الفهرس 
INTRODUCTIONOnly 14 pages are availabe for public view
 |  | from | 105 |  |  |
| | | from | 105 | | |
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.