Different exercise protocols improve metabolic syndrome markers, tissue triglycerides content and antioxidant status in rats

Diabetology & Metabolic Syndrome Different exercise protocols improve metabolic syndrome markers, tissue triglycerides content and antioxidant status in rats Jos D Botezelli 0 2 Lucieli T Cambri 0 2 Ana C Ghezzi 0 2 Rodrigo A Dalia 0 2 Pedro P M Scariot 0 2 Carla Ribeiro 0 2 Fabrcio A Voltarelli 1 Maria AR Mello 0 2 0 Physical Education Department, Sao Paulo State University - UNESP , 24-A Av. 1515, Rio Claro, Zip Code:13607-331 , Brazil 1 Physical Education Department, Mato Grosso Federal University-UFMT , Brasilia Av. 1200, Cuiaba, Zip Code: 78550-000 , Brazil 2 Physical Education Department, Sao Paulo State University - UNESP , 24-A Av. 1515, Rio Claro, Zip Code:13607-331 , Brazil Background: An increase in the prevalence of obesity entails great expenditure for governments. Physical exercise is a powerful tool in the combat against obesity and obesity-associated diseases. This study sought to determine the effect of three different exercise protocols on metabolic syndrome and lipid peroxidation markers and the activity of antioxidant enzymes in adult Wistar rats (120 days old). Methods: Animals were randomly divided into four groups: the control (C) group was kept sedentary throughout the study; the aerobic group (A) swam1 h per day, 5 days per week, at 80% lactate threshold intensity; the strength group (S) performed strength training with four series of 10 jumps, 5 days per week; and the Concurrent group (AS) was trained using the aerobic protocol three days per week and the strength protocol two days per week. Results: Groups A and S exhibited a reduction in body weight compared to group C. All exercised animals showed a reduction in triglyceride concentrations in fatty tissues and the liver. Exercised animals also exhibited a reduction in lipid peroxidation markers (TBARS) and an increase in serum superoxide dismutase activity. Animals in group A had increased levels of liver catalase and superoxide dismutase activities. Conclusions: We concluded that all physical activity protocols improved the antioxidant systems of the animals and decreased the storage of triglycerides in the investigated tissues. Physical exercise; liver damage; oxidative stress; rats - Background The increase in the incidence of obesity in industrialized countries in recent years has been associated with a decrease in daily energy expenditure. Studies indicate that, for the last 20 years, daily caloric intake has decreased; however, energy expenditure by means of physical activity has decreased even more. Thus, it is believed that the ongoing obesity epidemic might be more related to a reduction in physical activity than to an increase in caloric intake [1]. Obesity is associated with the appearance of systemic metabolic disorders, such as glucose intolerance, hyperinsulinemia, increased triglyceridemia, HDL cholesterol reduction and arterial hypertension. These disorders are highly associated with cardiovascular disease. This association is known as metabolic syndrome [2]. It is estimated that the prevalence of metabolic syndrome is 34% among adults and 50-60% in the population over 60 years of age in the United States, which constitutes a serious medical-social and economic problem [3,4]. Metabolic syndrome patients may also exhibit a state of chronic inflammation caused by an increased dependence on lipids as an energy source, which leads to the formation of oxygen reactive species and subsequent cell structure damage and protein structure disarray [5]. Physical activity is an important tool for the prevention of metabolic syndrome. It has been shown that aerobic training improves metabolic syndrome markers and tissue triglycerides content [6]. Also, the strength exercise can ameliorate the muscle loss and insulin sensitivity in insulin-resistant subjects [7,8]. Also, both aerobic and strength exercise can improve glucose tolerance and insulin sensitivity [6-9]. For this reason, this study sought to determine the effects of an aerobic, a strength and a concurrent (aerobic plus strength) exercise protocols on metabolic syndrome markers, lipid peroxidation markers and antioxidant enzyme activity in Wistar rats. Methods Animals and handling Thirty-two freshly weaned Wistar rats were used in this study. Animals were kept in shared cages (four animals per cage) at a controlled temperature of 25 1C and a 12 h sleep-awake cycle. Animals had free access to water and pelleted food Labina (Purina, So Paulo, Brazil). This study was performed at the Nutrition, Metabolism and Exercise Laboratory of So Paulo State University, So Paulo, Brazil. The weights of the animals were recorded weekly during the study, and the area under the curve (AUC) values were calculated using the trapezoidal rule [10] with Microsoft Excel 2007. This study was approved by the Animal Use Ethics Committee of the So Paulo State University, Biosciences Institute (CEUA), Rio Claro campus, and protocol n 005/ 2010. Experimental groups The Control (C) group was kept sedentary from 120 to 180 days of age. The Aerobic Training (A) group performed aerobic training 5 days per week (at 80% lactate threshold intensity) for 1 h per day from 120 to 180 days of age. The Strength Training (S) group performed strength training exercises [11] 5 days per week from 120 to 180 days of age. The Concurrent Training (AS) group performed aerobic training (at 80% lactate threshold intensity) 2 days per week (Tuesdays and Thursdays) for 1 h per day and strength training [11] 3 days per week (Mondays, Wednesdays and Fridays) from 120 to 180 days of age. Exercise protocol Aerobic training adaptation The sedentary (C) and aerobically trained (A and AS) groups were first adapted to the water environment. Adaptation was performedover10uninterrupted days in the same tank where the training was performed. The water temperature was kept at 31 1C [12]. The aim of adaptation was to reduce animal stress and to avoid possible physiological adaptations that might improve the physical capacity of the animals. Rats were placed in shallow water for 10 min for three days. The water depth was then increased, as was the effort length and load (1% body weight in the form of lead ballasts placed in a Velcro backpack attached to the thorax) carried by animals. By the fourth day, animals swam for 5 min in deep water. The length of time was increased by 10 min each day until the 12th day of adaptation [12]. Strength training adaptation Rats were placed in shallow water tanks (31 1C) for 10 min the first two days. On the third, fourth and fifth days, the depth level was increased, and the animals were kept in the tanks for 5, 10 and 15 min, consecutively. On the sixth and seventh days, a 30% body weight overload in a Velcro backpack was attached to the thorax of the animals, and they were swept into the tank with shallow water. In the last three days, the animals performed 10 jumps with a 30% overload attached to the thorax, while the depth of water was pro (...truncated)