TITLE:
Dietary Omega-3 Fatty Acids Deficiency Affects the Glutamatergic Transport System in Rat Retina: Modulatory Effects after High Intraocular Pressure
AUTHORS:
Letícia V. Siqueira, Eduardo P. Rico, Mário C. Bulla, Luciano Bellini, Luiz C. L. Silveira, Lúcia Vinadé, Diogo O. Souza, Júlia D. Moreira
KEYWORDS:
N-3 PUFAs; Retina; Ischemia; HIOP; Glaucoma; Glutamate Transporters
JOURNAL NAME:
Food and Nutrition Sciences,
Vol.4 No.9A,
September
23,
2013
ABSTRACT: Glutamate excitotoxicity has been
postulated as a putative mechanism involved in the physiopathology of glaucoma,
a disease that can cause retinal cell damage. Thus, the modulation of
glutamatergic parameters is a putative therapeutic target to prevent
excitotoxic retinal injury. Here, we investigated the effect of dietary omega-3
fatty acids (w3) in the retinal glutamate transport
system in basal and ischemic conditions. Female Wistar rats were divided into
two groups: w3 diet (w3 group) and w3 deficient-diet (D group). Their pups, at 60
days old, were used for the experiments. Retinal ischemia, a mechanism involved
in the physiopathology of glaucoma, was induced by high intraocular pressure
(HIOP, 140 180 mmHg for 45 min) to impair retinal
blood flow. Analyses were performed 7 days after ischemia. The D group showed a
decreased glutamate uptake in basal conditions and after HIOP when compared to
the w3 group. After HIOP, there was a
decrease in glutamate uptake in the D group that was not observed in the w3 group (p w3 group presented higher levels of GLT-1 compared
to the D group in basal and ischemic conditions. After HIOP, EAAC1 was
increased in both groups, while GLT-1 increased only in the D group, compared
to basal levels. GLAST and EAAT5 presented no alterations. The modulation of
the glutamatergic system by dietary w3 fatty acids points to a potential mechanism by
which w3 PUFAs exert beneficial effects in
the retina.