• Applied Biological Chemistry
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• v.13 no.2
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• pp.111-129
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• 1970

As a series of studies on the nucleic acids and their related substances 210 samples were collected from 76 places such as farm soil, compost of heap, nuruk and meju to obtain microbial strains which produce 5'-phosphodiesterase. From these samples total of 758 strains were isolated by the use of dilution pour plate method. For all isolated strains primary screening of the productivity of RNA depolymerase was performed and useful strains with regard to 5'-phosphodiesterase productivities were identified. For these useful strains optimum condition, the effect of various compounds on the activity of 5'-phosphodiesterase, and the optimum condition for enzyme reaction were discussed. The quantitative of 5'-mononucleotides produced by the action of 5'-phosphodiesterase was performed using anion-exchange column chromatography and their identified was done by paper chromatography, thinlayer chromatography, ultra violet spectrophotometry, and characteristic color reaction using carbazole and schiff's reagent. (1) Penicillium citreo-viride PO 2-11 and Streptomyces aureus SOA 4-21 from soil were identified as a potent 5'-phosphodiesterase producing strains. (2) Optimum culture conditions for Penicillium citreo-viride PO 2-11 strain isolated were found to be pH 5.0 and $30^{\circ}C$, and the optimum conditions for enzyme action of 5'-phosphodiesterase were pH 4.2 and $60^{\circ}C$. Best carbon source for the production of 5'-phosphodiesterase was found to be sucrose and ammonium nitrate for nitrogen source. Addition of 0.01% corn steep liquor or yeast extract exhibited 20% increase in the amount of 5'-phosphodiesterase production compared to the control. 5'-phosphodiesterase produced by this strain was activated by $Mg^{++},\;Ca^{++},\;Zn^{++},\;Mn^{++}$ and was inhibited by EDTA, citrate, $Cu^{++},\;CO^{++}$. 5'-phosphodiesterase produced 5'-mononucleotide from RNA at a rate of 65.81%, and among the 5'-mononucleotides accumulated 5'-GMP only was found to have flavorous and the strain was also found lack of 5'-AMP deaminase. Productivity of flavorous 5'-GMP was found to be 186.7mg per gram of RNA. (3) Optimum culture canditions for the isolated Streptomyces aureus SOA 4-21 strain were pH 7.0 and $28^{\circ}C$, and the optimum conditions for the action of 5'-phosphodiesterase were pH 7.3 and $50^{\circ}C$. The best carbon source for 5'-phosphodiesterase production was found to be glucose and that of nitrogen was asparagine. Addition of 0.01% yeast extract exhibited increased productivity of 5'-phosphodiesterase by 40% compared to the non-added control. 5'-phosphodiesterase produced by this strain was activated by $Ca^{++},\;Zn^{++},\;Mn^{++}$ and was inhibited by citrate, EDTA, $Cu^{++}$. It was also found that the strain produce 5'-AMP deaminase in addition to 5'-phosphodiesterase. For this reason although decomposition rate was 63.58% the accumulation of 5'-AMP, 5'-CMP, 5'-GMP and 5'-UMP occurred by the breakdown of RNA. In the course of these reaction 5'-AMP deaminase converted 60% of 5'-AMP thus produced into 5'-IMP and flavorous 5'-mono nucleotide production was significantly increased by this strain over the above mentioned one. Production rates were found to be 171.8mg per grain of RNA for 5'-IMP and 148.2mg per gram of RNA for 5'-GMP, respectively.

• Asian-Australasian Journal of Animal Sciences
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• v.20 no.8
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• pp.1297-1304
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• 2007

We conducted a series of investigations in order to elucidate role of nutritional status in regulating GLUT expression and energy metabolism in porcine muscle. Firstly, the role of mild undernutrition in regulating muscle GLUT gene expression and function was studied in growing pigs (3 wk of age) on a high (H) or low (L) food intake (H = 2L) at $35^{\circ}C$ or $26^{\circ}C$. Low food intake selectively upregulates GLUT1 and GLUT4 gene expression; mRNA levels were elevated in longissimus dorsi (L. dorsi) and rhomboideus muscles but not in diaphragm or cardiac muscles. Our next step was to determine whether dietary lysine, a major primary limiting amino acid in diets for pigs, affects muscle GLUT4 expression. Pigs of 6 wk of age were pair-fed a control or low lysine (LL) diet. The control diet contained optimal amounts of all essential amino acids, including 1.15% lysine. The LL diet was similar but contained only 0.70% lysine. GLUT4 mRNA expression was upregulated by the LL diet in L. dorsi and rhomboideus muscles, whereas that in cardiac muscle was unaffected. GLUT4 protein abundance was also higher in rhomboideus muscle of animals on the LL diet. We conducted another investigation in order to elucidate effects of the LL diet on post-GLUT4 glucose metabolism. Activity of hexokinase was unaffected by dietary lysine levels while that of citrate synthase was higher both in L. dorsi and rhomboideus muscles of pigs fed on the LL diet. Glucose 6-phosphate content was higher in L. dorsi msucle in the LL group. Glycogen content was higher both in L. dorsi and rhomboideus muscles in the LL group. Further, we determined the effects of dietary lysine levels on accumulation of intramuscular fat (IMF) in L. dorsi muscle of finishing pigs. A low lysine diet (lysine content was 0.40%) meeting approximately 70% of the requirement of lysine was given to finishing pigs for two months. IMF contents in L. dorsi of the pigs given the low lysine diet were twice higher than those of the pigs fed on a control diet (lysine content was 0.65%). Finally, we proved that a well known effect of breadcrumbs feeding to enhance IMF of finishing pigs could be attributed to shortage of amino acids in diets including breadcrumbs.

