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Volume 26, Issue 1
Displaying 1-11 of 11 articles from this issue
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Shuzo GOMIKAWA, Mitsuko OKADA1980 Volume 26 Issue 1 Pages 1-14
Published: 1980
Released on J-STAGE: April 28, 2009
JOURNAL FREE ACCESSThe activities of 3-hydroxy-3-methylglutaryl-CoA reduc tase [EC 1. 1. 1. 34] in the livers of pyridoxine-deficient and control rats were compared. The reductase activity, which is known to show a circadian rhythm, was about twice as high in pyridoxine-deficient rats during both the light and dark periods. After administration of cycloheximide the rate of decrease in reductase activity was similar in pyridoxine-deficient and control rats. The Km values from the two groups for DL-GMH-CoA, the heat stabilities and the microsomal lipid compositions were also similar. The effects of cytosolic activator and inactivator proteins on the reductase activities were also similar. These results show that the increased activity in pyridoxine-deficient rats is due to increased enzyme synthesis or increased specific activity induced by some unknown mechanism, but not to change in the state of phosphory lation of the enzyme.View full abstractDownload PDF (1294K) -
Fumio SHIMURA, Tsuneyuki OKU, Norimasa HOSOYA1980 Volume 26 Issue 1 Pages 15-23
Published: 1980
Released on J-STAGE: April 28, 2009
JOURNAL FREE ACCESSThe competence of the duodenal 1α, 25-(OH)2-D3 receptor system in embryonic chicks was studied in the reconstituted cytosol-chromatin system.
The sucrose density gradient centrifugation following incubation of duodenal cytosol with 1α, 25-dihydroxy-[3H]-vitamin D3 revealed that a cytosol 1α, 25-dihydroxyvitamin D3 receptor existed in the duodenum of 18-day-old embryos. In the duodenum of 14-day-old embryos, however, the cytosol 1α, 25-dihydroxyvitamin D3 receptor was not detected. In the reconstituted cytosol-chromatin system, duodenal cytosol of 18day-old embryos stimulated the association of 1α, 25-dihydroxy-[3H] vitamin D3 with chromatin of the vitamin D-deficient chick duodenum. The association of 1α, 25-dihydroxy-[3H]-vitamin D3 was shown to be saturable and temperature dependent.
In a system where duodenal chromation of 18-day-old embryos was reconstituted with cytosols, 1α, 25-dihydroxy-[3H]-vitamin D3 was revealed to associate specifically with the chromatin in the presence of duodenal cytosol obtained from 18-day-old embryos or vitamin Ddeficient chicks. No significant association of 1α, 25-dihydroxy-[3H]vitamin D3 with duodenal chromatin of 18-day-old embryos occurred in the absence of duodenal cytosol.
From these results, it was strongly suggested that the intestinal 1α, 25dihydroxyvitamin D3 receptor system in embryonic chicks has become competent for the intracellular transfer of 1α, 25-(OH)2-D3 before hatching.View full abstractDownload PDF (861K) -
Aritake MIZUNO, Yoshio KAMADA, Masanori KUNITA, Makoto MATSUDAI1980 Volume 26 Issue 1 Pages 25-32
Published: 1980
Released on J-STAGE: April 28, 2009
JOURNAL FREE ACCESSThe effect of several antivitamin B6 on γ-aminobutyric acid (GABA) metabolism was studied in the rat retina. The rat elec troretinogram (ERG) was also recorded after administration of these drugs. Aminooxyacetic acid (AOAA) and hydrazine administration increased the GABA content and inhibited the GABA degrading enzyme, GABA transaminase in retina. In addition, these drugs elongated the peak latency of the oscillatory potential in the rat ERG. In contrast, 4 deoxypyridoxine (DOP) or isonicotinic acid hydrazide (INAH) adminis tration decreased the GABA content and inhibited the GABA synthesiz ing enzyme, glutamic acid decarboxylase in retina, and administration of these drugs together with AOAA lessened the degrees of elevation of GABA content and of the elongation of the peak latency produced as compared with AOAA alone, though neither of the former drugs had a significant effect on ERG. The retinal GABA seems to play an important role in relation to the oscillatory potential of ERG.View full abstractDownload PDF (708K) -
Akiko KOGA, Shuichi KIMURA1980 Volume 26 Issue 1 Pages 33-38
Published: 1980
Released on J-STAGE: April 28, 2009
