Abdominal adipose tissue: early metabolic dysfunction associated to insulin resistance and oxidative stress induced by an unbalanced diet

REBOLLEDO OR; MARRA CA; RASCHIA A; RODRIGUEZ S; GAGLIARDINO JJ

Horm Metab Res

Año: 2008 vol. 40 p. 794 - 800

0018-5043

We studied the possible contribution of early changes in lipid composition, function and antioxidant status of abdominal adipose tissue (AAT) induced by a fructose-rich diet (FRD) to the development of insulin resistance (IR) and oxidative stress (OS). Wistar rats were fed a commercial diet with (FRD) or without 10% fructose in the drinking water for 3 weeks. We measured glucose (G), triglyceride (TG) and insulin (I) plasma levels, and the activity of antioxidant enzymes, lyposoluble antioxidants, total glutathione (GSH), lipid peroxidation as TBARS, fatty acid (FA) composition of AAT-TG as well as their release by incubated pieces of AAT. FRD rats have significantly higher plasma levels of G, TG and I. Their AAT showed a marked increase in content and ratios of saturated to monounsaturated and polyunsaturated FA, TBARS, and catalase, GSH-transferase and GSH-reductase, together with a decrease in superoxide dismutase and GSH-peroxidase activity, and total GSH, a-tocopherol, b-carotene and lycopene content. Incubated AAT from FRD released in vitro higher amount of FFA with higher ratios of saturated to monounsaturated and polyunsaturated FA. Our data suggest that FRD induced an early pro-oxidative state and metabolic dysfunction in AAT that would favor the overall development of IR and OS and further development of pancreatic b-cell failure; therefore, its early control would represent an appropriate strategy to prevent alterations such as the development of type 2 diabetes.