Diabetic Retinal Neurodegeneration Is Associated With Mitochondrial Oxidative Stress and Is Improved by an Angiotensin Receptor Blocker in a Model Combining Hypertension

OBJECTIVE—Diabetic retinopathy displays the features of a neurodegenerative disease. Oxidative stress is involved in the pathogenesis of diabetic retinopathy. This investigation sought to determine whether hypertension exacerbates the oxidative stress, neurodegeneration, and mitochondrial dysfunction that exists in diabetic retinopathy and whether these changes could be minimized by the angiotensin II type 1 (AT1) receptor blocker (ARB) losartan. RESEARCH DESIGN AND METHODS—Diabetes was in-duced in spontaneously hypertensive rats (SHRs) and normoten-sive Wistar-Kyoto (WKY) rats. The diabetic SHRs were assigned to receive or not receive losartan. RESULTS—The level of apoptosis in the retina was higher in diabetic WKY rats than in the control group, and higher levels were found in diabetic SHRs. The apoptotic cells expresse