We examined gap junction coupling of descending vasa recta (DVR). DVR endothelial cells or pericytes were depolarized to record the associated capacitance transients. Virtually all endothelia and some pericytes exhibited prolonged transients lasting 10 to 30 ms. Carbenoxolone (100 µM) and 18 glycyrrhetinic acid (18GRA, 100 µM) markedly shortened the endothelial transients. Carbenoxolone and heptanol (2 mM) reduced the pericyte capacitance transients when they were prolonged. Lucifer yellow (LY, 2 mM), was dialyzed into the cytoplasm of endothelial cells and pericytes. LY spread diffusely along the endothelial monolayer while in most pericytes, it was confined to a single cell. In some pericytes, complex patterns of LY spreading were observed. DVR cells were depolarized by voltage clamp as fluorescence of bis(1,3-dibutylbarbituric acid-(5)) trimethineoxonol (DiBAC₄(3)) was monitored ~200 µm away. A 40 mV endothelial depolarization was accompanied by a 26.1 ± 5.5 mV change in DiBAC₄(3) fluorescence. DiBAC₄(3) fluorescence did not change after 18GRA or when pericytes were depolarized. Similarly, propagated cytoplasmic Ca²⁺ responses arising from mechanical perturbation of the DVR wall were attenuated by 18GRA or heptanol. Connexin (Cx) immunostaining showed predominant linear staining of Cx40 and Cx43 in endothelia while Cx37 stained smooth muscle actin positive pericytes. We conclude that the DVR endothelium is an electrical syncytium and that gap junction coupling in DVR pericytes exists but is less pronounced.