PAR-1 mRNA and protein expression around hemotoma after intracerebral hemorrhage in rats

Objective To explore PAR-1 mRNA and protein expression around hematoma after intracerebral hemorrhage and relations between PAR-1 expression and thrombin. Methods Collagenase VII ,thrombin (TM) or hirudin was stereotaxically injected into right caudate nucleus in rats respectively. The expression of PAR-1 mRNA and protein was detected by RT-PCR method and immuohistochemical method respectively. Results PAR-1 mRNA and protein expression around hematoma was 0.802±0.143 and 19.65±1.12 at 6 h (P0.05), 1.825±0.214 and 33.34±1.09 at 24 h (P0.01) after intracerebral hemorrhage respectively. The increased expression of PAR-1 mRNA and protein lasted 72 h (P0.01) and then declined,and restored to normal level at 96th h after injection.The change pattern of PAR-1 mRNA and protein expression was similar to that of intracerebral hemorrhage after thrombin intracerebral injection. At all the time points,PAR-1 mRNA and protein after TM injection had no significant difference compared with ICH group (P0.05). There was no significant difference in PAR-1 mRNA and protein expression between hirudin group and control group (P 0.05). Conclusion PAR-1 mRNA and protein expression were markedly increased after intracerebral hemorrhage, which may be closely related to thrombin. Upregulation of PAR-1 expression may be involved in neurotoxic injury induced by thrombin.