The Effect of Aerobic Exercise on SREBP-1c Gene Expression in Skeletal Muscle in Obese Female Rats

Abstract

Background: Obesity causes skeletal muscle metabolic disorders by altering the expression of the genes involved in lipid metabolism. One of the genes that play an important role in lipid metabolism in skeletal muscle tissue is sterol regulatory element binding protein (SREBP). Objectives: Since the interacting effect of aerobic exercise and high-fat diet on the expression of this gene has not been well studied, the aim of the present study was to determine the effect of aerobic exercise on the expression of the SREBP-1c gene in skeletal muscle in obese female rats. Methods: Eighteen female Wistar rats in the weight range of 180 - 200 grams were selected and randomly divided into three groups: (1) control fed with a normal diet; (2) control fed with a high-fat diet; and (3) aerobic exercise plus a high-fat diet. The high-fat diet contained 40% fat (20% soybean oil and 20% animal fat), 13% protein, and 47% carbohydrates. The rats were initially fed with a high-fat diet for 6 weeks, and then they performed aerobic exercise on a treadmill 5 times a week for 6 weeks. Forty-eight hours after the last training session and after eleven hours of fasting, the rats were anesthetized with ketamine and xylazine. Quadriceps tissues were removed to determine the SREBP-1c gene’s expression by real-time PCR. Results: Feeding with a high-fat diet significantly increased the weight of rats (P = 0.001). The expression of the SREBP-1c gene in the group fed with the high-fat diet decreased significantly compared to the group fed with the normal diet (P = 0.001). Aerobic exercise significantly increased the expression of the SREBP-1c gene in the quadriceps muscle (P = 0.001), contradicting the effect of the high-fat diet on the expression of this gene. Conclusions: Aerobic training may alleviate lipid metabolism disorders in muscles by increasing the expression of the SREBP-1c gene. Therefore, aerobic exercises can be used to contradict the metabolic complications caused by the high-fat diet in skeletal muscles.