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