The Standard Food Tables of Japanese Foods was newly revised in 2000, and contains information on all of the vitamins except biotin. Thus, we carried out a survey of vitamin intake in Japanese women who were university seniors majoring a dietitian course. The subjects (n=33) consumed self-selected foods, and food intake was recorded by the weight method. We calculated the vitamin intake except for biotin from the food records using the Standard Food Tables of Japanese Foods. In terms of daily intake, vitamin A was 705±435μg (mean±SD), vitamin D 6±8μg, vitamin E 7, 7±3.0mg, vitamin K 191±156μg, vitamin B1 0.7±0.3mg (0.43±0.15mg/1, 000 kcal), vitamin B2 1.1±0.4mg (0.65±0.18mg/1, 000 kcal), vitamin B6 0.9±0.4mg (0.017±0, 005mg/g protein), vitamin B12 4.4±4.1μg, niacin equivalent 23±7 mg (14.4±4.9mg/1, 000 kcal), pantothenic acid 4.6±1.4mg, folic acid 267±115μg, and vitamin C 73±38mg. All of these averages were around the Japanese Recommended Dietary Allowance (RDA) for level “III (preferable)” of physical activity. Major vitamin A resources were vegetables; vitamin D resources, fish; vitamin E resources, fats and oils and vegetables; vitamin K resources, vegetables; vitamin B1 resources, cereals and animal meats; vitamin B2 resources, various foods; vitamin B6 resources, cereals, vegetables, fish, and animal meats; vitamin B12 resources, fish; niacin equivalent resources, fish, animal meats, and cereals; pantothenic acid resources, various foods; folic acid resources, vegetables; and vitamin C resources, vegetables and potatoes. From this survey, it was found that Japanese women college students consumed many kinds of food, and therefore, their vitamin nutrition was good as compared to the RDA values for level III of physical activity; however, their energy intake (1, 622±3 77 kcal) was lower than the RDA for level III (2, 050 kcal/d). Their strength of physical activity would be level I. Therefore, in consideration of their lifestyle, their energy intakes is considered adequate. In conclusion, a problem for student lifestyle is a shortage of food intake due to lack of exercise.
Thiamin pyrophosphokinase catalyzes the pyrophosphorylation of thiamin to thiamin pyrophosphate in the presence of ATP and Mgtt The kinetic properties of human thiamin pyrophosphokinase (hTPK1) were investigated using purified histidine-tagged recombinant protein. The plots of the initial velocity against MgATP concentrations gave a sigmoidal character when Mg2+/ATP was maintained at 1. However, the addition of an excess amount of Mg2+ resulted in the restoration of activity at lower concentrations of MgATP A steady-state kinetics study led us to conclude that the kinase reaction obeys a ping-ong mechanism. Site-directed mutagenesis was also performed on hTPK1 to examine the contributions of eight strictly conserved residues in thiamin pyrophosphokinase on the kinetic properties. Mutations D71N, D73N, and D100N reduced kcat markedly, indicating that these aspartic acids play a crucial role in carrying out the catalytic process of hTPK1. A selective decrease in the kcat/Kmthiamin value was observed in the D133N mutant, whereas the kcat/KmATV values of T99A and R131G were significantly decreased. Interestingly, the replacement of Gln-96 with Glu caused an increase in the kcat/Kmthiamin value (3.53-fold of the wild-type). It was therefore suggested that the residues Gln-96, Thr-99, Arg-131, and Asp-133 are conserved as functionally significant components for substrate recognition in thiamin pyrophosphokinase.
(-)-Hydroxycitric acid (HCA) is a competitive inhibitor of the enzyme ATPci-trate-lyase, which inhibits lipogenesis in the body. Moreover, HCA increases endurance exercise performance in trained mice and athletes. However, had not been investigated in untrained animals and humans. Therefore, we investigated the effects of short-term HCA ingestion on endurance exercise performance and fat metabolism in untrained women. In two experiments designed as a double-blind crossover test, six subjects ingested 250 mg of HCA or placebo (same amount of dextrin) via capsule for 5 d and then participated in cycle ergometer exercise. They cycled at 40% VO2max for 1h and then the exercise intensity was increased to 60% VO2max until exhaustion on day 5 of each experiment. HCA tended to decrease the respiratory exchange ratio (RER) and carbohydrate oxidation during 1 h of exercise. In addition, exercise time to exhaustion was significantly enhanced (p<0.05). These results suggest that HCA increases fat metabolism, which may be associated with a decrease in glycogen utilization during the same intensity exercise and enhanced exercise performance.
