Pflügers Archiv

, Volume 395, Issue 1, pp 84–86 | Cite as

Na and Ca spikes produced by ions passing through Ca channels in mouse ovarian oocytes

  • Shigeru Yoshida
Excitable Tissues and Central Nervous Physiology Letters and Notes


Ovarian oocyte membrane of the mouse was found to be excitable. Ca-dependent action potentials, which were blocked by Co2+, indicated the existence of Ca channels. In addition, Na-dependent action potentials were detected in Ca2+-free solution. These Na spikes were insensitive to tetrodotoxin (TTX) and were blocked by Co2+, Cd2+, or La3+, suggesting that the Na+ goes through the Ca channel instead of the Na channel. Such a Na current has not been reported in other eggs. It is concluded that both Na+ and Ca2+ pass through the Ca channels during excitation in mouse ovarian oocytes.

Key words

mouse ovarian oocytes Ca channels Na spikes 


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Copyright information

© Springer-Verlag 1982

Authors and Affiliations

  • Shigeru Yoshida
    • 1
  1. 1.Department of PhysiologyNagasaki University School of MedicineNagasakiJapan

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