title: Oxidative responses induced by pharmacologic vitreolysis and/or long-term hyperoxia treatment in rat lenses.
abstract: OBJECTIVE
  The aim of the study was to investigate the protective effects of intact vitreous gel on the lens after pharmacologic vitreolysis and hyperoxia exposure in rats in vivo.
  
  
  METHODS
  Eyes of Sprague-Dawley rats were induced to posterior vitreous detachment (PVD) by pharmacologic vitreolysis, and the rats with and without PVD were treated with hyperoxia 3 h per day for 5 months. Lens transparency was monitored by a slit-lamp biomicroscope. A series of biochemical measurements were made in extracts of the lens cortex and nucleus. Ascorbate levels were measured in the aqueous and vitreous humors.
  
  
  RESULTS
  No significant differences in lens transparency or morphology were observed in all groups, and no significant biochemical changes were observed in the cortex or nucleus of lenses of the PVD group. In the lens nucleus, the values of water-soluble protein concentration in PVD + hyperoxia group were lower than that of the PVD group. The levels of water-soluble proteins, glutathione (GSH) and ascorbate decreased in the hyperoxia group with an intact vitreous body. Vitreolysis enhanced the effect of hyperoxia, decreasing soluble protein, GSH and ascorbate below the levels seen in eyes with vitreolysis alone. The levels of antioxidants and soluble proteins were lower in the lens nucleus, and the effects of vitreolysis plus hyperoxia were more significant in the nucleus. Hyperoxia and hyperoxia plus vitreolysis reduced catalase activity and increased oxidized GSH to a greater extent in the lens cortex, although these treatments increased protein-GSH mixed disulfides in both regions. Long-term hyperoxia also lowered ascorbate levels in the vitreous and aqueous humors, an effect that was enhanced by vitreolysis.
  
