The measurement of urinary prostaglandin E in normal subjects and in high-renin states.

Antisera generated toward PGE was obtained from rabbits immunized with PGE2 conjugated to bovine thyroglobulin by the carbodiimide reaction. The specificity of the antibody is such that only PGE1 and PGE2 has significant cross-reactions. 13, 14-Dihydro and 15-keto PG's did not react. An RIA capable of measuring 6 pg of PGE2 was developed to measure PGE in human urine. Urine samples adjusted with buffer to pH-5 are extracted with 5% MeOH in CH2CI2 and chromatographed through Sephadex LH-20 columns. The second-antibody technique is used to separate bound from free. This urine method yields blank values of 2 +/- 2 pg per sample, with a between-assay precision determined by duplicate analysis of 14% and intra-assay precision of 8%. The mean urinary excretion rate is 500 +/- 74 (S.E.), +/- 209 (S.D.) ng/day (n = 8) in men and 300 +/- 70, +/- 242 (n = 12) in women. These values are in agreement with those reported by others using gas chromatography-mass spectrometry of receptor assay with hepatic plasma membranes. Patients in a high-renin state, whether normotensive or hypertensive, have elevated PGE in urine. These studies suggest a relationship between the renin-angiotensin system and renal PG's in man.