1. Plasma prostaglandins (PGE and PGFα) and catecholamine concentrations, and plasma renin activity were measured during an uninterrupted graded exercise test on the bicycle ergometer in 11 hypertensive patients. Blood was withdrawn from the brachial and pulmonary artery after 30 min recumbent rest, after 15 min rest sitting and at the final work load of the exercise test, which averaged 143 ± 16.5 W.
2. Exercise did not provoke a significant change in these plasma PGE or PGFα concentrations, but a rise (P < 0.001) in arterial plasma renin activity and (nor)adrenaline concentration was observed. It is thus unlikely that prostaglandins E or Fα are an important determinant of release of plasma renin during exercise.