This study was approved by the Ethical Committe in Research and Scientific Merit of the Universitary Center Hermínio Ometto – UNIARARAS (protocol number 634/2008). Adults male Wistar rats (333.6 ± 31.9 g; 70 days old) from buy STI571 the Central Animal Breeding Center, São Paulo State University, Botucatu campus, were used in the experiments. They were kept at 25 °C with a light/dark cycle of 12 h/12 h, and received Purina® rat chow and water ad libitum. Diabetes was induced by an intravenous injection (35 mg/kg b.w.) of Alloxan (Sigma). After 5 days, blood samples were obtained with animals in the fed state to determine

the plasma glucose concentration. Rats that were not diabetic (glucose < 11.2 mmol/L) were eliminated from the study. For the study, the rats were randomly allocated to one of four groups (n = 5 per group): sedentary control (SC), trained control (TC), sedentary diabetic (SD), and trained diabetic (TD). Training included daily swimming 1 h/day, 5 days/week, for 8 weeks, with a load of 4.8% (for diabetic animals) and 5.2% (for healthy animals), corresponding to the maximal lactate steady state (Gobatto et al., 2001). At the end of the experiment, rats from each group were kept at rest for 48 h after the last exercise session, without fasting. selleck screening library The blood was collected and centrifuged at 3000 rpm

for 10 min and from the serum glucose analysis was performed. Based on mean blood Endonuclease glucose, three animals most representative of each group were chosen to perform the histochemical analysis. The animals were sacrificed with prior anesthesia in CO2 chamber. After sacrifice, portions of the left ventricle of the selected animals were collected and fixed in Bouin. Tissues were embedded in historesin and microtome sectioned. The sections were then stained with PAS (Mcmanus, 1946), for detection of polysaccharides; Picrosirius-hematoxylin (for determination of total collagen) and ammoniacal silver

(for reticular fibers), adapted from Junqueira and Junqueira (1983). Slides with the stained sections were mounted with Canada balsam and photographed with light microscope Leica DM2000, Leica camera DFC280, with the IM50 software. A qualitative analysis of the slides was performed, based on the intensity of the reaction with the ventricular muscle. All results were expressed as mean ± standard deviation. Statistical comparisons were made by analysis of one-way (ANOVA) with post hoc Bonferroni or Kruskal–Wallis with post hoc Dunn, with significance level p < 0.05. Table 1 summarizes the serum glucose value previously to sacrifice and Table 2 presents the qualitative analysis from histochemical techniques for every individual of each group. The technique to evidence polysaccharides (PAS) shows that the individuals of group SD (Fig.