title: Effect of brimonidine on retinal and choroidal neovascularization in a mouse model of retinopathy of prematurity and laser-treated rats.
abstract: OBJECTIVE
  To determine whether chronic treatment with brimonidine (BRI) attenuates retinal vascular leakage and neovascularization in neonatal mice after exposure to high oxygen in a mouse model of retinopathy of prematurity (ROP), and choroidal neovascularization (CNV) in rats after laser treatment.
  
  
  METHODS
  Experimental CNV was induced by laser treatment in Brown Norway (BN) rats. BRI or vehicle (VEH) was administered by osmotic minipumps, and CNV formation was measured 11 days after laser treatment. Oxygen-induced retinopathy was generated in neonatal mice by exposure to 75% oxygen from postnatal day (P)7 to P12. BRI or VEH was administered by gavage, and vitreoretinal vascular endothelial growth factor (VEGF) concentrations and retinal vascular leakage, neovascularization, and vaso-obliteration were measured on P17. Experimental CNV was induced in rabbits by subretinal lipopolysaccharide/fibroblast growth factor-2 injection.
  
  
  RESULTS
  Systemic BRI treatment significantly attenuated laser-induced CNV formation in BN rats when initiated 3 days before or within 1 hour after laser treatment. BRI treatment initiated during exposure to high oxygen significantly attenuated vitreoretinal VEGF concentrations, retinal vascular leakage, and retinal neovascularization in P17 mice subjected to oxygen-induced retinopathy. Intravitreal treatment with BRI had no effect on CNV formation in a rabbit model of nonischemic angiogenesis.
  
  
  CONCLUSIONS
  BRI treatment significantly attenuated vitreoretinal VEGF concentrations, retinal vascular leakage, and retinal and choroidal neovascularization in animal models of ROP and CNV. BRI may inhibit underlying event(s) of ischemia responsible for upregulation of vitreoretinal VEGF and thus reduce vascular leakage and retinal-choroidal neovascularization.
authors.affiliation: Department of Biological Sciences, Allergan, Inc., Irvine, California 92612-1599, USA. kusari_jyoti@allergan.com
authors.forename: Jyotirmoy
authors.initials: J
authors.lastname: Kusari
authors.forename: Edwin
authors.initials: E
authors.lastname: Padillo
authors.forename: Sheila X
authors.initials: SX
authors.lastname: Zhou
authors.forename: Yanyan
authors.initials: Y
authors.lastname: Bai
authors.forename: Juanjuan
authors.initials: J
authors.lastname: Wang
authors.forename: Zhiming
authors.initials: Z
authors.lastname: Song
authors.forename: Meili
authors.initials: M
authors.lastname: Zhu
authors.forename: Yun-Zheng
authors.initials: YZ
authors.lastname: Le
authors.forename: Daniel W
authors.initials: DW
authors.lastname: Gil
mesh_terms: D058647:Adrenergic alpha-2 Receptor Agonists / Q000627:therapeutic use*; D000818:Animals; D000068438:Brimonidine Tartrate; D020256:Choroidal Neovascularization / Q000188:drug therapy* / Q000473:pathology; D004195:Disease Models, Animal; D004305:Dose-Response Relationship, Drug; D016222:Fibroblast Growth Factor 2; D005451:Fluorescein Angiography; D006801:Humans; D015151:Immunoblotting; D007231:Infant, Newborn; D058449:Intravitreal Injections; D017075:Laser Coagulation; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D010100:Oxygen / Q000633:toxicity; D011810:Quinoxalines / Q000627:therapeutic use*; D011817:Rabbits; D051381:Rats; D011914:Rats, Inbred BN; D015861:Retinal Neovascularization / Q000188:drug therapy* / Q000473:pathology; D012178:Retinopathy of Prematurity / Q000139:chemically induced / Q000188:drug therapy*; D013997:Time Factors
chemical_list: D058647:Adrenergic alpha-2 Receptor Agonists; D011810:Quinoxalines; D016222:Fibroblast Growth Factor 2; D000068438:Brimonidine Tartrate; D010100:Oxygen