LOCALIZATION OF HEME OXYGENASE IN RAT RETINA - EFFECT OF LIGHT ADAPTATION

Heme oxygenase-2 isozyme is the predominant form of heme oxygenase in rat brain by western blot analysis. Heme oxygenase-1 isozyme is not in duced by light adaptation in rat retina by western blot analysis. Immu nocytochemistry localizes heme oxygenase-2 in three areas of the retin a: the retinal pigment epithelium, inner segment and external nuclear layers of the rat retina. Ganglion cells and cell bodies of the intern al nuclear layer of the retina and Muller cells were largely unstained for heme oxygenase-2. The localization of heme oxygenase-2 in the ret ina implies that its function is not associated with phototransduction . Also, light adaptation does not appear to induce heme oxygenase-1, a measure of oxidative injury.