Disruption of erythroid K-Cl cotransporters alters erythrocyte volume and partially rescues erythrocyte dehydration in SAD mice
J. Clin. Invest. Marco B. Rust, et al. 117:1708 doi:10.1172/JCI30630 [
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Figure 4rbc K-Cl cotransport activity and K
+ content of SAD mice of various
Kcc genotypes.
(
A–
D) K
+ efflux from rbc measured as described in Methods in the presence of Cl
– or upon its substitution by SFA
–, measured under isotonic or hypotonic conditions and in the presence of 500 mM urea added to the isotonic solutions. Gray bars indicate a significant difference between isotonic and stimulated K
+ fluxes. Black bars indicate a significant difference between K
+ fluxes in a single condition in the presence and absence of Cl
–. (
A) The elevated isotonic K-Cl cotransport activity of SAD rbc (compare with WT rbc in Figure
2A) was further stimulated by hypotonicity and by urea. Absence of KCC1 had minimal effect on K-Cl cotransport activity (
B), whereas absence of KCC3 reduced K-Cl cotransport activity (
C), and absence of both KCC1 and KCC3 nearly abolished cotransport activity (
D). (
E) Disruption of KCC1 and KCC3 did not alter rbc K
+ content in the absence of the SAD transgene but rescued nearly completely the reduced K
+ content of SAD rbc. *
P ≤ 0.05.