Pharmacological Inhibition of sEH in Pulmonary Hypertension

All animal care and procedures were approved by French Animal Experimentation Ethics Committees and performed in accordance with the guidelines from the French National Research Council for the Care and Use of Laboratory Animals (permit numbers: Apafis #24107 and #11920). Experiments were performed in 10-week-old male wild-type Sprague–Dawley rats (Janvier Labs) rats. Male rats were used to minimize hormonal effects (e.g., estrogen). Rats received a single subcutaneous administration of the VEGF receptor antagonist SU5416 (20 mg/kg) and were then exposed to hypoxia (10% FiO₂) for 3 weeks [12 (link),13 (link)]. Then, these rats returned to normoxia (21% FiO₂) for 5 additional weeks before evaluation. Inhibition of sEH was achieved in SuHx rats using the oral administration of 1-trifluoromethoxyphenyl-3-(1-propionylpiperidin-4-yl) urea (TPPU; 5 mg/L in drinking water/PEG400, 99:1, v/v). TPPU treatment was started 5 weeks post-SU5416 injection and went on for 3 weeks. TPPU was provided by C.M. for the study. High in vivo exposure and sEH inhibitory potency, in particular at the cardiac level, of TPPU have already been shown at the dose of 5 mg/L of drinking water in adult male Sprague–Dawley rats [14 (link)]. Normoxic rats receiving vehicle or TPPU served as controls.