Inhibition of binding of ¹²⁵I-labeled mouse C5a (¹²⁵I-C5a) to peritoneal mouse neutrophils in vitro (a) and various organs in vivo (b) by αC5aR. (a) Binding of ¹²⁵I-C5a is expressed as cpm. Groups were treated (as indicated) for 20 minutes prior to binding of ¹²⁵I-C5a. Data are representative of five independent experiments per condition. (b) Binding of ¹²⁵I-C5a is expressed as the ratio of cpm per g organ to cpm in 100 μl blood from each animal (n = 4 per condition) obtained 10 minutes after intravenous injection of ¹²⁵I-C5a and 6 hours after CLP. αC5aR (6 μg/mouse) or an equal amount of irrelevant rabbit IgG (control) was administered intravenously 15 minutes prior to ¹²⁵I-C5a infusion. *Statistical significance in treated groups when compared with control animals. Ctrl, control.