1. The influence of mental stress, 30 min Kraepelin's arithmetic test under noise on the plasma concentration and urinary excretion of prostaglandin (PG) F2α was studied in patients with essential hypertension and in healthy subjects.
2. Before the arithmetic test the plasma PGF2α in hypertensive patients was significantly higher than in healthy subjects. The mental stress produced a significant increase in plasma PGF2α in healthy subjects but not in patients with essential hypertension.
3. Three hour urine excretion of PGF2a before stress was about two times lower in hypertensive patients than in healthy subjects. After exposure to stress a significant decrease in urinary excretion of PGF2α was found in healthy subjects, but not in hypertensive patients.
4. The stress-induced increase in plasma PGF2α of healthy subjects may reflect elevated brain PGF2α synthesis. The individual differences in response to stress in hypertensive patients may result from specific impairments in synthesis and/or prostaglandin turnover.