Action of pretreatments changes in potency (Δ–log EC<sub>50</sub>) of endothelin-1 (ET-1) in human isolated bronchi.

<p>Values were determined in paired human bronchi after incubation with 0.1 µM fenoterol or oxygenated Krebs–Henseleit solution (control) for 15 hours at 37°C with or without pretreatment co-incubated with fenoterol (<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0111350#pone-0111350-g005" target="_blank">Fig 5</a>–<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0111350#pone-0111350-g006" target="_blank">6</a>). ET-1 potency (−log EC<sub>50</sub>) was derived graphically from the log concentration-effect curves and defined as the negative log of the ET-1 concentration achieving 50% of the maximal effect. Δ(−log EC<sub>50</sub>) represents the difference between −log EC<sub>50</sub> obtained with the fenoterol-treated bronchi and −log EC50 obtained with their paired controls. The observed effect of pretreatment co-incubated with fenoterol is small (|<i>d</i>|≥.20), medium (|<i>d</i>|≥.50), or large (|<i>d</i>|≥.80) according to the Cohen's conventions <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0111350#pone.0111350-Cohen1" target="_blank">[36]</a>. The 95% CI for <i>d</i> consists of the uncertainty around the real effect of pretreatment. <sup>†</sup>Except for wortmaninn which was added in organ bath before concentration-response curve for ET-1. *<i>P</i><.05, **<i>P</i><.01, ***<i>P</i><.001 with vs without pretreatment.</p><p>Action of pretreatments changes in potency (Δ–log EC<sub>50</sub>) of endothelin-1 (ET-1) in human isolated bronchi.</p>