Changes in potassium content and membrane potassium channels in circulating cells from normal volunteers treated with cromakalim.
The effect of cromakalim, a K+-channel activator, on the intracellular concentration and transmembrane fluxes of Na+ and K+, was studied in 18 normal male subjects, using a double-blind parallel study design. After a run-in period on placebo for 1 week the subjects were treated with either placebo (n = 6) or cromakalim (n = 12) for 1 week. Blood pressure was not changed during cromakalim administration in these normal male subjects but heart rate was increased. The intraerythrocyte and intraleucocyte K+ concentration was decreased during cromakalim administration while the Ca2+-dependent K+ channels in the red blood cells were increased. No significant effect of cromakalim could be demonstrated on the intracellular Na+ and Mg2+ concentration, on the ouabain-sensitive or bumetanide-sensitive 86Rb uptake and on the maximal 3H-ouabain binding in erythrocytes and leucocytes. The red cell Na+Li+ countertransport, anion carrier and ground membrane leak of Na+ and K+ were also not changed in the cromakalim-treated subjects.
Department of Pathophysiology, University of Leuven, Belgium.
P
P
Lijnen
T
T
Weiping
R
R
Fagard
J
J
Staessen
A
A
Amery
D000328:Adult; D001578:Benzopyrans / Q000494:pharmacology*; D001794:Blood Pressure / Q000187:drug effects; D019806:Cromakalim; D004311:Double-Blind Method; D004912:Erythrocytes / Q000032:analysis*; D006339:Heart Rate / Q000187:drug effects; D006801:Humans; D007962:Leukocytes / Q000032:analysis*; D008274:Magnesium / Q000032:analysis; D008297:Male; D011188:Potassium / Q000032:analysis*; D015221:Potassium Channels / Q000187:drug effects*; D011758:Pyrroles / Q000494:pharmacology*; D011897:Random Allocation; D012964:Sodium / Q000032:analysis*
D001578:Benzopyrans; D015221:Potassium Channels; D011758:Pyrroles; D019806:Cromakalim; D012964:Sodium; D008274:Magnesium; D011188:Potassium