Author Ubuka, Toshihiko|
Published Date 1963
Publication Title Acta Medicinae Okayama
Volume volume17
Issue issue6
Content Type Journal Article
Author Ubuka, Toshihiko| Horiuchi, Katsumi| Shimomura, Takehira| Mizuhara, Shunzi|
Published Date 1964-04
Publication Title Acta Medicinae Okayama
Volume volume18
Issue issue2
Content Type Journal Article
Author Ubuka, Toshihiko| Horiuchi, Katsumi| Shimomura, Takehira| Azumi, Tsukasa|
Published Date 1964-08
Publication Title Acta Medicinae Okayama
Volume volume18
Issue issue4
Content Type Journal Article
JaLCDOI 10.18926/AMO/32307
FullText URL fulltext.pdf
Author Wrobel, Maria| Ubuka, Toshihiko| Yao, Wen-Bin| Abe, Tadashi|
Abstract <p>The effect of exogenous thyroxine (T4) administration on the activity of rhodanese, cystathionase, and 3-mercaptopyruvate sulfurtransferase (MPST) in the mitochondrial and cytosolic fractions of mouse liver was investigated. Three groups of mice were treated for 6 consecutive days with subcutaneous injections of T4 (50 micrograms, 100 micrograms, and 250 micrograms per 100 g of body wt, respectively). The other 3 groups were given 100 micrograms of T4 per 100 g of body wt for 1, 2, or 3 days. The dose of 100 micrograms T4 per 100 g of body wt given for 6 days exerted the strongest effect on the activity of all of the investigated enzymes. In comparison to the control, rhodanese activity diminished in the mitochondrial fraction by 40% (P &#60; 0.05), cystathionase activity diminished in the cytosolic fraction by 15% (P &#60; 0.05), and MPST activity in the mitochondrial fraction was reduced by 34% (P &#60; 0.05), whereas cytosolic MPST activity was unaltered. Simultaneously, in the liver homogenate, elevated levels of ATP and sulfate were observed after 6 days of T4 administration. Thus, the present results seem to suggest that in the mouse liver, after 6 days of administration of 100 micrograms T4 per 100 g of body wt, the desulfuration metabolism of L-cysteine is diminished, which is probably accompanied by an increase in oxidative L-cysteine metabolism. The dose of 100 micrograms per 100 g of body wt administered for a shorter period, and the use of a lower dosage (50 micrograms T4 per 100 g of body wt) for 6 days had a stimulatory effect upon MPST activity level, and an increased level of sulfane sulfur was observed.</p>
Keywords thyroxine rhodanese 3-mercaptopyruvate sulfurtransferase cystathionase sulfane sulful
Amo Type Article
Published Date 2000-02
Publication Title Acta Medica Okayama
Volume volume54
Issue issue1
Publisher Okayama University Medical School
Start Page 9
End Page 14
ISSN 0386-300X
NCID AA00508441
Content Type Journal Article
language 英語
File Version publisher
Refereed True
PubMed ID 10709617
Web of Sience KeyUT 000085526000002
JaLCDOI 10.18926/AMO/31941
FullText URL fulltext.pdf
Author Hosaki, Yasuhiro| Nishina, Hideo| Ubuka, Toshihiko|
Abstract <p>The metabolism of L-cysteine in guinea pig liver was studied. Guinea pig liver contained 0.45 +/- 0.05 (mean +/- SD) mumol of cysteine, 0.180 +/- 0.080 mumol of 3-mercaptolactate-cysteine disulfide [S-(2-hydroxy-2-carboxyethylthio)cysteine, HCETC], and 8.082 +/- 0.516 mumol of reduced glutathione per g of fresh tissue. The taurine content was 0.912 +/- 0.158 mumol per g of fresh liver. Cysteine dioxygenase (EC 1.13.11.20) activity was several-fold lower than cysteine aminotransferase (EC 2.6.1.3) activity. Lactate dehydrogenase (EC 1.1.1.27) activity was about 10-fold higher than 3-mercaptopyruvate sulfurtransferase (EC 2.8.1.2) activity. These results indicate that the oxidative metabolism of L-cysteine in the guinea pig liver is not as active as in the rat liver and that L-cysteine, at least in part, is metabolized via the transaminative pathway, in which 3-mercaptopyruvate is partly reduced to 3-mercaptolactate and is utilized to form HCETC.</p>
Keywords cysteine metabolism guinea pig liver 3-mercaptolactate-cysteine disulfide cysteine transamination.
