ACID MUCOPOLYSACCHARIDES OF HUMAN AORTA .2. VARIATIONS WITH ATHEROSCLEROTIC INVOLVEMENT

Concentrations of acid mucopolysaccharides (MPS) in the aortic intima and outer layers (externa) with varying extent and severity of atherosclerosis have been studied in Negro females. An increase initially, followed by a decrease, of MPS concentrations was observed as the disease extended from 10-55%. The increase of MPS was characteristic of the fatty streaks and the decrease characteristic of fibrous plaques, complicated and calcified lesions. Chondroitin sulfate B concentrations paralleled the extensiveness of the fatty streaks while it was almost absent in intimal tissue from vessels with fibrous plaques. The chondroitin sulfate B increase may represent an intimal reaction, the disappearance of which coincides with advancement of the disease. It appears that the variations in concentration of MPS in the aorta represent diffuse metabolic changes. Certain early changes predispose to the initiation of atherosclerosis, but progression of the disease is associated with a marked alteration of the content of specific MPS.