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H Kohno

Publications and source records attributed to H Kohno.

At least 379 records · Page 21Linked to original sources
PubMed1987

[Effects of dopamine and synthetic atrial natriuretic polypeptide on the release of norepinephrine and epinephrine from the adrenal medulla of rats].

We evaluated the effects of dopamine (DA) and synthetic atrial natriuretic polypeptide (ANP) on the release of catecholamines (CA) from the adrenal medulla. Adrenal glands of male Wistar rats were superfused with Ringer's solution saturated with 95%, O2, 5% CO2 by the use of a continuous flow incubation system, and norepinephrine (NE) and epinephrine (E) concentrations in the perfusate were continuously measured by high pressure liquid chromatography with fluorescent reaction. And the effects of DA and ANP on the CA release were evaluated. Next the effects of metoclopramide (MC), dopamine (D2) antagonist, and glucagon were added in the Ringer's solution, and the changes of NE and E in the perfusate were determined. Basal secretion of NE and E were 0.02-0.04 ng/mg.wet weight/min and 0.05-0.1 ng/mg.wet weight/min, respectively. DA remarkably decreased both NE and E release, and the suppressive effect was dependent on DA concentration in the perfusate. MC clearly raised NE and E release as well as glucagon. The increasing effect of MC was perfectly suppressed by 10(-4) M of DA. But the effect of glucagon was not blocked by the same dose of DA. Alpha rANP (10(-5)M) slightly decreased the releases of NE and E from adrenal medulla, and the magnitude of the effect of rANP was smaller than that of DA. MC significantly increased NE and E release even when the adrenal gland was superfused with Ringer's solution containing 10(-5)M of rANP. These data suggest that the release of CA from adrenal medulla may be regulated by DA, and that the receptors specifically binding to DA may exist in adrenal medulla as well as sympathetic presynaps. We concluded that DA (but not ANP) may play an important role in controlling (suppressing) the activity of sympathoadrenomedullary system.

Adrenal Medulla↗
PubMed1987

Isolation of the hemopexin receptor from human placenta.

A hemopexin receptor detected in detergent-solubilized placental membranes was purified from the human placenta, using hemopexin-Sepharose affinity chromatography. The solubilized membranes exhibited binding sites of 2.77 pmol of hemopexin/mg of protein with a dissociation constant (Kd) of 6.6 X 10(-8) M. The purified receptor has a molecular weight of 80,000, determined on sodium dodecyl sulfate-gel electrophoresis. Immunoinhibition experiments using the antibody against the placental receptor revealed inhibition of binding of 125I-hemopexin to human leukemia K562 and HL 60 cells, thereby strongly supporting that the polypeptide isolated from the human placenta was the hemopexin receptor.

Amino Acids↗
PubMed1987

Cell surface receptor for hemopexin in human leukemia HL60 cells. Specific binding, affinity labeling, and fate of heme.

The binding of 125I-labeled human hemopexin to human leukemia HL60 cell at 4 degrees C was saturable with time and with increasing concentrations of 125I-hemopexin. Scatchard analysis of the binding data revealed the presence of approximately 42,000 binding sites/cell with an apparent dissociation constant (Kd) of 1.0 X 10(-9) M. When cells were incubated with radioactive hemopexin at 37 degrees C, 125I-hemopexin was rapidly bound and then was dissociated after the release of heme. Treatment of surface-bound 125I-hemopexin with divalent lysine-directed cross-linking disuccinimidyl suberate revealed a membrane polypeptide of about 80,000 Da, to which hemopexin is cross-linked. To examine the fate of the internalized heme, lysates from the cells previously incubated with [59Fe]heme-hemopexin complex were analyzed by CM-cellulose and Sephacryl S-200 column chromatography. A considerable amount of the radioactivity was present in the fraction which co-eluted with the myeloperoxidase activity. When myeloperoxidase was isolated from the cells incubated with [59Fe]heme-hemopexin complex by immunoprecipitation with anti-myeloperoxidase antibody, radiolabeled iron associated with myeloperoxidase increased with time, and more than 30% of the radioactivity in the cells was present in the myeloperoxidase. These results indicate that the binding of hemopexin to the surface receptors triggers a release of heme and that this heme is incorporated into the intracellular myeloperoxidase.

Affinity Labels↗
PubMed1987

Evaluation of histamine induced acute inflammation by 67Ga-citrate in conscious rats.

Radioactivity of 67Ga in the paw edema and the edema rate were measured after subcutaneous injection of histamine into the paw of the conscious rat. The radioactivity increased almost parallel with the edema rate following the injection of histamine. The increase in the radioactivity and edema were almost completely prevented by pretreatment with a 10 mg/kg dose of chlorpheniramine, an antihistaminic agent. A good correlation between the edema rate and the radioactivity was demonstrated. These results suggest that 67Ga-citrate is useful for monitoring the process of acute inflammation in the pharmacological evaluation of anti inflammatory drugs. Moreover, there is also a possibility that 67Ga-citrate may be useful in measuring vascular permeability.

Animals↗
PubMed1987

Human liver regeneration after major hepatic resection. A study of normal liver and livers with chronic hepatitis and cirrhosis.

