Exercise Fatigue Induce the Oxidative Stress and the Expression of mGluR 4 and mGluR 5 on the Ventrolateral Thalamus in Rats

Abstract

Objective: The motor thalamus plays an important role during exercise. It aims to observe the changes of mGluR4 and mGluR5 in ventrolateral thalamus of rats induced by repeated exhaustive exercise, and to discuss the relationship of mGluR4, mGluR5 and oxidative damage occured during exhaustive exercise. Methods: There were 48 male wistar rats, which were randomly divided into four groups including CG, 0EG, 24EG and 48 EG, each group having 12 rats. Meanwhile, immunohistochemistry (IMM) technique was used to investigate the expression of positive cell and integrated optical density (IOD) of metabotropic glutamate receptor 4 (mGluR4) and metabotropic glutamate receptor 5 (mGluR5), and the impact of exhaustive exercise played on oxidative stress indexes such as malondialdehyde (MDA), glutathione peroxidase (GSH-PX) and superoxide dismutase (SOD) in ventrolateral thalamus of rats were also investigated in different groups. Results: Compared with CG, the expression of mGluR4 and mGluR5 protein of ventrolateral thalamus in 0EG and 24EG both significantly increased, and the value of mGluR4 in 48EG were still higher than control group, however the the value of mGluR5 in 48EG reduced to the rest level of control group. Meanwhile, the SOD activities of 0EG and 24EG group were significantly higher than the control group, and it was the same with GSH content in ventrolateral thalamus of rats. Meanwhile, MDA has been investigated that it increased significantly in 0EG and 24EG compared with control group, and the MDA level of 48EG was still significant higher than CG. Moreover, the indexes of muscle injury such as LD, CK and BUN all increased significantly post-exercise immediately and post-exercise 24 hours .Conclusion: Exercise fatigue could result in up-regulation of mGluR4 and mGluR5 and increace activity of SOD , GSH-PX and MDA in ventrolateral thalamus of rats, and it also induce the muscle injury by increase the level of LD, CK and BUN in serum, which suggested that ventrolateral thalamus was an important brain rigion to modulate the motor function, and mGluR4 and mGluR5 maybe two important receptors prevent from the increase of free radicals and muscle injury induced by exercise fatigue.