Abstract
Abstract: :
Purpose:To assess changes in neuronal population of the retina in the DBA/2J mouse with secondary angle–closure glaucoma, according to degree of the intraocular pressure (IOP). Methods: Immunohistochemistry using retinal specific markers, rhodopsin and red/green opsin for photoreceptors, protein kinase C (PKC) and recoverin for bipolar cells, γ–aminobutyric acid (GABA), glycine, choline acetyltransferase (ChAT), and nitric oxide synthase (NOS) for amacrine cells, Thy–1 for ganglion cells, and glutamine synthetase (GS) and glial fibrillary acidic protein (GFAP) for Müller cells, was performed to examine the retinas of 10 month–old DBA/2J mice, which are grouped into low–grade increased IOP (LIOP) and high–grade increased IOP (HIOP). Results: Thickness of the retina, especially inner plexiform layer (IPL), and number of retinal neuron, especially ganglion cell was decreased in DBA/2J mice with LIOP and HIOP. Rhodopsin, red/green opsin, PKC, and recoverin immunoreactivities did not change significantly. GABA, glycine, ChAT, and Thy–1 immunoreactivities were markedly decreased, while NOS immunoreactivity was increased. In addition, GS and GFAP immunoreactivities were increased. All of above changes and severity are generally dependent on the degree of increased IOP. Conclusions: DBA/2J mouse with secondary angle–closure glaucoma showed neurochemical changes in retina dependently on the increased IOP, indicating changes in neuronal population of the retina. That is, neurons located in the inner retina, amacrine cells and ganglion cells, are mainly affected and degenerated, while neurons in the outer retina, photoreceptors and bipolar cells, are little affected in DBA/2J mouse.These results suggest that glaucoma produces pressure–dependent degeneration of neurons in the inner retina and DBA/2J mouse represents a useful model to evaluate mechanisms of degeneration of the retinal neurons in glaucoma.
Keywords: immunohistochemistry • retinal degenerations: cell biology • ganglion cells