A study of the veil cells around normal, diabetic, and aged cutaneous microvessels.

The veil cells around normal, diabetic, and aged vessels were reconstructed in 3 dimensions by a computer graphics system from 120-140 serial ultrathin sections. The normal vessel was surrounded by a single layer of veil cells which had a wrinkled and pleated surface. The diabetic vessels were surrounded by 3-6 layers of cellular material produced by increased numbers of veil cells and their associated cytoplasmic sheets. The veil cells around aged vessels appeared to have the same length as young and diabetic veil cells but were underdeveloped in their lateral extensions so that they did not cover the vessel circumferentially as well as did the normal veil cells. Preliminary data suggest that young, diabetic, and aged veil cells have the same metabolic activity per unit area of cytoplasm and are of the same length. The abnormal thickness or thinness of the vascular wall of dermal microvessels appears to be related to the degree of development and numbers of veil cells around the vessels rather than any change in their basic metabolic activity from normal.