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H Kontani

Publications and source records attributed to H Kontani.

39 records · Page 3Linked to original sources
PubMed1976

Effects of metabolic inhibitors and ouabain on static afferent discharges from the isolated frog muscle spindle.

Effects of metabolic inhibitors and ouabain on the rate of afferent discharges from isolated muscle spindle of the bullfrog were examined in vitro to elucidate the mechanism for generating afferent action potentials. Dinitrophenol, NaCN, iodoacetic acid, and ouabain gradually reduced the rate of discharges. These drugs were without direct effect on the nerve axon. The rate of discharges was also reduced by Li+, which is known to be minimally extruded from the interior of cells by an active transport mechanism. The rate of discharges remained approximately 50% in the presence of NaCN or in the absence of oxygen, suggesting that the energy required for the maintenance of the Na+-pump can be supplied to some extent in an anaerobic condition. It appears that the metabolic inhibitors and ouabain reduce the afferent discharges from the frog muscle spindle by affecting the Na+-pump in fibers of nerve terminals.

Afferent Pathways↗
PubMed1976

[Effects of divalent cations on the muscle spindle of frogs].

Afferent discharges were recorded in the nerve from the isolated muscle spindle of the m. extensor longus digiti IV of the bullfrog. Discharges of about 10 Hz generated by a sustained stretch were reduced concentration-dependently when Ca2+, Mg2+ or Mn2+ (1.0 approximately 8.0 mM) was added to normal Ringer's solution containing 2.0 mM Ca2+. In terms of the decrease of discharges following the addition of Ca2+ or Mn2+ (4.0 mM), abortive spikes were observed. With an excess of Mg2+ (4.0 mM), abortive spikes were not apparent. Removal of Ca2+ from the Ringer's solution caused an increase in the rate of discharges, and normal levels were restored by the addition of Ca2+ (2.0 mM), Mg2+ (2.3 mM) or Mn2+ (1.8 mM). Application of much higher concentrations of these ions to the nerve trunk produced no alterations in the conduction of afferent discharges. It appears that Ca2+ in the external medium contributes to the inhibition of the mechanism responsible for generating afferent discharges in the muscle spindle and that Ca2+ action is not specific since Mg2+ and Mn2+ can act as substitutes for Ca2+ to regulate afferent discharges.

Afferent Pathways↗