Figure 4.

B2 receptor-mediated contraction of the isolated canine prostate. Representative traces of BK (10 μM)-induced tissue contraction in the presence of vehicle or 1 μM HOE-140 (a). The first addition of BK is the priming of tissues followed by a second addition of BK in the presence or absence of HOE-140, and then the tissues were challenged again with BK after washout (third addition) to study reversibility of the antagonist (a). BK (10 μM)-induced contraction was blocked with pretreatment with HOE-140 (black bar) that was partially recovered after washout (wash) (b). The B1 agonist (10 μM) did not contract the prostate strips, while inhibition of proteases resulted in a stronger BK-induced contraction (c). Responses were normalized to 10 μM BK. The bars represent the mean values and the vertical lines indicate standard errors of the mean of 3 (c) or 4 (b) independent experiments. Data shown in (b) are pooled from 13 tissue strips, while all the data shown in (b) are pooled from 11 tissue strips. ^**Significant statistical difference (P<0.001) of the values represented, by the corresponding bar, when compared to BK-induced contraction in the same tissue, pre- and post-treatment.