Urinary and systemic metabolites of prostacyclin in the perfused rabbit kidney

Rabbit kidneys were isolated and perfused with a solution to which tritiated or unlabeled prostacyclin was added continuously. The ureteral and venous effluents were collected separately and chromatographed. The peaks obtained by high-pressure liquid chromatography were analyzed using gas chromatography-mass spectrometry. The characteristic fragments of dinor-6-keto-PGF1 alpha could be detected from ureteral and venous effluents and represented material corresponding to 9.6 and 9.1% of the radioactivity recovered from chromatography, respectively. In addition, 39.2% (ureteral effluent) and 58.2% (renal venous effluent) of the radioactivity could be identified as 6-keto-PGF1 alpha, the stable in vitro hydrolysis product of prostacyclin. These results show that the kidney is able to degrade prostacyclin by beta-oxidation and that dinor-6-keto-PGF1 alpha formed in the kidney can be detected in both the vascular and urinary compartments.