Interendothelial junctions in kidney vessels.

The interendothelial junctions of all segments of the renal vasculature have been studied in eight species using the freeze-fracture technique. Three types of junctions have been found. Combinations of tight and gap junction elements are characteristic for interlobular arteries and proximal afferent arterioles. Continuous tight junction strands not subdivided into individual particles are typical for the glomerular arterioles close to the glomerulus and the vasa recta. The interendothelial junctions of glomerular and peritubular capillaries and cortical veins are characterized by slight elevations decorated with sparse arrays of particles on the P-face of the endothelial cell plasma membrane.