Biomedical subjects

T Shingai

Publications and source records attributed to T Shingai.

28 records · Page 2Linked to original sources

PubMed1987

Differences in drinking behavior between normal and laryngectomized man.

The properties of drinking in normal and laryngectomized groups were examined. Drinking associated with meals was more frequent in the 76 young and 37 older normal subjects than the 25 laryngectomized persons. The laryngectomized group preferred tea and coffee to water to alleviate thirst sensation, while such a preference was hardly seen in either normal group. Results suggest that the larynx may contribute not only to thirst sensation but may be associated with preference in drinking.

Adult↗

PubMed1985

Response characteristics of three taste nerves in mice.

Gustatory responses from 3 nerves, the chorda tympani, glossopharyngeal and superior laryngeal nerves were investigated in the mouse. Stimuli were NH4Cl, NaCl, KCl, HCl, quinine-HCl, sucrose, urea, glucose and distilled water. The 3 nerves responded differently to these stimuli. The chorda tympani responded strongly to HCl and sucrose, but weakly to quinine-HCl, while the glossopharyngeal responded well to quinine-HCl rather than to either HCl or sucrose. The order of effective stimulation was NH4Cl greater than NaCl greater than KCl for the chorda tympani, whereas NH4Cl greater than KCl greater than NaCl for the glossopharyngeal nerve. The responses of the superior laryngeal nerve were remarkably different from those of the others. Water was the most effective stimulus for the nerve and the response to water was depressed by either electrolytes or non-electrolytes added in water. These results suggest dissimilar contributions of the 3 nerves to the physiological functions.

Animals↗

PubMed1980

Water fibers in the superior laryngeal nerve of the rat.

Water responses elicited by application of water on the laryngeal mucosa were observed in the superior laryngeal nerve fibers in the rat. The response was augmented by K+ ions and was depressed by Na+ ions, while anions (Cl--, F--, SO42--, benzoate) showed no noticeable effect.

Action Potentials↗

PubMed1979

Physicochemical study of receptive mechanism of laryngeal water fibers in the rabbit.

The effects of various cations on the water unit activity were studied by recording unitary discharges in the superior laryngeal nerve fibers of the rabbit. Chloride salts of Li+, Na+, K+, Cs+ depressed the water response, while sulfate salts of Li+, Na+, NH4+, K+ facilitated it. Cations were less effective in stimulating action than anions. The depression of the water response in the laryngeal nerve has been thought to be caused by permeation of the stimulating anions through the receptor membrane and/or by destruction of the water structure on the membrane surface induced by adsorbed anions (SHINGAI, 1977 a). In order to differentiate these two possible actions of anions, the effects of benzenesulfonate and trichloroacetate were examined, because these anions were expected to be impermeant through the receptor membrane and to have a water structure-breaking effect. These anions showed no effect on the water response in concentrations below 320 mM. Measurements of the viscosity and the density of the electrolyte solutions showed that benzenesulfonate had a strong water structure-breaking effect. These results suggested that impermeant anions having water structure-breaking actions do not influence the excitability of the water receptor and that the depression of the water response by anions in the stimulating solution is caused by a hyperpolarization generated by permeation of the anions through the receptor membrane.

Animals↗

PubMed1977

Ionic mechanism of water receptors in the laryngeal mucosa of the rabbit.

The effects of various ions on water response was studied by recording unitary discharges in single superior laryngeal nerve fibers of the rabbit. The water response was strongly influenced by anions. The inorganic anions used were divided into two groups. One group consisted of anions which depress the water response (depressing anions), the depressing action sequence being SCN- greater than Br- greater than than Cl- greater than I- greater than NO-3. Another one consisted of anions which facilitate the water response (facilitating anions), the facilitating action sequence being citrate greater than SO34- greater than IO-3 greater than F- greater than BrO-3 greater than acetate. Physicochemically, facilitating anions belong to "the water structure-making ions" group; on the other hand, depressing anions belong to "the water structure-breaking ions" group. SO34- weakened the depressing effect of Cl- when the concentration of Cl- was below 60 mM, and enhanced it when the concentration was above 60 mM. Na+ and Li+ had no appreciable effect on the water unit activity, but K+ had a weakly stimulating effect. It is concluded that an outflux of anions through the membrane stimulates the water receptor while an influx of anions depresses it, and SO34- facilitates Cl- permeability. The mechanism of the facilitating effect of SO24- on Cl- permeation is discussed in terms of the interaction between the water structure surrounding the ions and the receptor membrane.

Animals↗

PubMed1976

Reflex swallowing elicited by water and chemical substances applied in the oral cavity, pharynx, and larynx of the rabbit.

Water and various chemical solutions were applied to the oral cavity, pharynx, and larynx of anesthetized rabbits to study their effects on the swallowing reflex. Laryngeal stimulation: Water was an effective stimulus in eliciting reflex swallowing; NaCL depressed this reflex. The effect of salt solutions on swallowing was dependent on anion species. Weakly hydrated anions had a depressing effect while greatly hydrated anions had a facilitating effect. The order of the depressing effect of the anions was Br-greater than SCN- greater than CL- congruent to NO3 -, and the order of the facilitating effect of anions was citrate greater than SO42 - greater than HCO3-. Oral and pharyngeal stimulation: Water elicited swallowing; however, this effect was less marked than that in the larynx. NaCL in concentrations lower than 200 mM had a depressing effect while at higher concentration it had a facilitating effect. Sucrose, acetic acid, and alcohol evoked successive swallowing in the first two or three trials. It was found that water applied to the laryngeal region had the marked effect of eliciting reflex swallowing and that most gustatory substances infused into the oral and pharyngeal regions had a facilitating effect on the initation of swallowing.

Acetates↗

PubMed1974