Nitric Oxide Synthase Inhibition by L-NAME in Streptozotocin Induced Diabetic Rats: Impacts on Oxidative Stress

Nitric Oxide Synthase Inhibition by L-NAME in Streptozotocin
Induced Diabetic Rats: Impacts on
Oxidative Stress

ARZU SEVEN, SAVAS GÜZEL, OKTAY SEYMEN,¹ SABIHA CIVELEK,
MURAT BOLAYIRLI,² GUNNUR YIGIT¹ and GÜLDEN BURÇAK

Department of Biochemistry, ¹Department of Physiology, and ²Fikret Biyal Central Research Laboratory, Cerrahpasa Medical Faculty, Istanbul University, Istanbul, Turkey

The effects of nitric oxide synthase (NOS) inhibition by Nw-nitro-L-arginine methyl ester (L-NAME) administration on oxidative stress parameters were investigated in streptozotocin (STZ) induced diabetic rats. Lipid peroxidation as reflected by thiobarbituric acid reactive substances (TBARS) was insignificantly higher in diabetic rats. Plasma NO₂+NO₃ values (p<0.05) and erythrocyte CuZn superoxide dismutase (CuZn SOD) and glutathione peroxidase (GSH Px) activities were significantly higher (p<0.01, p<0.001, respectively) in diabetic rats. L-NAME administration to diabetic rats caused significantly lower CuZn SOD and GSH Px activities (p<0.01) and NO₂+NO₃ values (p<0.001), whereas a significantly higher GSH level (p<0.01). TBARS/GSH ratio was significantly higher in diabetic rats than controls (p<0.05) and significantly lower in L-NAME administered diabetic rats than diabetic rats (p<0.05). This experimental study highlightens the importance of NOS inhibition by L-NAME in the attenuation of oxidative stress in STZ diabetic rats

Keywords —— nitric oxide; L-NAME; diabetes; oxidative stress

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Tohoku J. Exp. Med., 2003, 199, 205-210

Address for reprints: Prof. Dr. Arzu Seven, Akatlar Maya Sitesi c/11, AKATLAR 80600, Istanbul, Turkey.

e-mail: bbseven@superonline.com