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Biomedical subjects

H Satoh

Publications and source records attributed to H Satoh.

At least 955 records · Page 53Linked to original sources
PubMed1980

Prostaglandin production by minced carrageenin granuloma tissue of rats and its inhibition by dexamethasone and cycloheximide.

Seven-day-old carrageenin granuloma tissue of rats, when incubated in organ culture, produced 6-keto-prostaglandin F1 alpha, prostaglandin E2, prostaglandin F2 alpha, and thromboxane B2 in ratios of 16/7/1/1, respectively. Indomethacin (1 microgram/ml) inhibited this cyclooxygenase-mediated arachidonic acid metabolism. Dexamethasone (1 microgram/ml) also inhibited this metabolic cascade. Its inhibitory effect was not immediate; preincubation of the tissue with dexamethasone potentiated its inhibitory effectiveness. Cycloheximide (0.1 to 10 microgram/ml) also inhibited prostaglandin production. The inhibitory mechanism by cycloheximide of prostaglandin production was discussed in relation to that by dexamethasone.

6-Ketoprostaglandin F1 alpha↗
PubMed1980

Purification and properties of a membrane-bound phospholipase A2 from rat ascites hepatoma 108A cells.

A phospholipase A2 bound tightly to the particulate fractions of rat ascites hepatoma cells was purified approximately 13,000-fold with a reasonably high yield (34%) by extraction with sodium cholate, ammonium sulfate fractionation, solubilization with sodium dodecyl sulfate, column chromatographies on Sephadex G-150 in the presence of sodium dodecyl sulfate, and on DEAE-cellulose and CM-cellulose in the presence of Triton X-100. The enzyme has a unique substrate specificity; namely, it preferentially hydrolyzes phosphatidylethanolamine and, to a lesser degree, phosphatidylglycerol. However, it does not attack phosphatidylcholine, phosphatidic acid or cardiolipin in the present experimental conditions. The final preparation shows both phospholipase A2 and lysophospholipase L2 activities, but neither lysophospholipase L1 nor lipase activity. The purified enzyme has a rather broad pH optimum ranging from 7 to 9, requires Ca2+, and is resistant to heat-treatment at 95 degree C for 5 min.

Animals↗
PubMed1980

Hypotensive effect of captopril in relation to plasma renin activity in anesthetized rats.

the effect of captopril (D-3-mercapto-2-methylpropanoyl-L-proline), a converting enzyme inhibitor, on the systemic blood pressure in pentobarbital anesthetized rats was investigated. Experiments were performed in four groups of rats: untreated, Na-restricted, furosemide treated and bilaterally nephrectomized, respectively. Intravenous injection of 1 mg/kg of captopril caused a significant hypotensive effect in the three groups of rats but not in the nephrectomized group. Individual values for the hypotensive effect produced by captopril and plasma renin activity obtained just before injection of captopril showed a highly significant correlation.

Anesthesia↗
PubMed1980

Modified distribution of methylmercury by additional exposure to elemental mercury or mercuric chloride in mice fed methylmercuric chloride.

Male IVCS mice fed pellets containing 8 nmol methylmercuric chloride (MMC)/g feed for 32 days were additionally inhaled elemental mercury vapor (Hg0) or injected mercuric chloride (Hg2+). The modified distribution of accumulated organic mercury was observed 24 hr after exposure to inorganic mercurials. The body burden of organic mercury decreased significantly in MMC + Hg2+ treated mice and moderately (nor significant) in MMC + Hg0 treated mice when compared with MMC treated mice. In spite of the decreased body burden, the organic mercury levels in brain, kidneys and blood MMC + Hg0 treated mice, and in kidneys of MMC + Hg2+ treated mice were elevated. In bile, organic mercury concentration after Hg0 or Hg2+ exposure was reduced. The decrease of the blood cells-to-plasma ratio of organic mercury in mice after Hg0 exposure is in agreement with the data reported for workers exposed to mercury vapor.

Animals↗
PubMed1980

Dopamine receptor blocking activity of sulpiride in the canine exocrine pancreas.

