Effects Of Different Swimming Styles On The Expression Of NF-κB, Bcl-2, Bax Genes In Rat PVN Of Hypothalamus

Objective: To observe the expression of NF-?B, Bcl-2, Bax gene in hypothalamus pavaventricular nuclei (PVN) of adult rats after swimming, and investigate the mechanism of hypothalamus to different types of exercise.Offering new ideas for exercise induced disease prevention and sport treatment.Methods: One hundred SD rats were divided into the control group (n=10) and experimental group (n=90), model rats were established by continuous, intermittent and exhaustive swimming.The fresh cerebral tissues were divided on ice while the paraform-perfused brains were obtained at 0h, 4h, 8h, 12h, 16h, 24h after swimming. The former cerebral tissues were detected by Western blot in order to investigate the changes of NF-?B, Bcl-2, Bax in hypothalamus; however, the later perfused brains be done with frozen section, immunohistochemical staining, then the localization and distribution of NF-?B,Bcl-2,Bax protein were observed.Result: (1)The expression of NF-κB, Bcl-2, Bax increased highly after exercise than control group, but increased higher after exercise and then descended in time course.(2)The Bcl-2 protein is high in control group, it increased highly after exercise than control group after continuous exercise and intermittent exercise, presented higher and then descened in time course. The expression of Bcl-2 protein maintained in a high level, it has not declined obviously in 24h after exhaustive exercise.(3)The expression of Bax protein was increased than control group after continuous exercise and intermittent exercise, and it showed a lower expression totally;But bax expression was significant increased after exhaustive exercise.,showed high expression of the whole state.(4)The number of NF-?B p65 positive neurous in rats increased significantly after exercise(P<0.05), it acquired its peak at 4h after movement in the continuous exercise group and the intermittent exercise group. The number of NF-?B positive neurous increased to the top at 8h in the exhaustive exercise group, then declined graduallty, it decreased extremely in 24h after exercise. but it still higher than control group (P<0.05).(5)The positive Bcl-2 protein cells could be seen in rats PVN of every group after exercise, the bcl-2 protein of continuous exercise group and intermittent exercise group acquired its peak at 8h and 12h respectively. and then it decreased gradually, but it still higher after 24h of exercise than the control group (P<0.05); the number of Bcl-2 positive neurons increased in exhaustive exercise group, but the difference was not statistically significant in different times (P>0.05), Bcl-2 positive neurons were significantly reduced compared with the other two groups, it has statistical significance (P<0.05).(6)The positive Bax protein cells could be seen in rats PVN of every group after exercise, the number of Bcl-2 positive neurons increased in continuous exercise group, but the difference was not statistically significant in different times (P>0.05); The positive Bax protein cells increased greatly in intermittent group, it acquired its peak at 8h after exercise, and then decreased gradually, descent obviously after 24h, but there is no significant difference compared with control group and durative exercise group (P>0.05); the number of Bcl-2 positive neurons increased greatly in exhaustive exercise group, it acquired its peak at 12 h after exercise, there is no obvious descent after 24h, the difference was statistically significant compared with control group(P<0.05),Bax positive neurons were significantly increased compared with the other two groups, it has statistical significance (P<0.05).Conclusion: (1)The expression of NF-κB increased after different swimming exercises in hypothalamus, which demonstrate that NF-κB participate the regulation of movement in CNS.(2) NF-κB-mediated signal transduction pathway triggered apoptosis of different machanisms in different swimming ways, the higher expression of antiapoptotic Bcl-2 protein promoted the cell survival in the continuous and intermittent exercise group,and the higher expression of pro-apoptotic protein Bax led to cell apoptosis in the exhaustive exercise group.