title: Nitric oxide inhibition of cAMP synthesis in parotid acini: regulation of type 5/6 adenylyl cyclase.
abstract: The nitric oxide (NO) donor, GEA 3162, inhibited isoproterenol-induced cyclic AMP (cAMP) accumulation in a concentration- and time-dependent manner in mouse parotid acini; SIN-1 mimicked these effects. Inhibition of stimulated cAMP accumulation was independent of phosphodiesterase activity. GEA 3162 also inhibited forskolin-induced cAMP accumulation. Removal of extracellular Ca(2+), addition of La(3+), or the calmodulin (CaM) inhibitor, calmidazolium, did not prevent the NO-mediated response, and addition of the soluble guanylyl inhibitor, ODQ, did not reverse GEA 3162-induced inhibition of cAMP accumulation. GEA 3162 also inhibited adenylyl cyclase in vitro independently of Ca(2+)/CaM. Further studies revealed that the NO synthase (NOS) inhibitor, 7-nitroindazole (7-NI), reduced significantly thapsigargin-induced Ca(2+) release and capacitative Ca(2+) entry and reversed thapsigargin inhibition of the AC Type 5/6 isoform (AC5/6). Data suggest that NO produced endogenously has dual effects on cAMP accumulation in mouse parotid acini, an inhibitory effect on AC activity and a modulatory effect on capacitative Ca(2+) entry resulting in AC5/6 inhibition.
authors.affiliation: Department of Oral Biology, University of Washington, Seattle, 98195, USA. ewatson@u.washington.edu
authors.forename: E L
authors.initials: EL
authors.lastname: Watson
authors.forename: J C
authors.initials: JC
authors.lastname: Singh
authors.forename: K L
authors.initials: KL
authors.lastname: Jacobson
authors.forename: S M
authors.initials: SM
authors.lastname: Ott
mesh_terms: D000262:Adenylyl Cyclases / Q000378:metabolism*; D000818:Animals; D002118:Calcium / Q000502:physiology; D002478:Cells, Cultured; D005576:Colforsin / Q000494:pharmacology; D000242:Cyclic AMP / Q000096:biosynthesis*; D006152:Cyclic GMP / Q000502:physiology; D004305:Dose-Response Relationship, Drug; D004791:Enzyme Inhibitors / Q000494:pharmacology; D007527:Isoenzymes / Q000378:metabolism*; D007545:Isoproterenol / Q000494:pharmacology; D051379:Mice; D009569:Nitric Oxide / Q000502:physiology*; D020030:Nitric Oxide Donors / Q000494:pharmacology; D010069:Oxadiazoles / Q000494:pharmacology; D010306:Parotid Gland / Q000187:drug effects / Q000201:enzymology / Q000378:metabolism*; D010727:Phosphoric Diester Hydrolases / Q000378:metabolism; D011810:Quinoxalines / Q000494:pharmacology; D019284:Thapsigargin / Q000494:pharmacology; D014230:Triazoles / Q000494:pharmacology
chemical_list: C095284:1H-(1,2,4)oxadiazolo(4,3-a)quinoxalin-1-one; D004791:Enzyme Inhibitors; D007527:Isoenzymes; D020030:Nitric Oxide Donors; D010069:Oxadiazoles; D011810:Quinoxalines; D014230:Triazoles; D005576:Colforsin; D009569:Nitric Oxide; D019284:Thapsigargin; C082874:GEA 3162; D000242:Cyclic AMP; D010727:Phosphoric Diester Hydrolases; D000262:Adenylyl Cyclases; C121100:adenylyl cyclase 6; C419510:adenylyl cyclase type V; D006152:Cyclic GMP; D007545:Isoproterenol; D002118:Calcium