Percentage of degranulated MCs in selected tissues (A–D) determined by morphologic appearance (E, inset) of toluidine blue-stained MCs identified in sections of skin, trachea, stomach, and peritoneal lavage fluid in uninfected mice and then 4 h and 12 h or 24 h after CLP-induced infection (n=5–9 mice/group). (E) Photomicrograph of a representative section of skin 24 h after CLP stained with toluidine blue. Thick arrows indicate degranulated MCs, and thin arrows represent nondegranulated MCs, which show tightly packed cytoplasmic granules after toluidine blue staining (Non-degran), whereas degranulated MCs have less tightly packed granules, which can be seen spilling into the surrounding tissue (Degran). (F) Bacterial loads in the blood and peritoneum [peritoneal lavage (PL)] of mice, 4 h and 24 h after CLP. Error bars indicate sem; *P < 0.05.