Protective effect of alpha-melanocyte-stimulating hormone (a-MSH) on the recovery of ischemia/reperfusion (I/R)-induced retinal damage in a rat model.

Journal of molecular neuroscience : MN

PubMedID: 23504281

Varga B, Gesztelyi R, Bombicz M, Haines D, Szabo AM, Kemeny-Beke A, Antal M, Vecsernyes M, Juhasz B, Tosaki A. Protective effect of alpha-melanocyte-stimulating hormone (a-MSH) on the recovery of ischemia/reperfusion (I/R)-induced retinal damage in a rat model. J Mol Neurosci. 2013;50(3):558-70.
The present study demonstrates capacity of a-MSH to augment recovery from ischemia/reperfusion (I/R)-induced retinal damage in vivo and correlation of its protective effects with expression of heme oxygenase-1 (HO-1). Used techniques include ocular ischemia and reperfusion, electroretinography, histology, electron microscopy, and molecular-biological techniques. The results demonstrate the a-MSH-mediated inhibition of I/R-induced functional deterioration of the retina. Outcomes suggest that the protective effects of a-MSH occur mainly through HO-1-dependent pathways but HO-1-independent mechanisms may also contribute to protection. The observation that post-ischemic treatment with a-MSH exhibits therapeutic efficacy in the same range as pre-ischemic treatment, is a novel result. This outcome suggests a highly conserved protective role for a-MSH as a major stress response mechanism--and offers the possibility for development of novel therapeutic strategies utilizing this hormone, in particular in treatment of conditions resulting from I/R injury, such as deterioration of retinal microcirculation. The merit of the study lies in the fact that I/R injury contribute significantly to the severity of retinopathies. However, currently there are no evidence-based treatments for retinal I/R injury available for clinical use. Our finding suggests that a-MSH may have a very wide range of uses in the prevention of I/R-mediated pathologies.