Fig. 5. Ageing induces slight endothelial dysfunction and increased basal VSMC tone.

ACh concentration-response curves of PE-precontracted aortic rings (a), with logIC₅₀ value (b) and maximal effect (c) from non-linear regression analysis. Statistical analysis using two-way ANOVA (a) or one-way ANOVA (b, c). DEANO concentration-response curves of PE + L-NAME-precontracted aortic rings (d), with a calculated maximal effect (e) from non-linear regression analysis. Effect of replacing normal Krebs solution with 0Ca Krebs on isometric force (f). Data are listed as mean ± SEM (a, d, n > 8). Statistical analysis using two-way ANOVA (a, d), one-way ANOVA (b, c), or repeated one-sample t-test vs 100% (e) or 0 mN (f). Overall ANOVA significance (bottom of graph) and post hoc significance as indicated (above brackets) are listed (post hoc significance was not added in a, d). *p < 0.05, **p < 0.01, ***p < 0.001.