No consequence of dietary omega-3 polyunsaturated fatty acid deficiency on the severity of scopolamine-induced dry eye

International audience; Purpose:Epidemiological studies suggest that dietary omega-3 polyunsaturated fatty acids (PUFAs) may protect against prevalence of dry eye. This work aimed to evaluate whether a dietary deficiency in omega-3 PUFAs may increase the severity of dry eye in a scopolamine-induced rat model. Methods:Three consecutive generations of Lewis rats were bred under diets deprived of omega-3 PUFAs. Dry eye was experimentally induced by continuous scopolamine delivery in female animals from the third deficient generation and in female Lewis rats fed for three generations with a balanced diet. After 14 days of treatment, the clinical signs of ocular dryness were evaluated in vivo us…

Fructose diet induced short-term impairment of cone sensitivity and gene expression in rat retina

National audience; Abstract: Purpose A high fructose diet has been widely used to trigger insulin resistance in rodent; insulin resistance is one of the major risk factor for the development of type 2 diabetes. Thirty to 40% of diabetic patients develop diabetic retinopathy. In this study, we aimed to evaluate the short-term effect, at 1, 3, 5, 8 days, of a 60% fructose diet, on photoreceptor sensitivity and gene expression in the retina of Brown Norway rats. Methods: Flicker electroretinograms (8Hz) were recorded under anesthesia, from both eyes simultaneously in order to study sensitivity of photoreceptors. Then, rats were euthanized and enucleated. Retinae and posterior poles were collec…

Effect of dietary omega-3 and omega-6 fatty acids on IOP elevation, electroretinographic changes and retinal ganglion cell loss in a rat model of glaucoma induced by laser

Purpose To test the efficacy of dietary omega-3 and omega-6 fatty acids in a rat model of glaucoma induced by laser photocoagulation. Methods Rats were fed for 3 months with a diet containing either: 1) 17% of omega-3 fatty acids (10% EPA + 7% DHA), 2) 10% of omega-6 fatty acids (as GLA), or 3) a combination of both omega-3 and omega-6 fatty acids (10% EPA + 7% DHA + 10% GLA), by comparison with a control group of animals fed with a standard diet deprived of EPA, DHA and GLA. After 3 months of diet, glaucoma was induced in one eye of the animal by laser.IOP was regularly measured and the retinal function was evaluated by electroretinography (ERG) for 3 months. At the end of the experiment, …

Early adaptive response of the retina to a pro-diabetogenic diet: Impairment of cone response and gene expression changes in high-fructose fed rats

The lack of plasticity of neurons to respond to dietary changes, such as high fat and high fructose diets, by modulating gene and protein expression has been associated with functional and behavioral impairments that can have detrimental consequences. The inhibition of high fat-induced rewiring of hypothalamic neurons induced obesity. Feeding rodents with high fructose is a recognized and widely used model to trigger obesity and metabolic syndrome. However the adaptive response of the retina to short term feeding with high fructose is poorly documented. We therefore aimed to characterize both the functional and gene expression changes in the neurosensory retina of Brown Norway rats fed duri…

Étude animale de l’implantation du nerf auditif par voie transmodiolaire avec tentative de conservation de l’audition

But de la presentation L’implantation du nerf auditif est reconsideree comme un moyen de rehabilitation auditive en pouvant resoudre des difficultes de placement de porte-electrodes dans des cas difficiles (cochlees ossifiees). Elle peut augmenter la specificite de la stimulation, diminuer la consommation energetique, reduire les interferences entre les electrodes et donner acces a des fibres codant pour les frequences graves. Les voies d’abord pour l’implantation du nerf auditif ont ete jusqu’a aujourd’hui invasifs. Nous avons etudie la faisabilite d’une implantation du nerf transmodiolaire via les cavites de l’oreille moyenne chez l’homme. Cette voie semble possible grâce a la navigation …

Metabolic syndrome triggered by high-fructose diet favors choroidal neovascularization and impairs retinal light sensitivity in the rat

Diabetic retinopathy and age-related macular degeneration are the leading causes of blindness in Western populations. Although it is a matter of controversy, large-scale population-based studies have reported increased prevalence of age-related macular degeneration in patients with diabetes or diabetic retinopathy. We hypothesized that metabolic syndrome, one of the major risk factors for type 2 diabetes, would represent a favorable environment for the development of choroidal neovascularization, the main complication of age-related macular degeneration. The fructose-fed rat was used as a model for metabolic syndrome in which choroidal neovascularization was induced by laser photocoagulatio…

O32 Le syndrome métabolique induit par un régime enrichi en fructose est promoteur d’un développement néovasculaire et d’altérations fonctionnelles dans la rétine

Dietary polyunsaturated fatty acids reduce retinal stress induced by an elevation of intraocular pressure in rats.

International audience; N-6 and n-3 polyunsaturated fatty acids (PUFAs) have been shown to prevent tissue release of inflammatory molecules. We have shown that a combination of n-6 and n-3 PUFAs is more efficient than single supplementations on the long-term consequences of intraocular pressure elevation. We hypothesized that such an association is also more effective during early retinal stress by modifying retinal proinflammatory prostaglandin and cytokine productions. Rats were supplemented for 3 months with n-6 PUFAs, n-3 PUFAs, or both n-6 and n-3 PUFAs. After 3 months, a surgical elevation of intraocular pressure was induced. Retinal morphometry and glial cell activation were evaluate…