THE aorta consists of elastin, collagen and a number of other proteins; it also contains about 2 per cent of carbohydrate1. Elastin is usually isolated from aorta or ligamentum nuchae by treatment with acids and alkalis at elevated temperatures; however, a small amount of ill-defined carbohydrate appears to be held strongly and cannot be easily removed2. It is possible that this sugar moiety is an integral part of elastin.