Plasma prostaglandins, renin, and catecholamines at rest and during exercise in hypertensive humans.

Plasma prostaglandins (PGE and PGF alpha), catecholamine concentration, and plasma renin activity (PRA) were measured during an uninterrupted graded exercise test on the bicycle ergometer in 11 hypertensive patients. Blood was withdrawn from the brachial and pulmonary arteries after 30 min of recumbent rest, after 15 min of rest sitting, and at the final work load of the exercise test, which averaged 143 +/- 16.5 W. Exercise did not provoke a significant change in these plasma PGE or PGF alpha concentrations, whereas a rise (P less than 0.001) in arterial PRA and (nor)epinephrine concentration was observed. It is thus unlikely that PGE or PGF alpha is an important determinant of PRA release during exercise, although circulating levels of PGE and PGF alpha do not necessarily reflect release rate or activity in the kidney.