ABSTRACT
This chapter considers the potential that each of the cells has for interacting immunologically with the other cellular constituents of the dermal microvascular unit (DMU). Very little is known concerning the possibility that the various perivascular cellular components of the DMU might differ in density on the venous and arteriolar sides of dermal capillaries. The thesis that Dermal Microvascular Endothelial Cells have the capacity to participate in cutaneous immunological reactions has its roots in the observation that cultured endothelial cells from large vessels, such as those from umbilical veins, when stimulated can display an immunological phenotype. Phagocytosis has been one of the proposed physiological functions for the dermal dendrocytes. Macrophage-derived factors such as macrophage-derived growth factor and angiotropin have been shown to be capable of stimulating angiogenesis in mammalian skin. Two general categories of mediators have been identified and consist of preformed, granule-associated molecules and formed, unstored mediators which are synthesized at the time of mast cell stimulation.
