Differential effects of prostaglandins A1 and A2 on pulmonary vascular resistance in the dog.
The effects of PGA1 and PGA2 were studied in the canine pulmonary vascular bed. Infusion of PGA1 into the lobar artery decreased lobar arterial and venous pressure but did not change left atrial pressure. In contrast, PGA2 infusion increased lobar arterial and venous pressure and the effects of this substance were similar in experiments in which the lung was perfused with dextran or with blood. These data indicate that under conditions of controlled blood flow PGA1 decreases pulmonary vascular resistance by dilating intrapulmonary veins and to a lesser extent vessels upstream to the small veins, presumably small arteries. The present data show that PGA2 increases pulmonary vascular resistance by constricting intrapulmonary veins and upstream vessels. The predominant effect of PGA2 was on upstream vessels and the pressor effect was not due to interaction with formed elements in the blood or platelet aggregation.
D000818:Animals; D001011:Aorta / Q000502:physiology; D001158:Arteries / Q000502:physiology; D016275:Atrial Function; D001794:Blood Pressure / Q000187:drug effects; D003911:Dextrans / Q000494:pharmacology; D004285:Dogs; D005260:Female; D008168:Lung / Q000098:blood supply*; D008297:Male; D010477:Perfusion; D011454:Prostaglandins A / Q000494:pharmacology*; D011651:Pulmonary Artery / Q000502:physiology; D014655:Vascular Resistance / Q000187:drug effects*; D014680:Veins / Q000502:physiology; D014690:Venous Pressure / Q000187:drug effects
D003911:Dextrans; D011454:Prostaglandins A