The effects of vascular endothelial growth factor (vegf) on the expression of cerebral cortex in rats after overtraining

Introduction

 

The purpose of this research is to observe the influences of Overtraining produce on the expression of VEGF in the cerebral cortex and to probe into the relation between changes of microcirculation and that of expression in the same domain. The study may give insight into theoretical basis on the relation between the vary of cerebral cortex microcirculation and central nervous system fatigue induced by Overtraining.

Methods

12 rats were divided randomly into control group(Group C; n=6) and Overtraining group(Group O; n=6). The rats in group O were burdened and given 4 weeks of swimming exercise. At the end of the fifth week, all the rats were killed after perfusing and gained cerebral cortex. Those tissues were made to stain Hematoxylin-Eosin(HE), immunohisto-chemistry for VEGF and factor Ⅷimmunofluorescence for endothelial cells respectively. The slides were observed with light microscope. Use Nikon & Spot computer autosynthesie system to gain and synthesize photos. The selected indexes were
positive area; density max; density mean; density min and integrated optical density(IOD). Input these data into Microsoft Excel for further statistics.

Results

1).In the rats cerebral cortex, the six layers are seen clearly and there are abundant microvessels. 2) There are synchronistic relation among positive VEGF in endothelial cells and in neurons and the area of cortex microvessels.
3) The number of microvessels in group O are increased insignificantly , but the microvessels area of group O increased significantly.

Conclusion

1).Overtraining can promote VEGF expression in special site but not all over the cerebral cortex. 2)There are synchronistic relation among positive VEGF in endothelial cells and in neurons and the area of cortex microvessels.
3) VEGF may promote angiogenesis and increased permeability of endothelial cells. Furthermore, VEGF in neurons may have a neuroendocrinic function that could influence the structure and function of endothelial cells.

References

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