• Korean Journal of Microbiology
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• v.23 no.1
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• pp.69-76
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• 1985

This study was carried out to observe the formation of superoxide radicals and the changes in the activities of superoxide dismutase (EC.1.15.1.1.) from the various organs of a rat which was blocked tricarboxylic acid cycle. In order to block the tricarboxylic acid cycle, the beta-fluoroethylacetate was injected into peritoneal cavity of rat and removed the various tissues from the rat at internals of an hour. By tissue extracts being prepared by the method of Weigiger and Fridovich the activities of superoxide dismutase, aconitase, and contents of bliid glucose, citrates, and wuperoxide radicals were determined. The experimental results are summarized as follows: Accumulation of citrates if increased within three hours after treatment in the all tested tissues, especially, in the geart and spleen they are higher than one of other tissues as 12 and 20 times of control. The activities of aconitase are ingibited to 30-35% on an hour after beta-fluoroethylacetate treatment comparing with that of control rat. The content of blood glucose is increased to 1.6 fold of normal value after 5 hours of treatment. In all tested tissues, superoxide radicals are formed in the heart as 0.26 micromoles per gram tissue between one and three hours after treatment. The activities of total superoxide dismutase are increased between one and three hours after treatment in the all tested tissues and one of these enzymes in heart is highest. The activities of superoxide dismutase containing Mn are also increased with an increase of total superoxide dismutase activities.

• Journal of Nutrition and Health
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• v.40 no.3
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• pp.199-210
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• 2007

The aim of this study was to investigate the effects of mulberry juice and cake powder on blood glucose and lipid status along with intestinal disaccharidase and erythrocyte antioxidative enzyme system in streptozotocin (STZ)-induced diabetic rats. Sprague-Dawley male rats weighing $100{\pm}10g$ were randomly assigned to one normal group, and eight STZ-induced diabetic groups: control diet group without mulberry juice and cake powders (DM-C), three mulberry juice powder groups (0.5%: DM-0.5J, 1%: DM-1J, 2%: DM-2J) and low mulberry cake powder groups (0.25%: DM-0.25C, 0.5%: DM-0.5C, 1%: DM-1 C, 2%: DM-2C). After three-week feeding of each experimental diet, diabetes was induced by intravenous injection of 50 mg/kg body weight of STZ in sodium citrate buffer (pH 4.3) via tail vein of eight DM groups. Rats were sacrificed at the 9th day of diabetic states. Level of blood glucose was 505 mg/dl in DM-C group but it was 28% and 39% lower in mulberry juice and cake powder fed groups, respectively, than the DM-C group. Activities of maltase, sucrase and lactase in proximal part of small intestine were significantly lower in the mulberry juice and cake powder groups by $42{\sim}47%$ than those of DM-C group. Erythrocytic superoxide dismutase, glutathione peroxidase and catalase activities were significantly reduced by STZ but increased close to normal levels along with less accumulation of thiobarbituric acid reactive substances (TBARS). Serum levels of triglyceride and total cholesterol and HDL-cholesterol by STZ-DM were reduced and increased respectively, to the norma] levels by the mulberry juice and cake powder. Except the levels of TBARS, the effects on the other measurements by the various dietary levels of mulberry juice and cake powder were almost same and the effect of the cake powder was most significant at the lowest level. These results indicate that mulberry juice and cake powders have consityerable hypoglycemic effect and strengthening antioxidant defense systems at the low levels in diabetic state and may be able to reduce diabetic complications.

• The Korean Journal of Zoology
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• v.12 no.4
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• pp.114-122
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• 1969

Electron microscopic examination of the liver and heart tissues of methylene blue-treated rats before gamma-irradiation was observed in this study. 1. It was observed severe alteration and degeneration of organelles: accumulation of glycogen particles, severe swollen mitochondria, and broken endoplasmic reticulum in liver tissue of saline-treated rat(control) opposed by emthylene blue-treated rat at 64 and 212 hours following gamma-irradiation. 2. Heart muscles of both methylene blue-treated and saline-treated rats showed no significant alterations, but it was observed that slightly elongated mitochondria with broken cristae and some of vacuoles as well as increased glycogen particles in sarcoplasmic reticulum at 212 hours following gamma-irradiation. 3. It may be considered that methylene blue greatly reduces the sensitivities of rats to gamma-irradiation.