Cation transport and membrane potential properties of primary astroglial cultures from neonatal rat brains.

摘要: This paper describes K+ and Na+ content transport in primary monolayer cultures from dissociated newborn rat brains, considered to consist predominantly of astroglial cells. Net changes cation after addition ouabain, steady state fluxes using 86Rb+ as a marker for 22Na+ Na+, were measured. The results found indicate that the cells maintained conventional pattern homeostasis with net efflux being balanced by its active uptake extrusion mediated ouabain sensitive (Na+K) pump. These processes internal measured K+:Na+ ratios 12--25:1. normally flat but DBcAMP caused them round up form numerous processes, an appearance resembling vivo. treatment also reduced levels 15--30%, had no effect on initial rates uptake. membrane potentials treated studied, since only these easily impaled. separate groups gave means ranging --65 --75 mV at 35 degrees C, external concentration ([K+]o) 4.5 mM. dependence individual [K+]o was studied. slope potential per 10-fold change 55--57 mV, concentrations greater than 10--20 mM K+, diverged this below this. shows some permeability ions other K+. Assuming ion affecting potential, it calculated about 30 times less A similar result obtained based estimates experiments DBcAMP. are compared those cultured glial We conclude used present study show closest resemblance so far glia vivo, they large negative determined mainly However, have different properties reported studies vivo showing free