Effects of osteopontin against cerebral vasospasm after subarachnoid hemorrhage in rats

HE Junchi; LIU Mindi; LIU Zhen; LUO Liangsheng

Abstract：Objective The effect of recombinant osteopontin (r-OPN) against cerebral vasospasm (CVS) after subarachnoid hemorrhage (SAH) is investigated and the potential mechanisms are discussed.Methods Forty-eight rats were randomly assigned to sham+vehicle group (n=12), SAH+vehicle group (n=12), SAH+OPN 0.03 (0.03μg) group (n=12), and SAH+OPN 0.1 (0.1μg) group (n=12).The double injection model of cisterna magna was induced.Cerebrospinal fluid ( CSF ) was collected and rats were sacrificed at 72 h after the first hemorrhage induction.The degree of CVS was determined by the measurement of the cross-sectional area and thickness of basilar arteries (BA) under Hematoxylin-eosin (HE) staining.The level of endothelin-1 (ET-1) in CSF was tested using an enzyme-linked immunosorbent assays (ELISA) kit.Western blot analysis was applied to evaluate the expressions of phosphorylated endothelial nitric oxide synthase ( p-eNOS ) and inducible nitric oxide synthase (iNOS) in BA.Results The SAH+OPN 0.1 group showed significant increased cross-sectional area, decreased wall thickness, declined ET-1 level in CSF, increased expression of p-eNOS, and decreased expression of iNOS in BA, compared with the SAH+vehicle group.Conclusion r-OPN is demonstrated to attenuate CVS, and its possible mechanism may be involved in the suppression of ET-1 production and iNOS expression, and induction of p-eNOS expression.