title: The renal parathyroid hormone receptor-adenylate cyclase system in vitro and in vivo.
abstract: High affinity parathyroid hormone (PTH) receptors in chicken renal plasma membranes were identified and quantitated using bPTH((1-34) labeled by electrolytic iodination and purified by a membrane absorption procedure. Parallel studies of PTH-receptor binding and activation of adenylate cyclase indicated that these activities were coupled. The PTH sensitivity of the renal receptor-adenylate cyclase system was similar in vivo and in vitro (Km congruent to 20 nM), whereas a 'physiologic' concentration of circulating bPTH (1-34) infused into thyroparathyroidectomized/ultimobranchial-ectomized chickens was estimated to be at least 40 times lower. Small increments in cellular cyclic AMP levels are apparently sufficient to mediate actions of PTH on the kidney.
mesh_terms: D000262:Adenylyl Cyclases / Q000378:metabolism*; D000818:Animals; D002462:Cell Membrane / Q000378:metabolism; D002645:Chickens; D000242:Cyclic AMP / Q000378:metabolism; D004789:Enzyme Activation; D007668:Kidney / Q000378:metabolism*; D007684:Kidney Tubules / Q000187:drug effects / Q000378:metabolism; D007700:Kinetics; D010281:Parathyroid Hormone / Q000378:metabolism* / Q000494:pharmacology; D011956:Receptors, Cell Surface / Q000378:metabolism*; D018016:Receptors, Parathyroid Hormone
chemical_list: D010281:Parathyroid Hormone; D011956:Receptors, Cell Surface; D018016:Receptors, Parathyroid Hormone; D000242:Cyclic AMP; D000262:Adenylyl Cyclases