Neuroprotective effect of atrial natriuretic peptide against NMDA-induced neurotoxicity in the rat retina

• Published in: Brain research 2006-02, Vol.1071 (1), p.34-41
• Main Authors: Kuribayashi, Kohei, Kitaoka, Yasushi, Kumai, Toshio, Munemasa, Yasunari, Kitaoka, Yuka, Isenoumi, Kazuyuki, Motoki, Masamitsu, Kogo, Jiro, Hayashi, Yasuhiro, Kobayashi, Shinichi, Ueno, Satoki
• Format: Article
• Language: English
• Subjects: Analysis of Variance; Animals; Antibodies - pharmacology; Atrial Natriuretic Factor - administration & dosage; Atrial Natriuretic Factor - immunology; Atrial natriuretic peptide; Benzazepines - pharmacology; Biological and medical sciences; Blotting, Western - methods; Chromatography, High Pressure Liquid - methods; Disease Models, Animal; Domperidone - pharmacology; Dopamine; Dopamine - metabolism; Dopamine Antagonists - pharmacology; Dose-Response Relationship, Drug; Drug Interactions; Electrochemistry - methods; Excitatory Amino Acid Agonists - toxicity; Eye and associated structures. Visual pathways and centers. Vision; Fundamental and applied biological sciences. Psychology; Immunohistochemistry - methods; Intracellular Space - drug effects; Male; N-methyl- d-asparate; N-Methylaspartate - toxicity; Neuroprotection; Neuroprotective Agents - administration & dosage; Neuroprotective Agents - immunology; Neurotoxicity Syndromes - complications; Neurotoxicity Syndromes - etiology; Neurotoxicity Syndromes - pathology; PC12 Cells; Rats; Rats, Wistar; Retina; Retinal Degeneration - etiology; Retinal Degeneration - pathology; Retinal Degeneration - prevention & control; Reverse Transcriptase Polymerase Chain Reaction - methods; RNA, Messenger - metabolism; Tyrosine 3-Monooxygenase - metabolism; Tyrosine hydroxylase; Vertebrates: nervous system and sense organs
• ISSN: 0006-8993; 1872-6240
• DOI: 10.1016/j.brainres.2005.11.068

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.