Thoracic aorta prostacyclin production is not altered during early atherosclerosis development in young swine

Abstract

Decreased prostacyclin synthesis by atherosclerotic vascular tissue has been demonstrated in both adult animal models and man. The purpose of this study was to determine whether the decrease in prostacyclin synthesis by the vessel wall was evident during the initial stages of atherosclerosis development and thus a potential contributor to atherogenesis. Thirty-two Yucatan miniature swine entered the study at 3 months of age and were placed on either an atherogenic or regular diet for 10, 30, 90, or 180 days. At that time, the thoracic and abdominal aorta were harvested. Pairs of discs were punched out of the distal thoracic aorta and placed in Krebs Henseleit HEPES buffer. The buffer was then exchanged for either fresh buffer or stimulated with calcium ionophore A23187 (10 −4 m ). Aliquots were collected at 10 min for analysis of prostacyclin production by radioimmunoassay of its stable metabolite 6-keto-prostaglandin F 1α . Thoracic aorta sections were prepared for atherosclerosis assessment by light microscopy, and the abdominal aorta was stained with Sudan IV. No significant differences were noted between the diet groups at 10 and 30 days. After 90 days, a significant difference was noted ( P P > 0.05) were noted between the diet groups with regard to the basal and stimulated rates of prostacyclin production. Our findings showed that prostacyclin synthesis was not altered during the initial development or early progression of aortic atherosclerosis induced by hypercholesterolemia.