Improvement effect of BQ-123 on nerve function damage after subarachnoid hemorrhage in rats / 吉林大学学报(医学版)

ABSTRACT

Objective:To study the effect of endothelin receptor antagonist BQ-123 on the nerve function damage after subarachnoid hemorrhage (SAH)in the rats,and to explore the mechanisms.Methods:Total 120 male SD rats were divided into sham group,SAH group,low dose of BQ-123 group (50 μg· kg-1 )and high dose of BQ-123 group (75 μg·kg-1 ).The SAH rat models were established by injecting the autologous blood into cisterna magna twice.The morphological changes of hippocampus nerve cells of rat brain tissue were detected with HE staining, and the expressions of mTOR, Beclin-1 and LC3-Ⅱ in the hippocampus of rats were detected with immunohistochemistry and RT-PCR;the shuttle-box experiment was used to evaluate the abilities of learning and memory,and the holding power evaluation was used to evaluate the forelimb pulling force of the rats in various groups at each time point.Results:Compared with sham group,the morphological damages of neurons of the rats in SAH group were increased,the survival rate of neurons of the rats in SAH group was decreased (P <0.05),the expression levels of mTOR mRNA,Beclin-1 mRNA and LC3-Ⅱ mRNA in hippocampus tissue of the rats were increased (P < 0.05),and the abtilities of learning and memory and the values of holding power were decreased (P <0.05).Compared with SAH group,the morphological damages of neurons of the rats in BQ-123 groups were decreased,the survival rates of neurons of the rats in BQ-123 groups were increased (P < 0.05),the expression levels of mTOR mRNA of rats were decreased (P <0.05),the expression levels of Beclin-1 mRNA and LC3-ⅡmRNA in hippocampus tissue were increased (P <0.05),and the abilities of learning and memory and the values of holding power were increased (P < 0.05 ). The changes were more significant in high dose of BQ-123 group compared with low dose of BQ-123 group (P <0.05).Conclusion:BQ-123 can improve the nerve function damage after SAH in the rats,its mechanism may be related to regulating the mTOR/autophagy signaling pathway.