Aortic glycosaminoglycans in atherosclerosis-susceptible and -resistant pigeons

Abstract

Quantitative electrophoretic profiles of glycosaminoglycans (GAGs) in the upper thoracic aorta and at the celiac bifurcation were obtained from atherosclerosis-susceptible White Carneau (WC) and atherosclerosis-resistant Show Racer (SR) pigeons at four ages ranging from 1 day to 3 years. While thoracic aortas of WC and SR pigeons contained similar total amounts and similar amounts and profiles of the five individual GAGs (hyaluronic acid, heparitin sulfate, dermatan sulfate, chondroitin 4-sulfate, and chondroitin 6-sulfate) at each age, celiac sites did not show these similarities. Celiac sites in WC pigeons contained more total GAG than corresponding SR sites at all four ages, and, after 6 months of age, WC foci showed an increased amount of chondroitin 6-sulfate, decreased amounts of heparitin sulfate and chondroitin 4-sulfate, and a lower chondroitin 4-sulfate/chondroitin 6-sulfate ratio when compared with corresponding SR celiac foci. In addition, heparitin sulfate in preatherosclerotic and moderately atherosclerotic WC celiac foci was more heterogeneous than in the thoracic aorta of either breed or in SR celiac foci. Differences in GAG content between sites also existed, since the thoracic aorta contained more total GAGs than the celiac foci at each age examined. These findings indicate that changes in aortic GAG content occurring with age are different than those related to atherogenesis and suggests a role for specific GAGs in the pathogenesis of atherosclerosis.