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Volume 40 (1994)
- Issue 6 Pages 511-
- Issue 5 Pages 371-
- Issue 4 Pages 289-
- Issue 3 Pages 219-
- Issue 2 Pages 81-
- Issue 1 Pages 1-
Predecessor
Volume 40, Issue 3
Displaying 1-7 of 7 articles from this issue
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Nobuhiko ARAKAWA, Shino NEMOTO, Emiko SUZUKI, Megumi OTSUKA1994 Volume 40 Issue 3 Pages 219-227
Published: 1994
Released on J-STAGE: April 28, 2009
JOURNAL FREE ACCESSOrgan cultures have become an important method for the study of some of the biochemical reactions in which ascorbate takes part, and there are conflicting views on the stimulatory and inhibitory actions of ascorbate on cell growth. This study aimed to clarify the inhibitory mechanism of ascorbate using 3T6 fibroblasts. Cells were exposed to ascorbate at various concentrations in medium. The results showed that 3T6 fibroblasts were killed in medium containing more than 0.3mM ascorbate. This lethal effect of ascorbate on cells was inhibited by the addition of catalase, an enzyme that decomposes hydrogen peroxide (H2O2), to the medium. When the medium with ascorbate was incubated in the absence of cells, the amount of H2O2 generation depended on the ascorbate concentration, and decreased in inverse proportion to the serum concentration added to the medium. The addition of albumin, which is the main protein in serum, also inhibited H2O2 generation in the medium with ascorbate. However H2O2 generation was not inhibited completely by serum and albumin. These results indicate that cytotoxicity of ascor-bate is induced by H2O2.View full abstractDownload PDF (3903K) -
Yasuyoshi TORII, Kiyotaka HITOMI, Norihiro TSUKAGOSHI1994 Volume 40 Issue 3 Pages 229-238
Published: 1994
Released on J-STAGE: April 28, 2009
JOURNAL FREE ACCESSL-Ascorbic acid 2-phosphate (Asc-P: a stable ascorbic acid derivative) markedly stimulated synthesis of marker proteins for osteo-blastic differentiation such as alkaline phosphatase and osteocalcin in a murine osteoblastic cell line, MC3T3-E1, suggesting that Asc-P could promote osteoblastic differentiation. L-Azetidine 2-carboxylate (AzC) diminished the stimulatory effects of Asc-P on the synthesis of alkaline phosphatase and osteocalcin due to its inhibitory effects on mature colla-gen secretion. Growing cells on the dishes coated with type I collagen resulted in an increased expression of osteoblastic phenotypes even in the presence of AzC. Coating with fibronectin, however, failed to promote differentiation. These results suggest that the promotion of cell differen-tiation caused by Asc-P is mediated by the accumulation of mature collagen.View full abstractDownload PDF (1985K) -
Haruhito TSUGE, Motohide MAENO, Kayo NAGAE, Chie NOHISA, Takashi HAYAK ...1994 Volume 40 Issue 3 Pages 239-249
Published: 1994
Released on J-STAGE: June 15, 2009
JOURNAL FREE ACCESSBy using an HPLC method which we have developed, concentration changes of vitamin B-6 derivatives in blood of pregnant and lactating rats were studied. PLP and PL were the main derivatives in plasma and erythrocytes, and occasionally, PMP was found in the plasma of rats fed a normal solid diet which contained 8.3mg PN⋅HCl/kg diet. Upon pregnancy, the plasma PLP concentration decreased significantly (p<0.01), whereas plasma PL tended to increase (p<0.05). PLP con-centration in erythrocytes tended to increase upon pregnancy. These results suggest that metabolism or utilization of vitamin B-6 is altered upon pregnancy and that plasma PLP concentrations alone may not be a good indicator of nutritional status. Further confirmation was needed for the reliable determination of PMP because a large peak found at 7 min or so from erythrocyte samples under our analytical conditions was not converted to PIC-P via PLP, after the sample was treated with glyoxylic acid and then with KCN.View full abstractDownload PDF (1070K) -
Hidehisa TAKAHASHI, Nobuhisa WAKO, Tsutomu OKUBO, Noriyuki ISHIHARA, J ...1994 Volume 40 Issue 3 Pages 251-259
Published: 1994
Released on J-STAGE: April 28, 2009
JOURNAL FREE ACCESSA partially hydrolyzed guar gum preparation (PHGG, average molecular weight: 20, 000), obtained as a water-soluble dietary fiber by digestion of guar gum with β-D-endomannanase, was ad-ministered as a beverage (11g a day, bid) to 15 constipated women for 3 weeks. Defecating frequency, pH, weight, moisture, and bacterial flora of the feces were investigated and compared with the control periods. Average total dietary fiber taken from food was 9.7±0.1g/day during the experiment. PHGG caused an increase in the defecating frequency from 0.46±0.05 (frequency/day, M±SE) to 0.63±0.05. Fecal moisture signif-icantly increased from 69.1% in the control period to 73.8% by ingestion of PHGG. Fecal moisture content also increased consistent with lowering the pH of feces (γ=-0.478). The frequency of Lactobacillus spp. occurrence in feces significantly increased (p<0.05) compared with the control period. These results clearly indicate that PHGG softens and improves the output of feces.View full abstractDownload PDF (1010K) -