JOURNAL FREE ACCESSPreviously we reported that the small intestine of mice adapted to dietary restriction had low mitotic activity in the crypts. In that case there was no marked difference in the villus and crypt cell numbers, but the migrating speed from crypt to villus decreased, consequently the transit time was prolonged. The present study was undertaken in order to clarify whether or not the cell cycle of the proliferative cells in the crypts alters when the mitotic activity decreases. The results obtained in this study indicate that: 1) There are differences in cell cycle and labeling index between the unrestricted animals and restricted animals. 2) The cycle time of the duodenal and jejunal cells, particularly of G1 phase was prolonged under dietary restriction. 3) The prolongation of cycle time was not found in the ileum. It is thought that the proliferative cell number principally controls mitotic activity in the crypts. Still, reduction of the proliferative cell number will be accounted for by the increase of resting cells in G1 phase.View full abstractDownload PDF (508K) -
Toru RIKIMARU, Shigeru YAMAMOTO, Kohei MAEDA, Goro INOUE1980 Volume 26 Issue 1 Pages 39-57
Published: 1980
Released on J-STAGE: April 28, 2009
JOURNAL FREE ACCESSThe rates of gain, catabolism, synthesis and reutilization of myofibrillar protein were measured in adult rats fed a protein-free diet, low protein diet (2% lactalbumin) or control diet (10% lactalbumin) for 14 to 31 days. Two forms of synthesis were measured: exogenous synthesis (nitrogen derived from diet) and endogenous synthesis (nitrogen derived from catabolized body protein).
The rate of gain of myofibrillar protein was measured as the rate of increase in its weight and the rate of catabolism was determined from urinary 3-methylhistidine excretion. The rate of total synthesis was calculated as the sum of these two rates. Exogenous synthesis was calculated from the recovery of isotope in protein 24 hr after oral administration of 15N-leucine and endogenous synthesis was calculated as the difference between the total synthesis and exogenous synthesis. Reutilization was calculated as the ratio of endogeneous synthesis to catabolism.
The rate of catabolism was slightly decreased in protein deficiency (2.1, 2.1 and 2.6% in the protein-free, low protein and control groups, respectively), while that of synthesis was significantly decreased in protein deficiency (1.3, 2.0 and 3.3% in the respective groups). Restriction of protein intake resulted in a decrease in the rate of exogenous synthesis, without appreciable change of endogenous synthesis. The reutilization rate of endogenous N was estimated to be about 70% in rats with restricted protein intakes and about 50% in those with a normal protein intake.View full abstractDownload PDF (1603K) -
Masanori YASHIRO, Shuichi KIMURA1980 Volume 26 Issue 1 Pages 59-69
Published: 1980
Released on J-STAGE: April 28, 2009
JOURNAL FREE ACCESSThe effect of voluntary exercise on serum lipoprotein distributions, lecitin : cholesterol acryltransferase (LCAT) activity and serum electrophoretic patterns of mice fed different levels of dietary protein were investigated.
Serum cholesterol of all exercise groups (E) showed a lower value than that of the non-exercise groups (NE). Ratios of cholesteryl ester to serum total cholesterol tended to be higher in the exercise groups than in nonexercise groups. High density lipoprotein(HDL)-cholesterol/serum total cholesterol ratios and HDL-cholesterol/low density lipoprotein(LDL)cholesterol ratios were increased by voluntary exercise. With regard to low density lipoprotein cholesterol levels, there were significant differences between 20% E and 20% NE groups, 4% E and 4% NE groups, respectively. It was found thai HDL fractions in serum lipoprotein patterns of exercise groups differed from those of non-exercise groups. This seemed to be prominent in low protein diet groups. LCAT activity showed decreasing values as dietary protein levels decreased and its activity was raised by voluntary exercise in all groups.View full abstractDownload PDF (1232K) -
Masanori YASHIRO, Tadahiko HOSHINO, Shuichi KIMURA1980 Volume 26 Issue 1 Pages 71-76
Published: 1980
Released on J-STAGE: April 28, 2009
JOURNAL FREE ACCESSIn the present investigation, effects of voluntary exercise on serum glutamic pyruvic transaminase (SGPT) activity and histological alterations of liver tissue of mice fed 4%, 6% and 20% casein diet were examined.
