Effect of a bradykinin antagonist on the local inflammatory response following thermal injury

Partial and full thickness burns with intervening zones of stasis were created on the backs of New Zealand White rabbits (n = 23). Either saline or the bradykinin receptor antagonist, NPC 17731, was administered. Skin blood flow was measured hourly using a laser Doppler blood flowmeter. After 4 h skin samples were harvested for assessment of tissue oedema (wet/dry weights) and leucocyte accumulation (immunohistochemistry). Statistical analysis was performed using Analysis of Variance (ANOVA) and Mann-Whitney U test with a level of significance at P< 0.05. It was found that blood flow was decreased postburn in all groups. Bradykinin antagonist resulted in increased blood flow in partial thickness burns and zones of stasis compared to saline-treated animals (P< 0.05). Pretreatment with bradykinin antagonist showed reduced tissue oedema in full thickness burns (P< 0.05). No significant difference was observed in leucocyte accumulation between both groups. These data suggest a role for bradykinin in the pathogenesis of postburn microvascular changes which is independent of leucocyte-mediated injury.