AT inhibits HRPII-mediated procoagulant responses in mice. Mice were injected IP with saline or HRPII (10 µg/g) and AT (20 µg/g) followed by taking blood samples and collecting organs after 3.5 hours for analysis. (A) Plasma level of the TAT complex was measured with established ELISA. (B) Perfused lower right lobe of the lung was harvested in the tissue lysis buffer and immunoblotted for fibrin(ogen). (C) Densitometric analysis of fibrin(ogen) deposition in the lung tissue sample is presented. (D) Lung cryosections were fixed, permeabilized, and incubated with anti-CD31 (rat) and anti-fibrin(ogen) (rabbit) antibodies followed by Alexa Fluor 488-conjugated anti-rat and Alexa Fluor 562-conjugated anti-rabbit antibodies. DAPI was used to stain the nucleus. The arrows indicate intravascular thrombosis. (E) Perfused upper left lobe of the lung was collected and processed for histological analysis. Paraffin-embedded sections of the lung tissue were stained with hematoxylin and eosin. Inset boxes from each group are magnified. Blue arrows indicate thrombosis, and yellow arrows indicate inflammatory foci.