Amo Type Article
Published Date 1986-02
Publication Title Acta Medica Okayama
Volume volume40
Issue issue1
Publisher Okayama University Medical School
Start Page 11
End Page 15
ISSN 0386-300X
NCID AA00508441
Content Type Journal Article
language 英語
File Version publisher
Refereed True
PubMed ID 3457523
Web of Sience KeyUT A1986A190200002
JaLCDOI 10.18926/AMO/31741
FullText URL fulltext.pdf
Author Yao, Kenzabroh| Ubuka, Toshihiko|
Abstract <p>A new acidic ninhydrin method for determining free sialic acids is described. The method is based on the reaction of sialic acids with Gaitonde's acid ninhydrin reagent 2 which yields a stable color with an absorption maximum at 470 nm. The standard curve is linear in the range of 5 to 500 nmol of N-acetylneuraminic acid per 0.9 ml of reaction mixture. The reaction was specific only for sialic acids among the various sugars and sugar derivatives examined. Some interference of this method by cysteine, cystine and tryptophan was noted, although their absorption maxima differed from that of sialic acids. The interference by these amino acids was eliminated with the use of a small column of cation-exchange resin. The acidic ninhydrin method provides a simple and rapid method for the determination of free sialic acids in biological materials.</p>
Keywords sialic acid determination acidic ninhydrin reaction acidic ninhydrin method
Amo Type Article
Published Date 1987-12
Publication Title Acta Medica Okayama
Volume volume41
Issue issue6
Publisher Okayama University Medical School
Start Page 237
End Page 241
ISSN 0386-300X
NCID AA00508441
Content Type Journal Article
language 英語
File Version publisher
Refereed True
PubMed ID 3439478
Web of Sience KeyUT A1987L530300001
JaLCDOI 10.18926/AMO/31737
FullText URL fulltext.pdf
Author Akahori, Shuichiro| Ejiri, Kohei| Kanemori, Hirofumi| Kudo, Takafumi| Sekiba, Kaoru| Ubuka, Toshihiko| Akagi, Reiko|
Abstract <p>The enzyme activities involved in the transamination of L-cysteine sulfinate (L-alanine 3-sulfinic acid), L-aspartate and L-cysteine were examined in fetal, neonatal and maternal rat liver and placenta. In fetal and neonatal rat liver, aminotransferase activity was most active with L-cysteine sulfinate as a substrate and was also active with L-aspartate, while activity with L-cysteine was very low. The activity of transamination of L-cysteine sulfinate in rat liver developed in parallel with that of L-aspartate and L-cysteine. The aminotransferase activity markedly increased after the 19th day of gestation, reaching the same value as adult liver on the 3rd day after birth. The ratios of transamination of L-cysteine sulfinate to that of L-aspartate and to that of L-cysteine were constant during development. These observations suggest that L-cysteine sulfinate, L-aspartate and L-cysteine are transaminated by the same enzyme in the rat liver during development. Since placental aminotransferase activity was extremely low compared with that of the liver, it was suggested that the placenta did not play an important role in the transamination of these amino acids during pregnancy.</p>
Keywords L-cysteine sulfinate transamination rat liver developmental change placenta
Amo Type Article
Published Date 1987-12
Publication Title Acta Medica Okayama
Volume volume41
Issue issue6
Publisher Okayama University Medical School
Start Page 279
End Page 283
ISSN 0386-300X
NCID AA00508441
Content Type Journal Article
language 英語
File Version publisher
Refereed True
PubMed ID 3439482
Web of Sience KeyUT A1987L530300007
JaLCDOI 10.18926/AMO/31648
FullText URL fulltext.pdf
Author Nagamine, Noboru| Ohta, Jun| Masuoka, Noriyoshi| Kodama, Hiroyuki| Ubuka, Toshihiko|
