title: Distribution of parathyroid hormone-sensitive adenylate cyclase in isolated rabbit renal cortex microvessels and glomeruli.
abstract: The effect of the synthetic amino-terminal fragment of bovine parathyroid hormone, bPTH-(1-34), on the adenylate cyclase of microvessels and glomeruli isolated from rabbit kidney cortex was studied in the presence and absence of guanosine triphosphate (GTP). bPTH-(1-34) stimulated the vascular and glomerular adenylate cyclase in a dose-dependent manner with apparent ED50 values of 11.5 nM and 64 nM respectively, in the absence of GTP. 10(-4)M GTP greatly amplified the vascular response to bPTH-(1-34) while, in the glomeruli, both GTP and bPTH-(1-34) had only additive effects. In the presence of GTP, vascular and glomerular apparent ED50 were 190 nM and 64 nM respectively. [Nle8, Nle18, Tyr34] -bPTH-(3-34) amide, described as a PTH antagonist, inhibited the action of bPTH-(1-34) in the microvessels and to a lesser extent in the glomeruli. PTH is therefore a potent stimulator of adenylate cyclase in rabbit renal microvessels and glomeruli, and may play a role in the regulation of renal blood flow and glomerulo-tubular feedback control.
mesh_terms: D000262:Adenylyl Cyclases / Q000378:metabolism*; D000818:Animals; D002196:Capillaries / Q000187:drug effects / Q000201:enzymology*; D004305:Dose-Response Relationship, Drug; D007672:Kidney Cortex / Q000098:blood supply* / Q000201:enzymology; D007678:Kidney Glomerulus / Q000098:blood supply* / Q000201:enzymology; D010281:Parathyroid Hormone / Q000502:physiology*; D011817:Rabbits; D051381:Rats; D012079:Renal Circulation
chemical_list: D010281:Parathyroid Hormone; D000262:Adenylyl Cyclases