5-HT_2A receptor antagonist blocks the effects of (<i>R</i>)-DOI.

<p>Mice were pretreated with the selective 5-HT_2A receptor antagonist M100907 (1.0 mg/ml) (i.p.) 30 minutes prior to (<i>R</i>)-DOI (0.3 mg/ml; i.p.), followed 30 minutes later by TNF-α (i.p.). Pretreatment with antagonist blocked the effects of (<i>R</i>)-DOI to block TNF-α-induced pro-inflammatory gene expression as demonstrated here in the small intestine. (S = saline control; T = TNF; DT = DOI (0.3 mg/kg)+TNF; MDT = M100907 (1.0 mg/kg)+DOI (0.3 mg/kg)+TNF; MT = M100907 (1.0 mg/kg)+TNF; M = M100907 (1.0 mg/kg); n = 5 animals per treatment; * p<0.05 vs TNF-α; error bars represent ± SEM; ANOVA with Holm-Šídák post hoc test).