PURPOSE: To investigate if nitric oxide (NO) system contributes to the beneficial effect of angiotensin II type 1 receptor (AT(1)) blocker losartan in the retina of diabetic spontaneously hypertensive rats (SHR). METHODS: Diabetic SHR were randomized to receive oral treatment with losartan (DM-SHRLos). After 20 days, the rats were euthanized and the retinas collected. RESULTS: Diabetic SHR rats exhibited a significant increase in glial fibrillary acidic protein (GFAP) and decrease in occludin, markers of early diabetic retinopathy (DR). The oxidative status, evaluated by NO end-products (NO(x)(-)) levels along with the antioxidative system superoxide dismutase, revealed an accentuated imbalance in favor to oxidants in DM-SHR leading to a higher tyrosine nitration and DNA damage. The inducible NO synthase (iNOS) was also elevated in DM-SHR rats. The treatment with losartan ameliorated all of the above alterations. CONCLUSIONS: Oral treatment with losartan reduces iNOS expression and reestablishes the redox status, thus ameliorating the early markers of DR in a model of diabetes and hypertension.
PURPOSE: To investigate if nitric oxide (NO) system contributes to the beneficial effect of angiotensin II type 1 receptor (AT(1)) blocker losartan in the retina of diabetic spontaneously hypertensiverats (SHR). METHODS:Diabetic SHR were randomized to receive oral treatment with losartan (DM-SHRLos). After 20 days, the rats were euthanized and the retinas collected. RESULTS:Diabetic SHR rats exhibited a significant increase in glial fibrillary acidic protein (GFAP) and decrease in occludin, markers of early diabetic retinopathy (DR). The oxidative status, evaluated by NO end-products (NO(x)(-)) levels along with the antioxidative system superoxide dismutase, revealed an accentuated imbalance in favor to oxidants in DM-SHR leading to a higher tyrosine nitration and DNA damage. The inducible NO synthase (iNOS) was also elevated in DM-SHR rats. The treatment with losartan ameliorated all of the above alterations. CONCLUSIONS: Oral treatment with losartan reduces iNOS expression and reestablishes the redox status, thus ameliorating the early markers of DR in a model of diabetes and hypertension.
Authors: B Cameron Carr; Caitlyn E Emigh; Lea D Bennett; Andrew D Pansick; David G Birch; Chan Nguyen Journal: Retina Date: 2017-01 Impact factor: 4.256
Authors: Islam N Mohamed; Sahar A Soliman; Ahmed Alhusban; Suraporn Matragoon; Bindu A Pillai; Ahmed A Elmarkaby; Azza B El-Remessy Journal: Mol Vis Date: 2012-06-02 Impact factor: 2.367