Aortic Connective Tissue Changes in Miniature Pigs Fed a Lipid-Rich Diet

Abstract

Groups of miniature Hormel-Hanford pigs were made hypercholesterolemic by feeding lipid-rich diets. Aortic proline hydroxylase was elevated by 40% in thoracic aorta and 70% in abdominal aorta of animals maintained on a 3% cholesterol diet for 50 days at which time no evidence of atheroma was observed. Feeding of 6% cholesterol plus 15% lard for 50 days resulted in the production of plaque material in the abdominal aorta. Proline hydroxylase activity in this area was elevated 4-fold compared to control animals. Similar elevations of proline hydroxylase were observed in sections of aortic tissue taken fiom a plaqued area and from sections taken immediately adjacent to the plaque when compared to respective areas in control animals. Increase in proline hydroxylase of a similar magnitude were observed when vascular injury was produced in pigs by the daily injection of norepinephrine.