Abstract
Behaviors of acid mucopolysaccharides (aMPS) in cystic medionecrosis of the great vessels in 6 cases of Marfan syndrome, were histochemically studied in comparison with arteriosclerotic aneurysms (in 3 cases of dissecting aneurysms and 2 cases of non-dissecting aneurysms), syphilitic aneurysms (in 3 cases), pulmonary hypertension (in 2 cases of chronic cor pulmonale, 2 cases of mitral valvular diseases and 2 cases of primary pulmonary hypertension), and 20 cases of control subjects with ageranging from 2 years to 89 years old. The analysis was made by digestion method using enzymes such as testicular hyaluronidase, streptomyces hyaluronidase and chondroitinase AC and ABC.
The results were as follows.
1) The aortas in Marfan syndrome had spindle shaped aneurysm, dissecting aneurysm, and aortic valvular insufficiency macroscopically in all cases and microscopically showed high grade of cystic medionecrosis. The pulmonary arteries in Marfan syndrome showed macroscopically no such lesions, but microscopically showed some cystic medionecrosis in all cases. Variety of the cystic medionecrosis in the pulmonary arteries depended on the grade of hemodynamic load on them.
2) Behaviors of aMPS in the aortas and pulmonary arteries in Marfan srndrome were completely identical in each case, though the main components of aMPS were different case by case. The aMPS in the great vessels of Marfan syndrome consisted of hyaluronic acid or chondroitin sulfate AC as major component, and of chondroitin sulfate B as decreased or minor component in all cases.
3) The grade of cystic medionecrosis of the aortas in control subjects and cases with pulmonary hypertension was generally low except the old with hypertension.
4) In a part of the cases with dissecting and saccular aneurysms due to arteriosclerosis and syphilis, the grade of cystic medionecrosis was considerably high and the aMPS with various fractions (chondroitin sulfate ABC, hyaluronic acid and the others) was deposited in the portion of cystic medionecrosis in the aortas.
5) The metabolism of aMPS in smooth muscle cells in the great vessels of Marfan syndrome might be considered to be congenitally different from that of the other diseases, and the great vessels seemed to be abiotrophically exhausted through hemodynamic overload and to be followed by cystic medionecrosis.
