[Reduction of kidney prostaglandin synthesis in patients with essential hypertension. Stimulating effect of cicletanine].

The purpose of this study was to evaluate the level of renal synthesis of vasodilator and natriuretic prostaglandins I2 and E2 in patients with essential hypertension and to test the effect of cicletanine, a new antihypertensive drug, on the renal synthesis of these prostanoids in hypertensive patients. The first part of the study was carried out in 12 healthy normotensive subjects and in 25 patients of both sexes with essential hypertension. The effect of cicletanine administered in dose of 150 mg was assessed in 10 healthy volunteers and 12 hypertensive patients. The urinary levels of prostaglandins 6-keto-PGF1 alpha (a metabolite of prostacyclin PGI2) and PGE2 were measured (HPLC) by radioimmunoassay after extraction and chromatographic separation. In normal subjects the urinary excretion rate of 6-keto-PGF1 alpha was 134 +/- 26 pg/min and that of PGE2 was 180 +/- 25 pg/min. The corresponding values were significantly lower in hypertensive patients. This defect of PGI2 and PGE2 renal synthesis was found in 64 p. 100 and 72 p. 100 respectively of patients with hypertension. Cicletanine increased the urinary excretion of 6-keto-PGF1 alpha by 45 p. 100 and that of PGE2 by 59 p. 100 in hypertensive patients. It also brought to normal limits the secretion of these prostanoids in these subjects. At the dose of 150 mg the drug stimulated natriuresis significantly and increased glomerular filtration in patients with essential hypertension. This renal effect of cicletanine was acutely reduced by the presence of indomethacin.(ABSTRACT TRUNCATED AT 250 WORDS)