The regenerative process was evaluated in terms of liver size, function, and histology in 28 adults who had major hepatic resection: hepatocellular carcinoma (HCC) in 21, secondary liver cancer from colorectum in four, carcinoma of the gallbladder in one, Klatskin tumor in one, and Caroli's disease in one. There were 22 men and six women. Ages ranged from 17 to 74 years with a mean age of 56.7. All patients with HCC had underlying liver disease: liver cirrhosis in 14 and chronic hepatitis in seven. Extended right lobectomy was done on 10 patients, right lobectomy on 16 patients, and left lobectomy on two patients. The residual liver size was serially estimated with computed tomography (CT) in 15 patients: six with normal liver, five with chronic hepatitis, and four with cirrhosis. A complete restoration of the residual liver size was found within 3 months in 3 and 6 months, respectively, in two patients with normal livers. The liver was enlarged in all patients with the parenchymal diseases but obviously more slowly compared with normal liver. Liver functions were restored normally within 2-3 weeks in patients with normal livers, but hyperbilirubinemia persisted longer in those with chronic hepatitis and cirrhosis. A continuous rise of bilirubin was an ominous sign of liver failure and subsequent death, which occurred in five patients with cirrhosis. Serum alpha-fetoprotein did not rise in accordance with the regeneration. Histologically, evidence of active regeneration with increased mitotic activity was found at 10 and 35 days in those patients with normal livers. Mitosis was not seen in a specimen taken at 7 days. Enlarged cuboidal hepatocytes and cells with basophilic cytoplasm or two nuclei were observed more or less in all specimens. The livers with cirrhosis or hepatitis also showed histologic evidence of regeneration during the first 2 months but substantially less compared with normal liver, which was well supported by the volumetric study of the liver remnants with CT.

Adolescent↗
PubMed1987

[Mode of the anti-allergic action of cepharanthine on an experimental model of allergic rhinitis].

Cepharanthine, a biscouclaurine alkaloid of Stephania cepharantha, has been used for various clinical purposes. Cepharanthine was known to inhibit histamine release from mast cells obtained from sensitized animals. In vitro studies suggested that the mechanism of action of cepharanthine may be ascribed to the membrane stabilizing action. The membrane stabilization may be attained by reducing the elasticity of the membrane. However, in vivo mechanisms of the anti-allergic action of cepharanthine have not been examined. In the present in vivo study, the anti-allergic action of cepharanthine was examined using experimental allergic rhinitis in rats. The locally administered cepharanthine solution (0.1 mg/ml), by perfusing the nasal cavity, inhibited the dye leakage and an increase in lysosomal enzyme activity due to antigen stimulation. This is the reason for the membrane stabilization by cepharanthine. In the metyrapone (20 mg/kg, s.c., 5 days) pretreated rats of the rhinitis models, the anti-allergic action of cepharanthine was weaker. On the other hand, the effect of ketotifen was not altered by such an effect. The experimental results suggest that the anti-allergic mechanism of cepharanthine might be exerted by its membrane stabilizing action and by stimulation of the pituitary-adrenotropic function.

Alkaloids↗
PubMed1987

Effect of sodium citrate on the blood disappearance of 67Ga.

The effect of sodium citrate on the blood disappearance of 67Ga was examined in rats. The half life value of the alpha phase and the initial AUC value (0-60 min) were dose-dependently decreased by sodium citrate. The binding of 67Ga to serum proteins was also dose-dependently inhibited by sodium citrate.

Animals↗
PubMed1987

Utilization of 67Ga-citrate for the measurement of histamine-induced edema in anesthetized rats.

Radioactivity of the histamine-induced paw edema was measured after intravenous injection of 67Ga-citrate in anesthetized rats. The radioactivity was fluctuated almost parallel with the edema rate following subcutaneous injection of histamine. Both the radioactivity and the edema rate were almost equally reduced by pretreatment with chlorpheniramine, an antihistaminic agent. There was a good correlation between the edema rate and the radioactivity. These results suggest that 67Ga-citrate is useful for the pharmacological study of antiinflammatory drugs, or is available for measuring the vascular permeability.

Animals↗
PubMed1987

Cold storage of the rat heart for transplantation. Two types of solution required for optimal preservation.

Two solutions, our cardioplegic solution and Collins' solution, were tested with regard to preservation of the heart under deep hypothermia before transplantation. The setup used was the isolated perfused working rat heart model and 4 hours of preservation at 0 degree C. The following three groups were prepared: Group 1: the heart was arrested with the cardioplegic solution (potassium: 20 mmol/L, sodium: 87 mmol/L) and then flushed with and stored in Collins' solution (potassium: 117 mmol/L, sodium: 10 mmol/L); Group 2: the heart was arrested with and stored in Collins' solution; and Group 3: the heart was arrested with and stored in the cardioplegic solution. The recovery of cardiac function was more satisfactory in Group 1 than in Groups 2 and 3. The increase in lactate was greater, and adenosine triphosphate and total adenine nucleotide were more depleted during storage in Group 2 than in Groups 1 and 3. In Group 3 myocardial sodium accumulation and potassium depletion during storage were greater than in Groups 1 and 2, and myocardial sodium and calcium overload after reperfusion were greater than in Group 1. Myocardial calcium overload after reperfusion in Group 2 was also greater than that in Group 1. These findings plus coronary vascular resistance analysis revealed that Collins' solution damages the heart during arrest procedures and that the cardioplegic solution is less effective for storage of the arrested heart under deep hypothermia. Therefore the heart should be first arrested with the cardioplegic solution and then flushed with and kept in Collins' solution for simple cold storage.

Animals↗