150 STIMULATION OF ADENOSINE A2A RECEPTORS INDUCES POSTCONDITIONING IN ISOLATED HEPATOCYTES

Abstract

The aim of this work was to study the impact of age in oxidative damage and lipid and glucose metabolisms and the effect of the IGF-I therapy in aging rats. Methods: Three groups were included: yCO, young controls (17 weeks old); O, untreated old rats (103 w-o); and O+IGF-I, aging rats (103 w-o) treated with IGF-I (1 month, 2.25mg·100g bw-1·day-1). Analytical parameters were determined by routine methods and levels of testosterone, IGF-I and insulin by RIA. Results: Compared with young controls, old rats showed: a reduction of IGF-I, testosterone and serum total antioxidant status (TAS); increased levels of serum glucose, insulin and HOMA (an index of insulin resistance); elevated cholesterol and triglycerides with a significant reduction of free fatty acids (FFA); and increased levels of malondialdehyde (MDA, a marker of lipid peroxidation) in liver homogenates with a reduction of catalase activity. IGF-I therapy was able to restore all these parameters (see Table). Conclusion: low doses of IGF-I restore circulating IGF-I and age relatedchanges improving glucose and lipid metabolism, increasing testosterone levels and serum total antioxidant capability and reducing oxidative liver damage with a normalization of catalase activity.