Study On Mechanism And Effect Of Swimming Exercise Of Young Rats In Preventing Mature Obesity

Environmental factors in early development are closely linked with adult obesity. In the critical period of growth and development, genes of energy metabolism changed can produce programming effects on body metabolic mechanism, resulting in the molecular pathogenesis of obesity causes. Exercise directly affects the body energy metabolism, but also can change the gene expression levels of adipose tissue and hypothalamus. It suggests that at critical period of the growth and development exercise may long-term or permanently alter gene expression of adipose tissue and hypothalamus involved in energy metabolism. This research field has important theoretical significance for understanding the formation mechanism and early intervention of obesity.In this study, 3 weeks of age weaning rats swimming for 3 weeks were obeseved the change at 12 weeks of age and at 24 weeks of age with high fat diet induced 12 weeks. The change of body weight and body fat content changes, serum lipid metabolism, serum Leptin, Adiponctin and BDNF concentration levels, mRNA expression of Leptin, Adiponctin, PPARγ, TNF-αand BDNF of adipose tissue, mRNA expression of Leptin-Rb, AdipoR1, AdipoR2, POMC, NPY and BDNF, and BDNF protein levels of hypothalamus. The mRNA expression of adipose tissue and hypothalamus were tested by Real-time PCR method. The BDNF protein level was tested by Western blot method. The prevention effects of swimming exercise for high fat diet inuded obesity were analyzed and long-term effects of molecular biological mechanisms were investigated according to the experimental results at different stages.The experiment is consisted of two parts.PartⅠThe long-tem effect of swimming exercise at childhood on mRNA expression related to energy metabolism of adult rats induced obesity with high fat diet. Objective: The purpose of this study was to investigate the swimming exercise at childhood played a protective effect for adult rats indued by high fat diet obesity, to investigate the long-term effect between the change of the gene expression of adipose tissue and hypothalamus and body composition of adult rats with exercise at childhood. Methods: Weaning male SD rats were randomly assigned to two groups: control group(C), exercise-trained three weeks and rest six weeks group(E3). At 12 weeks of age, the rats of C group were assigned two group: fed with standard chow group(CC), fed with high fat diet group(CH); the rats of E3 group were assigned two group: fed with high fat diet group(E3H), fed with high fat diet and swimming exercise group(E3HE). At 24 weeks of age, all the rats were killed, and gene expression of adipose tissue and hypothalamus was tested. Results:①At 12 weeks of age, body weight, ratio of fat to body of CH group were higher than that of CC group. The GLU, TC, TG, LDL and Ins of serum of CH group were also higher than that of CC group, but HDL of serum was lower than that of CC group. The ratio of fat to body, GLU and Ins of serum of E3H group were lower than that of CH group. The other items were no significant difference between E3H group and CH group. The body weight, ratio of fat to body, TC and LDL of serum of E3HE were lower than that of E3H group. The other items were no significant difference between E3H group and E3HE group.②The serum Leptin concentration of CH group was higher than that of CC group, but BDNF concentration was lower than that of CC group. There was no significant difference between CH group and CC group on serum Adiponectin. There were no significant difference between E3H group and CH group on Leptin, Adiponectin and BDNF of serum. The serum Adiponectin of E3HE group was higher than that of E3H group. There were no significant difference between E3HE group and E3H group on Leptin and Adiponectin concentration of serum.③The Adiponectin and PPAR-γmRNA expression in adipose tissue of CH group were lower than that of CC group, but TNF-αand BDNF mRNA expression were higher than that of CC group. The Leptin expression in adipose tissue was no significant difference between CH group and CC group. PPAR-γmRNA expression in adipose tissue of E3H group was higher than that of CH group, but BDNF mRNA expression in adipose tissue of E3H group was lower than that of CH group. There were no significant difference between E3H group and CH group on Leptin, Adiponectin and TNF-αmRNA in adipose tissue. PPAR-γmRNA expression in adipose tissue of E3HE group was higher than that of E3H group. The other items of adipose tissue were no significant difference between E3HE group and E3H group.④AdipoR1, AdipoR2, NPY and POMC mRNA expression in hypothalamus of CH group and E3 group were higher than that of CC group. There were no significant difference between CH group and CC group on Leptin-Rb, BDNF mRNA expression and BDNF protein level. Leptin-Rb, AdipoR2 and NPY mRNA expression of E3H group were lower than that of CH group, but BDNF mRNA expression and protein level were higher than that of CH group. The AdipoR1 and POMCmRNA expression were no significant difference between E3H group and CH group. AdipoR1, NPY and POMCmRNA expression of E3HE group were higher than that of E3H group. Leptin-Rb, AdipoR2, BDNF mRNA expression and BDNF protein level were no significant difference between E3HE group and E3H group. Suggestion: Swimming exercise at childhood have a certain resistance effect for the adult rats with high fat induced obesity. The increasing of PPAR-γexpression of adipose tissue, decreasing of NPY expression of hypothalamus, increasing of POMC and BDNF expression of hypothalamus, are the