Considerations of aortic elastin chemistry in the genesis of the intimal plaque (Broad-Breasted White turkey)

Abstract

Fragmentation of internal and external elastic membranes occurs in the abdominal but not in the thoracic aorta of the Broad-Breasted White turkey during the early developmental period. In this early period, isolated elastin from the abdominal aorta contains more polar amino acid residues than elastin of the thoracic aorta. Additionally, the relative amount of a chemically unstable elastin cross-link, dehydrolysinonorleucine, is greater in the abdominal as compared to the thoracic aorta during the early developmental and adult periods. Cells of the abdominal aorta exposed to a higher arterial pressure and a greater rate of arterial pressure rise ( dp dt ) and in a region with a higher collagen:elastin ratio (reduced compliance to pulse-pressure-volume deformations) may synthesize a chemically unstable elastin which breaks down in regions of accentuated wall stress. Though these breaks of the internal elastic membranes, modified smooth muscle cells may migrate, proliferate and ultimately synthesize new elastin in forming the intimal plaque.