The inhibitory effect of sulpiride on dopamine receptors was investigated in the exocrine pancreas of dogs anesthetized with pentobarbital and with the stomach ligated at the pylorus. All test substances were given intravenously. Dopamine, acetylcholine, histamine and secretin produced a dose-related increase in pancreatic juice secretion, though the dose-effect curves of these secretagogues differed in shape. Epinephrine, norepinephrine, isoproterenol, methamphetamine and serotonin had no secretagogue effects. The effects of acetylcholine and histamine were inhibited by atropine and cimetidine, respectively. The effect of dopamine was blocked by haloperidol, but not by atropine, cimetidine, phentolamine and propranolol. These results suggest that dopamine acts on specific dopamine receptors related to the exocrine pancreatic secretion. Haloperidol had no effect on the effects of acetylcholine and histamine, but did inhibit the secretin-induced secretion, though the inhibitory effect was to a lesser extent than on the dopamine response. Sulpiride and chlorpromazine also suppressed dose-dependently the dopamine-induced secretion. The inhibitory activity of sulpiride was almost the same as that of haloperidol, and 12 times more potent than that of chlorpromazine. Sulpiride was found to be a potent dopamine antagonist in the canine exocrine pancreas.

Acetylcholine↗
PubMed1980

Human leukocyte antigen (HLA) in patients with idiopathic portal hypertension (IPH).

Both cryptogenic liver cirrhosis and idiopathic portal hypertension without pathological findings of liver cirrhosis (IPH) are relatively common in Japan. To find differrence between IPH and cryptogenic liver cirrhosis of Japanese, we investigated human leukocyte antigen (HLA), familial clustering of liver diseases as well as prevalence of HBs antigen in 31 patients with IPH. The age of patients with IPH ranged between 6 and 67 years old (mean, 40 years). The ratio of female to male in patients with IPH was 3.1. The incidence of chronic liver diseases in the relatives of patients with cryptogenic liver cirrhosis was significantly high (29.1%), whereas that in the relatives of patients with IPH was not high (12.9%) as compared with hospitalized controls (8.9%). The phenotype frequencies of the specificities of HLA A and B loci in patients with IPH did not differ from those in healthy controls. And the incidence of HBs antigen and antibody in patient with IPH (3.2% and 20.7%, respectively) was similar to those in normal subjects in Japan. These findings suggest that IPH in Japan is a different clinical entity from cryptogenic liver cirrhosis and that HB virus may not be one of the main causes of IPH.

Adolescent↗
PubMed1980

[A procedure for recording electroretinogram (ERG) in conscious monkeys, and effects of some drugs (author's transl)].

Stable ERG was successfully recorded using a contact lens-type electrode in conscious cynomolgus monkeys restrained in a monkey-chair with a specially devised head-holder. After adaptation to darkness, single photostimulation evoked ERG consisting of an initial negative wave (a-wave), followed by a positive wave superimposed with oscillatory potentials (b-wave), and a late positive (c-wave). The former two waves were clearly recorded but c-wave was often mixed with artifacts probably due to eye movements. Amplitudes and peak latencies of a- and b-waves increased in progression of dark adaptation and attained to maximum within 20 min. The optimal intensity of photostimulus and time-constant for recording stable a- and b-waves with intermediate amplitudes were found to be 2 joule and 0.1 sec, respectively. The amplitudes and peak latencies (mean +/- s.d.) of a- and b-waves obtained by these conditions were 163.3 +/- 44.9 and 437.0 +/-37.9 microV, and 17.3 +/- 0.5 and 53.5 +/- 3.2 msec, respectively. These waves were reproducible within 25% variations change in a-wave: pentobarbital increased the amplitude of b-wave, whereas ketamine reduced this amplitude. A 3-day treatment with 1,5-di(p-aminophenoxy)pentane (200 mg/kg/day, p.o.), a retinal toxic and behavioral signs of visual dysfunction. Histological abnormality of the retina was also detected. The results indicate that this technique is useful for recording ERG in order to evaluate the effect of chronically treated drugs on visual perception in conscious monkeys.

Adaptation, Ocular↗
PubMed1979

Effects of sodium selenite on methylmercury distribution in mice of late gestational period.

Mercury distribution in pregnant mice, subcutaneously injected with 1.5 or 15.0 mumol/kg of methylmercury chloride (MeHg) and 0, 1.5 or 15.0 mumol/kg of sodium selenite, was investigated. Selenite increased the retention of mercury in maternal brain in every combination of doses. Selenite also increased mercury concentrations in maternal blood except one combination (MeHg 1.5; selenite 1.5 mumol/kg), and the increased mercury was partitioned to red blood cells. The increased mercury retention by selenite was also found in fetal brain.

Amniotic Fluid↗