Plasma Potassium and Phosphate Concentrations—Influence by Adrenaline Infusion, β-blockade and Physical Exercise

ABSTRACT. Ljunghall S, Joborn H, Rastad J, Åkerström G (Departments of Internal Medicine, and Surgery, University Hospital, Uppsala, Sweden). Plasma potassium and phosphate concentrations—influence by adrenaline infusion, β-blockade and physical exercise. Acta Med Scand 1987; 221:83–93. Infusion of adrenaline into healthy male subjects reduced the plasma concentrations of both potassium and phosphate to a similar extent, in a dose-dependent manner, an effect which was prevented by the administration of propranolol. Ergometer bicycling until exhaustion, which caused marked accumulation of lactic acid in the blood and reduction of pH, induced great elevations of both plasma potassium and phosphate with close relationships between the raised plasma concentrations and the reduction in pH, also during β-blockade. However, longer-term aerobic exercise, without acidosis, also caused some rise of the potassium and phosphate concentrations. During recovery from anaerobic, but not from aerobic, exercise there was a rapid decrease of the plasma potassium levels while the phosphate values normalized gradually together with pH. From measurements of the ion concentrations both in the femoral effluent of one leg, which carried out maximal isokinetic work, and in the opposite antecubital vein it could be calculated that there was for potassium, but not for phosphate, a post-exercise uptake both in the exercised muscle and in the entire organism, indicating the participation of systemic factors.