Functional protection of photoreceptors from light-induced damage by dimethylthiourea and Ginkgo biloba extract. - Université Clermont Auvergne
Article Dans Une Revue Investigative Ophthalmology & Visual Science Année : 1999

Functional protection of photoreceptors from light-induced damage by dimethylthiourea and Ginkgo biloba extract.

Protection de la fonction des photorécepteurs contre les dommages induits par la lumière par la diméthylthiourée et l'extrait de Gingko biloba

Résumé

Purpose: To investigate the functional protective effect of a synthetic (dimethylthiourea, DMTU) and a natural antioxidant (Ginkgo biloba extract, EGb 761) against light-induced retinal degeneration. Methods: Wistar rats were exposed for 24 hours to 1700-lux light after treatment with DMTU or EGb 761. Electroretinograms were recorded before and on day (D)1, D3, D8, D15, D22, and D29 after light exposure. The b-wave amplitude was plotted against log L (ganzfeld luminance), providing the b-wave sensitivity curve. The Naka-Rushton function fitted to the sensitivity curve enabled derivation of the parameters Bmax (saturated amplitude) and K (luminance-inducing Bmax/2). In addition, rats from each group were killed for retinal morphometric analyses. Results: In the untreated group, light exposure caused collapse of the b-wave sensitivity curves. Bmax was reduced by 51% at D1 without subsequent recovery. K increased temporarily, reverting to normal values 8 days later. The outer nuclear layer thicknesses decreased markedly in the superior retina. In the treated groups, light exposure had a weaker effect on sensitivity curves. The values of Bmax were not significantly different from those in the unexposed-untreated group, although K increased temporarily. Retinal morphometry was preserved. Conclusions: Dimethylthiourea and EGb 761 afford functional protection against light-induced retinal damage.
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hal-04610180 , version 1 (12-06-2024)

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  • HAL Id : hal-04610180 , version 1
  • PUBMED : 10235553

Citer

isabelle Ranchon-Cole, J Gorrand, J Cluzel, M Droy-Lefaix, M Doly. Functional protection of photoreceptors from light-induced damage by dimethylthiourea and Ginkgo biloba extract.. Investigative Ophthalmology & Visual Science, 1999, 40 (6), pp.1191-9. ⟨hal-04610180⟩
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