title: [Contribution of divalent cations to the maintenance of membrane potentials in the oocytes of Pleurodeles waltlii Michah (Amphibia, Urodela)].
abstract: When the external concentration of Ca and Mg is changed, the oocyte membrane potential, in the Urodela Amphibian: Pleurodeles waltlii, is not significantly modified. The addition of chelator agents, EGTA and EDTA in Ca, Mg free Steinberg solution promotes a membrane depolarisation and the rise of membrane conductance. It is concluded that divalent ions Ca++ and Mg++ are needed to maintain a potential difference between internal and external medium of the oocyte.
mesh_terms: D000818:Animals; D001464:Barium / Q000494:pharmacology; D002118:Calcium / Q000494:pharmacology; D002413:Cations, Divalent / Q000494:pharmacology*; D004492:Edetic Acid / Q000494:pharmacology; D004533:Egtazic Acid / Q000494:pharmacology; D005260:Female; D008274:Magnesium / Q000494:pharmacology; D008564:Membrane Potentials / Q000187:drug effects*; D009865:Oocytes / Q000502:physiology*; D010063:Ovum / Q000502:physiology*; D012455:Salamandridae; D013324:Strontium / Q000494:pharmacology
chemical_list: D002413:Cations, Divalent; D001464:Barium; D004533:Egtazic Acid; D004492:Edetic Acid; D008274:Magnesium; D002118:Calcium; D013324:Strontium
vernacular_title: Contribution des cations divalents au maintien du potentiel de membrane des ovocytes de Pleurodeles waltii Michah (Amphibien Urodèle).