Volume 30, Issue 3 (5-2023)                   RJMS 2023, 30(3): 244-253 | Back to browse issues page

Ethics code: IR.IAU.M.REC.1396.186

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Professor, Department of Exercise Physiology, Islamic Azad University, Central Branch, Tehran, Iran , m_azarbayjani@iauctb.ac.ir
Abstract:   (872 Views)
Background & Aims: Obesity and related diseases such as type 2 diabetes, cardiovascular disease, and various types of cancer are major global health concerns. Increased adipose tissue in the body is one of the causes of obesity. Adipose tissue consists of two categories of white adipose tissue which store energy and brown adipose tissue, which controls the body's thermogenesis. Fatty acids in brown adipose tissue produce heat by burning and maintaining body temperature. Brown adipose tissue contains polyunsaturated lipid stores that provide rapid storage of fatty acids to generate heat and maintain body temperature, and thermogenesis, and has the flexibility to adapt to external stimuli such as cold and sympathetic stimulation for thermogenesis. Brown adipose tissue plays a regulatory role in whole-body metabolism and body weight. Thermogenesis is activated via the β3-adrenoceptor pathway and occurs in mitochondria in brown adipose tissue containing Mitochondrial uncoupling protein-1 (UCP-1). The family of Mitochondrial uncoupling proteins (UCPs) plays an important role in the thermogenesis of brown adipose tissue and the regulation of mitochondrial ROS excretion in various tissues. Changes in lifestyle and diet are one of the achievements of modern life today, which can be attributed to the tendency to overeat fast foods among family members or the community. Consumption of heated oils, in addition to increasing oxidative stress and apoptosis in tissues, leads to obesity by reducing the lipolysis pathway, inhibiting beta-adrenergic receptors, and increasing the accumulation of fat in visceral tissues. Aerobic exercise is used to prevent and treat obesity, insulin resistance, or type 2 diabetes because of its ability to improve mitochondrial function and fatty acid oxidation, reduce body fat, improve insulin sensitivity, and absorb glucose into skeletal muscle. Octopamine is an antioxidant and endogenous antioxidant biogenic amine that has properties similar to catecholamines such as norepinephrine. Octopamine has the ability to stimulate lipolysis and fat metabolism. The aim of the present study was to determine the interaction effect of 4 weeks of aerobic training and octopamine on the activity of brown adipose tissue of male rats fed with deep frying oil.
Methods: In an experimental study, 30 adults male Wistar rats weighing an average of 300 to 350 g and aged 8 weeks were purchased. All rats were kept in polycarbonate cages (5 mice per cage) at 22 2 2 ° C, 55% humidity, and under the light and dark cycle for 12:12 hours without restriction on water and food. Rats were randomly divided into five groups: healthy control (n=6), DFO (n=6), aerobic training + DFO (n=6), octopamine + DFO (n=6), and aerobic training + octopamine + DFO (n=6). Intraperitoneal injections of 10 ml/kg of octopamine and Gavage of deep frying oil were done five times a week and every day, respectively.
In order to adapt the rats in the aerobic training group, before starting the main training program, the rats in this group ran at a speed of 9 m / min for 20 minutes for a week. The aerobic exercise protocol consisted of 4 weeks of aerobic exercise and 5 sessions per week. The training session included 5 minutes of warm-up at 7 m / min and 5 minutes of cooling at 5 m / min. The intensity of training started in the first week with 50% vo2max and a speed of 16 m / min, and in the last week, it reached 65% vo2max and a speed of 26 m / min. To prepare deep frying oil, 8 liters of sunflower oil was heated for 190 consecutive days at a temperature of 190 to 200 ° C for 4 consecutive days.
48 hours after the last training session and 8 hours of fasting, all rats were anesthetized with chloroform and then sacrificed. The brown adipose tissue was immediately removed from the body and stored in a nitrogen tank at -80 ° C. Gene expression of UCP-1 was measured by Real-time PCR. Independent t-test, two-way analysis of variance, and Bonferroni post hoc tests were used to analyze the data. All the analyses were done by SPSS software version 21 and the charts were drawn using Microsoft Excel software version 16. The significance level was p <0.05.
Results: The results showed that consumption of deep frying oil induced a significant decrease in gene expression of UCP-1 (P < 0.05) compared to the healthy control group. The aerobic training and octopamine caused a significant increase in gene expression of UCP-1 (P >0.05) compared to the DFO group. The interaction effect of aerobic training and octopamine caused a nonsignificant increase in UCP-1 gene expression (P >0.05) in comparison with the DFO group.
Conclusion: Decreased expression of UCP-1 following consumption of deep heated oil may be due to disruption of metabolic pathways that have reduced metabolism. Regarding the significant increase in UCP-1 gene expression under the influence of aerobic exercise and octopamine supplementation, each of them alone, we can first mention the antioxidant properties of aerobic exercise and octopamine. According to previous studies, the variable UCP-1 itself is an antioxidant. And since aerobic exercise and octopamine, each has antioxidant properties on their own, they can enhance and increase the expression of the UCP-1 gene in brown adipose tissue. Increasing UCP-1 can reduce the excess ROS produced and act as a compatible mechanism to reduce the harmful effects of ROS. It is possible that exercise was able to stimulate brown adipose tissue through sympathetic enhancement, which in turn increased UCP-1 gene expression and mitochondrial biogenesis. Another reason is that octopamine is similar to norepinephrine. Octopamine can bind rapidly to β3 adrenergic receptors, increase cAMP gene expression, and increase lipolysis and fat metabolism in general. It seems that exercise and octopamine can activate brown adipose tissue.
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Type of Study: Research | Subject: Exercise Physiology

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