Arterial hypertension exacerbates oxidative stress in early diabetic retinopathy.
The present study was undertaken to investigate the redox status in the retina of an experimental model that combines hypertension and diabetes. Spontaneously hypertensive rats (SHR) and their control Wystar Kyoto (WKY) rats were rendered diabetic and, after 20 days, the rats were sacrificed and the retinas collected. The superoxide production was higher in diabetic than in control WKY (p < 0.03) and SHR rats showed elevated superoxide production compared with WKY groups (p < 0.009). The glutathione antioxidant system was diminished only in diabetic SHR (p < 0.04). Tirosyne nitration was higher in diabetic WKY and control SHR compared with control WKY (p < 0.03), and further increment was observed in diabetic SHR (p < 0.02). The DNA damage estimated by immunohystochemistry for 8-OHdG was higher in control SHR than in WKY, mainly in diabetic SHR (p < 0.0001). Hypertension aggravates oxidative-induced cytotoxicity in diabetic retina due to increasing of superoxide production and impairment of antioxidative system.
Pinto
Camila C
CC
Renal Pathophysiology Laboratory, Department of Internal Medicine, Faculty of Medical Sciences (FCM), State University of Campinas, Campinas, São Paulo, Brazil.
Silva
Kamila C
KC
Biswas
Subrata K
SK
Martins
Natássia
N
De Faria
José B Lopes
JB
De Faria
Jacqueline M Lopes
JM
D000080242:8-Hydroxy-2'-Deoxyguanosine; D000818:Animals; D000975:Antioxidants / Q000378:metabolism; D004249:DNA Damage; D003849:Deoxyguanosine / Q000031:analogs & derivatives / Q000737:chemistry; D003930:Diabetic Retinopathy / Q000150:complications* / Q000473:pathology*; D005978:Glutathione / Q000737:chemistry / Q000378:metabolism; D006973:Hypertension / Q000150:complications* / Q000473:pathology*; D008297:Male; D009584:Nitrogen / Q000737:chemistry; D018384:Oxidative Stress; D051381:Rats; D011918:Rats, Inbred SHR; D011921:Rats, Inbred WKY; D013482:Superoxide Dismutase / Q000737:chemistry; D014443:Tyrosine / Q000378:metabolism
D000975:Antioxidants; D014443:Tyrosine; D000080242:8-Hydroxy-2'-Deoxyguanosine; D013482:Superoxide Dismutase; D003849:Deoxyguanosine; D005978:Glutathione; D009584:Nitrogen