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 Grimm, C. Articles by Williams, T. P. Search for Related Content PubMed PubMed Citation Articles by Grimm, C. Articles by Williams, T. P.

Blue Light’s Effects on Rhodopsin: Photoreversal of Bleaching in Living Rat Eyes

¹ From the Department of Ophthalmology, University Eye Clinic, Zurich, Switzerland; and ² Department of Biological Science, Florida State University, Tallahassee.

PURPOSE. To determine whether blue light induces photoreversal of rhodopsin bleaching in vivo.

METHODS. Eyes of anesthetized albino rats were exposed to either green (550 nm) or deep blue (403 nm) light, and the time course of rhodopsin bleaching was determined. Rhodopsin was isolated from whole retinas by detergent extraction and measured photometrically. To inhibit photoreversal of bleaching, rats were perfused with 70 mM hydroxylamine (NH₂OH), a known inhibitor of photoreversal. To determine whether blue-absorbing, photoreversible photoproducts were formed, rhodopsin was bleached to near completion with green light and then exposed to blue light. Finally, experimental results were simulated on a computer by means of a simple, three-component model involving a long-lived photoreversible photoproduct.

RESULTS. Photoreversal of bleaching in blue light occurs in vivo as evidenced by the following: In the absence of NH₂OH, bleaching of rhodopsin by blue light was slow and complex. In the presence of NH₂OH, however, blue light bleached rhodopsin very fast with a simple, pseudo–first-order kinetic. A long-lived bleaching intermediate produced by green light exposure was photoreversed to rhodopsin by exposure to blue light. The three-component computer model, invoking a blue-absorbing, photoreversible, long-lived intermediate accurately described the data.

CONCLUSIONS. Because of the instantaneous, nonmetabolic regeneration of rhodopsin by the process of photoreversal of bleaching, blue light exposure permits the absorption of large numbers of photons by rhodopsin and by a photoreversible intermediate of bleaching in vivo. These data may have an important impact on resolving mechanisms of blue light–mediated damage to the retina.

This article has been cited by other articles:

				A. Laabich, G. P. Vissvesvaran, K. L. Lieu, K. Murata, T. E. McGinn, C. C. Manmoto, J. R. Sinclair, I. Karliga, D. W. Leung, A. Fawzi, et al. Protective Effect of Crocin against Blue Light- and White Light-Mediated Photoreceptor Cell Death in Bovine and Primate Retinal Primary Cell Culture. Invest. Ophthalmol. Vis. Sci., July 1, 2006; 47(7): 3156 - 3163. [Abstract] [Full Text] [PDF]

				A. Wenzel, V. Oberhauser, E. N. Pugh Jr., T. D. Lamb, C. Grimm, M. Samardzija, E. Fahl, M. W. Seeliger, C. E. Reme, and J. von Lintig The Retinal G Protein-coupled Receptor (RGR) Enhances Isomerohydrolase Activity Independent of Light J. Biol. Chem., August 19, 2005; 280(33): 29874 - 29884. [Abstract] [Full Text] [PDF]

				C. E. Reme The Dark Side of Light: Rhodopsin and the Silent Death of Vision The Proctor Lecture Invest. Ophthalmol. Vis. Sci., August 1, 2005; 46(8): 2672 - 2682. [Full Text] [PDF]

				M A Mainster and J R Sparrow How much blue light should an IOL transmit? Br. J. Ophthalmol., December 1, 2003; 87(12): 1523 - 1529. [Abstract] [Full Text] [PDF]

				D. T. Organisciak, R. M. Darrow, L. Barsalou, R. K. Kutty, and B. Wiggert Susceptibility to Retinal Light Damage in Transgenic Rats with Rhodopsin Mutations Invest. Ophthalmol. Vis. Sci., February 1, 2003; 44(2): 486 - 492. [Abstract] [Full Text] [PDF]

				W. C. Gordon, D. M. Casey, W. J. Lukiw, and N. G. Bazan DNA Damage and Repair in Light-Induced Photoreceptor Degeneration Invest. Ophthalmol. Vis. Sci., November 1, 2002; 43(11): 3511 - 3521. [Abstract] [Full Text] [PDF]

				J. W. Kijas, A. V. Cideciyan, T. S. Aleman, M. J. Pianta, S. E. Pearce-Kelling, B. J. Miller, S. G. Jacobson, G. D. Aguirre, and G. M. Acland Naturally occurring rhodopsin mutation in the dog causes retinal dysfunction and degeneration mimicking human dominant retinitis pigmentosa PNAS, April 30, 2002; 99(9): 6328 - 6333. [Abstract] [Full Text] [PDF]

				C. Grimm, A. Wenzel, T. P. Williams, P. O. Rol, F. Hafezi, and C. E. Remé Rhodopsin-Mediated Blue-Light Damage to the Rat Retina: Effect of Photoreversal of Bleaching Invest. Ophthalmol. Vis. Sci., February 1, 2001; 42(2): 497 - 505. [Abstract] [Full Text]

				F. J. Bartl, E. Ritter, and K. P. Hofmann Signaling States of Rhodopsin. ABSORPTION OF LIGHT IN ACTIVE METARHODOPSIN II GENERATES AN ALL-TRANS-RETINAL BOUND INACTIVE STATE J. Biol. Chem., August 3, 2001; 276(32): 30161 - 30166. [Abstract] [Full Text] [PDF]

				J. W. Kijas, A. V. Cideciyan, T. S. Aleman, M. J. Pianta, S. E. Pearce-Kelling, B. J. Miller, S. G. Jacobson, G. D. Aguirre, and G. M. Acland Naturally occurring rhodopsin mutation in the dog causes retinal dysfunction and degeneration mimicking human dominant retinitis pigmentosa PNAS, April 30, 2002; 99(9): 6328 - 6333. [Abstract] [Full Text] [PDF]