Attenuated endothelin- mRNA expression with endothelin- receptor blockade during hypoxaemia and reoxygenation in newborn piglets

Attenuated endothelin- mRNA expression with endothelin- receptor blockade during hypoxaemia and reoxygenation in newborn piglets. Medbo S, Beisvag V, Tollofsrud PA, Ellingsen O, Wright MS Department of Paediatric Research, Institute for Surgical Research, The National Hospital, Rikshospitalet, Oslo, Norway. sverre.medbo@rh.uio.no [Medline record in process] We investigated the cause of decreased plasma endothelin-1 (ET-1) during hypoxaemia and reoxygenation in newborn piglets subjected to simultaneous blocking of the ET-1 receptors. Changes in plasma ET-1 and prepro-ET-1 mRNA expression in the main pulmonary artery and the left lower lobe in the lung were studied in 1-2-d-old piglets. Ten minutes prior to hypoxaemia, the hypoxaemia group (n = 10) was given saline, two groups (both n = 9) were given 1 and 5 mg/kg i.v. SB 217242 (an ET-1 receptor antagonist). Two groups served as normoxic controls, with and without SB 217242 5 mg/kg i.v. Hypoxaemia was induced by ventilating with 8% O2 until base excess was