Abstract <p>Gamma-Glutamylpropargylglycylglycine (gamma-Glu-PPG-Gly) was isolated as a metabolite of propargylglycine (2-amino-4-pentynoic acid, a natural and synthetic inhibitor of cystathionine gamma-lyase) from human blood incubated with D,L-propargylglycine in the presence of L-glutamate and glycine, and identified by fast-atom-bombardment mass spectrometry, indicating that human blood can metabolize propargylglycine to gamma-Glu-PPG-Gly. When whole blood was incubated with 2 mM D,L-propargylglycine in the presence of 10 mM L-glutamate and 10 mM glycine at 37 degrees C for 16h, 0.094+/-0.013 micromol of gamma-Glu-PPG-Gly was formed per ml of whole blood. When erythrocytes were incubated under the same conditions for 16h, 0.323+/-0.060 micromol of gamma-Glu-PPG-Gly was formed per ml of erythrocytes, suggesting a large contribution of erythrocytes to gamma-Glu-PPG-Gly formation in whole blood. The apparent Km value of gamma-Glu-PPG-Gly formation in human erythrocytes for D,L-propargylglycine was 0.32 mM. The observed rate of gamma-Glu-PPG-Gly formation and the Km value for D,L-propargylglycine suggest that metabolism of propargylglycine to gamma-Glu-PPG-Gly can play a definite biological role in human subjects who are loaded with propargylglycine.</p>
Keywords propargylglycine glutathione analogue 2-amino-4-pentynoic acid cystathionine y-lyase
Amo Type Article
Published Date 1999-02
Publication Title Acta Medica Okayama
Volume volume53
Issue issue1
Publisher Okayama University Medical School
Start Page 19
End Page 25
ISSN 0386-300X
NCID AA00508441
Content Type Journal Article
language 英語
File Version publisher
Refereed True
Web of Sience KeyUT 000078897700004
JaLCDOI 10.18926/AMO/31647
FullText URL fulltext.pdf
Author Kurozumi, Yoshiatsu| Abe, Tadashi| Yao, Wen-Bin| Ubuka, Toshihiko|
Abstract <p>Experimental beta-alaninuria was induced in rats by injection of (aminooxy)acetate (AOA), a potent inhibitor of aminotransferases, in order to elucidate the pathogenesis of hyper-beta-alaninemia. A 27-fold increase of beta-alanine (BALA) excretion was induced by subcutaneous injection of 1 5 mg of AOA per kg of body weight. A 13-fold and a 9-fold increase of beta-aminoisobutyric acid (BAIBA) and gamma-aminobutyric acid (GABA), respectively, were also induced simultaneously by the AOA injection. Identification of BALA and BAIBA isolated from the rat urine was performed by chromatographic and mass spectrometric analyses. The effects of AOA injection on the tissue levels of these amino acids were also studied. Contents of BALA in the liver and kidney and GABA in the brain increased significantly in response to AOA injection. The present study indicates that BALA transaminase is involved in hyper-beta-alaninemia.</p>
Keywords beta-alanine beta-aminoisobutyric acid ganma-amlnobutyric-acid (aminooxy)acetate aminotransferase
Amo Type Article
Published Date 1999-02
Publication Title Acta Medica Okayama
Volume volume53
Issue issue1
Publisher Okayama University Medical School
Start Page 13
End Page 18
ISSN 0386-300X
NCID AA00508441
Content Type Journal Article
language 英語
File Version publisher
Refereed True
Web of Sience KeyUT 000078897700003
JaLCDOI 10.18926/AMO/31507
FullText URL fulltext.pdf
Author Hosaki, Yasuhiro| Nishina, Hideo| Ubuka, Toshihiko|
Abstract <p>Free amino acid contents in various guinea pig tissues were determined with an amino acid analyzer. The most abundant amino acids in these tissues were: Gly and Glu in the liver and kidney, Gln, Glu and Ala in the heart, Glu and Gln in the brain, Gly in the blood plasma and Lys in erythrocytes. Glutathione was present as the reduced form in these tissues. Cystine was not detected except in the blood plasma, but cysteine was present in these tissues. These results indicate that most thiols are present in the reduced form in these guinea pig tissues. Taurine contents were low compared with those in rat tissues. The results were discussed in relation to the metabolism of sulfur-containing amino acids, and it was suggested that the oxidative metabolism of L-cysteine was lower in guinea pig tissues than in rat tissues.</p>
Keywords free amino acids guinea pig cysteine
Amo Type Article
Published Date 1985-12
Publication Title Acta Medica Okayama
Volume volume39
Issue issue6
Publisher Okayama University Medical School
Start Page 425
End Page 429
ISSN 0386-300X
NCID AA00508441
Content Type Journal Article
language 英語
File Version publisher
Refereed True
PubMed ID 4091038
Web of Sience KeyUT A1985AWT4000001
JaLCDOI 10.18926/AMO/31323
FullText URL fulltext.pdf
Author Wakimoto, Masahiro| Masuoka, Noriyoshi| Nakano, Taku| Ubuka, Toshihiko|
