HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text Full Text (PDF) Submit a response Alert me when this article is cited Alert me when eLetters are posted Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Li, F. Articles by Anderson, R. E. Search for Related Content PubMed PubMed Citation Articles by Li, F. Articles by Anderson, R. E.

Alleviation of Constant-Light–Induced Photoreceptor Degeneration by Adaptation of Adult Albino Rat to Bright Cyclic Light

¹From the Departments of Ophthalmology and ²Cell Biology, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma; and the ³Dean A. McGee Eye Institute, Oklahoma City, Oklahoma.

PURPOSE. To further test the hypothesis that light-adaptation–mediated photoreceptor protection works through inhibition of apoptosis by activation and/or upregulation of neuroprotective molecules.

METHODS. Albino rats were born and raised in 5-lux cyclic light (12 hours OFF and ON). At 8 weeks of age, animals were adapted to 400-lux cyclic light for different periods. Light damage was induced by exposure to constant light for 1 day at an illumination of 1700 lux. Animals were killed, and their eyes were removed for morphometric and biochemical analysis. TUNEL assay was used to evaluate photoreceptor cell apoptosis and Western blot analyses were used to determine the levels of basic fibroblast growth factor (bFGF), neuronal nitric oxide synthase (nNOS), and caspase-3.

RESULTS. Exposure of dim-reared rats to constant light for 1 day dramatically increased TUNEL-positive cells in the outer nuclear layer. Adaptation to 400-lux bright cyclic light for 4 days significantly reduced TUNEL-positive cells induced by exposure to constant light, which correlated with a significant increase in bFGF expression. Compared with control retinas, caspase-3 levels were not changed by exposure to constant light or after adaptation to 400 lux. There was a significant increase in nNOS level in the constant-light–exposed group, but not in the group adapted to 400-lux bright light before exposure to constant light.

CONCLUSIONS. The retina of the adult rat can rapidly upregulate neuroprotective mechanisms when switched from dim to bright cyclic light. Identification of the molecules involved in this process may allow rational development of therapeutic approaches to treat retinal degenerative diseases.

This article has been cited by other articles:

				A. Rattner, L. Toulabi, J. Williams, H. Yu, and J. Nathans The Genomic Response of the Retinal Pigment Epithelium to Light Damage and Retinal Detachment J. Neurosci., September 24, 2008; 28(39): 9880 - 9889. [Abstract] [Full Text] [PDF]

				R. Maccarone, S. Di Marco, and S. Bisti Saffron Supplement Maintains Morphology and Function after Exposure to Damaging Light in Mammalian Retina Invest. Ophthalmol. Vis. Sci., March 1, 2008; 49(3): 1254 - 1261. [Abstract] [Full Text] [PDF]

				O. Perche, M. Doly, and I. Ranchon-Cole Caspase-Dependent Apoptosis in Light-Induced Retinal Degeneration Invest. Ophthalmol. Vis. Sci., June 1, 2007; 48(6): 2753 - 2759. [Abstract] [Full Text] [PDF]

				S. Joly, V. Pernet, S. Chemtob, A. Di Polo, and P. Lachapelle Neuroprotection in the Juvenile Rat Model of Light-Induced Retinopathy: Evidence Suggesting a Role for FGF-2 and CNTF Invest. Ophthalmol. Vis. Sci., May 1, 2007; 48(5): 2311 - 2320. [Abstract] [Full Text] [PDF]

				A. Rajala, R. E. Anderson, J.-X. Ma, J. Lem, M. R. Al-Ubaidi, and R. V. S. Rajala G-protein-coupled Receptor Rhodopsin Regulates the Phosphorylation of Retinal Insulin Receptor J. Biol. Chem., March 30, 2007; 282(13): 9865 - 9873. [Abstract] [Full Text] [PDF]

				G. Li, R. E. Anderson, H. Tomita, R. Adler, X. Liu, D. J. Zack, and R. V. S. Rajala Nonredundant Role of Akt2 for Neuroprotection of Rod Photoreceptor Cells from Light-Induced Cell Death J. Neurosci., January 3, 2007; 27(1): 203 - 211. [Abstract] [Full Text] [PDF]

				S. Joly, V. Pernet, A. L. Dorfman, S. Chemtob, and P. Lachapelle Light-induced retinopathy: comparing adult and juvenile rats. Invest. Ophthalmol. Vis. Sci., July 1, 2006; 47(7): 3202 - 3212. [Abstract] [Full Text] [PDF]

				A. Rattner and J. Nathans The Genomic Response to Retinal Disease and Injury: Evidence for Endothelin Signaling from Photoreceptors to Glia J. Neurosci., May 4, 2005; 25(18): 4540 - 4549. [Abstract] [Full Text] [PDF]

				R. Grewal, J. Stepczynski, R. Kelln, T. Erickson, R. Darrow, L. Barsalou, M. Patterson, D. T. Organisciak, and P. Wong Coordinated Changes in Classes of Ribosomal Protein Gene Expression Is Associated with Light-Induced Retinal Degeneration Invest. Ophthalmol. Vis. Sci., November 1, 2004; 45(11): 3885 - 3895. [Abstract] [Full Text] [PDF]

				H. Huang, F. Li, R. A. Alvarez, J. D. Ash, and R. E. Anderson Downregulation of ATP Synthase Subunit-6, Cytochrome c Oxidase-III, and NADH Dehydrogenase-3 by Bright Cyclic Light in the Rat Retina Invest. Ophthalmol. Vis. Sci., August 1, 2004; 45(8): 2489 - 2496. [Abstract] [Full Text] [PDF]

				C. Zhang, B. Lei, T. T. Lam, F. Yang, D. Sinha, and M. O. M. Tso Neuroprotection of Photoreceptors by Minocycline in Light-Induced Retinal Degeneration Invest. Ophthalmol. Vis. Sci., August 1, 2004; 45(8): 2753 - 2759. [Abstract] [Full Text] [PDF]