Fig. 5

IL-6 knockout is protective against decreased cerebral blood flow, vasospasm, and secondary cascades. On post-bleed day 5, no significant increase in vasospasm was seen in the SAH IL-6 KO group. When IL-6 was administered to the knockout mice in context of SAH, vasospasm developed (p < 0.01) (A). IL-6 administration to the SAH KO mice significantly increased p-STAT3 compared to saline (p < 0.001) and to SAH IL-6 KO without administration (p < 0.01). p-STAT3 and TLR4 co-localization was similar between the SAH IL-6 KO mice with IL-6 administration and SAH wild-type mice (B). A significant decrease in RMCA/LMCA ratio cerebral blood flow was seen 48 h after SAH p < 0.001. This was partially mitigated by IL-6 blockade (p < 0.01) and IL-6 KO (p < 0.05) (C). Black scale bare = 100 μm. White scale bar = 50 μm. *comparison to saline. ^#b = comparison to SAH + KO. ^#c = comparison to SAH