title: Vasodilator actions of prostaglandin 6-keto-E1 in the pulmonary vascular bed.
abstract: The pulmonary vascular effects of the newly discovered prostacyclin metabolite, 6-keto-prostaglandin E1 (6-keto-PGE1) were investigated in the intact-chest cat. Intrapulmonary injections of 6-keto-PGE1 decreased lobar arterial prefusion pressure in a dose-dependent manner. Inasmuch as pulmonary blood flow was held constant, and left atrial pressure was unchanged, the fall in lobar vascular resistance. Decreases in lobar arterial pressure in response to 6-keto-PGE1 were greatly enhanced when tone in the pulmonary vascular bed was increased by infusion of a stable prostaglandin endoperoxide analog. 6-Keto-PGE1 decreased systemic arterial pressure increased cardiac output and reduced systemic vascular resistance in the cat. Decreases in systemic arterial pressure and systemic vascular resistance were similar when 6-keto-PGE1 was injected into the right or left atrium, suggesting that the substance is not converted to less active metabolites in passage through the feline pulmonary vascular bed. 6-Keto-PGE1 reversed the hypertensive effects of ADP in the pulmonary vascular bed suggesting this agent may inhibit ADP-induced platelet aggregation in small intrapulmonary vessels. These data indicate that 6-keto-PGE1 has marked vasodilator activity in the feline pulmonary and systemic vascular beds and since 6-keto-PGE1 is not inactivated in the lung it could serve as a circulating hormone.
mesh_terms: D000527:Alprostadil / Q000031:analogs & derivatives*; D000818:Animals; D001794:Blood Pressure / Q000187:drug effects; D002415:Cats; D005260:Female; D008168:Lung / Q000098:blood supply*; D008297:Male; D011453:Prostaglandins / Q000494:pharmacology*; D011458:Prostaglandins E / Q000494:pharmacology; D011651:Pulmonary Artery; D012039:Regional Blood Flow / Q000187:drug effects; D014664:Vasodilation / Q000187:drug effects*; D014665:Vasodilator Agents
chemical_list: D011453:Prostaglandins; D011458:Prostaglandins E; D014665:Vasodilator Agents; C022950:6-ketoprostaglandin E1; D000527:Alprostadil