Effects of the tyrosine kinase inhibitor genistein and the src kinase inhibitor PP2 and their negative controls daidzein and PP3, respectively (10 μM each), on NA- and SPC-induced vasoconstriction. Data are means±s.e.mean of 5–6 experiments. The following P-values for overall treatment effect were obtained for NA (P<0.0001 genistein vs vehicle, P=0.0017 genistein vs daidzein) and SPC (P=0.0248 genistein vs vehicle, P=0.0030 PP2 vs vehicle) in a two-way ANOVA, *P<0.05 for individual agonist concentrations vs vehicle in Bonferroni post-tests.