MODERATE EXERCISE PREVENTS MORPHOLOGICAL AND FUNCTIONAL ADRENOCORTICAL ALTERATIONS IN RATS WITH SUCROSE-INDUCED INSULIN RESISTANCE

MARTINEZ CALJEMAN, CAMILA; DI GRUCCIO, JUAN MARTÍN; JAUME, DAIANA; SANCHEZ, ROCÍO; MERCAU, MARÍA ELISA; ASTORT, FRANCISCO; ARIAS, PABLO; CYMERYNG, CORA BEATRIZ

BERLIN

Congreso; 48th EASD Annual Meeting; 2012

EUROPEAN ASSOCIATION FOR THE STUDY OF DIABETES

Background and aims: Previous results from our group demonstrate the impact of sucrose-induced insulin resistance on rat adrenocortical function and morphology. Physical activity reduces insulin resistance both in patients and in animal models with this metabolic derangement. Thus, we studied the effects of moderate physical exercise on the adrenocortical alterations already detected in rats with insulin resistance induced by sucrose-rich diets (SRD).Materials and methods: Adult male Wistar rats received 30% sucrose in the drinking water or their usual diet for a period of 9 weeks. Sucrose-treated and control animals underwent a protocol of moderate physical exercise on a treadmill (at 0.8 km/h up to 6 min, 5 days per week, groups SRD-E and C-E respectively). After 9 weeks, we measured insulin sensitivity (insulin tolerance test or ITT with 0.75 IU/kg insulin i.p.), adrenal function (basal and ACTH-stimulated serum corticosterone levels) and plasma ACTH levels. In adrenocortical tissue we determined triacylglyceride (TAG) and total cholesterol concentrations, the expression of proteins involved in steroidogenesis (StAR and CYP11A1) and its regulation (MCR2 ACTH receptor),  and inflammatory markers (TNF alpha, F4/80, COX-2).We also performed a histochemical evaluation of the adrenal cortex. Similar analysis were performed also in sedentary animals receiving a SRD (SRD-S) or their usual diet (C-S). Values are expressed as mean ± SEM. Differences between groups were analyzed by unpaired t test or by factorial one-way ANOVA followed by Tukey?s test, as appropriated. SRD-E animals exhibited lower body weight and glucose and insulin levels as compared to those measured in the corresponding SRD-S group.  Results obtained by means of the ITT showed a significant amelioration of the k value (SRD-E 1.88 ± 0.43 vs. SRD-S 1.68 ± 0.4,  mg*ml/min, p