title: Pulmonary formation of prostacyclin in man.
abstract: The pulmonary formation of prostacyclin (PGI2), as reflected by the difference in concentration of pulmonary and systemic arterial radioimmunoassayed 6-keto-PGF1 alpha, was determined in six healthy waking subjects. The systemic arterial 6-keto-PGF1 alpha levels were low (less than or equal to 50 pg/ml), and no evidence of pulmonary formation and release of the compound was noted. In other experiments systemic arterial 6-keto-PGF1 alpha levels were determined in patients prior to and during artificial ventilation, as well as during and after occlusion of the pulmonary circulation (extra-corporeal circulation, ECC). The arterial 6-keto-PGF1 alpha concentration prior to artificial ventilation was 17 +/- 4 pg/ml, i.e. within the range observed in the healthy subjects. During artificial ventilation the arterial levels of 6-keto-PGF1 alpha increased to 191 +/- 21 pg/ml, suggesting that pulmonary formation of PGI2 was stimulated. In the patients subjected to ECC with occluded pulmonary circulation the arterial content of 6-keto-PGF1 alpha was stabilised at an elevated level (120-170 pg/ml). Following re-establishment of the pulmonary circulation the arterial concentrations of 6-keto-PGF1 alpha increased markedly, to 284 +/- 50 pg/ml. It is suggested that the basal pulmonary formation of PGI2 in man is low or non-existent, and that enhanced formation of the compound in the lungs is a consequence of intervention with normal pulmonary ventilation of perfusion.
mesh_terms: D015121:6-Ketoprostaglandin F1 alpha / Q000096:biosynthesis; D000328:Adult; D000368:Aged; D006348:Cardiac Surgical Procedures; D011464:Epoprostenol / Q000096:biosynthesis*; D005260:Female; D006801:Humans; D008168:Lung / Q000378:metabolism*; D008297:Male; D008875:Middle Aged; D011453:Prostaglandins / Q000096:biosynthesis*; D011863:Radioimmunoassay; D012121:Respiration, Artificial
chemical_list: D011453:Prostaglandins; D015121:6-Ketoprostaglandin F1 alpha; D011464:Epoprostenol