The effects of selected bradykinin receptor antagonists on leukocyte infiltration
into the lungs were studied in a model of guinea pig lung inflammation induced by
the intravenous injection of Sephadex beads. The bradykinin B1 receptor antagonist,
[Leu8]desArg9-BK (40 mg kg(-1) 24 h(-1)) and the bradykinin B2 receptor antagonist,
DArg[Hyp3,Thi5,DTic7,Oic8]BK (code name HOE 140; 4 mg kg(-1) 24 h(-1)), administered
intravenously by osmotic pumps, significantly reduced eosinophil counts by 33% and
42% in bronchoalveolar fluid, respectively. HOE 140 decreased neutrophil counts by
35%. LysLys[Hyp3,Igl5,D-Igl7,Oic8]desArg9BK+ ++ (code name B 9858), a newly described
bradykinin B1 receptor antagonist, administered intraperitoneally (1 mg kg(-1)), decreased
eosinophil and neutrophil counts by 45% in bronchoalveolar fluid. D-Arg[Hyp3,Igl5,D-Igl7,Oic8]BK
(code name B 9430), a non-selective bradykinin B1/B2 receptor antagonist, also administered
intraperitoneally (1 mg kg(-1)), decreased eosinophil and macrophage counts by 62%
and 80% in bronchoalveolar fluid. These results suggest that bradykinin B1 and B2
receptors are involved in leukocyte recruitment in our model of lung inflammation.