The effect of inhibition of prostaglandin synthesis on plasma renin activity and blood pressure in essential hypertension.

The influence of oral indomethacin treatment (75 mg daily for a week) on urinary excretion of prostaglandin (PG) F2alpha, plasma renin activity (PRA), blood pressure (BP) and electrolyte excretion (Na+ and K+) was studied in 21 patients with untreated essential hypertension (9 women and 12 men, aged from 40 to 45 years). PGF2alpha excretion and PRA were markedly suppressed by indomethacin in both sexes. A close correlation was found between the decreases in PGF2alpha excretion and PRA. 13,14dihydro-15keto-PGF2alpha (a metabolite of PGF2alpha) excretion also tended to be lowered during the indomethacin treatment. BP tended to increase but urine volume and electrolyte excretion were unchanged during the indomethacin period. The results suggest that in essential hypertension inhibition of the PG synthesis causes a concomitant suppression in PRA and may slightly increase BP.