Erythrocyte and leucocyte sodium and potassium transport systems during long-term diuretic administration in men.
The effect of xipamide on the intracellular concentration and transmembrane fluxes of Na+ and K+ was studied in 12 normal male subjects, using a double-blind cross-over design. After a run-in period on placebo for 1 week, the subjects were treated with either placebo (n = 6) or xipamide 20 mg once a day (n = 6) for 16 weeks and were then switched to the alternative medication for another 16 weeks. The intra-erythrocyte and intra-leucocyte Na+ concentration was increased by 11 and 7%, respectively, during xipamide administration, while the intracellular K+ concentration was decreased by 3 and 4%, respectively. No significant effect of xipamide could however be demonstrated on the ouabain-sensitive, bumetanide-sensitive or ouabain-bumetanide-resistant 86Rb uptake and on the maximal 3H-ouabain binding in erythrocytes and leucocytes. The red cell Na+-Li+ countertransport was also not changed in the xipamide-treated subjects. Our data suggest that the increased intracellular Na+ concentration and the decreased K+ concentration in red and white blood cells of xipamide-treated subjects cannot be attributed to changes in the activity of the Na+ pump, the Na+-K+ cotransport or Na+-Li+ countertransport system or to changes in the number of active Na+ pump units.
Lijnen
P
P
Department of Pathophysiology, University Hospital Gasthuisberg, University of Leuven, Belgium.
Hespel
P
P
Fagard
R
R
Staessen
J
J
Goossens
W
W
Lissens
W
W
Amery
A
A
D000328:Adult; D001693:Biological Transport, Active / Q000187:drug effects; D002463:Cell Membrane Permeability / Q000187:drug effects; D004232:Diuretics / Q000008:administration & dosage*; D004311:Double-Blind Method; D004912:Erythrocytes / Q000187:drug effects* / Q000378:metabolism; D006801:Humans; D007962:Leukocytes / Q000187:drug effects* / Q000378:metabolism; D008297:Male; D010919:Placebos; D011188:Potassium / Q000032:analysis / Q000378:metabolism*; D011897:Random Allocation; D012964:Sodium / Q000032:analysis / Q000378:metabolism*; D014988:Xipamide / Q000008:administration & dosage*
D004232:Diuretics; D010919:Placebos; D014988:Xipamide; D012964:Sodium; D011188:Potassium