Hormonal regulation of potassium shifts during graded exhausting exercise

Serum potassium, aldosterone and insulin, and plasma adrenaline, noradrenaline and cyclic adenosine 3':5'-monophosphate (cAMP) concentrations were measured during graded exhausting exercise and during the following 30 min recovery period in six untrained young men. During exercise there was an increase in concentration of serum potassium (4.74 mmol.l-1, SEM 0.12 at the end of exercise vs 3.80 mmol.l-1, SEM 0.05 basal, P less than 0.001), plasma adrenaline (2.14 nmol.l-1, SEM 0.05 at the end of exercise vs 0.30 nmol.l-1, SEM 0.02 basal, P less than 0.001), plasma noradrenaline (1.10 nmol.l-1, SEM 0.64 at the end of exercise vs 1.50 nmol.l-1, SEM 0.05 basal, P less than 0.001), serum aldosterone (0.92 nmol.l-1, SEM 0.14 at the end of exercise vs 0.36 nmol.l-1, SEM 0.05 basal, P less than 0.01), and plasma cAMP (35.4 nmol.l-1, SEM 2.3 at the end of exercise vs 21.4 nmol.l-1, SEM 4.5 basal, P less than 0.05). While concentrations of serum potassium, plasma adrenaline and cAMP returned to their basal levels immediately after exercise, those of plasma noradrenaline and serum aldosterone remained elevated 30 min later (1.90 nmol.l-1, SEM 0.01, P less than 0.01; and 0.85 nmol.l-1, SEM 0.12, P less than 0.01, respectively). Serum insulin concentration did not change during exercise (6.47 mlU.l-1, SEM 0.58 at the end of exercise vs 5.47 mlU.l-1, SEM 0.41 basal, NS) but increased significantly (P less than 0.02) at the end of the recovery period (7.12 mlU.l-1, SEM 0.65).(ABSTRACT TRUNCATED AT 250 WORDS)