Abstrakt: |
Summary In 10 K artificial seawater (ASW). D2O replacement reduced the Na efflux of squid axons by about one third. In 0 K ASW, D2O replacement had little effect. D2O reduced the K+ sensitivity of the efllux but increased the affinity for K+. A 4° decrease in temperature mimicked the effects of D2O. When axons were injected with arginine, to decrease the ATP/ADP ratio, they lost K+ sensitivity in normal ASW, as expected. Their efflux into 0 K ASW became D2O sensitive. The results are discussed in terms of conformational changes in the Na pump molecular complex. |