title: Calcium-dependent chloride transient currents in the immature oocyte of the frog, Rana esculenta.
abstract: Transient currents of chloride were studied in the plasma membrane of immature frog oocyte in voltage clamp conditions. The transients appeared to be activated by an influx of Ca2+ from the external medium. The mechanism leading to a surge of intracellular Ca2+ concentration needed at least 30 sec before full recovery. It was inhibited by substituting Ba2+ for Ca2+ in the external medium, or in the presence of La3+, Co2+ and Cd2+, or when external Na+ was replaced by Li+. Verapamil proved ineffective. The data suggest that an intracellular system of Ca-activated Ca-release is present in the frog oocyte, which can be primarily activated by membrane hyperpolarization via an influx of Ca2+ through non-selective channels.
authors: Istituto di Fisiologia Generale, Università di Pavia, Italy.
authors: M
authors: M
authors: Toselli
authors: V
authors: V
authors: Taglietti
authors: F
authors: F
authors: Tanzi
authors: E
authors: E
authors: D'Angelo
mesh_terms: D000818:Animals; D002118:Calcium / Q000494:pharmacology / Q000502:physiology*; D002712:Chlorides / Q000502:physiology*; D004558:Electric Stimulation; D008564:Membrane Potentials; D009865:Oocytes / Q000502:physiology*; D011893:Rana esculenta / Q000502:physiology*
chemical_list: D002712:Chlorides; D002118:Calcium