Abstract <p>A new method for the determination of glutathione peroxidase activity in erythrocytes was developed. The present method was applied to the measurement of hydrogen peroxide removal rates by glutathione peroxidase in erythrocytes at 70 microM hydrogen peroxide under simulated in vivo conditions. The removal rates by glutathione peroxidase in mouse erythrocytes were twenty-times faster than those in human ones and were 5.2 mumol/sec/g of Hb. The removal rates in acatalasemic mouse erythrocytes indicate that glutathione peroxidase is the main means of hydrogen peroxide removal in acatalasemic mouse erythrocytes. Based on these results, we concluded that glutathione peroxidase in mouse erythrocytes had sufficient ability to remove hydrogen peroxide at even relatively high concentrations. This may be one of the reasons why acatalasemic mice suffer no health problems while Japanese acatalasemic patients suffer from Takahara disease when infected with hydrogen peroxide-generating bacteria.</p>
Keywords glutathione peroxidase erythrocyte hydrogen peroxide acatalasemic mouse Takahara disease
Amo Type Article
Published Date 1998-10
Publication Title Acta Medica Okayama
Volume volume52
Issue issue5
Publisher Okayama University Medical School
Start Page 233
End Page 237
ISSN 0386-300X
NCID AA00508441
Content Type Journal Article
language 英語
File Version publisher
Refereed True
PubMed ID 9810432
Web of Sience KeyUT 000076694300001
JaLCDOI 10.18926/AMO/31315
FullText URL fulltext.pdf
Author Yukihiro, Keishi| Tomozawa, Masaru| Abe, Tadashi| Yao, Wen-Bin| Ohta, Jun| Ubuka, Toshihiko|
Abstract <p>Sulfate and taurine are the main metabolites of L-cysteine in mammals and are excreted in the urine. The effect of a high protein diet on the ratio of sulfate to taurine excretion was studied in rats using synthetic 25% (standard protein diet group, group A) and 40% (high protein diet group, group B) casein diets. Average taurine and sulfate excretions (mumol/kg of body weight per day) were 280.4 +/- 93.8 and 943.2 +/- 144.8 in group A and 553.4 +/- 124.5 and 2675.0 +/- 390.9 in group B, respectively. Thus, the average taurine/sulfate ratio in group A was 0.30 +/- 0.08. By a single administration of 5 mmol of L-cysteine/kg of body weight in group A, the average taurine and sulfate excretions increased to 1127.5 +/- 120.2 and 4043.0 +/- 305.6, respectively, but the taurine/sulfate ratio changed only slightly (0.28). The average taurine/sulfate ratio in group B was 0.22 +/- 0.07, a significantly lower ratio than that in group A, which means that daily intake of a high protein diet resulted in more sulfate excretion. The taurine/sulfate ratio in group B was affected only slightly (0.19) by the cysteine administration as well. These results suggest that the ratio of taurine and sulfate production was determined by dietary protein content and that the increase in sulfate production is larger than that of taurine production when the intake of dietary protein is increased.</p>
Keywords high protein diet sulfate taurine cysteine metabolism
Amo Type Article
Published Date 1998-04
Publication Title Acta Medica Okayama
Volume volume52
Issue issue2
Publisher Okayama University Medical School
Start Page 71
End Page 75
ISSN 0386-300X
NCID AA00508441
Content Type Journal Article
language 英語
File Version publisher
Refereed True
PubMed ID 9588221
Web of Sience KeyUT 000073363000001
JaLCDOI 10.18926/AMO/31312
FullText URL fulltext.pdf
Author Tomozawa, Masaru| Yukihiro, Keishi| Yao, Wen-Bin| Abe, Tadashi| Ohta, Jun| Ubuka, Toshihiko|
