Coordinated regulation of Na/H exchange and [K-Cl] cotransport in dog red cells.
Swelling-activated [K-Cl] cotransport and shrinkage-activated Na/H exchange were studied in dog red cells with altered internal Mg or Li content. The two pathways responded in a coordinated fashion. When cells were depleted of Mg, [K-Cl] cotransport was stimulated and Na/H exchange was inhibited. Raising internal Mg had the opposite effect: [K-Cl] cotransport was inhibited and Na/H exchange was stimulated. Li loading, previously shown to stimulate Na/H exchange, inhibited [K-Cl] cotransport. From these reciprocal effects and from other evidence, we surmise that the regulation of Na/H exchange and [K-Cl] cotransport is conducted and coordinated by a discrete mechanism that responds to changes in cell volume and is sensitive to cytoplasmic Mg and Li concentrations.
Parker
J C
JC
Department of Medicine, University of North Carolina, Chapel Hill 27599.
McManus
T J
TJ
Starke
L C
LC
Gitelman
H J
HJ
D000818:Animals; D000001:Calcimycin / Q000494:pharmacology; D002352:Carrier Proteins / Q000097:blood*; D002712:Chlorides / Q000097:blood*; D004285:Dogs; D004912:Erythrocytes / Q000378:metabolism*; D007700:Kinetics; D008094:Lithium / Q000494:pharmacology; D008274:Magnesium / Q000494:pharmacology; D011188:Potassium / Q000097:blood*; D017923:Sodium-Hydrogen Exchangers; D027981:Symporters; D000096922:K Cl- Cotransporters
D000001:Calcimycin; D002352:Carrier Proteins; D002712:Chlorides; D008094:Lithium; D008274:Magnesium; D011188:Potassium; D017923:Sodium-Hydrogen Exchangers; D027981:Symporters; D000096922:K Cl- Cotransporters