Increase in plasma potassium concentration following indomethacin administration: absence of a role for membrane Na-K ATPase.
To elucidate whether indomethacin-induced hyperkalaemia is due to an inhibition of Na-K ATPase in the membranes, indomethacin (25 mg t.d.s.) was administered to 7 normal subjects for 7 days. This resulted in an increase in plasma potassium concentrations in all 7 subjects: median (range) for the entire group increased from 4.19 (3.98-4.79) mmol/l to 4.29 (4.13-4.87) mmol/l. Leucocytes prepared from these subjects prior to and after indomethacin were tested for 86Rb influx and [3H]-ouabain binding (an index of Na-K ATPase sites). Neither 86Rb influx (total, ouabain sensitive and ouabain insensitive) nor [3H]-ouabain binding changed significantly following indomethacin. We conclude that (a) indomethacin-induced hyperkalaemia is not due to alterations in potassium influx into cells and (b) the modulation of Na-K ATPase sites/activity is in leucocytes not dependent upon prostaglandins.
Padhani
A
A
Department of Chemical Pathology and Human Metabolism, Royal Free Hospital and School of Medicine, London, U.K.
Turaihi
K
K
Junglee
D
D
Menon
R K
RK
Dandona
P
P
D000328:Adult; D005260:Female; D006801:Humans; D007213:Indomethacin / Q000494:pharmacology*; D007962:Leukocytes / Q000378:metabolism; D008297:Male; D008566:Membranes / Q000201:enzymology; D008875:Middle Aged; D010042:Ouabain / Q000378:metabolism; D011188:Potassium / Q000097:blood*; D012414:Rubidium Radioisotopes; D000254:Sodium-Potassium-Exchanging ATPase / Q000378:metabolism*
D012414:Rubidium Radioisotopes; D010042:Ouabain; D000254:Sodium-Potassium-Exchanging ATPase; D011188:Potassium; D007213:Indomethacin