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H Mutoh

Publications and source records attributed to H Mutoh.

At least 73 records · Page 4Linked to original sources
PubMed1990

Protective role of intracellular glutathione against ethanol-induced damage in cultured rat gastric mucosal cells.

This study investigated whether intracellular glutathione is cytoprotective against ethanol-induced injury to cultured rat gastric mucosal cells in vitro. Secondly, it investigated whether reduced glutathione or oxidized glutathione is responsible for this cytoprotection. Cytolysis was quantified by measuring 51Cr release from prelabeled cells. Concentrations of ethanol greater than 12% caused cell damage and increased 51Cr release in a dose-dependent and time-related fashion. When a substrate for glutathione synthesis, N-acetyl-L-cysteine, was provided to cultured cells for 4 h before challenge with ethanol, cytolysis was significantly decreased corresponding with an increase in cellular glutathione content. Pretreatment with diethyl maleate, which depletes reduced glutathione without forming oxidized glutathione, potentiated ethanol-induced cell damage in a dose-dependent manner with the decrease of cellular glutathione content. The administration of tert-butyl hydroperoxide (which is specifically reduced by glutathione peroxidase to generate oxidized glutathione from reduced glutathione) or diamide (which nonenzymatically oxidizes reduced glutathione to oxidized glutathione) enhanced ethanol injury. We conclude that in cultured gastric mucosal cells, (a) intracellular glutathione maintains integrity of gastric mucosal cells against ethanol in vitro; and (b) reduced glutathione rather than oxidized glutathione is responsible for this cytoprotection. We postulate that the presence of reduced glutathione is essential to allow glutathione peroxidase to catalyze the ethanol-generated toxic oxygen radical, hydrogen peroxide.

Acetylcysteine↗
PubMed1990

Role of oxygen radicals in ethanol-induced damage to cultured gastric mucosal cells.

We have examined the role of oxygen radicals in ethanol-induced damage to cultured rat gastric mucosal cells. Cultured cells exposed to ethanol produced superoxide anion, as assessed by the reduction of cytochrome c, in a time-related fashion. The production of superoxide anion increased dose dependently as the concentration of ethanol increased. Cellular damage increased in a similar fashion to the production of superoxide anion. Both superoxide dismutase (SOD) and catalase diminished ethanol-induced injury dose dependently. SOD and catalase were able to maintain their enzymatic activities in the presence of 15% ethanol, respectively. Pretreatment with deferoxamine, an iron-chelating agent, decreased ethanol-induced injury dose dependently. Furthermore, dimethyl sulfoxide decreased ethanol-induced damage dose dependently. We conclude that cultured gastric mucosal cells exposed to ethanol generate oxygen radicals and that the production of oxygen radicals is closely linked with ethanol-induced damage to the cells. Hydroxyl radical, produced by the iron-catalyzed Haber-Weiss reaction, seems to be the main mediator of ethanol-induced damage to gastric mucosal cells in vitro.

Animals↗
PubMed1990

Ultrasound-guided percutaneous injection of ethanolamine oleate for hypersplenism. An experimental study in dogs.

In order to evaluate a possible therapy for hypersplenism, an experiment with animals was done. In nine dogs, 0.6 ml/kg body weight of 5% ethanolamine oleate was injected percutaneously into the spleen under ultrasound guidance. The injection was repeated three times at intervals of 1 week. Three dogs each were killed at 1, 4, and 8 weeks after the final injection. All dogs tolerated the procedure well and lived until they were killed. The platelet count and leukocyte count increased after the injections, and remained higher than the pretreatment level until death. This effect probably is due to depressed splenic function. The autopsy showed 40% of the spleen to be infarcted with complete destruction of the normal structure. No serious complications occurred. In addition, injection of ethanolamine oleate in six fully heparinized dogs showed that there was little risk of hemorrhage. Ultrasound-guided percutaneous injection of ethanolamine oleate might be a simple and effective therapy for hypersplenism.

Administration, Cutaneous↗
PubMed1989

Effect of adenosine and adenosine analogs on [14C]aminopyrine accumulation by rabbit parietal cells.

