Ectonucleotidases in the kidney

摘要: Members of all four families ectonucleotidases, namely ectonucleoside triphosphate diphosphohydrolases (NTPDases), ectonucleotide pyrophosphatase/phosphodiesterases (NPPs), ecto-5′-nucleotidase and alkaline phosphatases, have been identified in the renal vasculature and/or tubular structures. In rats mice, NTPDase1, which hydrolyses ATP through to AMP, is prominent throughout most also present thin ascending limb Henle medullary collecting duct. NTPDase2 NTPDase3, both prefer over ADP as a substrate, are found nephron segments beyond proximal tubule. NPPs catalyse not only hydrolysis ADP, but diadenosine polyphosphates. NPP1 has distal tubules mouse, while NPP3 expressed rat glomerulus pars recta, more segments. Ecto-5′-nucleotidase, catalyses conversion AMP adenosine, apical membranes convoluted tubule intercalated cells nephron, well peritubular space. Finally, an phosphatase, can theoretically entire chain from nucleoside nucleoside, tubules; however, this enzyme exhibits relatively high Km values for adenine nucleotides. Although information on ectonucleotidases still incomplete, enzymes’ varied distribution along suggests that they profoundly influence purinoceptor activity hydrolysis, generation, agonists various subtypes. This review provides update speculates functional significance these enzymes terms glomerular physiology pathophysiology.