title: Biochemical characterization and cytochemical localization of a catecholamine-sensitive adenylate cyclase in isolated capillary endothelium.
abstract: Capillaries were isolated from epididymal fat, and a catecholamine-sensitive adenylate cyclase found in these capillaries was characterized. The effect of various hormones on the accumulation of adenosine 3':5'-cyclic monophosphate in capillary endothelial cells was determined and the cyclase was found to exhibit mixed alpha and beta characteristics. Cyclase was cytochemically localized in these endothelial cells with 5'-adenylyl-imidodiphosphate as a specific cyclase substrate and alloxan as a specific cyclase inhibitor. Lead imidodiphosphate was precipitated at or near the site of cyclase activity upon hydrolysis of 5'-adenylyl-imidodiphosphate by cyclase. This reaction product was observed primarily on the luminal surface of intact capillaries, in micropinocytic invaginations, in free vesicles within the cytoplasm, and in the intracellular junctions.
mesh_terms: D000255:Adenosine Triphosphate / Q000378:metabolism; D000067956:Adenylyl Cyclase Inhibitors; D000262:Adenylyl Cyclases / Q000032:analysis* / Q000378:metabolism; D000273:Adipose Tissue / Q000098:blood supply; D000818:Animals; D002196:Capillaries / Q000166:cytology / Q000201:enzymology*; D002395:Catecholamines / Q000494:pharmacology*; D004727:Endothelium / Q000201:enzymology; D004822:Epididymis / Q000098:blood supply*; D004847:Epithelial Cells; D004848:Epithelium / Q000201:enzymology; D007094:Imides / Q000378:metabolism; D008297:Male; D008854:Microscopy, Electron; D008858:Microscopy, Phase-Contrast; D010710:Phosphates / Q000378:metabolism; D051381:Rats
chemical_list: D000067956:Adenylyl Cyclase Inhibitors; D002395:Catecholamines; D007094:Imides; D010710:Phosphates; D000255:Adenosine Triphosphate; D000262:Adenylyl Cyclases