| Abstract: | The possibility of fine structural deformation related to skin biopsy and the subsequent immersion fixation procedure were investigated, because little attention has yet been focused on artifacts of the dermal microvasculature. Contraction of the material following biopsy removal was marked in skin regions with thin epidermis and resulted in capillary collapse. As the collapse of the vessels increased, lining cells became thicker and more rugged, endothelial fenestrations disappeared, and 10 nm filaments aggregated. Simultaneously, perivascular connective tissue material was separated from the dermal element in which the vessels were embedded and appeared as a homogenous areola around the endothelial tube. Basal lamina appeared folded and partially multilaminated around the vascular circumference, particularly in the venous segment of the microvasculature; these are considered to be the definite characteristics of dermal capillaries. In contrast to the skin regions with thin epidermis, the vessels in “well developed” dermal papillae did not collapse and bore close similarities to the perfused ones. The present study indicates that most of the so-called characteristics of dermal capillaries in biopsy skin is attributable to artifacts following the removal of the skin before fixation. |
