Effect of membrane potential on furosemide-inhibitable sodium influxes in human red blood cells |
| |
Authors: | George R Kracke Philip B Dunham |
| |
Institution: | (1) Department of Biology, Syracuse University, 13244 Syracuse, New York |
| |
Abstract: | Summary Furosemide-inhibitable Na influx (a measure of Na/K/Cl cotransport) was determined as a function of membrane potential in human red blood cells. The membrane potential was varied from –42 to +118 mV using valinomycin and gradients of K. The furosemide-inhibitable, unidirectional Na influx was independent of membrane potential over the entire range of potentials. The change in flux per mV, 0.443 mol/(liter cells·hr· mV), was not significantly different from zero. The mean flux was 153±16 mol/(liter cells·hr) (±sem,n=71). The ouabain and furosemide-resistant influexes of Na and K were also measured as functions of membrane potential using either valinomycin and K or a chloride-free, tartrate flux medium to vary membrane potential. The unidirectional Na influx decreased slightly as the membrane potential was increased from negative potentials to about +10 mV. At higher membrane potentials Na influx rose dramatically with potential. This increase was not reversible and was also observed with K influx. |
| |
Keywords: | Na/K/Cl cotransport furosemide valinomycin erythrocytes DIDS |
本文献已被 SpringerLink 等数据库收录! |
|