Effects of aminoguanidine on lipid and protein oxidation in diabetic rat kidneys.
Nonenzymatic glycation of tissue and plasma proteins may stimulate the production of oxidant and carbonyl stress in diabetes. The aim of this study was to evaluate the effects of aminoguanidine (AG) on lipid peroxidation, protein oxidation and nitric oxide (NO) release in diabetic rat kidneys. After induction of diabetes with streptozotocin, female Wistar rats were divided into 2 groups. Group DAG (n=9) rats were given AG hydrogen carbonate (1 g/L) in drinking water and group D (n=8) was diabetic control rats given only tap water. Group H (n=8) was followed as healthy controls. At the end of an 8 week period, NO release, lipid and protein oxidation were determined in kidney tissues. NO release was significantly lower in diabetic rats compared with healthy controls (p<0.05). Lipid peroxidation was significantly high in group D (3.9 +/- 0.3 nmol MDA/g tissue) compared with the group DAG (2.6 0.1 nmol MDA/g tissue, p<0.01) and group H (2.4 +/- 0.2 nmol MDA/g tissue). Protein oxidation was significantly higher in diabetics than healthy controls (563.8 +/- 23.9, 655.8 +/- 7.2, 431.5 +/- 8.8 mmol carbonyl / g tissue for group DAG, D and H, respectively, p< 0.05). A positive correlation between albuminuria and thiobarbituric acid reactive substance (TBARS) levels (r= 0.54,p<0.005) and carbonyl content (r=0.70, p<0.0005) in kidney homogenate were observed. Although AG treatment had no effect on NO release, it significantly decreased lipid peroxidation in diabetic rat cortices. Consequently increased lipid peroxidation -as well as- protein oxidation could be involved in the pathogenesis of diabetic albuminuria.
Gogasyavuz
Dilek
D
Department of Internal Medicine Section of Endocrinology and Metabolism, School of Medicine, Marmara University, Istanbul Turkey. dyavuz@turk.net
Küçükkaya
Belgin
B
Ersoz
H Onder
HO
Yalçin
A Suha
AS
Emerk
Kaya
K
Akalin
Sema
S
D000419:Albuminuria; D000818:Animals; D003921:Diabetes Mellitus, Experimental / Q000378:metabolism*; D003928:Diabetic Nephropathies / Q000378:metabolism*; D005260:Female; D006146:Guanidines / Q000378:metabolism*; D007668:Kidney / Q000187:drug effects / Q000378:metabolism*; D007672:Kidney Cortex / Q000187:drug effects / Q000378:metabolism; D050356:Lipid Metabolism; D015227:Lipid Peroxidation / Q000187:drug effects*; D009569:Nitric Oxide / Q000378:metabolism; D010084:Oxidation-Reduction; D011506:Proteins / Q000187:drug effects / Q000378:metabolism*; D051381:Rats; D017208:Rats, Wistar; D017392:Thiobarbituric Acid Reactive Substances / Q000378:metabolism
D006146:Guanidines; D011506:Proteins; D017392:Thiobarbituric Acid Reactive Substances; D009569:Nitric Oxide; C004479:pimagedine