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Biomedical subjects

M Asano

Publications and source records attributed to M Asano.

At least 577 records · Page 32Linked to original sources
PubMed1978

A novel vascular relaxing agent, N-(6--aminohexyl)-5-chloro-1-naphthalensulfonamide which affects vascular smooth muscle actomyosin.

The relaxing effect and possible mechanism of N-(6-aminohexyl)-5-chloro-1-naphthalenesulfonamide (W-7) on isolated rabbit artery were investigated. The addition of W-7 in concentrations ranging from 1 X 10(-6) to 3 X 10(-4) M caused a significant relaxation of isolated rabbit vascular strips contracted by KCl, prostaglandin F2alpha, norepinephrine, histamine, CaCl2, serotonin or angiotensin II. W-7 also caused a shift to the right of the dose-response curves for all agonists tested. Propranolol and atropine did not affect W-7 induced relaxation, suggesting that this drug does not act through beta adrenergic or cholinergic receptors. Superprecipitation of actomyosin from bovine aorta smooth muscle was inhibited by the addition of W-7 in a dose-dependent fashion. The concentration of W-7 which inhibited superprecipitation of bovine aorta smooth muscle actomyosin was in good agreement with the dose producing relaxation of isolated vascular strips. These facts suggest that W-7 produces relaxation of isolated vascular strips by inhibiting actin and myosin interaction.

Actomyosin↗
PubMed1977

Relaxation of isolated aorta of the rabbit by picolinic acids.

1 When the isolated thoracic aorta of the rabbit was contracted with prostaglandin F2alpha, 5-alkylpicolinic acids produced dose-dependent relaxations. 2 Picolinic acid, 2,5-pyridinedicarboxylic acid and 5-acetylpicolinic acid which do not have the 5-alkyl residue failed to relax blood vessels. 3 The vascular relaxation was dependent on the number of carbon atoms in the 5-alkyl compounds. 4 Relaxations which occurred with 5-alkylpicolinic acids were not affected by pretreatment with either propranolol or atropine. 5 It is concluded that the 5-alkyl residue is necessary for the vascular relaxation with 5-alkylpicolinic acid and that it was not produced by stimulation of beta-adrenoceptors or cholinoceptors but rather through an activation of the basic process.

Aminophylline↗
PubMed1977

Histotoxic properties of carbon monoxide in the living organ I. Fluorometry of oxidation-reduction state of the rabbit kidney in situ.

Effect of carbon monoxide on the redox state and blood flow in the renal cortex of the rabbit was examined by the fluorometric method. By a short-period (1-3 min) inhalation of CO in concentrations over 1%, the following were revealed: (1) Reduced pyridine nucleotide was increased, (2) oscillatory change of the reduced pyridine nucleotide, which is characteristic for the histotoxic reaction, developed, and (3) extent of the fluorescence changes tended to be in proportion to the concentration of CO, but no change was caused by inhalation of CO in lower concentrations (0.1%, 0.5%) even if the inhalation was continued for 30 min. As to the blood flow, CO in concentrations over 0.5% decreased it, whereas anoxia due to nitrogen increased it. Some implications were discussed from toxicological points of view on the results obtained.

Animals↗
PubMed1976

Stabilization of configurational states and enzyme activities in subcellular fractions after fixation with extremely low concentrations of glutaraldehyde.

The activities of various enzymes in some subcellular organelle fractions were examined after fixation in glutaraldehyde of various concentrations. A high speed centrifuge was used to shorten the fixation time. At the lowest concentration (0.01%) glutaraldehyde stabilized instable configurational states of mitochondria as revealed by electron microscopy. In addition, at this concentration, at least 70% of the original monoamine oxidase, ATPase and cytochrome oxidase activities were preserved. The activity of acid phosphatase, on the other hand, was enhanced in a lysosomal fraction when fixed with the aldehyde at higher concentrations, e.g. 0.1% and 1.0%. It is possible that the aldehyde at higher concentrations has the same effects on the lysosomal membrane as freeze-thawing. Glucose-6-phosphatase activity was well-preserved in a microsomal fraction fixed with 0.01% glutaraldehyde but was decreased drastically when the concentration of the aldehyde was greater than 0.05%.

Adenosine Triphosphatases↗
PubMed1976

Steroidogenesis in the zona glomerulosa of the adrenal coretx. I. Isolation and some properties of mitochondria from the zona glomerulosa of the bovine adrenal cortex.

