[Electrophysiological study of frog eggs at different stages of development. II) Outward rectification in oocytes at the final stage of vitellogenesis].
Voltage-clamp experiments in full-grown frog oocytes, in a range of membrane potentials from 90 mV negative to 30 mV positive, have revealed the presence of voltage-dependent channels selective for K+, blocked by extracellular TEA. The percentage of open K+-channels increases with membrane depolarizations over a range from -40 mV to +10 mV, thus supporting the outward rectification in the I/V relationship. The current transport through the K+-channels open at different potential levels and in various [K+]o takes place in accordance with the constant-field assumptions. The leakage current of the oocyte membrane was found to be considerable large.
D000818:Animals; D004594:Electrophysiology; D005260:Female; D007473:Ion Channels / Q000502:physiology*; D008433:Mathematics; D008564:Membrane Potentials; D009865:Oocytes / Q000502:physiology*; D011188:Potassium / Q000378:metabolism; D011893:Rana esculenta; D014818:Vitellogenesis
D007473:Ion Channels; D011188:Potassium
Studio elettrofisiologico dell'uovo di rana a vari stadi di sviluppo. II) Outward rectification" nell'oocita allo stadio finale della vitellogenesi.