Platelets are sequestered and activated in the lungs after intratracheal LPS and ASA attenuates these responses. CD41 immunostaining of lung tissue sections from (A) control mice (PBS), (B) LPS-challenged mice treated with vehicle (DMSO), or (C) LPS-challenged mice treated with ASA. Images are representative of ≥3 animals per group. Original magnification, ×60; zoom of outlined areas. Scale bar = 20 µm. Arrows indicate CD41⁺ events in the intra-alveolar spaces. (D) CD41 protein expression and densitometric analysis from lung digestion samples in PBS controls and LPS-challenged mice ± ASA. †††P < .001 vs PBS; ****P < .0001 vs vehicle. (E) Platelet activation was assessed by measuring TXB₂ plasma levels in PBS and LPS-challenged mice ± ASA. †P < .05 vs PBS; ****P < .0001 vs vehicle. Data are mean ± SD of 4 to 9 animals per group.