  
  CONCLUSIONS
  Exposure to excess molecular oxygen produces significant oxidative damage to the lens, especially the lens nucleus. These effects were enhanced by pharmacologic vitreolysis, indicating that intact vitreous gel protects the lens from oxidative damage.
authors.affiliation: Department of Ophthalmology, Tangdu Hospital, Xi'an, China.
authors.forename: Qi
authors.initials: Q
authors.lastname: Li
authors.forename: Hong
authors.initials: H
authors.lastname: Yan
authors.forename: Tian-Bing
authors.initials: TB
authors.lastname: Ding
authors.forename: Jing
authors.initials: J
authors.lastname: Han
authors.forename: Ying-Bo
authors.initials: YB
authors.lastname: Shui
authors.forename: David C
authors.initials: DC
authors.lastname: Beebe
mesh_terms: D000818:Animals; D000975:Antioxidants / Q000378:metabolism; D001082:Aqueous Humor / Q000378:metabolism; D001205:Ascorbic Acid / Q000378:metabolism; D002374:Catalase / Q000378:metabolism; D005978:Glutathione / Q000378:metabolism; D006821:Hyaluronoglucosaminidase / Q000494:pharmacology; D018496:Hyperoxia / Q000378:metabolism*; D007908:Lens, Crystalline / Q000378:metabolism* / Q000648:ultrastructure; D008297:Male; D064347:Microscopy, Electrochemical, Scanning; D018384:Oxidative Stress / Q000502:physiology*; D051381:Rats; D017207:Rats, Sprague-Dawley; D014822:Vitreous Body / Q000378:metabolism* / Q000648:ultrastructure; D020255:Vitreous Detachment / Q000139:chemically induced / Q000378:metabolism*
chemical_list: D000975:Antioxidants; D002374:Catalase; D006821:Hyaluronoglucosaminidase; D005978:Glutathione; D001205:Ascorbic Acid
references.citation: Biochim Biophys Acta. 1988 Jun 9;947(2):335-66
references.pmid: 3285893
references.citation: Exp Eye Res. 1992 Dec;55(6):889-96
references.pmid: 1486943
references.citation: Exp Eye Res. 2009 Jun;88(6):1165-70
references.pmid: 19450459
references.citation: Biochem Soc Trans. 1996 Aug;24(3):881-4
references.pmid: 8878867
references.citation: FASEB J. 1995 Sep;9(12):1173-82
references.pmid: 7672510
references.citation: Invest Ophthalmol Vis Sci. 2001 Jun;42(7):1449-54
references.pmid: 11381046
references.citation: Br J Ophthalmol. 1984 Feb;68(2):113-7
references.pmid: 6691953
references.citation: Exp Eye Res. 2009 Feb;88(2):286-92
references.pmid: 18835558
references.citation: Am J Ophthalmol. 2010 Jan;149(1):32-6
references.pmid: 19875090
references.citation: Philos Trans R Soc Lond B Biol Sci. 2011 Apr 27;366(1568):1293-300
references.pmid: 21402587
references.citation: Ophthalmic Res. 1988;20(3):191-9
references.pmid: 3186192
references.citation: J Ocul Pharmacol Ther. 2000 Apr;16(2):121-35
references.pmid: 10803423
references.citation: Exp Eye Res. 2005 May;80(5):709-25
references.pmid: 15862178
references.citation: Retina. 2007 Oct;27(8):1090-6
references.pmid: 18040251
references.citation: Ophthalmic Res. 2010;44(3):155-65
references.pmid: 20829639
references.citation: Biochem J. 1970 May;117(5):957-60
references.pmid: 5451916
references.citation: Acta Ophthalmol Scand. 2002 Apr;80(2):188-90
references.pmid: 11952487
references.citation: J Biol Chem. 1952 Mar;195(1):133-40
references.pmid: 14938361
references.citation: Invest Ophthalmol Vis Sci. 2000 Sep;41(10):3061-73
references.pmid: 10967065
references.citation: Mol Vis. 2009 Dec 31;15:2945-52
references.pmid: 20057910
references.citation: Exp Eye Res. 2007 Mar;84(3):455-63
references.pmid: 17174302
references.citation: Acta Ophthalmol Scand. 2004 Aug;82(4):449-53
references.pmid: 15291940
references.citation: Invest Ophthalmol Vis Sci. 1992 Sep;33(10):2926-35
references.pmid: 1388145
references.citation: Free Radic Biol Med. 2006 Jan 15;40(2):335-40
references.pmid: 16413415
references.citation: Invest Ophthalmol Vis Sci. 2003 Nov;44(11):4639-43
references.pmid: 14578379
references.citation: Invest Ophthalmol Vis Sci. 1999 Nov;40(12):3021-6
references.pmid: 10549667
references.citation: Arch Ophthalmol. 2009 Apr;127(4):475-82
references.pmid: 19365028
references.citation: Arch Ophthalmol. 2004 Apr;122(4):477-85
references.pmid: 15078664
references.citation: Exp Eye Res. 2003 Apr;76(4):405-15
references.pmid: 12634105
references.citation: Clin Chim Acta. 1980 May 9;103(3):259-68
references.pmid: 7398071
references.citation: Am J Ophthalmol. 2006 Jun;141(6):1027-32
references.pmid: 16765670
references.citation: Exp Eye Res. 1995 Mar;60(3):219-35
references.pmid: 7789403
references.citation: Invest Ophthalmol Vis Sci. 2004 Jan;45(1):77-85
references.pmid: 14691157
references.citation: Free Radic Biol Med. 1991;11(2):207-13
references.pmid: 1937139
references.citation: Arch Ophthalmol. 2006 Nov;124(11):1586-90
references.pmid: 17102006
references.citation: Curr Eye Res. 2000 Feb;20(2):121-6
references.pmid: 10617913
references.citation: Curr Eye Res. 2006 Jan;31(1):1-11
references.pmid: 16421014
references.citation: Invest Ophthalmol Vis Sci. 2006 Apr;47(4):1571-80
references.pmid: 16565394
references.citation: Invest Ophthalmol Vis Sci. 1989 Nov;30(11):2320-31
references.pmid: 2807790
references.citation: Invest Ophthalmol Vis Sci. 2005 Dec;46(12):4641-51
references.pmid: 16303961
references.citation: Exp Eye Res. 1990 Jun;50(6):819-26
references.pmid: 2373174
references.citation: Am J Ophthalmol. 2005 Feb;139(2):302-10
references.pmid: 15733992
references.citation: Invest Ophthalmol Vis Sci. 1988 Aug;29(8):1312-9
references.pmid: 3417415
references.citation: Exp Eye Res. 2004 May;78(5):917-24
references.pmid: 15051473