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Biomedical subjects

Y Shiba

Publications and source records attributed to Y Shiba.

At least 109 records · Page 6Linked to original sources
PubMed1978

Further study on the effect of mersalyl, an organic mercurial, on relaxing response of a molluscan smooth muscle to monoamines.

The effect of mersalyl on the relaxation of catch by various monoamines was studied in the anterior byssal retractor muscle of Mytilus. As has already been reported, mersalyl blocked the relaxing response to indoleamines but not block that to catecholamines. The relaxations in response to catecholamine-related compounds (dopa, octopamine, tyramine, phenylephrine, beta-phenylethylamine and phenylethanolamine) and hexylamine were, however, antagonized more or less effectively with mersalyl. It was suggested that the catecholamine-related compounds and hexylamine can act on relaxing nerve endings to increase neurotransmitter serotonin in the junctional clefts, and mersalyl antagonizes the relaxation in response to these compounds by blocking the serotonin.

Animals↗
PubMed1978

Effects of heavy metal ions on the electrical properties of mucous epithelial cells in the newt stomach.

Zinc ion, Cu2+ and Cd2+ at 10(-4) M or lower concentrations caused a marked decrease in the membrane potential of mucous epithelial cells in the isolated newt stomach without appreciable change in the effective membrane resistance and electrical coupling ratio. Cysteine and acetylpenicillamine antagonized the action of these ions. These ions as well as ouabain blocked the hyperpolarization of membrane due to an increase in intracellular Na+. The effect of the ions on the relationship between external K+-concentration and membrane potential was similar to that of ouabain. Discussion is made on the possibility that the ions inhibit active ion transport by combining with a SH-group of the cell membrane and, thus, bring about a decrease in membrane potential.

Animals↗
PubMed1977

Energy requirement for the maintenance of membrane potential in rat liver cells in situ.

The transmembrane potential of female rat liver cells in situ was-52.4 mV. This was decreased to -42.9 mV by ethacrynic acid (4 mg/100 g), but not by ouabain (1 mg). DL-Ethionine (25-100 mg) caused a decrease in the membrane potential and tissue ATP content. A high dose ethionine (100 mg) increased tissue Na content and decreased K content. By applying adenine (25 mg) to the animals treated with ethionine (100 mg), the membrane potential, ATP content and K content were increased and the Na content was decreased. The repolarized membrane potential in the animals treated with adenine following the ethionine was again depolarized by the administration of ouabain, but not by the administration of ethacrynic acid. These results suggest that two kinds of active ion transport mechanisms, ethacrynic acid-sensitive and ouabain-sensitive mechanisms, may be involved in maintenance of the membrane potential of rat liver cells.

Adenine↗