Abstract
To investigate the interrelationship between the renin-angiotensin-aldosterone system and prostaglandin system, plasma renin activity, plasma aldosterone concentration, urinary sodium excretion, urinary prostaglandin E excretion and blood pressure were determined before and after administration of indomethacin, a prostaglandin synthetase inhibitor, during sodium depletion with furosemide administration and low sodium diets in 11 patients with essential hypertension. With the addition of indomethacin, plasma renin activity decreased from 52.9±8.6 ng/ml to 8.5±1.3 ng/ml, plasma aldosterone concentration from 20.4±3.7 ng/100 ml to 5.4±1.3 ng/100 ml, and urinary prostaglandin E excretion from 330.1±58.8 ng/day to 168.8±32.8 ng/day. Significant positive correlation was found between the change of plasma renin activity and that of urinary prostaglandin E excretion (r=0.73, p<0.01). The addition of indomethacin did not produce any significant change in urinary sodium excretion (from 78.0±10.6 mEq/day to 61.2±11.6 mEq/day); whereas indomethacin administration diminished the hypotensive effects of furosemide administration and low sodium diets. The present results show that renal prostaglandin E may be one of the regulators of renal renin release, and that the use of indomethacin, an antiinflammatory drug frequently prescribed in recent years, may diminish the hypotensive effects of furosemide and other diuretics.
