Fig. 4From: Functional changes in long-term incubated rat precision-cut lung slicesEndothelin-1 (ET-1)-induced bronchoconstriction in long-term cultivated rat precision-cut lung slices (PCLS). PCLS with intact airways and surrounding epithelium were used in measurements of ET-1-induced bronchoconstriction on measuring days. Different concentrations of ET-1 (10–9–10–6 M) were added to the slice, constriction was measured via microscope. Images were analysed with ImageJ. For each timepoint, measurements were performed in duplicates, n = 4, the same slices were used for measurements with ET-1 on every measuring day. Data is expressed as mean ± standard deviation (SD). First image of non-constricted airway of each measuring day was set as 100%. ET-1-induced reduction of airway area was expressed as percentage of the initial airway area (%-IAA) (A). Using GraphPad Prism 9, nonlinear regression with a four-parameter logistic equation was conducted from data of ET-1-induced bronchoconstriction (10–9–10–6 M). Maximal constriction (= efficacy) (B), maximal airway area (C) and half-maximal response (EC50) (D) were calculated. Analysis was performed based on control image of every measuring day ( ) and that of the first measuring day (●). Statistics were carried out using the general mixed model analysis (PROC GLIMMIX, SAS 9.4, SAS Institute Inc., Cary, NC, USA), statistical differences to day 1 are indicated by asterisks (**0.001 ≤ p < 0.01, ***p < 0.001)Back to article page