Swelling-Stimulated Passive Potassium Transport in Camel Erythrocytes: Inhibitory Effects of Furosemide and Sodium Fluoride

The inhibitory effects of furosemide, sodium fluoride, and age on volume-dependent, ouabain-resistant K+ influx were investigated in camel red blood cells. Swelling of young camel erythrocytes hypotonically stimulates ouabain-resistant potassium influx, a response that was lacking in old camel erythrocytes. The swelling-stimulated influx was partially inhibited by 1 mM furosemide and by 10 and 20 mM sodium fluoride. The inhibitory effect of furosemide was significantly increased if rubidium was added to the flux media. There was a significant correlation between potassium influx in normo-and hypotonic media which might indicate that the anion-dependent transport system operates, to some extent, to regulate cell volume.