Blood vessel structure in Duchenne muscular dystrophy. I. Light and electron microscopic observations in resting muscle.

Skeletal muscle blood vessels from eight patients with documented Duchenne type muscular dystrophy were examined by light and electron microscopy, with particular attention to the capillary-venous bed. The characteristic lesions of vasoactive amine injury were not present. Endothelial degeneration and regeneration also were absent. Lamellation of capillary basement membranes was noted without true hypertrophy or evidence of discontunuities. Thrombus formation and platelet interaction were absent. Lumenal obliteration was not noted at the arterial level. Rarely, venous obliteration was present in association with nodular connective tissue overgrowth. The minimal abnormalities appear to be nonspecific and do not substantiate postulated vascular injury by vasoactive mediators or ischemia. The role of a nonspecific chronic inflammatory reaction with phagocytes derived from the vascular compartment should be considered with respect to those described basement membrane changes.