Injury and Repair in Arterial Tissue in the Rabbit

Abstract

The aortic wall in rabbits was injured by pulling an inflated balloon catheter through the aorta. This was followed by an increase of the RNA-DNA ratio in the aortic wall 3 days after the injury. At the same time, the cathodic lactate dehydrogenase (LDH) isoenzymes composed of M subunits increased. The changes in LDH may reflect tissue hypoxia at the early phase after the injury. At 6 days protocollagen proline hydroxylase activity was increased, suggesting increased capacity for collagen formation in the injured aorta. Two weeks after injury the total content of hydroxyproline and DNA were increased, indicating connective tissue proliferation and hyperplasia in the injured aorta. The biochemical changes were interpreted as a repair response of the arterial connective tissue to injury. Gross arteriosclerosis of the aorta developed simultaneously with the biochemical alterations.