Potassium transport in lamprey (Lampetra fluviatilis) erythrocytes: evidence for K+ channels.
1. Unidirectional K+ (86Rb) influx in lamprey red blood cells was studied under different conditions. 2. The influx of 86Rb was markedly inhibited by 1 mM Ba2+ when cells were incubated in saline containing 4 mM K+. In K(+)-free media, the influx rate constant of 86Rb was lower, and 1 mM Ba2+ had no blocking effect. 3. Treatment of the red cells with 0.1 mM ouabain in the absence of external K+ resulted in the appearance of the component of 86Rb influx inhibited by 1 mM Ba2+, quinine, TEA or amiloride. 4. Similar results were obtained in red cells incubated in Na(+)-free media MgCl2-sucrose. 5. The results obtained provide evidence for the existence of K+ channels in the red cell membrane of the lamprey. Under physiological conditions (in the presence of 4 mM K+) the total rate constant for the 86Rb influx in erythrocytes was about 1.9/hr, including ouabain-sensitive (0.6/hr), Ba(2+)-sensitive (1.1/hr) and residual (0.2/hr) components.
Institute of Evolutionary Physiology and Biochemistry, Academy of Sciences of U.S.S.R., Leningrad.
G P
GP
Gusev
A O
AO
Sherstobitov
I A
IA
Skulskii
D000584:Amiloride / Q000494:pharmacology; D000818:Animals; D001464:Barium / Q000494:pharmacology; D001692:Biological Transport; D002118:Calcium / Q000378:metabolism; D004912:Erythrocytes / Q000378:metabolism*; D007798:Lampreys; D015636:Magnesium Chloride / Q000378:metabolism; D011188:Potassium / Q000378:metabolism*; D015221:Potassium Channels / Q000378:metabolism*; D011803:Quinine; D012414:Rubidium Radioisotopes; D012964:Sodium / Q000378:metabolism; D013395:Sucrose / Q000378:metabolism; D013662:Tea
D015221:Potassium Channels; D012414:Rubidium Radioisotopes; D013662:Tea; D015636:Magnesium Chloride; D001464:Barium; D013395:Sucrose; D000584:Amiloride; D012964:Sodium; D011803:Quinine; D011188:Potassium; D002118:Calcium