Fig. 5.

Abcc8^−/− mice have less necrosis and hemorrhage after SCI. (A) Longitudinal sections of spinal cords, obtained at the times indicated, from WT and Abcc8^−/− (null) mice that sustained hemicord T9 SCI and were administered PI before death to identify necrotic cells. The sections shown either were unprocessed to demonstrate expanding contusion in WT but not in Abcc8^−/− mice (top row, left) or were imaged with a fluorescent microscope to visualize PI-positive nuclei at high magnification at 24 hours in a WT mouse (red dots, top row right) or at low magnification at the times indicated and in the mice indicated (white dots, lower row of images). Asterisks, impact site; rows of arrows, pial surface contralateral to the impact site. Bar graph, mean ± SEM of PI-positive nuclei in the indicated conditions (three to five mice per group). **P < 0.01. (B) Phase-contrast (left) and fluorescent (middle and right) images of primary cultures of TNFα-exposed brain microvascular endothelial cells from WT and Abcc8^−/− (null) mice. After depleting ATP, necrotic cells were identified with PI. Bar graph, percent (mean ± SEM) necrotic cells for each condition (n = 6). **P < 0.01. (C) Longitudinal sections (left) and homogenates (middle) of spinal cords from WT and Abcc8^−/− (null) mice 24 hours after hemicord T9 SCI. Bar graph, volume (mean ± SEM) of extravasated blood (five mice per group). **P < 0.01. (D) Sections from the penumbra of wild-type and Abcc8^−/− (null) mice 24 hours after sustaining hemicord T9 SCI, immunolabeled for laminin or CD31. Asterisks, impact sites. Bar graphs, lengths (mean ± SEM) of capillaries measured with laminin or CD31 in three groups of mice, as indicated. **P < 0.01. Images shown are representative of three mice per group.