Bacterial Lipopolysaccharide Provides Histological and Functional Protection Against Light-Induced Retinal Damage in Rats

LANZANI, MF; FRANCO, PJ; FERNANDEZ, DIEGO; LÓPEZ-COSTA, JJ; ROSENSTEIN R.E

Fort Lauderdale, USA

Congreso; The Association for Research in Vision and Ophthalmology; 2009

The Association for Research in Vision and Ophthalmology

Invest Ophthalmol Vis Sci 2009;50: E-Abstract 686.© 2009 ARVO 686—D740 Bacterial Lipopolysaccharide Provides Histological and Functional Protection Against Light-Induced Retinal Damage in RatsM. F. Lanzani1, P. Franco2, D. Fernandez2, J. J. López-Costa3A and R. E. Rosenstein3B 1Human Biochemistry, School of Medicine University of Buenos, Buenos Aires, Argentina2Human Biochemistry, School of Medicine University of Buenos, CEFyBO/CONICET, Buenos Aires, ArgentinaAHistology, BHuman Biochemistry, 3Institute of Cell Biology and Neurosciences "Prof. E. De Robertis," School of Medicine, University of Buenos Aires, Buenos Aires, Argentina Commercial Relationships: M.F. Lanzani, None; P. Franco, None; D. Fernandez, None; J.J. López-Costa, None; R.E. Rosenstein, None. Support: Ruth Rosenstein, BID 1728 PICT 25364 Abstract Purpose:In a previous report, we showed that intravitreal injections of bacterial lipopolysaccharide (LPS) 24 h before ischemia induce a significant protection against ischemia/reperfusion damage. The aim of the present work was to analyze the effect of LPS on light-induced damage. Methods:Male Wistar rats were intravitreously injected with 3 µg LPS in one eye and vehicle in the contralateral eye. One day after injections, rats were placed for 24 h in an open white acrylic box of 60 cm x 60 cm x 60 cm with 12 halogen lamps (12 V 50 W each) located on top. White light spectrum was used, and lighting level was 12,000 lux. The lighting box was kept in an air-conditioned room, and temperature was monitored and maintained at 24°C. All the animals received food and water ad libitum. Subsequently, 7 or 14 days after light exposure, rats were subjected to electroretinography and histological analysis Results:Constant light for 24 h induced a significant decrease in scotopic ERG a- and b-wave amplitude. The light-induced decrease in both a- and b-wave amplitude was significantly lower in eyes treated with 3µg LPS both at 7 and 14 days after light exposure. Moreover, significant alterations in the outer nuclear and the outer plexiform layers and the pigment epithelium were observed in eyes exposed to constant light. The injection of LPS reduced light-induced photoreceptor degeneration and protected the outer plexiform layer and the pigment epithelium. Conclusions:For the first time, these results indicate that LPS provides functional and histological protection against the deleterious effects of constant light. Keywords: oxidation/oxidative or free radical damage • neuroprotection • retina © 2009, The Association for Research in Vision and Ophthalmology, Inc., all rights reserved. Permission to republish any abstract or part of an abstract in any form must be obtained in writing from the ARVO Office prior to publication.