Abstract <p>The effects of a low protein diet on the excretion of sulfate and taurine, major metabolites of L-cysteine in mammals, were studied in rats fed with synthetic 10% (group A) and 25% (group B) casein diets. The average excretions of total taurine (taurine plus hypotaurine) and total sulfate (free plus ester sulfate) (mumol/kg of body weight per day after the adaptation to the synthetic diet) in group A were 14.2 +/- 13.4 and 122.3 +/- 39.6, respectively, which were very low compared with 280.4 +/- 93.8 and 943.2 +/- 144.8, respectively, in group B. The taurine/sulfate ratio in group A was 0.12 +/- 0.11, which was significantly lower than that (0.30 +/- 0.08) in group B. A single intraperitoneal injection of 5 mmol of L-cysteine per kg of body weight in group A resulted in an increase in average taurine and sulfate excretion to 693.4 +/- 195.6 and 2440.6 +/- 270.0, respectively, and thus the average taurine/sulfate ratio increased to 0.29. These increases were transient and low taurine excretion resumed again 24 h after the L-cysteine administration. L-Cysteine injection in group B resulted in a similar increase in taurine and sulfate excretion, but the ratio changed only slightly (0.28). The present results suggest that in vivo production of taurine is reduced preferentially over sulfate production when sulfur amino acid supply is limited. </p>
Keywords low protein diet taurine sulfate crstein metabolism
Amo Type Article
Published Date 1998-04
Publication Title Acta Medica Okayama
Volume volume52
Issue issue2
Publisher Okayama University Medical School
Start Page 77
End Page 81
ISSN 0386-300X
NCID AA00508441
Content Type Journal Article
language 英語
File Version publisher
Refereed True
PubMed ID 9588222
Web of Sience KeyUT 000073363000002
JaLCDOI 10.18926/AMO/31022
FullText URL fulltext.pdf
Author Masuoka, Noriyoshi| Ubuka, Toshihiko| Kinuta, Masahiro| Yoshida, Shigeko| Taguchi, Tazuko|
Abstract <p>A new gas chromatographic method for the determination of sulfate was developed. In this method, sulfate was quantitatively converted to a volatile derivative, dimethyl sulfate, by a two-step procedure. First, sulfate was converted to silver sulfate by reaction with silver oxide, and then to dimethyl sulfate by reaction with methyl iodide. The derivative was analyzed by gas chromatography. Methyl methanesulfonate was used as an internal standard. The method was applied to the determination of total urinary sulfate. Phosphate and chloride ions, which interfered with the present method, were eliminated with the use of basic magnesium carbonate and an excess of silver oxide, respectively. Recovery was over 96% when 5 to 40 mumol/ml of sulfate was added to human urine samples.</p>
Keywords gas chromatography sulfate determination dimethy1 sulfate sulfuric acid urinary sulfate
Amo Type Article
Published Date 1988-10
Publication Title Acta Medica Okayama
Volume volume42
Issue issue5
Publisher Okayama University Medical School
Start Page 247
End Page 252
ISSN 0386-300X
NCID AA00508441
Content Type Journal Article
language 英語
File Version publisher
Refereed True
PubMed ID 3223336
Web of Sience KeyUT A1988Q771900001
JaLCDOI 10.18926/AMO/30881
FullText URL fulltext.pdf
Author Masuoka, Noriyoshi| Ubuka, Toshihiko| Akagi, Reiko| Yao, Kenzaburoh| Ishino, Kazushi|
Abstract <p>A new volatile derivative of taurine, N-isobutoxycarbonyltaurine methyl ester (methyl 2-(N-isobutoxycarbonylamino)ethanesulfonate), was prepared by a three-step procedure for the gas chromatographic determination of taurine in urine. First, taurine was converted to its silver salt by reaction with silver oxide; next the silver salt was reacted with isobutyl chloroformate to form the N-isobutoxycarbonyl derivative, and finally the derivative was reacted with methyl iodide to form N-isobutoxycarbonyltaurine methyl ester. The volatile derivative was analyzed by gas chromatography using a column of 3% OV-101 on Chromosorb W. When methyl 3-(N-isobutoxycarbonylamino) propanesulfonate was used as an internal standard, the calibration curve was linear between 0.5 and 5.0 mumol of taurine/ml and showed a good reproducibility. This method was applied to the determination of taurine in human urine. Recovery was 98.6 +/- 5.2%, when 1.25 to 5.0 mumol/ml of taurine was added to human urine.</p>
Keywords taurine gas chromatography taurine determination methyI 2-(N-isobutoxycarbonylamino) ethanesulfoate taurine excretion
Amo Type Article
Published Date 1989-10
Publication Title Acta Medica Okayama
Volume volume43
Issue issue5
Publisher Okayama University Medical School
Start Page 253
End Page 259
ISSN 0386-300X
NCID AA00508441
Content Type Journal Article
language 英語
File Version publisher
Refereed True
