Aerobic Conditioning And Hepatic Steatosis Markers In Exercise-trained Diabetic Rats

Abstract

PURPOSE: The present study aimed to analyze the effects of exercise performed at aerobic/anaerobic transition intensity on both aerobic conditioning and on non-alcoholic hepatic steatosis (NAHS) markers, as Aspartate Aminotransferase (AST) and Alanine Aminotransferase (ALT) enzymes, in diabetic rats. METHODS: Adult (90 days) male Wistar rats were divided into 4 groups: Sedentary Control (SC), Trained Control (TC), Sedentary Diabetic (SD) and Trained Diabetic (TD). At the beginning of the experiment, all the animals were submitted to maximal lactate steady state (MLSS) test in order to identify the aerobic/anaerobic metabolic transition intensity during swimming exercise. The trained groups were submitted to swimming, supporting overloads (% of body weight - bw) equivalent to aerobic/anaerobic metabolic transition intensity, 1h/day, 5 days/week, during 8 weeks. We analyzed: body weight, aerobic conditioning (MLSS after the training period), total lipid concentrations in the liver, and serum ALT and AST concentrations as well as serum glucose and FFA levels. RESULTS: The DS group showed higher serum glucose in relation to the other groups (SC= 102 ± 10; TC= 105 ± 9; SD= 323 ± 12; TD= 301 ± 13). The diabetic groups showed higher serum FFA (SD= 15.5 %; D= 17.4%) and weight loss (SD= 0.8%; TD= 10.5%) when compared to control groups. The aerobic/anaerobic metabolic transition intensity (overload, in % of bw) obtained by MLSS test was similar in TD (4.7%) and TC (5.6%) groups after exercise-training. The NAHS markers (U/L) did not show differences (two-way ANOVA, P<0.05) between groups (AST: SC= 81.6 ± 15.0; TC= 87.0 ± 23.2; SD= 69.8 ± 47.3 and TD= 78.7 ± 29.9; ALT: SC= 39.7 ± 14.6; TC= 38.9 ± 9.4; SD= 40.0 ± 17.4 and TD= 44.6 ± 17.0). The same was observed for total liver lipid concentrations (mg/100mg) (SC= 3.5 ± 0.4; TC= 3.5 ± 0.5; SD= 3.6 ± 0.6 and TD= 3.7 ± 0.8). CONCLUSION: Taken together, the results of the present study suggest that physical training performed at the aerobic/anaerobic metabolic transition intensity was able to maintain the aerobic conditioning of diabetic rats similar to the control animals as well as to improve the glycaemic condition of the DT group. In addition, serum ALT and AST enzymes proved to be adequate markers of liver lipid levels in this animal model. Supported by CNPq, Fapesp and CAPES