Effect of Melatonin and Analogues on Corneal Wound Healing: Involvement of Mt2 Melatonin Receptor

• Published in: Current eye research 2015-01, Vol.40 (1), p.56-65
• Main Authors: Crooke, Almudena, Guzman-Aranguez, Ana, Mediero, Aranzazu, Alarma-Estrany, Pilar, Carracedo, Gonzalo, Pelaez, Teresa, Peral, Assumpta, Pintor, Jesús
• Format: Article
• Language: English
• Subjects: Animals; Antioxidants - metabolism; Antioxidants - pharmacology; Blotting, Western; Burns, Chemical - drug therapy; Burns, Chemical - metabolism; Burns, Chemical - pathology; Cell Line; Corneal wound healing; Epithelium, Corneal - drug effects; Epithelium, Corneal - metabolism; Epithelium, Corneal - pathology; Eye Burns - chemically induced; Eye Burns - metabolism; Eye Burns - pathology; Eye Proteins - metabolism; Heptanol; Immunohistochemistry; Isoindoles - pharmacology; Male; melatonin; Melatonin - metabolism; Melatonin - pharmacology; melatonin agonists; melatonin antagonists; melatonin receptors; Rabbits; Receptor, Melatonin, MT2 - agonists; Receptor, Melatonin, MT2 - antagonists & inhibitors; Receptor, Melatonin, MT2 - metabolism; Reverse Transcriptase Polymerase Chain Reaction; Tears - metabolism; Tryptamines - pharmacology; Wound Healing - drug effects
• ISSN: 0271-3683; 1460-2202
• DOI: 10.3109/02713683.2014.914540

Abstract Purpose: We have investigated the effect of melatonin and its analogues on rabbit corneal epithelial wound healing. Methods: New Zealand rabbits were anaesthetised and wounds were made by placing Whatman paper discs soaked in n-heptanol on the cornea. Melatonin and analogues (all 10 nmol) were instilled. Wound diameter was measured every 2 hours by means of fluorescein application with a Topcon SL-8Z slit lamp. Melatonin antagonists (all 10 nmol) were applied 2 hours before the application of the n-heptanol-soaked disc and then every 6 hours together with melatonin. To confirm the presence of MT2 receptors in corneal epithelial cells immunohistochemistry, Western blot and RT-PCR assays in native tissue and in rabbit corneal epithelial cells were performed. The tear components were extracted then processed by HPLC to quantify melatonin in tears. Results: Migration assays revealed that melatonin and particularly the treatment with the MT2 agonist IIK7, accelerated the rate of healing (p