title: Resistance to osmotic lysis in BXD-31 mouse erythrocytes: association with upregulated K-Cl cotransport.
abstract: The decreased osmotic fragility and reduced K+ content of BXD-31 mouse erythrocytes arise from variation at a single genetic locus. We compared ion transport in erythrocytes from BXD-31 mice and the parental strain, DBA/2J. The strains had similar rates for Na-K pump, Na/H exchange, Na-K-2Cl cotransport, Ca2+ activated K+ channel, or AE1-mediated SO4 transport. In contrast, K-Cl cotransport was twice as active in BXD-31 as in DBA/2J cells. Cl- dependent K+ efflux from BXD-31 cells displayed steep activation by acid pH (with maximal transport occurring at pH 6.75), whereas DBA/2J erythrocytes displayed a far less dramatic response to pH. Both strains displayed regulatory volume decrease in response to cell swelling. However, a 62% greater loss of cell K+ via K-Cl cotransport was observed in the BXD-31 strain. Furthermore the decreased osmotic fragility of BXD-31 red blood cells was normalized by treatment with nystatin to achieve normal cell K+ and water content. Thus upregulated K-Cl cotransport induces cell dehydration and K+ deficit in BXD-31 erythrocytes and causes their characteristic resistance to osmotic lysis.
authors.affiliation: Department of Laboratory Medicine, The Children's Hospital, Boston, Massachusetts 02115, USA.
authors.forename: C C
authors.initials: CC
authors.lastname: Armsby
authors.forename: A K
authors.initials: AK
authors.lastname: Stuart-Tilley
authors.forename: S L
authors.initials: SL
authors.lastname: Alper
authors.forename: C
authors.initials: C
authors.lastname: Brugnara
mesh_terms: D017878:4,4'-Diisothiocyanostilbene-2,2'-Disulfonic Acid / Q000494:pharmacology; D000818:Animals; D002034:Bumetanide / Q000494:pharmacology; D002352:Carrier Proteins / Q000097:blood*; D003433:Crosses, Genetic; D004912:Erythrocytes / Q000187:drug effects / Q000502:physiology*; D006400:Hematocrit; D006461:Hemolysis / Q000187:drug effects; D006863:Hydrogen-Ion Concentration; D006982:Hypertonic Solutions; D007038:Hypotonic Solutions; D066298:In Vitro Techniques; D008274:Magnesium / Q000097:blood; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D008811:Mice, Inbred DBA; D008815:Mice, Inbred Strains; D011188:Potassium / Q000097:blood*; D012964:Sodium / Q000097:blood; D028021:Sodium-Potassium-Chloride Symporters; D013045:Species Specificity; D013431:Sulfates / Q000097:blood; D027981:Symporters; D000096922:K Cl- Cotransporters
chemical_list: D017878:4,4'-Diisothiocyanostilbene-2,2'-Disulfonic Acid; D002034:Bumetanide; D002352:Carrier Proteins; D006982:Hypertonic Solutions; D007038:Hypotonic Solutions; D008274:Magnesium; D011188:Potassium; D012964:Sodium; D028021:Sodium-Potassium-Chloride Symporters; D013431:Sulfates; D027981:Symporters; D000096922:K Cl- Cotransporters