Effect of systemic LPS on platelet sequestration in lung, liver, and spleen in wild-type and TLR4^defmice. Wild-type and TLR4^def mice were untreated or treated with LPS for 3 hours. At this time, the mice received 4 to 8 × 10⁸⁵¹Cr-labeled platelets in 0.2 mL per mouse that were allowed to circulate for 1 hour. Untreated and LPS treated wild-type mice received platelets (PLT) from wild-type mice (WT PLT into WT mice) or from TLR4^def mice (TLR4^def PLT into WT mice). Untreated and LPS-treated TLR4^def mice received platelets from wild-type mice (WT mice into TLR4^def mice). Lung (A), liver (B), spleen (C), and other organs were then harvested and radioactivity was analyzed, as explained in “Materials and methods.” Platelet sequestration in the different organs was evaluated by analyzing ⁵¹Cr activity (see “Materials and methods”). Data are expressed as the arithmetic mean ± SEM from 4 mice in each group. ^*P < .005 versus untreated wild-type mice.