Myoendothelial contacts in the small arterioles of human kidney

Human renal biopsies were examined electron microscopically to investigate the intercellular relationships between endothelium and smooth muscle in renal arterioles. Three types of contacts were seen occurring through perforations in the basal lamina. These were classified by their origin either, from an endothelial cell, from a smooth muscle cell or from both. The cell processes involved were usually irregular but some were identified as club-shaped. The nature of the contacts was predominantly via simple appositions with an intercellular space of 6.9-13 nm. These myoendothelial contacts may play an important role as sensors of hypertensive load.