Analysis of curves Na-24 efflux from membrane labyrinth containing stria vascularis

The efflux of Na-24 was investigated in isolated labyrinths from a membrane section containing stria vascularis and spiral ligament in artificial endolymph medium. The efflux curves were calculated and compartmental analyses were made. The theoretical possibility of a exchange of sodium between compartments connected in different ways was considered. The calculated values of rate constant of transmembranal sodium fluxes are 0.0282+/-0.0052 min-1 and the half-time of the exchange of sodium between intracellular compartments is 24.27+/-4.53 min. The distribution of sodium in tissue with a commonly applied simplification gives 90% Na+ in the extracellular compartment and 3% Na+ in the intracellular compartment of the total tissue sodium content. The possibility of measuring the rate constant of transmembranal electrolyte fluxes in this tissue seems encouraging for future investigation of the mechanism by which they are transported.