Li Jing JIU, Naomi MORIKAWA, Naomi OMI, Ikuko EZAWA1994 Volume 40 Issue 3 Pages 261-273
Published: 1994
Released on J-STAGE: April 28, 2009
JOURNAL FREE ACCESSIn this study, Tochu bark extract was examined to find out whether it is effective in preventing bone loss after menopause. Six-week-old Sprague-Dawley female rats were ovariectomized (OVX) or were sham-operated (sham). The rats in the OVX and the sham groups were fed a low-calcium diet (Ca 0.01%, P 0.3%) for 33 days. Thereafter, the rats in the OVX group were subdivided into two groups: a control group and a Tochu group. The diet for the Tochu group contained 2% Tochu bark extract (Ca 0.3%, P 0.3%). The diet for the control group and the sham group was the control diet; it contained 0.3% Ca and 0.3% P. The rats in each group were fed each experimental diet for the next 31 days. The bone mineral density (BMD) and the breaking strength of the control group were lower than those of the sham group. However, the BMD and the bone strength had improved in the Tochu group. These results suggest that the Tochu bark extraction could be effective in the prevention of osteoporosis. Moreover, in the Tochu group, intestinal Ca absorption increased. This means the Tochu bark extract accelerated the intestinal Ca absorption. This could possibly affect the increase of the BMD and the bone strength. Moreover, the muscle weight of the Tochu group was higher than that of the control group. These results suggest that Tochu bark extract is also effective for the improvement of the bone and the muscle metabolism in sedentary people with back pains and/or joint pains.View full abstractDownload PDF (1280K) -
Ikuo IKEDA, Youji IMASATO, Mioko NAKAYAMA, Katsumi IMAIZUMI, Michihiro ...1994 Volume 40 Issue 3 Pages 275-282
Published: 1994
Released on J-STAGE: April 28, 2009
JOURNAL FREE ACCESSLymphatic transport of stearic acid, given as completely hydrogenated rapeseed oil (R10), 9 to 1 (R9) and 5 to 5 (R5) mixtures of Rio, and soybean oil and completely hydrogenated tallow (T) was examined in the rat cannulated thoracic duct. R10, R9, R5, and T contained 91.4, 81.5, 46.5, and 63.6% stearic acid, respectively. A large portion of the remaining fatty acids in T was palmitic acid (31%). These fats were emulsified with bile salt and albumin, and administered via a stomach tube. Lymphatic recovery of stearic acid at 24h was lowest in R10 and highest in R5, and intermediate in R9 and T. Recovery of oleic and linoleic acids in rats given R5 was almost complete and significantly higher than that of stearic acid. When T was given, the 24 h recovery of stearic acid was significantly lower than that of palmitic acid. A highly inverse correlation between the recovery and the content of stearic acid in administered fats was observed in R 10, R9, and R5. Lymphatic recovery of cholesterol was almost parallel with that of stearic acid. Although the content of stearic acid in T was lower than that in R9, the recovery of stearic acid and cholesterol was almost similar. The results indicate that the rate of lymphatic recovery of stearic acid is affected by the quantity and quality of coexisting fatty acids.View full abstractDownload PDF (780K) -
Yuan Ying LIU, Yosuke SHIGEMATSU, Igor BYKOV, Akio NAKAI, Yoshiharu KI ...1994 Volume 40 Issue 3 Pages 283-288
Published: 1994
Released on J-STAGE: April 28, 2009
JOURNAL FREE ACCESSThe relative proportions (% of total fatty acids) of odd-chain (15:0-29:0) and long-chain (22:0-30:0) saturated fatty acids in phospholipids of biotin-deficient rat lymphocytes were significantly in-creased as compared with biotin-supplemented rats, and the ratio of unsaturated fatty acids to saturated fatty acids in the former was signifi-cantly decreased mainly due to the reduced composition of poly-unsaturated fatty acids in the ω-3, ω-6, and ω-9 pathway. The ratio of cis-vaccenic acid to palmitoleic acid in biotin-deficient rats was signifi-cantly lower than that in control rats, and was thought to be another important, but previously unreported indicator of biotin deficiency. These changes imply that the elongation and desaturation of unsaturated fatty acids are depressed in lymphocytes of biotin-deficient rats, and may contribute to the associated immunological dysfunction in biotin deficien-cy through abnormal prostaglandin metabolism and/or cell membrane functions.View full abstractDownload PDF (685K)
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