Relaxation effects of acetylcholine on untreated α₁ receptor agonist and thromboxane A₂ receptor agonist-contracted mouse aortas across PAR2 genotypes.

<p>Male (top) and female (bottom) aortic rings were contracted submaximally by phenylephrine (a, c) and U46619 (b, d) then relaxed by the cumulative addition of acetylcholine under isometric tension conditions. Symbols are means ± S.E.M., n = number of mice. Lines represent 4 parameter logistic curves which calculate the variables: pD₂, E_max and hill-slope. Variables were compared by 2 way ANOVA (sex x genotype) followed by Bonferonni post-hoc tests. (a, c) ^**<i>P</i><0.01, pD₂, main genotype effect. (b) ^***<i>P</i><0.001, E_max, PAR2-WT vs PAR2-KO genotype effect. (c) ^Φ<i>P</i><0.05, E_max, main gender effect. ^ΦΦ<i>P</i><0.05, pD₂, PAR2-HET male vs female. ^ΦΦΦ<i>P</i><0.001, pD₂, PAR2-WT male vs female. (d) ^Φ<i>P</i><0.05, E_max, PAR₂-WT and PAR2-HET male vs female.