PubMed ID 2610003
Web of Sience KeyUT A1989CA06200001
JaLCDOI 10.18926/AMO/30880
FullText URL fulltext.pdf
Author Yoshida, Shigeko| Akagi, Rriko| Ubuka, Toshihiko|
Abstract <p>Excretion of sulfate and taurine, two major metabolites of sulfur, was examined in rats to study the nutritional status of sulfur metabolism in the mammals. Rats maintained on a conventional laboratory diet excreted 1.83 +/- 0.14 mmol of free sulfate and 229.0 +/- 75.3 mumol of taurine/kg of body weight per day. When the diet was changed to a synthetic 25% casein diet, the taurine excretion decreased to 15% of the previous daily excretion, but sulfate excretion decreased only slightly. These decreased levels returned to the original levels when 5 mmol of L-cysteine/kg of body weight was administered into the stomach through a catheter. One week after the first L-cysteine administration, when sulfate and taurine excretion had returned to the original levels, 5 mmol of L-cysteine/kg of body weight was administered likewise. The rats excreted sulfur corresponding to about 95% of L-cysteine administered in the form of free sulfate and taurine within a few days following L-cysteine administration, and sulfate excretion was 3.5 times more than taurine excretion. These results seem to suggest that, in rats, sulfur metabolism is in a state of equilibrium and that sulfate is formed preferentially to taurine.</p>
Keywords sulfate taurine cysteine sulfur metabolism
Amo Type Article
Published Date 1989-10
Publication Title Acta Medica Okayama
Volume volume43
Issue issue5
Publisher Okayama University Medical School
Start Page 281
End Page 288
ISSN 0386-300X
NCID AA00508441
Content Type Journal Article
language 英語
File Version publisher
Refereed True
PubMed ID 2610005
Web of Sience KeyUT A1989CA06200004
JaLCDOI 10.18926/AMO/30871
FullText URL fulltext.pdf
Author Ohta, Jun| Ubuka, Toshihiko|
Abstract <p>It has been assumed that the in vivo reduction of 3-mercaptopyruvate, an intermediate of cysteine metabolism, to 3-mercaptolactate is catalyzed by lactate dehydrogenase (EC 1.1.1.27) though no definitive evidence has been presented. In order to examine this assumption, reduction of 3-mercaptopyruvate and its inhibition were studied using rat liver homogenate, lactate dehydrogenase purified from rat liver and anti-lactate dehydrogenase antiserum. Reduction of 3-mercaptopyruvate was actively catalyzed by rat liver homogenate and by the purified lactate dehydrogenase. This reducing activity was completely inhibited by anti-lactate dehydrogenase antiserum. These results indicate that the reduction of 3-mercaptopyruvate to 3-mercaptolactate in rat liver is catalyzed by lactate dehydrogenase.</p>
Keywords 3-mercaptopyruvate 3-mercaptolactate lactate dehydrogenase antiserum cysteine metabolism
Amo Type Article
Published Date 1989-04
Publication Title Acta Medica Okayama
Volume volume43
Issue issue2
Publisher Okayama University Medical School
Start Page 89
End Page 95
ISSN 0386-300X
NCID AA00508441
Content Type Journal Article
language 英語
File Version publisher
Refereed True
PubMed ID 2499162
Web of Sience KeyUT A1989U578500003
JaLCDOI 10.18926/AMO/30463
FullText URL fulltext.pdf
Author Yuasa, Shigeki| Akagi, Reiko| Ubuka, Toshihiko|
Abstract <p>A method for the simultaneous determination of hypotaurine and taurine was developed. The method consisted of the elimination of urea, which interfered with the determination of hypotaurine, by immobilized urease, and determination of hypotaurine and taurine with an amino acid analyzer. The analyzer equipped with a cation-exchange column was operated at 32 degrees C with 0.2 M sodium citrate buffer, pH 2.8. Using this method, the dynamics of hypotaurine and taurine in blood plasma of rats was studied after the intraperitoneal injection of L-cysteine. The concentration of cysteine reached the maximum 1 h after L-cysteine loading. The concentration of hypotaurine and taurine increased in parallel and reached the maximum 2 h after L-cysteine loading. These changes seem to indicate the precursor-product relationship of these substances and the rapid conversion of hypotaurine to taurine in vivo.</p>
