Effects Of Different Swimming Styles On The Expression Of C-fos Gene In Rat PVN,SON And ARC Of Hypothalamus

Objective: To observe the expression of c-fos gene in hypothalamus of adult rats after swimming, and investigate the mechanism of hypothalamus to different types of exercise. Providing theoretical evidences for exercise training and sport-record elevating, and offering new ideas for exercise induced disease prevention and sport treatment.Methods: One hundred and ten SD rats were divided into the experimental group (n=100) and control group (n=10), model rats were established by durative and intermittent swimming. The fresh cerebral tissues were divided on icewater bath while the paraform-perfused brains were obtained at 0h, 0.5h, 1h, 2h, 4h after swimming. The former cerebral tissues were detected by RT-PCR in order to investigate the changes of c-fos mRNA in hypothalamus, however, the later perfused brains be done with frozen section, immunohistochemical staining, then the localization and distribution of Fos protein were observed. All of the experimental data were analyzed by SPSS13.0 statistical software.Results: (1). The expression of c-fos mRNA was extremely lower in control group, but increased higher after exercise and than descended in time course. (2). Several Fos+ neurons of control group distributed in the hypothalamus dispersively while the experimental groups expressed significantly higher especially in pavaventricular nuclei (PVN),supraoptic neclei (SON) and arcuate nuclei(ARC). In parvicellular part of PVN (pPVN), the number of Fos+ neurons increased to the top at 1h after durative swimming but at 2h after intermittent swimming, and the number in intermittent was numerous than that in durative at the same time. In magnocellar part of PVN (mPVN),for the durative swimming, the Fos+ neurons increased gently and then descended at 2h, however, the number of Fos+ neuron for intermittent swimming had no statistic change (P>0.05). There was no significant difference for the number of Fos+ neuron in the 4 hours after exercises in SON of both groups (P>0.05). In ARC, the number of Fos+ neuron of durative swimming significantly increased to the top at 0h (P>0.05) , but that of intermittent swimming increased after exercise and got to the top at 0.5h, however, both of them decreased to the control level at 4h after exercise.Conclusion: The SON,PVN and ARC in hypothalamus play an important role in physical regulation after exercise; the pPVN and ARC is more sensitive to response to different types of exercise stress.