Increased Prostacyclin Generation in Minipig Vascular Tissue After Atherogenic Diet

The effect of an atherogenic diet on PGI₂-generation was studied in 24 miniature pigs fed a diet consisting of 25.6% lard, 2.65% peanut oil, 2.65% cholesterol and 69.1% commercial minipig chow. In all the minipigs the abdominal aortic endothelium was detached with an arterial embolectomy catheter. Prostacyclin generation in the thoracic and abdominal aorta and pulmonary artery was assessed in terms of inhibition of platelet aggregation compared with the effect of a synthetic standard. Blood and tissue lipid levels and the morphology of the arteries and different organs were examined. PGI₂-formation was greater in the pulmonary artery, followed by thoracic and abdominal aorta. Balloon catheterization caused a 50% decrease in PGI₂-synthesis. PGI₂-production increased with ascending blood and tissue lipid levels; at the highest serum cholesterol level (1147 mg%) saturation of PGI₂-release by the thoracic aortic segment was observed. In control animals (4) PGI₂-generation in thoracic and abdominal aortic segments was 35% lower in the male than in the female pigs.