Erythrocyte sodium transport in dialyzed uremic patients

Abstract

To investigate the status of the Na+ concentration and ionic fluxes in red cells of human subjects with dialyzed chronic uremia, the authors measured the Na(+)-K+ pump activity as well as Na(+)-K+ cotransport (CoT), Na(+)-Li+ countertransport (CTT) and Na+ passive permeability in erythrocytes from 37 normal subjects and 23 chronic uremic patients receiving maintenance hemodialysis. The mean intracellular Na+ concentration [Na+]i value in the pre-dialytic group was significantly lower than that in control subjects (p less than .0001), but tended to recover to the normal value of [Na+]i in the post-dialytic group. The mean intracellular K+ concentration value in the post-dialytic group was significantly higher than that of the control group (p less than .001), but not significantly different from that of the pre-dialytic group. It was found that the Na(+)-K+ pump activity of erythrocytes in the pre- and post-dialytic groups markedly decreased over that of the normal control group with statistical significance (p less than .0001, respectively). The Na(+)-K+ pump activity in the post-dialytic group, however, tended to recover, but not significantly. The rate constant for ouabain-sensitive Na+ efflux in the post-dialytic group was significantly decreased over that of the normal controls (p less than .05). The authors observed a significant decrease of the Na+ CoT value (p less than .001 respectively) and rate constant for Na+ CoT (p less than .05, respectively) in the patients with pre- and post-dialytic uremia vs. that of normal subjects.(ABSTRACT TRUNCATED AT 250 WORDS)

Fig. 1.

Intracellular Na⁺, K⁺ concentration in normal controls and hemodialytic (HD) uremia. ^*p<001, ^**<.0001 vs. control. Mean ± S.M.

Fig. 2.

Na⁺–K⁺ pump activity in normal controls and hemodialytic (HD) uremia. ^*p<.05, ^**p< 0001 vs. control. Mean ± S.E.M.

Fig. 3.

Na⁺ cotransport in normal controls and hemodialytic (HD) uremia. ^*p<.05, ^**p<.01, ^***p<.001 vs. control. Mean ± S.E.M.

Fig. 4.

Li⁺-Na⁺ countertransport in normal controls and hemodialytic (HD) uremia. ^*p<.05 vs. control. Mean ± S.E.M.

Fig. 5.

Passive Na⁺ permeability in normal controls and hemodialytic (HD) uremia. ^*p<. 01. ^**p<.00001 vs control. Mean ± S.E.M. ^*p<.05 vs control. Mean ± S.E.M.