Expression of mRNA of matrix metalloproteinase and tissue inhibitor of matrix metalloproteinase after cardiopulmonary resuscitation for asphyxial cardiac arrest in rat

Objective: To study the change in mRNA expression of matrix metalloproteinase (MMPs) and tissue inhibitor-1 of matrix metalloproteinase (TIMP-1) in brain after cardiopulmonary resuscitation (CPR) for asphyxial cardiac arrest in rat.

Methods: The animal model of cardiac arrest was reproduced by clamping endotracheal tube at the expiration. Eighty male SD rats were randomly divided into two groups: control group and resuscitation group, and they were again divided into 0, 0.5, 3, 6, 9 hours subgroups (n=8). Evans blue content and mRNA expressions of MMPs and TIMP-1 in the brain after CPR were determined respectively.

Results: The mRNA expression of MMP-9 and TIMP-1 was up-regulated 3 hours after restoration of spontaneous circulation (ROSC). At 6 hours after ROSC, they were markedly high, and the ratio of MMP-9/TIMP-1 was higher too. The mRNA expression of MMP-2 showed no significant change at 9 hours after ROSC.

Conclusions: The mRNA expression of MMP-9 and TIMP-1 and MMP-9/TIMP-1 are increased at early stage after CPR, but the mRNA expression of MMP-2 shows no significant change.