Human abdominal aortic aneurysm is closely associated with compositional and specific structural modifications at the glycosaminoglycan level

Human abdominal aortic aneurysm (AAA) is a commonly occuring disease of blo od vessels and is related to alterations in extracellular matrix molecules. In this study we report on the type and fine structural characterization o f glycosaminoglycans (GAGs) present in AAA as compared with those present i n normal abdominal aorta. Hyaluronan (HA), the galactosaminoglycans-chondro itin sulfate (CS) and dermatan sulfate (DS) with average molecular size (M- r) of 35-kDa-as well as heparan sulfate (HS) with M-r of 40-kDa were identi fied in both tissues. No significant intrabatch differences in total GAG co ntent were identified in normal and aneurysmal aortas. Comparing; however, tissue composition and structure of GAGs between AAAs and normal aortas, si gnificant differences (P less than or equal to 0.001) were found. The overa ll GAG content in AAAs was approx. 60% lower than the normal ones. A 90% de crease in HS content, and 65 and 73% in CS and HA, respectively, were also recorded. In contrast, only a slight decrease in the amount of DS was noted (8%). Structural alterations in disaccharide composition of GAGs correspon d mainly to significant decreases (P less than or equal to 0.001) of MS-der ived N-sulfated disaccharides, CS-derived 6-sulfated disaccharide and DS-de rived disulfated disaccharides. These results demonstrate that the developm ent of AAA is related to dramatic quantitative and structural modifications at the GAG level and this may well be attributed to the destruction of art erial wall architecture and further significant functional inadequacies of the tissue. (C) 1999 Elsevier Science Ireland Ltd. All rights reserved.