Beta adrenergic modulation of extrarenal potassium disposal in terminal uraemia

In order to study the effect of epinephrine on potassium (K) metabolism, an epinephrine infusion (0.1 micrograms/kg/min for 30 min) was carried out in 12 essentially anuric and usually hyperkalaemic haemodialysis patients, 72 hr post-dialysis. Two groups emerged, group I (five patients) serum K decreased at least 0.75 mEq/L (from 6.6 +/- 0.2 to 5.4 +/- 0.1 mEq/L) and there were increases in heart rate, serum glucose and insulin values, group II (seven patients), serum K did not decrease and heart rate remained unchanged, but serum glucose and insulin increased slightly. Plasma renin, aldosterone and arterial pH did not change in either group. Propranolol blocked the epinephrine induced decrease in serum K in group I patients. Patients from group II had higher pre-infusion endogenous epinephrine concentrations than patients from group I. In haemodialysis patients beta adrenergic stimulation enhances extrarenal K disposal but about 50 per cent of patients fail to respond, perhaps because of receptor occupancy due to higher endogenous epinephrine concentrations.