الفهرس | Only 14 pages are availabe for public view |
Abstract Obesity is a chronic metabolic disease affecting nearly all physiological functions in the body resulting in an increase in morbidity and mortality. The adipose tissue (AT) is a highly active metabolic organ that plays an important role in the regulation of energy homeostasis. AT remodeling is a continuous well-orchestrated mechanism modulated by the coordinated response of AT resident cell types. In obesity, the adipose tissue expands beyond its capacity resulting in persistent hypoxia, followed by increased angiogenesis, extracellular matrix overproduction and immune cell infiltration. Exercise is considered as an important intervention for treatment of several diseases including obesity. Moderate exercise is of great choice in preventing obesity. It may provide long lasting protection against cardiometabolic changes induced by HFD. The aim of the present work was to study the effect of moderate swimming exercise on gene expression of adipose tissue remodeling markers in HFD-induced obesity in rats. This study was conducted on 32 male wistar rats aged (2-3 months). Rats were randomly divided into two equal main groups. group I (non-obese group): Rats of this group received standard diet containing (28.7% proteins, 58.5% carbohydrates and 12.8% fat) for 12 weeks and served as control. group II (obese group): Rats of this group received a high fat diet containing (20% proteins, 35% carbohydrates and 45% fat) for 12 weeks. Rats of both groups were further subdivided into 2 equal subgroups: Sedentary and exercised subgroups. After 4 weeks from the beginning of the experiment, rats of both exercised subgroups were assigned to moderate exercise swimming program for 8 weeks. The moderate swimming exercise program included 2 phases: adaptation and training. Adaptation training time was gradually increased from 10 min in the first week to reach 30 min. After one week of adaptation, the training phase started. Rats of both exercised sub groups were assigned to swim for 30 min /day, 5 days/week for 8 weeks. At the end of the experiment, final body weight and length were recorded for all rats to calculate body mass index (BMI) and lee index. Rats were scarified and blood samples were collected. Sera were separated by centrifugation for determination of (lipid profile, fasting glucose and insulin levels were assayed and insulin resistance was calculated). Visceral white adipose tissues from the epididymal, mesenteric, perirenal and retroperitoneal regions were excised from all rats, weighed with estimation of adiposity index, then VAT was divided into two sections. The first section was homogenized in phosphate buffer (pH 7.4), centrifuged and the supernatant were collected and stored at −80°C for determination of cytokines (TNF-α& IL-10). The second section was used for RNA extraction to analyze genes expression of angiogenesis markers (VEGF-A& HIF-1α), macrophages surface markers (CD11c& CD163) and extracellular matrix (ECM) remodeling markers (OPN& CD44). Summary, Conclusion & Recommendation 61 Results revealed that HFD induced significant increase in final body weights, body mass index, lee index, visceral fat weight, serum lipid profile, fasting glucose, insulin, HOMA–IR and TNF-α levels and significant decrease in HDL-C in serum and IL10 levels in VAT in obese sedentary subgroup as compared to other subgroups. HFD induced upregulation of VEGF-A, HIF-1α, CD11c, OPN, CD44 and downregulation of CD163 in VAT of obese sedentary subgroup as compared to other subgroups. The moderate swimming exercise reversed all effects of HFD in obese exercised subgroup as compared to obese sedentary subgroup. VEGF-A expression was positively correlated with visceral fat weight and adiposity index in both obese sedentary and exercised subgroups.HIF-1α and CD11c expressions were positively correlated with HOMA-IR in both obese subgroups and negatively correlated with IL-10 in obese exercised subgroup only. In addition CD11c expression was positively correlated with TNF-α in obese sedentary and exercised subgroups.CD163 expression was negatively correlated with HOMA-IR and TNF-α in obese exercise subgroup and positively correlated with IL-10 in both obese subgroups. OPN and CD44 expressions were positively correlated with HOMA-IR and TNF-α and negatively correlated with IL-10 in both obese subgroups. |