Deep hypothermia decreases MMP-9 and NPY protein levels in brain of ischemia rats / 基础医学与临床

ABSTRACT

Objective To find the influence of deep hypothermic circulatory arrest on expression of MMP-9 and NPY in brains of rat. Methods Rats were divided randomly into three groups normal comparison group (NC), normal temperature circulatory arrest group (NTCA) and deep hypothermic circulatory arrest group (DHCA). After establishment of the extracorporeal circulation model, the NC group with no hypothermia or circulatory arrest, maintain circulatory 10 min. In NTCA group, rats were circulatory arrested under normal temperature with 10 min. In DHCA group, circulatory arrest was performed in 18.5 ℃～20 ℃ with 10 min. Then removed the brains immediately, measure water content of the brains. Results The water content of the brains in NTCA group was much higer than that in DHCA group and NC group, but the survival rate of nerve cells in NTCA group was lower than that in other two groups obviously (P＜0.05). The expression of MMP-9 in NTCA group and DHCA group was much higher than that in NC group (P＜0.05), and the expression of MMP-9 in DHCA group was lower than that in NTCA group (P＜0.05). The expression of NPY in NTCA group and DHCA group was much lower than that in NC group (P＜0.05), but in DHCA group, the expression of NPY was higher than that in NTCA group (P＜0.05). Conclusions Deep hypothermia can increase the survival rate of neurons by reducing the magnitude of NPY and the expression of MMP-9.