Molecular determinants of the profibrogenic effects of endothelin-1 in pancreatic stellate cells

Figure 3 ET-1 induces phosphorylation of ERK1/2 and p38. PSC were starved of serum for 16 h before they were stimulated with ET-1 (100 nmol/L) for the indicated periods of time (A, D). ERK1/2 and p38 phosphorylation were analyzed by immunoblotting (B, E). Reprobing of the blots with anti-ERK1/2 and anti-p38 protein-specific antibodies revealed no systematic differences in the ERK1/2 and p38 amount among the samples (C, F). Fluorescence signal intensities of phospho (p)-ERK1/2, ERK1/2 protein, phospho (p)-p38 and p38 protein were quantified using Odyssey^® software version 3.0. Subsequently, the ratios of phospho-ERK/ERK protein (C) and phospho-p38/p38 (F) protein were calculated. A ratio of one hundred percent corresponds to unstimulated control cultures. The data shown are representative of three independent experiments.