Isolation procedures for mitochondria from the zona glomerulosa of the bovine adrenal cortex are described and the properties of the mitochondria thus prepared are compared with those isolated from the zona fasciculoreticularis. The cristal membranes of mitochondria in the zona glomerulosa in situ are tubular or tubulovesicular, whereas those of mitochondria in the zona fasciculoreticularis in situ are vesicular. When mitochondria are isolated from the former zone, they invariably showed the condensed configuration regardless of isolation media, whereas those isolated from the latter zone in an ST medium showed the orthodox configuration. When Ca2+ was added to mitochondria isolated either from the zona glomerulosa or the zona fasciculoreticularis in an STE medium in the condensed configuration, a transition from the condensed to the orthodox configuration tool place; the cristal membranes of mitochondria from the zona glomerulosa became tubular or tubulovesicular and those of mitochondria from the zona fasciculoreticularis became vesicular. Contaminations of mitrochondria of the zona glomerulosa with other cellular organelles were examined using various marker enzymes. There was no difference in cytochrome content between mitochondria of the two zones specified above. The coupling efficiency of mitochondria of the zona glomerulosa was found to be remarkably effected by temperature during the isolation procedures. Effects of various substrates, isolation media, and bovine serum albumin on the coupling efficiency of mitochondria of the zona glomerulosa are also described.

Adrenal Cortex↗
PubMed1976

Steroidogenesis in the zona glomerulosa of the adrenal cortex. II. Distribution of cytochrome P-450 in the zona glomerulosa of the bovine adrenal cortex.

Microsomes were obtained from the zona glomerulosa of the bovine adrenal cortex. Contamination of microsomes with other cellular organelles was examined using various marker enzymes and the electron microscope. Distribution of cytochrome P-450 in mitochondria and in microsomes was determined to be 0.73 and 0.32 nmol/mg protein, respectively. The CO difference spectrum was affected not only by the concentration of added deoxycholate but also by the incubation time after addition. Approximately 40-50% of cytochrome P-450 in the samples was converted to cytochrome P-420 within 20-30 sec of incubation with deoxycholate. The content of RNA, phospholipids, and cytochrome b5 in microsomes obtained from the zona glomerulosa is also evaluated in comparison to that in microsomes obtained from the zona fasciculoreticularis.

Adrenal Cortex↗
PubMed1976

Zonation of the adrenal cortex. II. Effect of BSA on coupling efficiency of mitochondria isolated from the zona glomerulosa of the bovine adrenal cortex.

Effect of bovine serum albumin on coupling efficiency of mitochondria isolated from the zona glomerulosa of the bovine adrenal cortex in various media was examined polarographically and electron microscopically. Albumin restored the coupling efficiency of mitochondria isolated from the zona glomerulosa regardless of isolation media when succinate or malate was oxidizable substrate. Respiratory controls greater than 5 were obtained. Albumin, however, had no effect when glutamate, beta-hydroxybutylate and pyruvate were the oxidizable substrates. The conditions have been found under which mitochondria of the zona glomerulosa stay in the orthodox configuration and yet coupled.

Adrenal Cortex↗
PubMed1976

Accuracy of diagnosis of cancer among autopsy cases: JNIH--ABCC population for Hiroshima and Nagasaki.

The accuracy of death certificate diagnoses of cancer in the fixed population of about 100,000 samples in Hiroshima and Nagasaki was determined for the period 1961 approximately 1970 by comparison with autopsy findings. In general, when the death certificate listed cancer as a cause of death it was found at autopsy in a high proportion of cases. However, cancer was not always reported on death certificates, indicating that cancer occurs more frequently than recorded by official mortality statistics. Older persons, persons who die at home, and persons with certain cancers are more likely not to have cancer named on their death certificates. It is estimated that in the 10,749 deaths occurring at home or in hospital, there were 32% more deaths due to cancer than certified on death certificates (3,095 vs. 2,345) and for persons aged 70 or more dying at home it is estimated there were 55% more stomach cancer (269 estimated vs. 174 listed) and 244% more lung cancer (141 estimated vs. 41 listed) than were certified on death certificates. The death certificate is not a good source of information for cancer of the cervix because many cases of this disease reported on death certificates as cancer of the uterus. This practice needs to be taken into account in the use of mortality data for cervical cancer in Japan.

Age Factors↗
PubMed1976

Zonation of the adrenal cortex. III. Distribution of cytochrome P-450 in the zona glomerulosa of the bovine adrenal cortex.

A microsomal fraction was obtained from the zona glomerulosa of the bovine adrenal cortex. Glucose-6-phosphate activity of the fraction was found to be much lower than that of the liver. Contents of RNA and phospholipids, besides electron microscopic findings, of the fraction also indicate that it is rich in smooth-surfaced endoplasmic reticulum. Distribution of cytochrome P-450 in the zona glomerulosa was studied using various fractions including the microsomal fraction described above. The amount of cytochrome P-450 in mitochondria and that in microsomes were determined to be 0.73 and 0.32 nmoles/mg protein, respectively. The CO-difference spectrum was affected not only by the concentration of added deoxycholate but also by the incubation time after addition. Approximately 40-50% of cytochrome P-450 in the samples were converted to cytochrome P-420 within 20-30 seconds of incubation with deoxycholate.

Adrenal Cortex↗