title: Central bombesin possibly induces S-nitrosylation of cyclooxygenase-1 in pre-sympathetic neurons of rat hypothalamic paraventricular nucleus.
abstract: OBJECTIVE
  Cyclooxygenase (COX) can be activated by nitric oxide-induced (NO-induced) conversion of cysteine thiol group of COX into S-nitrosothiol. We previously reported the involvement of brain COX/NO synthase (NOS) in centrally administered bombesin-, a stress-related neuropeptide, induced secretion of rat adrenal noradrenaline and adrenaline. To examine a possible involvement of the NO-induced modification of COX in bombesin-induced response, we investigated whether bombesin induces close proximity of COX-1 and neuronal NOS (nNOS) or S-nitroso-cysteine in pre-sympathetic spinally projecting neurons in the rat hypothalamic paraventricular nucleus (PVN), a regulatory center of adrenomedullary outflow.
  
  
  METHODS
  In twelve-week-old male Wistar rats, pre-sympathetic spinally projecting neurons in the PVN were labeled with a retrograde tracer Fluoro-Gold (FG). After intracerebroventricular administration of bombesin, we performed double immunohistochemical analysis for Fos and COX-1 or nNOS in FG-labeled PVN neurons. We also performed a fluorescent in situ proximity ligation assay (PLA) for visualizing of close proximity (<40 nm) of COX-1 with nNOS or S-nitroso-cysteine.
  
  
  RESULTS
  Bombesin significantly increased the number of Fos-immunoreactive cells in FG-labeled PVN neurons with COX-1 or nNOS immunoreactivity. 7-Nitroindazole, a selective nNOS inhibitor, abolished Fos-immunoreactivity induced by bombesin in COX-1-immunoreactive FG-labeled PVN neurons. Bombesin also induced PLA-positive signals indicating close proximity of COX-1/nNOS and COX-1/S-nitroso-cysteine in FG-labeled PVN neurons.
  
  
  CONCLUSIONS
  Centrally administered bombesin possibly induces S-nitrosylation of COX-1 through close proximity of COX-1 and nNOS in pre-sympathetic spinally projecting PVN neurons, thereby activating COX-1 during the bombesin-induced activation of central adrenomedullary outflow in the rat.
authors: Department of Pharmacology, Kochi University School of Medicine, Nankoku, Kochi 783-8505, Japan.
authors: Kenjiro
authors: K
authors: Tanaka
authors: Department of Pharmacology, Kochi University School of Medicine, Nankoku, Kochi 783-8505, Japan. Electronic address: shimizu@kochi-u.ac.jp.
authors: Takahiro
authors: T
authors: Shimizu
authors: Department of Neurosurgery, Kochi University School of Medicine, Nankoku, Kochi 783-8505, Japan.
authors: Youichirou
authors: Y
authors: Higashi
authors: Department of Pharmacology, Kochi University School of Medicine, Nankoku, Kochi 783-8505, Japan.
authors: Kumiko
authors: K
authors: Nakamura
authors: Department of Pharmacology, Kochi University School of Medicine, Nankoku, Kochi 783-8505, Japan.
authors: Keisuke
authors: K
authors: Taniuchi
authors: B' Urologic Department, Papageorgiou General Hospital, Aristotle University School of Medicine, Thessaloniki, Greece.
authors: Fotios
authors: F
authors: Dimitriadis
authors: Division of Molecular Pharmacology, Tottori University School of Medicine, Yonago, Tottori 683-8503, Japan.
authors: Shogo
authors: S
authors: Shimizu
authors: Department of Pharmacology, Kochi University School of Medicine, Nankoku, Kochi 783-8505, Japan.
authors: Kunihiko
authors: K
authors: Yokotani
authors: Department of Pharmacology, Kochi University School of Medicine, Nankoku, Kochi 783-8505, Japan.
authors: Motoaki
authors: M
authors: Saito
mesh_terms: D000818:Animals; D001839:Bombesin / Q000008:administration & dosage / Q000494:pharmacology*; D051545:Cyclooxygenase 1 / Q000378:metabolism*; D005456:Fluorescent Dyes; D007124:Immunoenzyme Techniques; D007276:Injections, Intraventricular; D008297:Male; D009474:Neurons / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism; D018377:Neurotransmitter Agents / Q000008:administration & dosage / Q000494:pharmacology*; D052248:Nitric Oxide Synthase Type I / Q000378:metabolism*; D010286:Paraventricular Hypothalamic Nucleus / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism; D051381:Rats; D017208:Rats, Wistar; D026403:S-Nitrosothiols / Q000494:pharmacology; D013116:Spinal Cord / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism; D013266:Stilbamidines; D019014:fas Receptor / Q000378:metabolism
chemical_list: C049774:2-hydroxy-4,4'-diamidinostilbene, methanesulfonate salt; C491898:Fas protein, rat; D005456:Fluorescent Dyes; D018377:Neurotransmitter Agents; D026403:S-Nitrosothiols; D013266:Stilbamidines; D019014:fas Receptor; D052248:Nitric Oxide Synthase Type I; D051545:Cyclooxygenase 1; D001839:Bombesin
keywords: Bombesin; Cyclooxygenase-1; Hypothalamic paraventricular nucleus; Neuronal nitric oxide synthase; S-nitrosylation