Study On The Correlation Between Apolipoprotein E And Cerebral Endothclialnitric Oxide Synthase After Subarachnoid Hemorrhage

Objective: To explore the association between apolipoprotein E (apoE)and cerebral endothelial nitric oxide synthase (eNOS) after subarachnoidhemorrhage (SAH). Methods: Thirty apoE knock out (apoE KO) mice and30apoE wild type (apoE WT) mice were randomly and equally dividedinto3groups: control group, SAH group and intervention group. Mousemodel of SAH were induced with blood injection into magna cysterna,while control group with only normal saline. Intervention group waspreconditioned by orally administered with liver X receptor (LXR) agonistT0901317at dose of10mg/(kg.d) for6weeks before blood injected intomagna cysterna. Expression of eNOS mRNA and protein were detected inthe brain tissue by RT-PCR and Western blotting respectively. Results:There were no significant differences in expressions of eNOS mRNA andprotein in the control groups of apoE KO mice and apoE WT mice.Compared with the control groups, the expressions of eNOS mRNA andprotein were significantly reduced in both SAH groups (P<0.05), and the expressions of eNOS mRNA and protein in apoE KO mice were significantlower than those in apoE WT mice (P<0.05). The expressions of eNOSmRNA and protein in apoE WT intervention group were higher than thosein apoE WT SAH group(P<0.05), but there was no significant differencebetween apoE KO intervention group and apoE KO SAH group(P＞0.05).Conclusions: There is an obvious correlation between the expression ofapoE and cerebral eNOS after SAH, and enhancement in cerebral apoEexpression can significantly promote the expression of eNOS leading toalleviate cerebral vasospasm after SAH.