The effects of exercises on the expression of matrix metalloproteinase-9 in perihematomal brain tissue after intra cerebral hemorrhage in rats / 中华物理医学与康复杂志

ABSTRACT

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 ). In exercises group, MMP-9 expressed weakly at the 3rd d, and peaked at the 7th d, then declined gradually. In control group, MMP-9 expression peaked at the 3rd d, then decreased slowly. MMP-9 protein expression was in accord with mRNA. MMP-9 expression in exer-cises group was significantly different from control group on the 3rd and 7th d (P < 0.05 ) , but not at the 14th and 21st d ( 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.