AJP - Endocrinology and Metabolism, Vol 242, Issue 3 171-E177, Copyright © 1982 by American Physiological Society
Urinary excretion of arterial blood prostaglandins and thromboxanes in man
R. D. Zipser and K. Martin
To determine the fraction of the arterial prostaglandin E2 (PGE2),
6-ketoprostaglandin F1 alpha (6-keto-PGF1 alpha), and thromboxane B2 (TXB2)
that is excreted unmetabolized into human urine, the 3H-labeled compounds
were separately infused into the renal artery or brachial vein of 23
subjects. Urine extracts were subjected to sequential chromatography on
thin-layer plates, Sephadex LH-20, and reverse-phase high-pressure liquid
chromatography to isolate the unmetabolized fraction. Dual isotope ratio
techniques were used to identify peak fractions, to assess purity, and to
calculate recovery. Following renal artery infusions, 32.2% of 6-keto-PGF1
alpha, 13.5% of TXB2, and 3.9% of PGE2 were excreted unmetabolized.
Calculated fractional excretion of these compounds on a single transit
through the kidney are approximately 30, 13, and 3.9%, respectively.
Following brachial vein infusion of [3H]prostaglandin I2, 2.7% of the
infusate was excreted as 6-keto-PGF1 alpha, suggesting that circulating
prostaglandin I2 may contribute to urinary 6-keto-PGF1 alpha. When combined
with published measurements of urinary PGE2, 6-keto-PGF1 alpha, and TXB2,
these data can be used to calculate the maximum arterial blood
concentration of these substances. The results indicate that arterial blood
concentration of PGE2, TXB2, and 6-keto-PGF1 alpha in man are only a few
picograms per milliliter or less.
