Cimetidine prevents suppression of delayed hypersensitivity in an animal model of haemorrhagic shock.

Abstract

Cimetidine reverses immunosuppression following trauma, however, its effect on pure haemorrhagic shock is unknown. Mice sensitized by injection of sheep red blood cells (SRBCs), were subjected to cardiac puncture and randomized to a control group-A (n=11) and three shock groups (35% of blood volume extracted): group-S had no treatment (n=16), group-CP received cimetidine 50mg/kg intraperitoneally (n=16), group-CW received oral cimetidine (200mg/kg per day, n=16). After 5 days, animals were challenged by injection of SRBCs into the foot-pad of the right hind paw (same volume of saline was injected into left paw). Foot-pad thickness ratios (FPTRs) were determined at 16 and 40 h, and inflammatory response was assessed histologically. At 16 h, FPTRs were greater in group-CW than group-S (P=0.01). There were no differences at 40 h. More animals in groups-CP and -CW had grade 3/4 inflammation, whilst group-S had the least inflammatory response (NS). Cimetidine prevents suppression of delayed hypersensitivity in this model.