This paper studies the effects of soy oligosaccharides on plasma and cecal isoflavones and floral enzyme activities in adult mice. The isoflavones used in this experiment were daidzein and genistein. Male 6-wk-old mice were fed a soy oligosaccharide-isofla-vone (SOT) diet or cellulose-isoflavone (CEI) diet for 10 d. Plasma and cecal isoflavones were analyzed by HPLC, and cecal bacterial β-glucosidase and β-glucuronidase activities were also measured. The plasma genistein concentration was significantly higher in the SOT diet group than in the CEI diet group, but no significant difference was observed in plasma daidzein concentration between the two dietary groups. The total amount of cecal isoflavones existing as aglycone were significantly greater in the SOT diet group than in the CEI diet group, and both cecal β-glucosidase and β-glucuronidase activities were significantly higher in the SOT diet group than in the CEI diet group. These results indicate that soy oligosaccharides have an impact on the metabolic activity of intestinal microflora, plasma concentrations of isoflavones, and amount of isoflavones in the intestine. The present study suggests that ingestion of soy oligosaccharides may influence the effect of dietary isoflavones on the host.
While severe protein energy malnutrition (PEM) has been known to depress several immune functions, allergies are suppressed by decreasing IgE and impairing vascular permeability and mast cell functions. To address the effect of moderate protein malnutrition without growth arrest and protein hypernutrition on type I allergy, we examined the effect of various levels of protein nutrition on allergy at humoral immunity and the regulation of Th cell function levels. Mice fed 100g/kg (moderate protein malnutrition; MPM), 200g/kg (normal protein nutrition; PN) and 400g/kg (protein hypernutrition; PH) protein diets were intraperitoneally sensitized to ovalbumin (OVA) in aluminum hydroxide. Higher elevations of OVA-specific IgE and total IgE in the serum were observed in the PH group as compared to the PN group. However, OVA-specific IgE in the MPM group was not significantly different from that in the PN group, although the former appeared higher than the latter. While CD3, CD4, CD8 and B220 expressions in the splenic lymphocytes were decreased in the MPM group, B220 expressions were increased in the PH group. Splenic lymphocyte proliferative responses to OVA were augmented in the PH group and depressed in the MPM group. IFN-yproduction from splenic lymphocytes was significantly decreased; however, IL-4 production was not affected significantly in the MPM group, and increased in the PH group. These findings suggest that immune functions to specific antigens in the MPM state are depressed at the cytokine level but not in terms of IgE responses. They also suggest that immune functions become Th2-predominant in the PH state, resulting in an increased risk of type I allergy.
Besides functioning as a mucosal barrier and transporting nutrients, intestinal epithelial cells (IECs) also serve as antigen-presenting cells (APCs). Modification of protein antigens by proteolysis is one of the principal steps in antigen presentation to Th cells. We used a Caco-2 intestinal epithelial cell line to investigate the transepithelial transport of the dietary antigen, ovalbumin (OVA). We also examined the effects of the proinflammatory cytokine interferon-γ (IFN-γ) on the antigen transport process in Caco-2 cell layers. Caco-2 cell layers transferred both intact and degraded OVA from the mucosal to the serosal side. IFN-γ stimulated OVA transport and most of the transported OVA in such cells were degraded. We also examined OVA uptake by Caco-2 cells using immunohistochemical means. Caco-2 cells incorporated OVA in a time-dependent manner and IFN-γ significantly enhanced antigen internalization. Flow cytometry also demonstrated that IFN-γ elevated the internalization of FITC-OVA. We also determined the effects of low and high concentrations of IFN-y on mucosal permeability and internalization of FITC-OVA. Althoughh both 10 and 50ng/mL IFN-γ stimulated mucosal permeability to the same extent, more FITC-OVA was internalized by Caco-2 cells incubated with 50 than with 10ng/mL IFN-y. These results suggest that the effects of IFN-γ on mucosal permeability and the internalization of antigens by intestinal epithelial cells are brought about by different mechanisms. Therefore, higher concentrations of IFN-γ stimulate the uptake, processing, and transport of dietary antigens by IECs.
