Comparison of the pulmonary, hepatic and renal extraction of PGI 2 and 6-KETO-PGE 1

Abstract

Prostaglandin (PG)I 2 and 6-keto-PGE 1 were infused into the aortic, arch, femoral vein, renal artery and portal vein in anestized dogs over a dose range to produce aa stable decrease in systemic blood pressure after 7 min of infusion. Mesenteric artery blood flow was measured continously with a non-cannulating electromagnetic flow probe. Parallel log dose-response relationships were seen for decreases in blood pressure and increases in mesenteric blood flow with both prostaglandins when infused into the aortic arch. The dose responses for intra-aortic and intra-aortic and intravenous infusion of PGI 2 were not different shifted to the right with intrarenal and intraportal infusions. With 6-keto-PGE 1 the dose responses after intravenous, intrarenal and intraportal infusions were all shifted to the right. By comparing doses which reduced blood pressure by 10 mm Hg, the extraction of the PGs by the lungs, kidney and liver was calculated. PGI 2 had no significant pulmonary extraction, 31% renal and 75% hepatic extraction. In contrast, 6-keto-PGE 1 had extractions of 40, 66 and 51% for pulmonary, renal, and hepatic vascular beds, respectively. We conclude that 6-keto-PGE 1 is reasonably well extracted by the lungs, kidney, and liver.