Glycosaminoglycan content is increased in dissecting aneurysms of human thoracic aorta.

Ten thoracic aortas were obtained from cases of dissecting aneurysms and 10 from age-matched controls. Full wall thickness samples (1 cm diameter) were taken at 12 sites for both groups. Content, concentration and ratio to total glycosaminoglycan (GAG) were determined for chondroitin sulphate (CS), hyaluronate (HA), heparan sulphate (HS) and dermatan sulphate (DS). When compared with controls, content of CS and HS increased over the whole length of dissected aortas, whereas increased HA and DS were localised to dissected areas of affected aortas as were increased tissue mass and collagen and elastin content. Changes in concentration and ratios, significant for some GAGs and consequent upon these increases, may help to compromise the mechanical properties of the aortic wall. The localised increases in HA and DS content in areas where collagen and elastin were increased suggests that these GAGs are functionally related to these fibrous proteins in aorta, whereas CS and HS are not.