SGPT activity showed decreasing values accompanied by dietary protein level increases. In 4% casein diet groups, SGPT activity of the exercise group was markedly lower than that of the non-exercise group. Furthermore, there was a negative correlation between SGPT and LCAT activity.
In histological evaluation, the non-exercise group on 4% casein diet revealed diffuse fatty degeneration of the liver, but the exercise group did not show such changes.View full abstractDownload PDF (1662K) -
Sachiko TOKUHISA, Kumiyo SAISU, Haruhisa YOSHIKAWA, Shigeo BABA1980 Volume 26 Issue 1 Pages 77-85
Published: 1980
Released on J-STAGE: April 28, 2009
JOURNAL FREE ACCESSL-[2', 3', 5', 6'-d]Tyrosine (Tyr-d4) and L-[2', 6'-d]Tyr (Tyr-d2) were prepared. Tyr was heated in conc. DCl at 180°C for 4 hr to obtain DL-[2, 2', 3', 5', 6'-d]Tyr '(Tyr-d5), then the deuterium on the 2-position of the compound was successfully replaced with proton by refluxing with an acetic acid-acetic anhydride mixture. The isotopic purity of DL-Tyr-d4 was about 60%. The racemic mixture was resolved enzymatically. L-Tyr-d2 was prepared by refluxing the resultant Tyr-d4 with 5.5 N HCI. The deuterated amino acids were analyzed as the N, O-bis (trifluoroacetyl) methyl ester or N, O-bis(heptafluorobutyryl) methyl ester derivatives by the gas chromatography-selective ion monitoring method (SIM). The calibration curves showed good linearity in the range where the molar ratios of Tyr-d4/Tyr-do and Tyr-d2/Tyr-do were above 5/1, 000. The results indicate that the protein-bound Tyr-d4 may possibly be determined as Tyr-d2 after hydrolysis of protein.View full abstractDownload PDF (627K) -
Yoshio YOSHINO, Yukihiko HIRAI, Tetsuo AOKI, Toshisada MORITA, Yoshita ...1980 Volume 26 Issue 1 Pages 87-97
Published: 1980
Released on J-STAGE: April 28, 2009
JOURNAL FREE ACCESSTwo-site immunoradiometric assay for serum ferritin was developed by anti-human liver ferritin antiserum applied on polyvinyl V bottom microtiter plates. The coefficient of variation was 4.45.9% of liver ferritin dissolved in 1/4 diluted human serum at a concentration of 0.625-125ng/ml. The lowest concentration (0.625ng/ml) was statistically distinguishable from the background by Student's t test (p<0.05). Isoferritin patterns of serum ferritin and tissue ferritins were examined by the combination of gel isoelectric focussing and 2-site immunoradiometric assay in order to explore any similarities in pls within these ferritins. Although serum ferritin had wide range of pls, its basic isomers corresponded well to those of liver and spleen ferritin. Geometric means and their 95% confidence limits in serum ferritin concentration were 70ng/ml and 12-411ng/ml, respectively, in sera of 205 healthy males (16-25 years), and 12 ng/ml and 1-211ng/ml, respectively, in 421 healthy females (16-59 years).View full abstractDownload PDF (1035K) -
Hisateru MITSUDA, Kenji NAKAJIMA, Hiroshi MIZUNO, Fumio KAWAI, Aijiro ...1980 Volume 26 Issue 1 Pages 99-102
Published: 1980
Released on J-STAGE: April 28, 2009
JOURNAL FREE ACCESSDownload PDF (834K) -
1980 Volume 26 Issue 1 Pages e1
Published: 1980
Released on J-STAGE: April 28, 2009
JOURNAL FREE ACCESSDownload PDF (24K)
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