Adenosine triphosphate (ATP) accumulation and ATP-mediated induction of PAD4 and CitH3 in blood neutrophils and cerebral cortical tissue after MCAO in male Sprague-Dawley (SD) rats. (A) ATP levels were measured using ATP luminescence kit in plasma collected at 6 and 12 h post-MCAO. (B,C) Levels of PAD4 and CitH3 in blood neutrophils (blood PMNs) or in cortical penumbra were examined at 3, 6, 12, and 24 h post-MCAO by immunoblotting. (D) BzATP (0.5, 1, 2.5, or 5 mg/kg, i.v.) was administered 6 h post-MCAO and PAD4 and CitH3 levels were examined in cortical penumbra at 12 h post-MCAO by immunoblotting. (E) ATP (5, 10, 20, or 50 mg/kg, i.v.) was administered to normal rats and PAD4 and CitH3 levels were examined in blood PMNs isolated 4 h after ATP administration by immunoblotting. (F) BzATP (5 mg/kg, i.v.) was administered to normal rats and PAD4 and CitH3 levels were examined in blood parenchyma and in circulating neutrophils (PMNs) isolated 1, 3, or 6 h after BzATP administration by immunoblotting. Immunoblots are representative of 2 or 3 independent experiments. Numbers under the blot indicate band intensities. ATP levels were presented as mean ± SEM (n = 4). ** p < 0.01 versus sham controls.