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Biomedical subjects

T Ohno

Publications and source records attributed to T Ohno.

At least 865 records · Page 48Linked to original sources
PubMed1981

Studies of metabolism of tripamide, a new antihypertensive agent. II. Metabolism by the hepatic microsomal enzymes.

1. The metabolism of tripamide, N-(4-aza-endo-tricyclo[5.2.1.0(2.6)]decan-4-yl)-4-chloro-3-sulphamoylbenzamide, has been studied with rat liver microsomal preparations. 2. Hydrolysis of tripamide was induced by phenobarbitone pretreatment and inhibited by O-ethyl O-p-nitrophenyl phenylphosphonothioate (EPN), a classical inhibitor of hepatic microsomal arylamidase. The hydrolysis was also catalysed by partially purified rabbit liver microsomal arylamidase. 3. The hydroxylation of tripamide was induced by 3-methylcholanthrene and inhibited by CO. 4. Inhibition of the hydroxylation of tripamide by antibodies of cytochrome P-450 and P-448 was studied. The 8-hydroxylation was inhibited by both antibodies, but 3-hydroxylation was inhibited by neither.

Aminopeptidases↗
PubMed1981

[Effect of temperature acclimation on plasma high density lipoprotein in rats (author's transl)].

Effect of temperature acclimation to cold as well as heat on plasma high-density lipoprotein cholesterol (HDL) was investigated in rats. Cold acclimation (5 degrees C, 4 weeks) caused significant increase in plasma HDL, while heat acclimation (34 degrees C, 4 weeks) caused significant decrease in plasma HDL. Noradrenaline treatment (50 micrograms/100 g, sc., 2 times a day) did not affect plasma HDL level. These results indicate that temperature acclimation could influence HDL metabolism, possibly not via noradrenaline.

Acclimatization↗
PubMed1980

The possibility of centrifugal projections to the retina in the rat.

In rats, glutamic acid decarboxylase activity increased in the proximal portion of the optic nerve after its ligation, whereas the activities of choline acetyltransferase and tyrosine hydroxylase remained constant. Possible centrifugal neurons to the retina are GABAergic.

Animals↗
PubMed1980

Recombinant plasmids containing avian vitellogenin structural gene sequences derived from complementary DNA.

Purified mRNA coding for chicken vitellogenin, a precursor of egg yolk proteins, was transcribed to complementary DNA (cDNAvit) with avian myeloblastosis virus (AMV) reverse transcriptase. Double-stranded cDNA was synthesized with Escherichia coli DNA polymerase I (fragment A) using the self priming ability of the cDNA. Following S1 nuclease digestion the double-stranded cDNA was inserted into the Hind III site of plasmid pBR322 using the poly(dA) . poly(dT) tailing method, and the hybrid molecules were used to transform Escherichia coli chi 1776. Ampicillin-resistant colonies were screened by colony hybridization with 125I-labeled vitellogenen mRNA. Further screening of positive clones was done by agarose gel electrophoresis and in situ hybridization with 125I-labeled vitellogenin mRNA. In addition, plasmid DNA covalently bound to diazotized paper was used to select complementary mRNA sequences. The cloned vitellogenin sequences were shown to hybridize to a mRNA which directs the synthesis of immunoprecipitable vitellogenin when translated in a reticulocyte lysate cell-free system. The length of the inserted cDNA was determined by agarose gel electrophoresis and heteroduplex mapping. The largest insertion was about 2500 base pairs. Restriction mapping indicates that at least three plasmids out of four have different sequences.

Animals↗
PubMed1980

Possible role of polyamines in the function of brown adipose tissue.

In order to ascertain possible involvement of polyamines in the physiological regulation of brown fat function, effect of temperature acclimation on the polyamine contents of this tissue and effects of polyamines on the noradrenaline-induced thermogenesis is isolated brown adipocytes were investigated in rats. Daily urinary excretion of polyamines measured collectively for spermidine and spermidine per body weight was decreased in heat acclimation and increased in cold acclimation. Polyamine concentrations per fresh weight of brown fat showed extremely low values compared with those of other tissues previously reported. Putrescine and spermidine contents per fat-free dry matter of brown fat were decreased in cold acclimation, but were not affected in heat acclimation. Spermidine and spermine inhibited the noradrenaline-induced thermogenesis of brown adipocytes dose-dependently. These results suggest that polyamines regulate the heat production of brown adipose tissue in an inhibitory way and cold acclimation potentiates heat production of this tissue by reducing polyamine levels.

Acclimatization↗