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Volume 38, Issue 4
Displaying 1-11 of 11 articles from this issue
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Tetsunori KAWATA, Tomomi TAKADA, Fusako MORIMOTO, Naoko FUJIMOTO, Nobu ...1992 Volume 38 Issue 4 Pages 305-316
Published: 1992
Released on J-STAGE: April 28, 2009
JOURNAL FREE ACCESSThe state of vitamin B12-deficiency in rats was evaluated by determination of hepatic vitamin B12-dependent enzyme activities after the animals had fed on a vitamin B12-deficient soybean protein diet for 150 days. The effect of vitamin B12-deficiency on testicular tissue was also studied by morphological observations. Growth of vitamin B12-deficient rats was retarded and marked increase in urinary methylmalonic acid was observed. Vitamin B12 contents in the organs were depressed distinctly by the deficiency, especially in testes, vitamin B12 content decreased to 2.5ng/g. Hepatic methionine synthase and methylmalonyl-CoA mutase ac-tivities showed striking depression to 5% of the control rats and extreme vitamin B12-deficiency was confirmed. Testes weight also showed marked decrease together with their relative weight per 100 g body weight. Mor-phological observations of testes of vitamin B12-deficient rats revealed atrophy of the seminiferous tubules and aplasia of sperms and spermatids. The above results proved that vitamin B12-deficiency affected rat testes, and suggested that the rat could be the animal model for elucidation of themechanism of B12 action on testicular functions.View full abstractDownload PDF (2078K) -
Masayoshi SUGAWARA, Kunio SUZUKI, Kimiko ENDO, Yasuhito TASHIRO, Katsu ...1992 Volume 38 Issue 4 Pages 317-328
Published: 1992
Released on J-STAGE: April 28, 2009
JOURNAL FREE ACCESSThe effects of dietary fat and dietary fiber (DF) levels in diet on fecal flora, activities of three fecal enzymes, putrefactive metabo-lites, fecal mutagenicity and fecal properties were studied in eight healthy volunteers. They were given low fat and low DF diet (LF: fat energy ratio was 13.9%, and DF intake was 9.0g/day) for 10 days, high fat and low DF diet (HF: fat energy ratio was 52.7%, and DF intake was 7.1g/day) for 10 days, and high fat and high DF diet (HFF: fat energy ratio was 52.0%, and DF intake was 24.8g/day) for 10 days. No change of fecal flora at the bacterial group level was observed throughout the experimental period, except that the population of lactobacilli showed a tendency to increase in HF period. Fecal activities of β-glucuronidase, β-glucosidase and nitroreductase and some putrefactive products were unchanged between LF and HF, while these values decreased in HFF period. No significant change of fecal properties was observed between LF and HF, while by HFF supplementation fecal weight increased and fecal pH value was lower than that in LF and HF. Excretions of iron, zinc and calcium in feces did not increase by high DF supplementation.View full abstractDownload PDF (1110K) -
Yoko FUJIYAMA-FUJIWARA, Rumi UMEDA, Osamu IGARASHI1992 Volume 38 Issue 4 Pages 329-334
Published: 1992
Released on J-STAGE: June 15, 2009
JOURNAL FREE ACCESSThe metabolism of arachidonic acid (AA), eicosapenta-enoic acid (EPA), and docosahexaenoic acid (DHA) was examined in HepG2 cells, a human hepatoma cell line, and rat hepatocytes. The AA level in HepG2 cells was lower than in rat hepatocytes and incorporation of AA into HepG2 was also smaller than into rat hepatocytes. Both cells could not increase the level of cellular DHA by the addition of exogenous 22:5 (n-3); whereas, rat hepatocytes, but not HepG2 cells, increased the levels of AA from 20:3 (n-6) and EPA from 20:4 (n-3). In both cells, retroconversion of AA to 20:3 (n-6) occurred, but EPA was not retro-converted to 20:4 (n-3). These results suggested that the levels of AA and DHA in both types of cells, were regulated more severely than EPA and that the activity of fatty acid desaturation might be different between n-6 and n-3 families.View full abstractDownload PDF (531K) -
Kimio SUGIYAMA, Hirokazu KAWAGISHI, Akio TANAKA, Shigeru SAEKI, Satosh ...1992 Volume 38 Issue 4 Pages 335-342
Published: 1992
Released on J-STAGE: June 15, 2009
