Erythrocyte transport function in cystic fibrosis.

ATPase activity and monovalent cation transport were examined in erythrocytes (RBC) of 
subjects with cystic fibrosis (CF). The RBC membrane (Ca2+)ATPase activity of 
homozygous patients and obligate heterozygotes was indistinguishable from that of normal 
control subjects. This was true similarly for total, ouabain-sensitive, and ouabain-insensitive 
(Na+-K+)ATPase. Total, ouabain-sensitive, and ouabain-insensitive 24Na+ transport were normal in CF 
cells. Ouabain-induced Na+ accumulation was similar in CF and normal RBC. 
Measurements of K+ transport in CF RBC were, likewise, normal. We 
conclude that intrinsic ATPase and monovalent transport functions are normal in 
CF RBC. We were unable to confirm several abnormalities in these 
cells reported previously. The CF RBC is not helpful in defining 
a transport abnormality in that entity. These studies document normal intrinsic 
transport function in RBC of patients with CF. There have been 
reports of an abnormal serum factor in patients with CF. This 
factor might be involved in the production of a transport defect 
in CF. Further studies are indicated to determine whether CF plasma 
contains a factor capable of altering membrane transport functions of normal 
RBC. 