Shuxuetong promotes collateral circulation formation and cerebrovascular reserve capacity in mouse models after ischemic stroke

Objective To investigate the effect of Shuxuetong (SXT) on promoting collateral circulation formation and enhancing cerebrovascular reserve capacity in mouse models after ischemic stroke. Methods Fifty-eight C57BL/6 mice were randomly divided into blank control group (n=6), SXT group (n=26) and control group (n=26). The mice in the SXT group and control group were subjected to distal middle cerebral artery occlusion (dMCAO) by electrocoagulation, and intraperitoneal administration of SXT (1.5 mL/kg) or equal volume of saline was given 30 min after stroke and repeated every 12 h for the next 3 d. TTC staining was used to assess the volume of infarction one d after ischemic stroke. Adhesive removal tests were performed to evaluate sensorimotor function of the mice before and one, 3, 7, 14, 21 and 28 d after stroke. Standardized regional cerebral blood flow (SrCBF) was measured by laser speckle contrast imaging before and one, 3, and 7 d after stroke. Immunofluorescence was used to evaluate the numbers of deoxyuridine 5'-monophosphate disodium (BrdU)+, BrdU+/von Willebrand factor (vWF)+ and BrdU+/Laminin+ cells and vessel density 7 d after stroke. The expression levels of total protein kinase (AKT), phosphorylated (p)-AKT, vascular endothelial growth factor (VEGF) and myeloperoxidase (MPO) were explored by Western blotting one d after stroke. Results As compared with those in the control group, the infarction volume of SXT group was significantly smaller one d after stroke, SrCBF was significantly higher 3 and 7 d after stroke, and vessel density was significantly increased and numbers of BrdU+/vWF+ and BrdU+/laminin+ cells in the subventricular zone and peri-infarction region were statistically larger 7 d after stroke (P<0.05). The results of SXT group in behavior experiments were significantly better than those of control group one d after stroke (P<0.05). The levels of p-AKT and VEGF of SXT group were significantly up-regulated, while MPO level was significantly decreased in peri-infarction tissues as compared with those in the control group one d after stroke (P<0.05). Conclusion SXT can promote the formation of collateral circulation and enhance the cerebrovascular reserve capacity. Key words: Shuxuetong; Ischemic stroke; Angiogenesis; Collateral circulation; Cerebrovascular reserve capacity