Platelet-derived growth factor (PDGF) plays an important role in the pathogenic course of atherosclerosis, pulmonary fibrosis, and gloerulonephritis, and increased activity of the PDGF signaling pathway has been implicated as a contributing factor in the progression of the diseases. Taurine may be a prophylactic amino acid for atherosclerosis not only by decreasing plasma cholesterol level, but also by inhibiting the cell proliferation signaling pathway. To elucidate how taurine affects the signaling pathway, we investigated the effect of taurine on the expression of immediate-early genes and activation of mitogenactivated protein kinases (MAPKs) in NIH/3T3 cells as standard mesenchymal cells. Tau-rine inhibited PDGF-BB-induced c-fos and c-jun mRNA expressions dose-dependently, although structural analogues of taurine did not. Taurine decreased the PDGF-induced p44/p42 ERK (extracellular signal-regulated kinase) phosphorylation state dose-depen-dently, although no phosphorylation was observed on JNK/SAPK (c-Jun N-terminal kinase/ stress-activated protein kinase) and p38 MAPK. Further, PDGF-BB-induced tyrosine phos-phorylation of the PDGF-β receptor was not influenced by treatment with taurine, indicating that taurine never affects ligand-receptor interaction, and may act downstream of the PDGF receptor. Thus, the inhibitory mechanism of taurine on PDGF-induced c-fos and c-jun mRNA expressions may depend on the p44/p42 ERK pathway, but not on PDGF-β receptor tyrosine phosphorylation, JNK/SAPK or p38 MAPK pathway, These results suggest that taurine may suppress the cell proliferation-signaling pathway through the inhibition of ERK activity and immediate-early gene expression.
The presence of a significant amount of 9, 11-conjugated linoleic acid (CLA, 9, 11-18%2) was confirmed in the liver and plasma lipids of rats fed a 1% (w/w % of diet) eleo-stearic acid (ESA, 9, 11, 13-18 e 3 ) diet for 4 wk, The chemical structure of the 9, 11-CLA apparent in the tissue lipids was identified by gas chromatography-electron impact mass spectrometry after its conversion to a 4, 4-dimethyloxazoline derivative. The concentration of CLA in the total fatty acids of the liver and plasma lipids reached to about 1% for each in the CLA-supplemented rats, while reaching 3.2% and 2.5%, respectively, in the ESA-supplemented rats, The results suggest that α-ESA is metabolized partially to CLA via a delta 13-saturation reaction in the rat. Some biological activities observed in α-ESA-fed animals may be ascribed also to CLA that is formed from ESA in the body.
The balance of minerals (sodium [Na], potassium [K], calcium [Ca], and magnesium [Mg]) was measured in six female students for 10 d while under a relatively low Na intake (100mmol/d or 2.2g/d) with receiving adequate Ca (20mmol/d or 800mg/d) and Mg (12mmol/d or 280mg/d), Both the plasma renin activity (PRA) and aldosterone level were above the reference ranges throughout the experiment, which implied that the subjects were Na deficient. However, the urine Na excretion was about the same as that ingested, while there was no substantial reduction of sweat Na concentration observed during moderate physical exercise (13.2±2.6mmol/L) (mean±SD), On the other hand, the urine Ca and Mg levels were high, but the apparent absorption of Ca and Mg was moderate (21±5%, 34±4%, respectively), which resulted in a negative balance of these two elements. It seems that the stored Na in the bone is eluted so as to compensate for the low dietary Na intake, while any excess Ca and Mg also inevitably flows into the blood stream with Na, which inhibited the intestinal absorption of both Ca and Mg and accelerates their excretion in urine.
The effect of dietary supplementation with n-3 fatty acids, primarily docosa-hexaenoic acid (DHA) With high purity, on the fatty acid composition, especially very-long-chain fatty acids (VLCFA) longer than DHA, with four or six double bonds, in the rod outer segment (ROS) membranes of young Sprague-Dawley rats was investigated. After several weeks of feeding, diets high in n-3 fatty acids increased the DHA level significantly, while there were decreased levels of most n-6 fatty acids, such as arachidonic acid and 22:5n-6. Six kinds of VLCFA Were detected by gas chromatography-mass spectrometry (GC-MS). Feeding a high n-3 fatty acid diet significantly increased the content of some n-3 VLCFAs such as 26:4n-3 and 30:4n-3 in ROS membranes, but not all detected n-3 VLCFAs. This study demonstrates that the dietary level of n-3 fatty acids not only affects the level of DHA, but also the levels of VLCFA in ROS membranes.
We investigated the effect of palatinose on mental concentration using the Uchida-Kraepelin psycho diagnostic test. A significant increase (p<0.01) in calculation ability was observed in both the sucrose and palatinose groups after administration. Although calculation ability in the sucrose group at 150 min decreased from the level achieved at 90min in the same group, that in the palatinose group at 150min decreased only slightly from the level achieved at 90min. At the same time points, significant increases were observed even when 5g of palatinose was administered.