title: Neuroprotective effect of atrial natriuretic peptide against NMDA-induced neurotoxicity in the rat retina.
abstract: Atrial natriuretic peptide (ANP) can regulate aqueous humor production in the eye and has recently been suggested to play some functional roles in the retina. It has also been reported that ANP increases tyrosine hydroxylase (TH) mRNA levels and intracellular dopamine levels in PC12 cells. The effect of ANP on TH levels and the role of ANP in retinal excitotoxicity remain unknown. In this study, we investigated the effects of ANP on TH expression and dopamine levels in rat retina after intravitreal injection of NMDA. Immunohistochemistry localized natriuretic peptide receptor-A (NPRA) in the ganglion cell layer (GCL), the inner nuclear layer (INL) and the outer nuclear layer (ONL) in the rat retina. Quantitative real-time PCR and Western blot analysis showed a dramatic reduction in retinal TH levels 5 days after NMDA injection, while ANP, at a concentration of 10(-4) M, ameliorated this reduction in TH mRNA and TH protein levels. High-performance liquid chromatography (HPLC) analysis showed that NMDA reduced dopamine levels in the retina, and that ANP attenuated this reduction. Moreover, morphological analysis showed that ANP ameliorated NMDA-induced neurotoxicity through NPRA. The ameliorative effect of ANP was inhibited by a dopamine D(1) receptor antagonist. These results suggest that ANP may have a neuroprotective effect through possible involvement of dopamine induction.
authors.affiliation: Department of Ophthalmology, St. Marianna University School of Medicine, 2-16-1 Sugao, Kawasaki-shi, Kanagawa 216-8511, Japan. shiyabari9@marianna-u.ac.jp
authors.forename: Kohei
authors.initials: K
authors.lastname: Kuribayashi
authors.forename: Yasushi
authors.initials: Y
authors.lastname: Kitaoka
authors.forename: Toshio
authors.initials: T
authors.lastname: Kumai
authors.forename: Yasunari
authors.initials: Y
authors.lastname: Munemasa
authors.forename: Yuka
authors.initials: Y
authors.lastname: Kitaoka
authors.forename: Kazuyuki
authors.initials: K
authors.lastname: Isenoumi
authors.forename: Masamitsu
authors.initials: M
authors.lastname: Motoki
authors.forename: Jiro
authors.initials: J
authors.lastname: Kogo
authors.forename: Yasuhiro
authors.initials: Y
authors.lastname: Hayashi
authors.forename: Shinichi
authors.initials: S
authors.lastname: Kobayashi
authors.forename: Satoki
authors.initials: S
authors.lastname: Ueno
mesh_terms: D000704:Analysis of Variance; D000818:Animals; D000906:Antibodies / Q000494:pharmacology; D009320:Atrial Natriuretic Factor / Q000008:administration & dosage* / Q000276:immunology; D001552:Benzazepines / Q000494:pharmacology; D015153:Blotting, Western / Q000379:methods; D002851:Chromatography, High Pressure Liquid / Q000379:methods; D004195:Disease Models, Animal; D004294:Domperidone / Q000494:pharmacology; D004298:Dopamine / Q000378:metabolism; D018492:Dopamine Antagonists / Q000494:pharmacology; D004305:Dose-Response Relationship, Drug; D004347:Drug Interactions; D004563:Electrochemistry / Q000379:methods; D018690:Excitatory Amino Acid Agonists / Q000633:toxicity*; D007150:Immunohistochemistry / Q000379:methods; D042541:Intracellular Space / Q000187:drug effects; D008297:Male; D016202:N-Methylaspartate / Q000633:toxicity*; D018696:Neuroprotective Agents / Q000008:administration & dosage* / Q000276:immunology; D020258:Neurotoxicity Syndromes / Q000150:complications / Q000209:etiology* / Q000473:pathology; D016716:PC12 Cells; D012333:RNA, Messenger / Q000378:metabolism; D051381:Rats; D017208:Rats, Wistar; D012162:Retinal Degeneration / Q000209:etiology / Q000473:pathology / Q000517:prevention & control*; D020133:Reverse Transcriptase Polymerase Chain Reaction / Q000379:methods; D014446:Tyrosine 3-Monooxygenase / Q000378:metabolism
chemical_list: D000906:Antibodies; D001552:Benzazepines; D018492:Dopamine Antagonists; D018690:Excitatory Amino Acid Agonists; D018696:Neuroprotective Agents; D012333:RNA, Messenger; D004294:Domperidone; D016202:N-Methylaspartate; D009320:Atrial Natriuretic Factor; D014446:Tyrosine 3-Monooxygenase; D004298:Dopamine