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Abstract #12358 Published in IGR 7-2
Long-term glial reactivity in rat retinas ipsilateral and contralateral to experimental glaucoma
Kanamori A; Nakamura M; Nakanishi Y; Yamada Y; Negi AExperimental Eye Research 2005; 81: 48-56
Although glaucoma is known to alter glial reactivity, the long-term effect of elevated intraocular pressure (IOP) on glial change has not been fully elucidated. This study aimed to examine how chronically elevated IOP induced by episcleral vein cauterization (EVC) in unilateral eyes affect reactivities of astrocytes and Muller cells of rats in the treated as well as contralateral eyes over time. EVC in unilateral eyes of Sprague-Dawley rats were performed to produce chronically elevated IOP. Flat mounted retina preparations were made at several points until 6 months, which were subjected to immunostaining for glial fibrillary acidic protein (GFAP). Retinal homogenates were one- or two-dimensionally electrophoresed, followed by GFAP immunoblotting. EVC significantly increased IOPs up to 27.8 from 13.1 mmHg, which gradually decreased over time. In flat mounted retinas, astrocytes lost but Muller cells gained GFAP immunoreactivity at 3 days after cauterization. The glial changes were partially reversed over time but last even after IOP normalization. In the contralateral eyes, similar glial changes gradually appeared at 1 month after EVC and thereafter. Immunoblotting demonstrated not only molecular size shifts but also alteration of isoelectric focusing of GFAP both in treated and contralateral retina as compared with age-matched control retina. EVC led to opposite reactions in astrocytes and Muller cells in terms of GFAP immunoreactivity. Late-onset glial reactivity also occurred in the contralateral retina.
Dr. A. Kanamori, Division of Ophthalmology, Department of Organ Therapeutics, Kobe University Graduate School of Medicine, 7-5-2 Kusunoki-cho, Chuo-ku, Kobe-shi 650-0017, Japan
Classification:
2.13 Retina and retinal nerve fibre layer (Part of: 2 Anatomical structures in glaucoma)
3.3 Immunohistochemistry (Part of: 3 Laboratory methods)
5 Experimental glaucoma; animal models