(A) Effect of IL-1β (1 and 5 ng paw−1, 60 min) or des-Arg9-BK (100 nmol paw−1, 20 min), given alone or after IL-1β (1 ng paw−1) i.d. injection, on MPO activity in the rat paw. (B) Effect of the co-injection of the B1 receptor selective antagonist des-Arg9-[Leu8]-BK (100 nmol paw−1) on IL-1β (1 ng paw−1, 60 min) plus des-Arg9-BK (100 nmol paw−1, 20 min)-induced increase in MPO activity in the rat paw. Each column represents the means±s.e.mean of four experiments. Significantly different from values obtained in PBS- (*), IL-1β- (#) or IL-β plus des-Arg9-BK (+) injected paws, P<0.05 (one-way ANOVA followed by Newman-Keuls test).