Abstract
Abstract: :
Purpose: To characterize retinal Müller and amacrine cell changes in eyes of DBA/2NNia (DBA) mice that develop an inherited angle-closure glaucoma. Methods: 38 DBA and 27 control C57BL/6J mice of different age groups (2 to 23 months of age) were studied. Morphological investigations included NADPH-diaphorase staining of retinal whole mounts and fluorescence immunohistochemistry of cryosections with antibodies against neuronal nitric oxide synthase (nNOS), tyrosin hydroxylase (TH), GABA, vesicular acetylcholine transporter (VAChT), GFAP, and alphaB-crystallin. Results: Immunohistochemistry of the retinae of DBA mice revealed no significant differences in GFAP and alphaB-crystallin staining between the two mouse strains indicating no activation of Müller cells in the glaucomatous eyes. Regarding amacrine cell subpopulations, no staining differences were seen in the two mouse strains at all ages using antibodies against TH, GABA, and VAChT. However, staining with nNOS and NADPH diaphorase revealed significant differences between the DBA strain and the C57BL/6J mice. With the onset of elevated IOP at 6 months in the DBA mice, the total number of NOS positive amacrine cells continuosly decreased from 1000 cells at 6 months of age down to 480 cells in animals older than 20 months of age. Conclusions: We previously described a parafoveal loss of nNOS positive amacrine cells in the monkey glaucoma model (May et al. Ophthalmologica 1997;211:161-171). The fact that there is also a significant loss of nNOS amacrine cells in the glaucomatous mouse eye suggests a specific pathological or protective role for decreased nNOS in amacrine cells in the glaucomatous retina.
Keywords: retina • amacrine cells • immunohistochemistry