Cation transport in mouse erythrocytes: role of K(+)-Cl- cotransport in regulatory volume decrease.
We investigated cation transport and cell volume regulation in erythrocytes of CD1 and C57/B6 mice. Swelling of cells from either strain stimulated K+ efflux that was insensitive to ouabain, bumetanide, and clotrimazole. Seventy-five percent of swelling-induced K+ efflux was Cl- dependent (inhibited by sulfamate or methanesulfonate, partially by NO3-, but not by SCN-) and was inhibited by okadaic acid (OA; 50% inhibitory concentration = 18 +/- 6 nM in CD1 and 10 +/- 4 nM in C57/B6). In both strains, K+ efflux into isotonic medium was stimulated by staurosporine or by N-ethylmaleimide, and the latter was partially blocked by pretreatment of cells with OA. When cells of either strain were incubated in hypotonic medium or preswollen isosmotically with nystatin, OA-sensitive regulatory volume decrease (RVD) and K+ loss were observed. RVD produced by hypotonic swelling was prevented by Cl- replacement with sulfamate or methanesulfonate. These properties suggest the presence in outbred and inbred mouse erythrocytes of RVD mediated by K(+)-Cl- cotransport.
Armsby
C C
CC
Department of Laboratory Medicine, Children's Hospital, Boston, Massachusetts, USA.
Brugnara
C
C
Alper
S L
SL
D000818:Animals; D001692:Biological Transport; D002034:Bumetanide / Q000494:pharmacology; D002352:Carrier Proteins / Q000378:metabolism*; D002412:Cations / Q000378:metabolism*; D004351:Drug Resistance; D004912:Erythrocytes / Q000166:cytology* / Q000378:metabolism*; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D008815:Mice, Inbred Strains; D010042:Ouabain / Q000494:pharmacology; D011188:Potassium / Q000378:metabolism; D027981:Symporters; D000096922:K Cl- Cotransporters
D002034:Bumetanide; D002352:Carrier Proteins; D002412:Cations; D010042:Ouabain; D011188:Potassium; D027981:Symporters; D000096922:K Cl- Cotransporters