Adenosine receptors that modulate adenylate cyclase activity have been identified recently in a number of tissues. Adenosine A2 receptor is stimulatory to adenylate cyclase, whereas adenosine A1 receptor is inhibitory to adenylate cyclase. We investigated the effect of adenosine and its analogs on [14C]aminopyrine accumulation by rabbit parietal cells. Rabbit gastric mucosal cells were isolated by enzyme digestion. Parietal cells were enriched by nonlinear percoll gradients. [14C]Aminopyrine accumulation was used as an indicator of acid secretion. The effect of 2-chloroadenosine on histamine-stimulated [14C]aminopyrine accumulation was studied. The effects of N-ethylcarboxamideadenosine, 2-chloroadenosine, stable analogs of adenosine, and adenosine on [14C]aminopyrine accumulation were assessed. Cyclic AMP content of parietal cells was determined by radioimmunoassay. Histamine and carbachol, known secretagogues, stimulated [14C]aminopyrine accumulation. 2-Chloroadenosine did not suppress histamine-stimulated [14C]aminopyrine accumulation. 2-Chloroadenosine, N-ethylcarboxamideadenosine, and adenosine dose dependently increased [14C]aminopyrine accumulation. The order of potency was N-ethylcarboxamideadenosine greater than 2-chloroadenosine greater than adenosine. 8-Phenyltheophylline and theophylline, adenosine-receptor antagonists, or cimetidine did not have significant effects on the increase of AP uptake induced by 2-chloroadenosine. Coadministration of dipyridamole, and adenosine uptake inhibitor, augmented the effect of adenosine on [14C]aminopyrine accumulation. 2-Chloroadenosine, N-ethylcarboxamideadenosine, and adenosine each induced a significant increase in cellular cyclic AMP. We conclude that there may be adenosine A2 receptors on rabbit parietal cells which modulate gastric acid secretion.

2-Chloroadenosine↗
PubMed1989

[Establishment and characterization of a tumor marker producing cell line (JR-1) derived from a gastric scirrhous cancer].

Despite the importance of in vitro study of gastric cancer, the established cell lines derived from human gastric carcinoma are very few. We have recently established a new cell line derived from human gastric cancer which has the ability to produce several tumor markers. This cell line has been designated JR-1. The cancer cells were obtained from the cerebrospinal fluid of a 37 year-old female patient who had metastatic brain tumor of the poorly differentiated gastric adenocarcinoma. The cells were inoculated into the tissue culture flask containing Ham's F-12 medium supplemented with 10% fetal bovine serum, antibiotics. Within 24 hours, the cells attached to the surface of the flask and started to grow. The first subcultures were performed at 1 week, and subsequent subcultures have been done once a week. This cell line has been maintained for more than 15 months through 60 passages with a stable growth. Chromosome analysis of the cells was performed. The doubling time of the 20th passage was 72 hours. Under phase contrast microscopy, monolayered pavement-like cell arrangement was observed. PAS staining showed intracellular mucin granules. Transmission and scanning electron microscopy revealed spindle-shaped cells with numerous microvilli and fine projections as well as intracellular granules, indicating mucin. Tumor markers produced by this cell line were CEA, CA19-9, TPA and Procollagen III.

Adenocarcinoma, Scirrhous↗
PubMed1981

Freeze-fracture study on the whorls of rough endoplasmic reticulum in the exocrine pancreatic cells of the Japanese newt and African clawed toad.

The whorls of rough endoplasmic reticulum (rER) in the exocrine pancreatic cells of starved newts and clawed toads were examined by a freeze-fracture technique. The whorl appeared to be roughly ovoidal in shape and composed of tightly packed, narrow cisternae arranged like the layers of an onion. The clusters of interdigitating projections of the cisternal membranes were located at several places on the whorl. Some of these projections extended to the vesicular rER around the whorl. The fenestra-like, raised or hollowed craters were seldom seen on the fractured membrane faces of the whorls in the exocrine pancreatic cells of the starved newts.

Animals↗
PubMed1981

Comparative ultrastructural study of the Ito cells in the liver in some reptiles.

The Ito cell (fat-storing cell) in the liver of the lizard, snake and turtle was studied by electron microscopy. The Ito cell was positioned in the perisinusoidal space of Disse and contained characteristic fat droplets in all of the animals studied. The fat droplets in the Ito cells of turtles, fed commercially obtained pig liver, were numerous and large. The Ito cells contained fewer and smaller fat droplets in the lizards and snakes, caught in their natural habitat and sacrificed. There were frequently Ito cells without fat droplets, designated as empty Ito cells, in the snake liver. Dilated cisternae of rough endoplasmic reticulum were found in the Ito cells of the lizard and snake liver, but they were absent from the Ito cells of the turtle liver. It is suggested that the nutritional state of animals, especially the vitamin A concentration in the food, might induce these differences in the Ito cell.

Adipose Tissue↗