Keywords hypotaurine taurine determination cysteine metabolisn amino acid analysis
Amo Type Article
Published Date 1990-02
Publication Title Acta Medica Okayama
Volume volume44
Issue issue1
Publisher Okayama University Medical School
Start Page 47
End Page 50
ISSN 0386-300X
NCID AA00508441
Content Type Journal Article
language 英語
File Version publisher
Refereed True
PubMed ID 2330845
Web of Sience KeyUT A1990CT06800007
JaLCDOI 10.18926/AMO/30459
FullText URL fulltext.pdf
Author Yuasa, Shigeki| Akagi, Reiko| Ubuka, Toshihiko| Masuoka, Noriyoshi| Yao, Kenzaburoh|
Abstract <p>The excretion of 3-mercaptolactate-cysteine mixed disulfide [S-(2-hydroxy-2-carboxyethylthio)-L-cysteine, HCETC], sulfate and taurine in the urine of normal adults was investigated before and after oral administration of L-cysteine and related sulfur-containing amino acids. Before the loading of amino acids, the excretion (mean +/- SD) per kg of body weight per day of HCETC, free sulfate and taurine was 0.096 +/- 0.042, 305.7 +/- 66.1 and 31.9 +/- 8.7 mumols, respectively. After the loading of L-cysteine (800 mumols/kg of body weight), the average excretion in the 24-h urine of HCETC increased 2-fold and that of taurine increased 1.6-fold. The average excretion of free sulfate after the L-cysteine loading was 989.4 +/- 145.1 and 388.8 +/- 51.6 mumols/kg per day in the first and second 24-h urine, respectively, indicating that the sulfur corresponding to 85% of the L-cysteine loaded was excreted as free sulfate in 24 h. Administration of L-cystine (400 mumols/kg) resulted in similar results. The increase in HCETC after L-cysteine or L-cystine administration indicates that L-cysteine is metabolized in part through the transamination pathway (3-mercaptopyruvate pathway) and that an equilibrium exists between the intake and excretion of sulfur in humans.</p>
Keywords 3-mercaptolactate-cysteine mixed disulfide cysteine matabolism 3-mercaptopyruvate pathway sulfur amino acid sulfate excretion
Amo Type Article
Published Date 1990-06
Publication Title Acta Medica Okayama
Volume volume44
Issue issue3
Publisher Okayama University Medical School
Start Page 117
End Page 122
ISSN 0386-300X
NCID AA00508441
Content Type Journal Article
language 英語
File Version publisher
Refereed True
PubMed ID 2382576
Web of Sience KeyUT A1990DM18300001
JaLCDOI 10.18926/AMO/30456
FullText URL fulltext.pdf
Author Taguchi, Tazuko| Akagi, Reiko| Ubuka, Toshihiko|
Abstract <p>&lt;p&gt;Tissue contents and urinary excretion of taurine were studied in rats after the administration of L-cysteine and its derivatives. Average taurine content in the liver of rats fed a 25% casein diet for 7 days increased 2-fold 2h after the intraperitoneal administration of 5 mmol of L-cysteine per kg of body weight, whereas that in rats fed a 5% casein diet for 2 days increased only slightly. The difference in the liver taurine contents between these two groups was discussed in relation to cysteine dioxygenase. Taurine contents in the heart, brain and blood did not differ significantly between these two groups or between the control and the group of rats which received L-cysteine. The increase in liver taurine concentrations after L-cysteine administration was much higher than that after L-cystine administration, suggesting a difference in their absorption. The intraperitoneal administration of 5 mmol/kg of L-2-oxothiazolidine-4-carboxylate (OTCA) resulted in a 3-fold increase in liver taurine content. The average increase in taurine excretion in the 24-h urine after OTCA administration corresponded to about 6.0% and that in the next 24-h urine to about 2.6% of OTCA administered, suggesting that nearly 10% of OTCA was metabolized to taurine and excreted in the urine.&lt;/p&gt;</p>
Keywords taurine cysteine metabolism 2-oxothiazolidine-4-carboxyylate
Amo Type Article
Published Date 1990-06
Publication Title Acta Medica Okayama
Volume volume44
Issue issue3
Publisher Okayama University Medical School
Start Page 123
End Page 128
ISSN 0386-300X
NCID AA00508441
Content Type Journal Article
language 英語
File Version publisher
Refereed True
PubMed ID 2382577
Web of Sience KeyUT A1990DM18300002