important biological mechanisms that childhood exercise prevent adult rats with high fat diet indeued obesity.PartⅡThe effect of swimming exercise at childhood on mRNA expression related to energy metabolism of adult ratsObjective:The purpose of this study was to investigate the effect of 3 weeks swimming exercise after weaning on the gene expression of adipose tissue and hypothalamus at 12 weeks of age (adult), and analyze the continued effect of gene of adipose tissue and hypothalamus after swimming exercise at childhood. Methods: Weaning male SD rats were randomly assigned to three groups: control group(C); exercise-trained nine weeks group (E9); exercise-trained three weeks and rest six weeks group(E3). At 12 weeks of age, all the rats were killed, and gene expression of adipose tissue and hypothalamus was tested. Results:①At 12 weeks of age, body weight, weight of visceral fat pads and ratio of fat to body of E9 group were lower than that of C group and E3 group. Body weight was no significant difference between E3 group and C group. The ratio of fat to body of E3 group was lower than that of C group, and was no significant difference with E9 group. Serum TC of E9 group was lower than that of C group, and other items of serum were no significant difference between E9 group and C group. Serum TC and HDL were higher than that of E9 group, and other items of serum were no significant difference between E3 group and E9 group. Serum HDL was higher than that of C group, and other items of serum were no significant difference between E3 group and C group.②The serum Leptin concentration of E9 group was lower than that of C group, and there were no significant difference between E9 group and C group on serum Adiponectin and BDNF concentration. Serum Leptin concentration of E3 group was higher than that of E9 group, BDNF concentration of E3 group was lower than that of E9 group, and Adiponectin concentration was no significant difference between E3 group and E 9 group. Serum BDNF concentration of E3 group was lower than that of C group, and Leptin and Adiponectin concentration were no significant between E3 group and C group.③Leptin, Adiponectin and PPAR-γmRNA expression in adipose tissue of E9 group were lower than that of C group, TNF-αmRNA in adipose tissue of E9 group was higher than that of C group, and BDNF mRNA in adipose tissue was no significant difference between E9 group and C group. There were no significant difference between E3 group and E9 group on Leptin, Adiponectin, PPAR-γ, TNF-αand BDNF mRNA expression in adipose tissue. Leptin and Adiponectin mRNA expression in adipose tissue of E3 group were lower than that of C group, TNF-αand BDNF mRNA expression in adipose tissue were higher than that of C group, and PPAR-γmRNA expression in adipose tissue was no significant difference between E3 group and C group.④Leptin-Rb mRNA expression in hypothalamus of E9 group was higher than that of C group, and AdipoR1 and AdipoR2 mRNA expression in hypothalamus was no significant difference between E9 group and C group. There were no significant difference between E3 group and E9 group on Leptin-Rb, AdipoR1 and AdipoR2 mRNA expression in hypothalamus. Leptin-Rb mRNA expression in hypothalamus of E3 group was higher than that of C group, and AdipoR1 and AdipoR2 mRNA expression in hypothalamus was no significant difference between E3 group and C group. NPY and POMC mRNA expression in hypothalamus of E9 group were higher than that of C group. BDNF mRNA expression in hypothalamus was no significant difference between E9 group and C group, but BDNF protein level of E9 group was higher than that of C group. NPYmRNA expression of E3 group was lower than that of E9 group, but there were no significant difference between E3 group and E9 group on POMC, BDNF mRNA expression and BDNF protein level in hypothalamus. POMC mRNA expression in hypothalamus of E3 group was higher than that of C group. NPY and BDNF mRNA expression and BDNF protein level in hypothalamus were no significant difference between E3 group and C group. Suggestion: Three-week swimming exercise decrease the contents of adipose tissue of rats at 12 weeks of age. The decreasing of Leptin and Adiponectin in adipose tissue expression, increasing of TNF-αand BDNF in adipose tissue expression, and increasing of Letpin-Rb and POMC in hypothalamus expression, are the main biological mechanisms that three-week swimming exercise change body composition at adult period.Conclusion:①Three-week swimming exercise at childhood has the effect that inhibite the increasing of the contents of adipose tissue of body at 12 weeks of age, and has the protective effect of body composition of rats with high fat diet induced obesity after 12 weeks of age.②The incresing of PPAR-γexpression in adipose tissue and decreasing of NPY expression of hypothalamus and increasing of POMC and BDNF expression of hypothalamus are the long-term biological mechanisms that prevent high fat induced obesity at adult period for rats with the swimming exercise at childhood.③The decreasing of Leptin and Adiponectin in adipose tissue and increasing TNF-αand BDNF in adipose tissue and increasing of Leptin-Rb and POMC in hypothalamus are the early biological mechanisms that decrease fat composition at adult period for rats with the swimming exercise at childhood.④Exercise at childhood period has the early or long-term effects that change the gene expression of the adipose tissue and hypothalamus, but the time of alteration of the gene expression is not clear. And the effects that the changing of these key genes expression prevent glucose and lipid metabolism disorder need further research.