors involved in driving. Males performed better in tests involving space perception while females obtained higher scores in the test for visual memory.View full abstractDownload PDF (1199K) -
Hideo MAEDA, Kana MIYAMOTO, Toshiaki SANO1997 Volume 43 Issue 5 Pages 553-563
Published: 1997
Released on J-STAGE: April 28, 2009
JOURNAL FREE ACCESSThe effects of dietary field horsetail (Equisetum arvense L.) powder on lipid components were studied in rats fed a 20% casein diet with or without cholesterol (0.5% cholesterol and 0.15% sodium cholate) for 14 days. The ingestion of 0.4% or 4% Equisetum arvense L. powder did not influence food intake or growth. However, a cholesterol diet with
Equisetum arvense L. at 4% caused dermatitis at the neck, head and back in about 20-65% of the rats. This dermatitis was reversed when the diet was changed to commercial pellets. There were no apparent effects on serum or liver lipids in the rats fed Equisetum arvense L. irrespective of dietary cholesterol. Serum IgE levels measured by enzyme-linked immunoassay revealed that the induction of IgE may not necessarily be involved in the dermatitis caused by the intake of Equisetum arvense L. These results suggest that the ingestion of large amounts of Equisetum arvense L. as cooking material is not recommended for those with a cholesterol-rich diet.View full abstractDownload PDF (1517K) -
Takemi TANAKA, Sachiko TAKASE, Toshinao GODA1997 Volume 43 Issue 5 Pages 565-573
Published: 1997
Released on J-STAGE: June 15, 2009
JOURNAL FREE ACCESSLactase-phlorizin hydrolase (LPH), an enterocyte-specific disaccharidase, displays not only a post weaning decline but also regional differences in the small intestine. To investigate the mechanisms of regional LPH expression along the small intestine, the correlation between LPH mRNA abundance, lactase activity and the amount of a nuclear factor (NF-LPH 1) binding to a cis-element was determined in various intestinal segments of suckling and adult rats. In suckling rats, both LPH mRNA and lactase activity were expressed at maximum in the jejunum, but they were hardly detected in the colon. In adult rats, both LPH mRNA and lactase activity were the highest in the jejunum and virtually absent in the ileum. Lactase activity and LPH mRNA abundance in suckling rats were 2-3 times more than those of adult rats in all regions of the small intestine. An electromobility shift assays of nuclear proteins revealed that NF-LPH 1 was present in rat small intestine as well as in Caco-2 cells. The amount of NF-LPH 1 binding to the cis-element was also approximately 2-fold more in the intestinal nuclear extracts of suckling rats than that of adult rats. NF-LPH 1 was detected in all regions of the small intestine in both suckling and adult rats. In both cases, the amounts of NF-LPH 1 binding to the cis-element increased from the duodenum to upper jejunum, and decreased toward the ileum. The coordinate postnatal declines of LPH mRNA and NF-LPH 1 expression in various regions of the small intestine suggest that NF-LPH1 might be involved not only in the regulation of postnatal LPH gene expression but in region-specific LPH gene expression as well.View full abstractDownload PDF (1969K) -
Yuko MIYAGI, Sumie SHINJO, Ryoko NISHIDA, Chika MIYAGI, Kiyoharu TAKAM ...1997 Volume 43 Issue 5 Pages 575-580
Published: 1997
Released on J-STAGE: June 15, 2009
JOURNAL FREE ACCESSThe effect of trypsin inhibitor (TI) in soybean on the prevention of cancer has been reported in animal studies. However, the actual intake of active TI in daily life is not known. In this experiment we measured TI activity in various soybean products and the effects of some factors of processing on the TI activity. Average TI activity in whole soybean was 4, 819 U/100g, and the average percentages of remaining activity in products against that of whole soybean were momen-tofu 2.5%, yose-tofu 3.4%, kinugoshi-tofu 4.3%, jyuten-tofu 7.9%, soymilk 13.0%, natto 0.7%, soy sauce 0.8% and miso 0.3%. By heating soymilk at 100°C, TI activity decreased to 11% at 10 min and 5 % at 20 min. After heating soymilk in a water-bath for 15 min at 75 and 100°C, TI activity decreased to 35 and 12%, respectively. The TI activity of tofu was proportional to the remaining whey. The effects of chemicals used for the coagulation of soy protein and foam-removal on TI activity were little. The results suggest that soybean products retain 2.5-12.5% TI activity of the whole soybean and that humans are consuming some active TI in their daily lives.View full abstractDownload PDF (706K) -
Sumi SUGIYAMA, Kozo OHTSUKI, Kenji SATO, Makoto KAWABATA1997 Volume 43 Issue 5 Pages 581-589
Published: 1997
Released on J-STAGE: April 28, 2009
JOURNAL FREE ACCESSKiwifruit (Actinidia chinensis) contains abundant protease, actinidin, and two possible components which were named Al and A2. However, a comparison of the two components has not been thoroughly conducted. We have previously shown the presence of six proteases named KPI, KP2, KP3, KP4, KP5 and KP6 in kiwifruit, and that each purified kiwifruit protease was chromatographically pure. It was also indicated that the two representative components, KP4 and KP6, must be Al and A2. To establish whether or not the two proteases, KP4 and KP6, have the same specificity in proteolytic activity, their enzymatic properties were compared. Between the two proteases, differences in substrate specificity against several protein-substrates (casein, gelatin, collagen, ovalbumin and bovine serum albumin) were not observed by digestion-product analysis with sodium dodecyl sulfate-polyacrylamide gel electrophoresis. The kinetic parameters of KP4 against N-α-carbobenzoxyl-lysinep-nitrophenyl esters were different from those of KP6. The pH-activity profiles of KP4 and KP6 against S-3-trimethylaminopropyl-lysozyme, a wide-pH range soluble substrate, and N-α-carbobenzoxyl-lysine p-nitrophenyl esters were different.View full abstractDownload PDF (1989K) -
Naofumi MORITA, Jun SHIRAI1997 Volume 43 Issue 5 Pages 591-600
Published: 1997
Released on J-STAGE: June 15, 2009
JOURNAL FREE ACCESSThe effects of microcapsulated docosahexaenoic acid powder (hereinafter DHA powder) on some viscoelastic properties of wheat flour dough and loaf volume were studied. The addition of DHA powder in the range of 0.1 to 0.3% caused a significant increase in the loaf volume of bread after baking. Dough containing 0.2 or 0.3% DHA powder had greater modulus of elasticity, viscosity coefficient and relaxation time than that not containing DHA powder (control). Farinography revealed that DHA powder alone did not decrease the arrival and development times more than those of the control, but increased the stability time significantly. There was no considerable change in the gelatinization temperature or enthalpy of starch in the dough. The size of gas cells in crumbs baked with the DHA powder increased slightly. DHA powder suspension did not appreciably decompose on heating at 120°C for 30 min, nor in the fermentation or baking processes in a home baker.View full abstractDownload PDF (1595K)
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