Expression of MMP-9 mRNA and ZO-1 mRNA in brain tissue of hypoxic-ischemic neonatal rats

Objective: To investigate the significance of MMP-9 mRNA and ZO-1 mRNA expressions after hypoxic-ischemic brain damage(HIBD).Methods: Neonatal 7-day-old SD rats were randomly divided into control group,HIBD 3,6,24,48 and 72 h groups(n=6 per group).The ligated cerebral hemisphere was observed for the morphological changes.The expression of MMP-9 mRNA and ZO-1 mRNA was measured by Real-time Q-PCR method.Results:(1)As compared to HIBD group,the expression of MMP-9 mRNA was lower in the sham-operation control group(P0.05).After HIBD,it began to increase at 3 h,and peaked at 24 h,maintained the high level at 72 h.(2)As compared to HIBD group,the expression of ZO-1 mRNA was higher in the sham-operation control group(P0.05).After HIBD,it began to decrease at 3 h,lowest at 24 h,and maintained the low level at 72 h.(3)The expression of MMP-9 mRNA negatively correlated with the expression of ZO-1 mRNA(r=-0.659,P0.05).⑷The ligated cerebral hemisphere showed obvious edema from 24 h to 48 h after hypoxia-ischemia in the neonatal rats.Conclusion: The increased expression of MMP-9 mRNA and the decreased expression of ZO-1 mRNA after HIBD may play a role in the pathogenesis of HIBD in neonatal rats.