Abstract
Purpose: :
The results of DCCT/EDIC revealed a strong association of dyslipidemia with the development of diabetic retinopathy. However, there are no experimental data on retinal fatty acid (FA) metabolism in diabetes. In this study we compared retinal, liver and blood plasma FA profiles as well as expression levels of FA elongases and desaturases, in control and STZ diabetic rats.
Methods: :
STZ-injected male Wistar rat model of Type I diabetes was used. Rats were maintained on control or DHA enriched diets for 9 weeks. Saponified rat retinal fatty acids were analyzed by HPLC. Elovl4 protein expression level was analyzed by Western Blot.
Results: :
Retinal FA profiles were highly enriched in DHA. The retinas of diabetic animals had 85% less DHA compared to controls. The decrease in retinal DHA was independent of liver and blood plasma fatty acid profile changes suggesting the effect of diabetes on retinal-specific fatty acid metabolism. Control retinas had a very high expression level of retinal specific elongase Elovl4, moreover, diabetes induced a ten times decrease in retinal expression levels of Elovl4. DHA enriched diet helped to restore retinal DHA levels to non-diabetic levels without any significant change in Elovl4 protein expression.
Conclusions: :
Diabetes induced retinal specific decrease in fatty acid elongation leading to severe DHA deficiency in diabetic retina. Diabetes induced deficiency retinal fatty acid metabolism can be overcome by dietary supplementation with DHA.
Keywords: diabetic retinopathy • lipids • inflammation