JOURNAL FREE ACCESSThe present study was undertaken to isolate component(s) which contributes to the hypocholesterolemic action of Ningyotake (Polyporus confluens) mushroom. The mushroom powder was extracted with 80% ethanol, and the extract and residue were fractionated into five fractions according to the solubility to solvents. When each fraction was added to a diet containing 1 % cholesterol and 0.25% sodium cholate and fed to rats, the plasma cholesterol level was significantly decreased only by ethyl acetate-soluble fraction. Therefore, ethyl acetate-soluble fraction was further fractionated by silica gel column chromatography. Two major compounds, which comprised 45.0% and 28.5% of the ethyl acetate-soluble fraction, were obtained in a pure form by the chromatog-raphy, and the compounds were identified as grifolin (2-trans, trans-farnesyl-5-methylresorcinol) and neogrifolin (4-trans, trans-farnesyl-5-methylresorcinol), respectively. The addition of grifolin and neogrifolin to the high cholesterol diet was found to lower plama cholesterol level significantly.View full abstractDownload PDF (744K) -
Katsumi IMAIZUMI, Keizaburo HIRATA, Mohsen ZOMMARA, Michihiro SUGANO, ...1992 Volume 38 Issue 4 Pages 343-351
Published: 1992
Released on J-STAGE: April 28, 2009
JOURNAL FREE ACCESSWhey preparations prepared from cultured milk by 19 Lactobacillus (2 species) and 20 Bifidobacterium (5 species) strains were examined for the effects of secretion and synthesis of bile acids in primary cultured rat hepatocytes. The stimulating effect of whey preparation on bile acid secretion depended on the species as well as the strains used for milk fermentation. Two strains belonging to L. casei SBT 2230 (LC2230) and B. longum SBT 2912 (BL2912) produced the whey which stimulates both the secretion of bile acid and the activity of cholesterol 7α-hydroxyl-ase, a rate-limiting enzyme for bile acid synthesis. When the cultured products by these two strains were given to rats for 14 days, the products from L. casei (LC2230) were found to stimulate the biliary secretion of bile acids. These results suggest that primary cultured hepatocytes were a useful experimental system as an initial screening for an active principle modulating cholesterol metabolism.View full abstractDownload PDF (839K) -
Yoko FUJIYAMA-FUJIWARA, Rumi UMEDA, Osamu IGARASHI1992 Volume 38 Issue 4 Pages 353-363
Published: 1992
Released on J-STAGE: June 15, 2009
JOURNAL FREE ACCESSEffects of sesamin and curcumin on Δ5-desaturation and chain elongation of polyunsaturated fatty acid (PUFA) were studied in rat primary cultured hepatocytes. When sesamin was added to culture medium containing 20:4 (n-3), rat hepatocytes after 24 h of incubation produced 20:5 (n-3) from 20:4 (n-3), whereas when incubated with 20:3 (n-6), the metabolite by Δ5-desaturation did not accumulate, and consequently, the ratio of 20:3 (n-6)20:4 (n-6) increased with the amount of sesamin added. Curcumin was more effective than sesamin in this respect. Both sesamin and curcumin interfered with chain elongation of PUFAs. An addition of 18:3 (n-6) or 18:4 (n-3) increased the cellular concentrations of 20:3 (n-6) or 20:4 (n-3), respectively, but the simultaneous addition of sesamin or curcumin inhibited the chain elonga-tion of C18 acids (the fatty acids with 18 carbons) into corresponding C20 and C18 acids. Similarly, the elongation from C20 of n-3 and n-6 families to C22 was also inhibited with sesamin and curcumin. These results suggested that: 1) sesamin and curcumin inhibited Δ5-desaturation of n-6 fatty acid, but not n-3 fatty acid in rat hepatocytes; 2) curcumin was more effective than sesamin; 3) chain elongation was also inhibited by sesamin and curcumin.View full abstractDownload PDF (1054K) -
Hisae SHINOHARA, Toshinao GODA, Sachiko TAKASE1992 Volume 38 Issue 4 Pages 365-374
Published: 1992
Released on J-STAGE: April 28, 2009
JOURNAL FREE ACCESSThe effect of jejunum-bypass operation on lactase in rat small intestine was examined. Three groups of four or five rats were designated as jejunum-bypassed, sham-operated and normal rats. All animals including normal rats received by pair-feeding 5% glucose/l% NaCI for 5 days following the operation; thereafter they were fed ad libitum the laboratory chow diet. Three weeks after the jejunal bypass operation, the proximal ileum exhibited a hypera plasia as evidenced by a concomitant increase in mucosal contents of both total proteins and DNA. The specific activity of lactase in this segment was significantly lower in the operated rats than sham-operated controls, whereas the specific activity of sucrase in this segment was significantly elevated. The reduction of lactase activity was also evident in the proximal jejunal segment as well as in the distal jejunum which was deprived of luminal nutrition, suggesting that some hormonal factor (s) might be involved in the decrease of lactase activity in jejunum-bypassed animals. Electroim-munoassay revealed that the amount of immunoreactive lactase also declined in the operated rats relative to the sham-operated controls. Our results thus suggest that lactase activity in residual ileum is not only unable to compensate for the loss of digestive-absorptive surface of jejunum, but lactase activity even decreases following jejunum-bypass operation.View full abstractDownload PDF (1028K) -
