Analysis of 6-keto-prostaglandin F1 alpha in human urine: age-specific differences.

A radioimmunoassay (RIA) for the estimation of 6-keto-PGF1 alpha in human urine is described in detail. The RIA method was validated by direct comparison to gas chromatography-mass spectrometry. In adults and in one year old children basal excretion of 6-keto-PGF1 alpha was found to be lower than that reported for PGE2 or PGF2 alpha. However, during the first week of life, significantly more 6-keto-PGF1 alpha was excreted. The very high levels of 6-keto-PGF in urine seen on the third day of life seemed already to decrease during the first week of life. It is concluded that prostacyclin may have a major role for kidney function in the newborn, possibly by protecting the immature kidney from high levels of angiotensin II.