Figure 2

Choline suppresses systemic TNF levels during endotoxemia through an α7nAChR-dependent mechanism. (A) Choline or vehicle (V, saline) was injected i.p. in BALB/c mice (n = 10 per group) at 6 h, and at 30 min, prior to endotoxin (6 mg/kg, i.p.) administration. Serum TNF was analyzed by ELISA in blood obtained 90 min after endotoxin administration. Results show the mean ± SEM for each group (*P < 0.05 as compared with vehicle (V) administered controls). (B) Choline (50 mg/kg, i.p.) or saline was injected i.p. in age-matched WT and α7nAchR KO mice (WT n = 8–9/group, α7nAChR KO n = 7–9/group) at 6 h, and at 30 min, prior to endotoxin (6 mg/kg, i.p.) administration. Serum TNF was analyzed by ELISA in blood obtained 90 min after endotoxin administration. Results show the mean ± SEM for each treatment group (*P < 0.001 as compared with saline administered controls). (C) Peritoneal macrophages from age-matched WT and α7nAChR KO mice were incubated with the indicated concentrations of choline or vehicle (V) for 10 min prior to exposure to endotoxin (100 ng/mL). TNF in cell culture media was determined by ELISA 4 h after endotoxin addition. Results represent the mean ± SEM of three independent experiments conducted in duplicate (*P < 0.04, **P < 0.02, ***P < 0.002 as compared with lowest choline concentration tested).