title: Matrix metalloproteinase-9 expression in retinal ganglion cell layer and effect of topically applied brimonidine tartrate 0.2% therapy on this expression in an endothelin-1-induced optic nerve ischemia model.
abstract: The purpose of this research is to investigate the expression of matrix metalloproteinase-9 (MMP-9) in retinal ganglion cells (RGC) and the impact of topically applied brimonidine tartrate 0.2% (BMD) on this expression in an endothelin-1 (ET-1)-induced chronic optic nerve (ON) ischemia model of rabbit. Osmotically driven minipumps were implanted in one eye of 16 New Zealand albino rabbits to deliver ET-1 at the constant rate of 0.5 microl/h for 2 weeks. ET-1 was given with (group 3) and without topical BMD therapy (group 1). Groups 2 and 4 were taken as controls. MMP-9 expression by immunohistochemically and proportion of cells undergoing apoptosis in RGC layer were investigated. The correlation between the MMP-9 immunopositivity and the proportion of cells undergoing apoptosis in the RGC layer was evaluated. MMP-9 immunopositivity was found to be significantly higher in both groups 1 and 3 compared to that of the controls. There was no difference between groups 1 and 3 regarding MMP-9 expression (p = 0.495). A positive correlation was found between the proportion of cells undergoing apoptosis and MMP-9 expressions in the RGC layer in group 1 (p = 0.031, r = 0.754). MMP-9 expression in the RGC layer seems to significantly increase in the ET-1-induced chronic ON ischemia model. Topical BMD therapy does not seem to affect this MMP-9 expression.
authors.affiliation: Department of Ophthalmology, Gazi University Medical Faculty, Ankara, Turkey. drzeynep2000@yahoo.com
authors.forename: Zeynep
authors.initials: Z
authors.lastname: Aktas
authors.forename: Gokhan
authors.initials: G
authors.lastname: Gurelik
authors.forename: Pinar Uyar
authors.initials: PU
authors.lastname: Göçün
authors.forename: Nalan
authors.initials: N
authors.lastname: Akyürek
authors.forename: Merih
authors.initials: M
authors.lastname: Onol
authors.forename: Berati
authors.initials: B
authors.lastname: Hasanreisoğlu
mesh_terms: D000316:Adrenergic alpha-Agonists / Q000627:therapeutic use; D000818:Animals; D000068438:Brimonidine Tartrate; D015971:Gene Expression Regulation, Enzymologic; D020287:In Situ Nick-End Labeling; D007260:Infusion Pumps; D007429:Intraocular Pressure / Q000187:drug effects; D020780:Matrix Metalloproteinase 9 / Q000235:genetics*; D018917:Optic Neuropathy, Ischemic / Q000139:chemically induced* / Q000188:drug therapy*; D011810:Quinoxalines / Q000008:administration & dosage / Q000627:therapeutic use*; D011817:Rabbits; D012165:Retinal Ganglion Cells / Q000187:drug effects / Q000201:enzymology*
chemical_list: D000316:Adrenergic alpha-Agonists; D011810:Quinoxalines; D000068438:Brimonidine Tartrate; D020780:Matrix Metalloproteinase 9