Fig. 4

In the chronic mild hypoxia model, tissue hypoxia is most severe in the WM. Frozen spinal cord sections taken from mice exposed to hypoxia (8% O₂) that had received daily intraperitoneal injections of the anti-mouse β1 integrin function-blocking antibody or isotype control antibody for 4 days, followed by an intraperitoneal injection of hypoxyprobe 2 h before tissue samples were collected, were stained for fibrinogen (Cy-3) and hypoxyprobe (AlexaFluor-488) (A), or TER-119 (AlexaFluor-488) and hypoxyprobe (Cy3) (C). Scale bars = 500 μm. White dotted line demarcates the GM (inside) from the WM (outside). B. Quantification of the number of hypoxyprobe ⁺ events/FOV in the spinal cord after 4-days hypoxia. Results are expressed as the mean ± SEM (n = 4–5 mice/group). Note that most hypoxyprobe ⁺ events occurred in the WM, that many vascular leaks, but not all, were associated with a hypoxyprobe ⁺ region, and that β1 integrin inhibition while greatly increasing the number of vascular leaks, had no effect on the appearance or distribution of hypoxic regions