[Characteristics of the electrophysiological parameters of the embryonic cell membranes in the loach during Na+, K+-ATPase inhibition].

Influence of ouabain on changes in transmembrane potential (TMP) and the membrane conductance has been studied in developing embryos of the loach Misgurnus fossilis L. Ouabain does not cause any significant changes in TMP level within 10-15 min after treatment but the membrane was then depolarized to a degree depending on developmental stage. Exposure to ouabain increases the conductance and changes the selectivity of membranes. Reversion potential of ionic current is then decreased from -70- -100 to -5- -30 mV. It is supposed that gradual membrane depolarization owing to the decrease of K+ gradient favors the membrane conductance changes under the influence of ouabain. It has been established that the active transport of Na+ and K+ takes part in realization of the rhythm of TMP level periodical oscillations during synchronous cleavage division.