2.5 Statistics
The data and statistical analyses comply with the recommendations of theBritish Journal of Pharmacology on experimental design and analysis in pharmacology(Curtis et al., 2018). Data were analyzed using GraphPad Prism (version9, GraphPad Software, San Diego, CA, USA) and summary data are shown as mean ± SEM for small data sets (N < 20, under the assumption of normal distribution) and as median and interquartile range for larger data sets (N > 30, not meeting normal distribution). Data on the effect of pharmacological tools on the contractile responses to K+ are shown as the percentage of the second contraction induced by 32 mM K+. Data on the effect of inhibitors on contractions induced by ET-1 are shown as the concentration of ET-1 required to achieve amplitude-matching to contractions induced by 32 mM K+. Relaxations were calculated as the percentage reduction of the contraction. Individual cumulative-concentration response curves (CCRCs) were fitted using a non-linear regression curve with variable slope. Effects of inhibitors were studied in parallel with an untreated control and statistical analyses were carried out under the assumption of normal distribution by comparisons of the potency (pD2 values) and efficacy (Emax values) using one-way mixed-effects model ANOVA. A Dunnett’s post-hoc test was used to correct for multiple comparisons. Results of experiments in arterial segments from the same patient and in those from different patients, were compared by paired two-sided t -test and by unpaired two-sided t -test, respectively. P < 0.05 was accepted to denote statistical significance