Administration of elastase blocks the formation of fragmented elastic fibers in aorta of rabbit.

Fragmented elastic fibers are known to be associated with atherosclerotic lesions, angitis and age-related changes of the vessel wall. We produced fragmented elastic fibers in the thoracic aorta by immunizing rabbits with elastin peptides. Fragmented elastic fibers in the media were associated with degenerative smooth muscle cells, and the number of fine elastic fibers beneath the endothelium was decreased. The lesion presented here resembled age-related changes of the vessel wall. We also evaluated the influence of elastase administration on the formation of this lesion. In rabbits receiving elastin immunization with simultaneous intraperitoneal administration of elastase, fragmented elastic fibers were apparently decreased and the appearance of the elastic fibers resembled that of normal rabbits. These data suggest the possibility that administered elastase blocks the formation of fragmented elastic fibers in the aortic wall.