In vivo effects of misoprostol on macrophage maturation during peritonitis. (A) Misoprostol down-regulates CD115 and up-regulates SOCS1 in bone marrow cells of WT mice but not EP2^−/− mice in a model of thioglycollate peritonitis. Two hours before and 10 hours after intraperitoneal thioglycollate injection, mice were injected subcutaneously with 200 μL of saline containing either 50 μg of the nonselective PGE2 analog misoprostol in 0.5% DMSO or DMSO alone. After 24 hours, WT and EP2^−/− mice were killed, and bone marrow cells were isolated and analyzed for the expression of CD115 and SOCS1 with qRT-PCR. Data shown are expressed as the mean ± SEM from 6 experiments, each using a different mouse (*P < .05). (B) Misoprostol attenuates macrophage accumulation in the peritoneal cavity in a model of thioglycollate peritonitis. Mice were treated as described in panel A. After 4 days, peritoneal cells of EP2^−/− and WT mice were lavaged and counted. The percentage of mononuclear cells was determined from modified Wright-Giemsa–stained cytospins. Data are expressed as the mean ± SEM from 8 experiments, each using a different mouse. (C) Misoprostol fails to attenuate CCL2 (MCP-1) production. Mice were treated as described in panel A. After 24 hours, the peritoneal cavities of EP2^−/− and WT mice were lavaged with 1 mL of lavage buffer, and the supernatant was analyzed for MCP-1 using ELISA. Data are expressed as the mean ± SEM from 6 experiments, each using a different mouse. Thio indicates thioglycollate and miso, misoprostol.