Output of prostaglandins from the rabbit kidney, its increase on renal nerve stimulation and its inhibition by indomethacin.

1. In each of six experiments, prostaglandins were identified in the renal venous blood of the rabbit. The concentrations in renal venous blood were up to 45 times higher than in aortic blood, suggesting that most of the prostaglandins originate from the kidney.2. Prostaglandins E(2), F(2a) and a prostaglandin of the A, C or B series were estimated by biological assay after solvent partition and column or thin-layer chromatography.3. Prostaglandins E(2) and F(2a) were identified conclusively by combined gas chromatography-mass spectrometry.4. Electrical stimulation of the renal nerve increased the output of prostaglandins.5. Indomethacin (10 mg/kg) injected intravenously, reduced the output of prostaglandins into renal venous blood and prevented the increase in output on renal nerve stimulation.