Biomaterial Database

Role of exercise and rapamycin on the expression of energy metabolism genes in liver tissues of rats fed a high‑fat diet. 2020

Genghong Tu, and Chunyan Dai, and Haofei Qu, and Yunzhen Wang, and Bagen Liao

Department of Sports Medicine, Guangzhou Sport University, Guangzhou, Guangdong 510150, P.R. China.

The mTOR pathway serves an important role in the development of insulin resistance induced by obesity. Exercise improves obesity‑associated insulin resistance and hepatic energy metabolism; however, the precise mechanism of this process remains unknown. Therefore, the present study investigated the role of rapamycin, an inhibitor of mTOR, on exercise‑induced expression of hepatic energy metabolism genes in rats fed a high‑fat diet (HFD). A total of 30 male rats were divided into the following groups: Normal group (n=6) fed chow diets and HFD group (n=24) fed an HFD for 6 weeks. The HFD rats performed exercise adaptation for 1 week and were randomly divided into the four following groups (each containing six rats): i) Group of HFD rats with sedentary (H group); ii) group of HFD rats with exercise (HE group); iii) group of HFD rats with rapamycin (HR group); and iv) group of HFD rats with exercise and rapamycin (HER group). Both HE and HER rats were placed on incremental treadmill training for 4 weeks (from week 8‑11). Both HR and HER rats were injected with rapamycin intraperitoneally at the dose of 2 mg/kg once a day for 2 weeks (from week 10‑11). All rats were sacrificed following a 12‑16 h fasting period at the end of week 11. The levels of mitochondrial and oxidative enzyme activities, as well as of the expression of genes involved in energy metabolism were assessed in liver tissues. Biochemical assays and oil red staining were used to assess the content of hepatic triglycerides (TGs). The results indicated that exercise, but not rapamycin, reduced TG content in the liver of HFD rats. Further analysis indicated that rapamycin reduced the activity of cytochrome c oxidase, but not the activities of succinate dehydrogenase and β‑hydroxyacyl‑CoA dehydrogenase in the liver of HFD rats. Exercise significantly upregulated the mRNA expression of peroxisome proliferator‑activated receptor γ coactivator 1 β, while rapamycin exhibited no effect on the mRNA expression levels of hepatic transcription factors associated with energy metabolism enzymes in the liver of HFD rats. Collectively, the results indicated that exercise reduced TG content and upregulated mitochondrial metabolic gene expression in the liver of HFD rats. Moreover, this mechanism may not involve the mTOR pathway.

UI	MeSH Term	Description	Entries
D007333	Insulin Resistance	Diminished effectiveness of INSULIN in lowering blood sugar levels: requiring the use of 200 units or more of insulin per day to prevent HYPERGLYCEMIA or KETOSIS.	Insulin Sensitivity,Resistance, Insulin,Sensitivity, Insulin
D008099	Liver	A large lobed glandular organ in the abdomen of vertebrates that is responsible for detoxification, metabolism, synthesis and storage of various substances.	Livers
D008297	Male		Males
D008928	Mitochondria	Semiautonomous, self-reproducing organelles that occur in the cytoplasm of all cells of most, but not all, eukaryotes. Each mitochondrion is surrounded by a double limiting membrane. The inner membrane is highly invaginated, and its projections are called cristae. Mitochondria are the sites of the reactions of oxidative phosphorylation, which result in the formation of ATP. They contain distinctive RIBOSOMES, transfer RNAs (RNA, TRANSFER); AMINO ACYL T RNA SYNTHETASES; and elongation and termination factors. Mitochondria depend upon genes within the nucleus of the cells in which they reside for many essential messenger RNAs (RNA, MESSENGER). Mitochondria are believed to have arisen from aerobic bacteria that established a symbiotic relationship with primitive protoeukaryotes. (King & Stansfield, A Dictionary of Genetics, 4th ed)	Mitochondrial Contraction,Mitochondrion,Contraction, Mitochondrial,Contractions, Mitochondrial,Mitochondrial Contractions
D009765	Obesity	A status with BODY WEIGHT that is grossly above the recommended standards, usually due to accumulation of excess FATS in the body. The standards may vary with age, sex, genetic or cultural background. In the BODY MASS INDEX, a BMI greater than 30.0 kg/m2 is considered obese, and a BMI greater than 40.0 kg/m2 is considered morbidly obese (MORBID OBESITY).
D010805	Physical Conditioning, Animal	Diet modification and physical exercise to improve the ability of animals to perform physical activities.	Animal Physical Conditioning,Animal Physical Conditionings,Conditioning, Animal Physical,Conditionings, Animal Physical,Physical Conditionings, Animal
D004734	Energy Metabolism	The chemical reactions involved in the production and utilization of various forms of energy in cells.	Bioenergetics,Energy Expenditure,Bioenergetic,Energy Expenditures,Energy Metabolisms,Expenditure, Energy,Expenditures, Energy,Metabolism, Energy,Metabolisms, Energy
D005080	Exercise Test	Controlled physical activity which is performed in order to allow assessment of physiological functions, particularly cardiovascular and pulmonary, but also aerobic capacity. Maximal (most intense) exercise is usually required but submaximal exercise is also used.	Arm Ergometry Test,Bicycle Ergometry Test,Cardiopulmonary Exercise Testing,Exercise Testing,Step Test,Stress Test,Treadmill Test,Cardiopulmonary Exercise Test,EuroFit Tests,Eurofit Test Battery,European Fitness Testing Battery,Fitness Testing,Physical Fitness Testing,Arm Ergometry Tests,Bicycle Ergometry Tests,Cardiopulmonary Exercise Tests,Ergometry Test, Arm,Ergometry Test, Bicycle,Ergometry Tests, Arm,Ergometry Tests, Bicycle,EuroFit Test,Eurofit Test Batteries,Exercise Test, Cardiopulmonary,Exercise Testing, Cardiopulmonary,Exercise Tests,Exercise Tests, Cardiopulmonary,Fitness Testing, Physical,Fitness Testings,Step Tests,Stress Tests,Test Battery, Eurofit,Test, Arm Ergometry,Test, Bicycle Ergometry,Test, Cardiopulmonary Exercise,Test, EuroFit,Test, Exercise,Test, Step,Test, Stress,Test, Treadmill,Testing, Cardiopulmonary Exercise,Testing, Exercise,Testing, Fitness,Testing, Physical Fitness,Tests, Arm Ergometry,Tests, Bicycle Ergometry,Tests, Cardiopulmonary Exercise,Tests, EuroFit,Tests, Exercise,Tests, Step,Tests, Stress,Tests, Treadmill,Treadmill Tests
D000818	Animals	Unicellular or multicellular, heterotrophic organisms, that have sensation and the power of voluntary movement. Under the older five kingdom paradigm, Animalia was one of the kingdoms. Under the modern three domain model, Animalia represents one of the many groups in the domain EUKARYOTA.	Animal,Metazoa,Animalia
D012420	Running	An activity in which the body is propelled by moving the legs rapidly. Running is performed at a moderate to rapid pace and should be differentiated from JOGGING, which is performed at a much slower pace.	Runnings