Effect of different exercise intensities on the pancreas of animals with metabolic syndrome

Abstract

Fernanda Amaral,1 Nathalia EA Lima,1 Elisabete Ornelas,1 Lucila Simardi,2 Fernando Luiz Affonso Fonseca,2,3 Laura Beatriz Mesiano Maifrino1,4 1Laboratório de Estudos Morfoquantitativo e Imunohistoquímico, Universidade São Judas Tadeu, São Paulo, Brazil; 2Faculdade de Medicina do ABC, Santo André, São Paulo, Brazil; 3Departamento de Ciências Biológicas, Universidade Federal de São Paulo, São Paulo, Brazil; 4Instituto Dante Pazzanese de Cardiologia, São Paulo, Brazil Introduction: Metabolic syndrome (MS) comprises several metabolic disorders that are risk factors for cardiovascular disease and has its source connected to the accumulation of visceral adipose tissue (VAT) and development of insulin resistance. Despite studies showing beneficial results of exercise on several risk factors for cardiovascular disease, studies evaluating the effects of different intensities of exercise training on the pancreas with experimental models are scarce. Methods: In total, 20 Wistar rats were used, divided into four groups: control (C), metabolic syndrome (MS and without exercise), metabolic syndrome and practice of walking (MSWalk), and metabolic syndrome and practice of running (MSRun). The applied procedures were induction of MS by fructose in drinking water; experimental protocol of walking and running; weighing of body mass and VAT; sacrifice of animals with blood collection and removal of organs and processing of samples for light microscopy using the analysis of volume densities (Vv) of the studied structures. Results: Running showed a reduction of VAT weight (–54%), triglyceride levels (–40%), Vv[islet] (–62%), Vv[islet.cells] (–22%), Vv[islet.insterstitial] (–44%), and Vv[acinar.insterstitial] (–24%) and an increase of Vv[acini] (+21%) and Vv[acinar.cells] (+22%). Regarding walking, we observed a decrease of VAT weight (–34%) and triglyceride levels (–27%), an increase of Vv[islet.cells] (+72%) and Vv[acinar.cells] (+7%), and a decrease of Vv[acini] (–4%) and Vv[acinar.insterstitial] (–16%) when compared with those in the MS group. Conclusion: Our results suggest that the experimental model with low-intensity exercise (walking) seems to be more particularly recommended for preventing morphological and metabolic disorders occurring in the MS. Keywords: metabolic syndrome, pancreas, exercise, visceral adipose tissue, insulin resistance