The effects of exercises on the expression of matrix metalloproteinase-9 in perihematomal brain tissue after intra cerebral hemorrhage in rats

Objective To study the effects of exercises training on the recovery of neurological function and the expression of matrix metalloproteinase-9 (MMP-9) in perihematomal brain tissue after intra cerebral hemorrhage (ICH) in rats. Methods Sixty-four male adult Sprague-Dawley rats were randomly divided into exercises group and control group. ICH model was induced by autobiood injection. The rats in exercises group were given balance, grasping and walking exercises every day. The rats in control group exercised freely in standard cages. Neurological function in both groups was measured at the 3rd, 7th, 14th and 21st d. All the rats were sacrificed and the concentration of MMP-9 was measured with immunohistochemical method and in situhybridization. Results In both groups neurological function scores was lowest at the 3rd d, were highest at the 21st d. There was no significant difference between two groups at the 3rd d, but at the 7th, 14th and 21st d the differences between two groups were significant ( P 0.05 ). Conclusions Early exercises can inhibit the expression of MMP-9 that could play a role in protecting neurons. Daily exercises can stimulates the expression of MMP-9 so as to have a positive role in midstage of disease. MMP-9 may be involved in tissue remodelling and vascular repairing, which prompt neu-rofunction recovery. Key words: Exercises; Rat; Intracerebral hemorrhage; Matrix metalloproteinase-9