Fig. 2From: Chronic hypoxia aggravates monocrotaline-induced pulmonary arterial hypertension: a rodent relevant model to the human severe form of the diseaseEvaluation of intrapulmonary arterial contraction in pulmonary arterial hypertension models. Contractions of rat intrapulmonary arterial rings induced by cumulative concentrations of phenylephrine (PHE, 10−11 to 10−5M, a), or of prostaglandin F2α (PGF2α, 10−9 to 10−4M, b). Contractions were studied ex vivo after sacrifice at Day 28 in control rats (CTRL), after chronic hypoxia (Hx), after monocrotaline treatment (MCT), of after combination of MCT and 4 weeks of Hx (MCT + Hx). Results are expressed as the percentage of maximal contraction and are presented as means ± SEM with n = 12–15 rats per group. Determination of statistically significant differences between concentration-response curves was assessed with a two-way analysis of variance. ***p < 0.001 versus control concentration-response curves. ### p < 0.001 versus Hx concentration-response curves. $$$ p < 0.001 versus MCT concentration-response curves. Values of -Log EC50 (half maximal effective concentrations, means ± SEM) are shown in Table c Back to article page