Nobuhiko ARAKAWA, Mihyang KIM, Megumi OTSUKA1992 Volume 38 Issue 4 Pages 375-380
Published: 1992
Released on J-STAGE: April 28, 2009
JOURNAL FREE ACCESSA high-performance liquid chromatographic (HPLC) method for determination of pyridinoline and its application to connective tissues are described. The chromatographic separation was accomplished by using Inertsil ODS-2 column and a mixture of 0.1M sodium phosphate and acetonitrile (75:25, v/v) containing sodium dodecyl sulfate (SDS) and ethylenediamine tetraacetic acid (EDTA) as eluent. The chromato-gram was developed isocratically and the eluted components were moni-tored with excitation at 295nm and emission at 395 nm. The pyridinoline in crude hydrolysate of connective tissues can be determined in 5 min, with as little as 1 pmol of sample. The present method is rapid, simple and can be used for the routine analysis of connective tissues such as cartilage, bone, Achilles tendon and aorta.View full abstractDownload PDF (537K) -
Tsutomu NAKAYAMA, Munetaka YAMADA, Toshihiko OSAWA, Shunro KAWAKISHI1992 Volume 38 Issue 4 Pages 381-390
Published: 1992
Released on J-STAGE: April 28, 2009
JOURNAL FREE ACCESSLipid peroxidation of liposome made of egg lecithin was induced by glucosone (D-arabino-hexos-2-ulose), a secondary product of Maillard reaction or glycation of protein. Lipid peroxidation was assessed with measurement of TBARS (thiobarbituric acid reacting substances), POV (peroxide value), and HPLC measurement of MDA (malondialde-hyde). EDTA and DTPA (diethylenetriamine-pentaacetic acid) in-hibited the lipid peroxidation assessed by each method described above, indicating involvement of metal ions. The observed reduction of Fe3+ to Fe2+ by glucosone might be a critical step of the lipid peroxidation. Our findings suggest a possible role of lipid peroxidation of low-density lipo-proteins (LDL) induced by glucosone in atherosis caused by diabetes mellitus.View full abstractDownload PDF (920K) -
Yoshiaki SONE, Chie MAKINO, Akira MISAKI1992 Volume 38 Issue 4 Pages 391-395
Published: 1992
Released on J-STAGE: April 28, 2009
JOURNAL FREE ACCESSWe studied the effects of oligosaccharides which were obtained from tamarind xyloglucan by cellulase digestion on absorption of 3-O-methyl-D-glucose using the everted sacs from rat small intestine. Among oligosaccharides tested, octasaccharide and nonasaccharide, which contain D-galactose residue at non-reducing terminals, inhibited effectively absorption of 3-O-methyl-D-glucose, and their inhibitory effects were concentration-dependent. On the other hand, heptasaccharide not having D-galactose residue at its non-reducing terminal showed no in-hibitory effect on absorption of 3-O-methyl-D-glucose. These results indicate that the octasaccharide and nonasaccharide may not only serve as a soluble dietary fiber with small molecular weight but also lower the blood sugar level.View full abstractDownload PDF (412K) -
Naoko HARADA, Shin-ichi SAITO, Kayoko MINAKATA1992 Volume 38 Issue 4 Pages 397-404
Published: 1992
Released on J-STAGE: April 28, 2009
JOURNAL FREE ACCESSWeaning rats were divided into two groups, one group being fed a vitamin E-deficient diet, and the other an α-tocopherol-containing (50mg/kg) control diet. Rats were killed at 1, 2, 3 and 4 months of feeding.
The following results were obtained.
1. Both plasma and liver α-tocopherol levels decreased greatly by feeding vitamin E-deficient diet for 1 month, and thereafter decreased gradually by continued feeding.
2. Somehow different results were obtained concerning liver perox-idation value by the method of analysis. In the case of chemilumines-cence, the value increased by vitamin E deficiency during the first 2 months, but thereafter, the value was almost unchanged. On the contra-ry, in the case of TBA-RS, the value increased gradually throughout the entire 4 months of feeding period.
3. Both plasma α-CPI level and pyruvate kinase activity increased by vitamin E deficiency, showing similar pattern of change with feeding period. Especially, marked increase of these values was observed in vitamin E-deficient rats fed for longer than 2 months, and differences from control groups were highly significant (in both cases, at 2 months, p<0.005, and at 3 and 4 months, p<0.001). And, in vitamin E-deficient group, including all the rats fed on test diet for 1 to 4 months, correlation between both values was very high, and was highly significant (r=0.9060, p<0.001).View full abstractDownload PDF (631K)
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