Diazoxide is protective in the rat retina against ischemic injury induced by bilateral carotid occlusion and glutamate-induced degeneration.

Diazoxide (DIAZ) has been shown to be neuroprotective in animal models of different brain pathologies. However, the direct protective effect of DIAZ in different in vivo models of retinal degeneration has not yet been shown. Therefore, the aim of the present study was to investigate the neuroprotective role of this compound in two rodent model systems: monosodium-glutamate (MSG)- and chronic bilateral carotid artery occlusion (BCAO)-induced retinal degeneration. Rats were subjected either to s.c. MSG treatment on postnatal days 1, 5 and 9, or to BCAO at 2 months of age, followed by intravitreal DIAZ treatment. Histological examination was carried out 14 or 21 days after treatments, respectively. MSG treatment destroyed almost the entire inner retina, with the inner nuclear and ganglion cell layers being fused. DIAZ treatment significantly ameliorated the MSG-induced retinal degeneration. BCAO led to a severe degeneration of all retinal layers, and DIAZ proved to be protective also in this model. Our results may have clinical implications in reducing glutamate-induced excitotoxicity or ischemic retinal degeneration in ophthalmic diseases.