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T Noguchi

Publications and source records attributed to T Noguchi.

At least 1,099 records · Page 61Linked to original sources
PubMed1977

Characteristics of hepatic serine-pyruvate aminotransferase in different mammalian species.

1. Serine-pyruvate aminotransferase was purified from mouse, rat, dog and cat liver. Each enzyme preparation was homogeneous as judged by polyacrylamide-disc-gel electrophoresis in the presence of sodium dodecyl sulphate. However, isoelectric focusing resulted in the detection of two or more active forms from enzyme preparations from dog, cat and mouse. A single active form was obtained with the rat enzyme. All four enzyme preparations had similar pH optima and molecular weights. 2. Both mouse and rat preparations catalysed transamination between a number of L-amino acids (serine, leucine, asparagine, methionine, glutamine, ornithine, histidine, phenylalanine or tyrosine) and pyruvate. Effective amino acceptors were pyruvate, phenylpyruvate and glyoxylate with serine as amino donor. The reverse transamination activity, with hydroxypyruvate and alanine as subtrates, was lower than with serine and pyruvate for both species. Serine-pyruvate aminotransferase activities were inhibited by isonicotinic acid hydrazide. 3. In contrast, both dog and cat enzyme preparations were highly specific for serine as amino donor with pyruvate, and utilized pyruvate and glyoxylate as effective amino acceptors. A little activity was detected with phenylpyruvate. The reverse activity was higher than with serine and pyruvate for both species. Serine-pyruvate amino-transferase activities were not inhibited by isonicotinic acid hydrazide.

Amino Acids↗
PubMed1977

Identity of rat kidney histidine-pyruvate aminotransferase with glutamine-oxo acid aminotransferase.

Histidine-pyruvate aminotransferase and glutamine-phenylpyruvate aminotransferase were purified from rat kidney by the same procedure. The ratio of the two activities remained constant during purification and was unchanged by a variety of treatments of the purified enzyme. Glutamine was found to act as a competitive inhibitor of histidine-pyruvate aminotransferase. These results suggest that rat kidney histidine-pyruvate aminotransferase is identical with glutamine-oxo acid aminotransferase. Identity of the two enzymes in other tissues of rats is discussed.

Animals↗
PubMed1977

Use of rabbits for GI drug absorption studies.

A novel procedure to control the stomach emptying rate in rabbits is presented. Rabbits were given a special solid diet for 1 week, and then the gastric contents were washed out with saline. Then the rabbits were muzzled to prevent coprophagy during the night. Fifty grams of special soft diet given to the "stomach-emptying-controlled" rabbit transferred exponentially from the stomach into the small intestine and almost disappeared from the stomach within 5 hr. Griseofulvin, indomethacin, or nalidixic acid was administered in a hard gelatin capsule or tablet, with subsequent feeding of a special soft diet. Good correlations were observed between the plasma level-time curves of these drugs in the stomach-emptying-controlled rabbits and in human subjects.

Animals↗
PubMed1977

Fractional flux rates of Nt-methylhistidine in skin and gastrointestine: the contribution of these tissues to urinary excretion of Nt-methylhistidine in the rat.

1. Fractional flux rates of Ntau-methylhistidine (3-methylhistidine; Me-His) of skin and gastrointestine were measured by administering [methyl-3H]methionine to rats. 2. The results showed that the contribution of these tissues to urinary excretion of Me-His was at least 16-6%. This means that when fractional catabolic rates of myosin and actin were estimated from urinary excretion of Me-His, the part of Me-His derived from skin and gastrointestine should not be neglected.

Animals↗
PubMed1977

Species distribution and properties of hepatic phenylalanine (histidine):pyruvate aminotransferase.

Hepatic phenylalanine(histidine):pyruvate aminotransferase activity is much higher in the mouse and rat than in other animal species (human, guinea-pig, rabbit, pig, dog and chicken). The activity is elevated in the mouse and rat by the injection of glucagon but not in other species (guinea-pig, rabbit and chicken). The enzyme was purified from the mitochondrial fraction of mouse liver to homogeneity as judged by polyacrylamide disc gel electrophoresis in the presence of dodecylsulphate. With histidine as amino donor, the enzyme was active with pyruvate, oxaloacetate and hydroxypyruvate as amino acceptors but not with 2-oxoglutarate. Effective amino donors were histidine, phenylalanine and tyrosine with pyruvate, and methionine, serine and glutamine with phenylpyruvate. The apparent Km for histidine was about 6.9 mM with pyruvate and that for pyruvate was 21 mM with histidine. The enzyme is probably composed of two identical subunits with a molecular weight of approximately 40000. The pH optimum was near 9.0. Isoelectric focusing of the purified enzyme resulted in the detection of four forms with pI 6.0, 6.2, 6.5 and 6.7, respectively, all of which were responsive to glucagon. These four forms were nearly identical with the purified enzyme before the focusing with respect to physical and enzymic properties. A possible mechanism of this multiplicity is discussed.

Animals↗
PubMed1977

Glutamate-glyoxylate aminotransferase in rat liver cytosol. Purification, properties and identity with alanine-2-oxoglutarate aminotransferase.

After cortisone injection, virtually identical increases in rat liver cytosol alanine-2-oxoglutarate aminotransferase and glutamate-glyoxylate aminotransferase activities were observed. The two activities were co-purified to homogeneity from rat liver cytosol. The purified enzyme was specific for L-alanine with 2-oxoglutarate as amino acceptor. With glyoxylate, however, the enzyme utilized various L-amino acids as amino donors in the following order of activity: glutamate greater than alanine greater than glutamine greater than methionine. The ratio of alanine-2-oxoglutarate aminotransferase activity to glutamate-glyoxylate aminotransferase activity remained constant during purification and was unchanged by a variety of treatments of the purified enzyme. These results suggest that glutamate-glyoxylate aminotransferase is identical with alanine-2-oxoglutarate aminotransferase. Evidence was obtained that the two enzyme activities in the cytosol of dog, cat and human liver are also properties of the same protein.

Alanine Transaminase↗