Acta physiologica Scandinavica
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Acta Physiol. Scand. · Aug 1995
Endothelin infusion reduces hypoxic pulmonary hypertension in pigs in vivo.
Previous work has shown that the plasma levels of the potent vasoactive peptide endothelin (ET) are increased in pathophysiological conditions with increased pulmonary vascular resistance and it has been speculated that ET may play some part in hypoxic pulmonary hypertension. We have therefore evaluated the effects of ET-infusion in the porcine pulmonary circulation after hypoxia-induced hypertension. Pits under general anaesthesia were artificially ventilated through an endotracheal tube and hypoxia was induced by decreasing the fraction inhaled O2 from 0.21 to 0.10. ⋯ Infusion of ET-1 (25 ng kg-1 min-1) evoked a rapidly developing decrease in PVR and MPAP which was quickly normalized upon cessation of the ET-infusion. ET-1 infusion at this concentration did not per se influence the haemodynamic parameters during normoxia. It is concluded that in the pig, short-term ET-infusion reduces the pulmonary hypertension associated with acute hypoxia.