Leukotrienes have been implicated in the pathogenesis of hypoxic pulmonary hypertension in adult animals and in persistent pulmonary hypertension with accompanying hypoxemia in the neonate. In order to elucidate the role of leukotrienes in hypoxic pulmonary hypertension in a young animal model, the effects of a leukotriene antagonist, FPL 57231, were evaluated in anesthetized piglets. Cardiac output and vascular pressures were measured and pulmonary and systemic vascular resistances calculated prior to and during hypoxia. These measurements were compared during continued hypoxia between a control and treatment group which received FPL 57231. FPL 57231 infusion resulted in significant decreases in mean pulmonary artery pressure (p < 0.04), pulmonary vascular resistance (p < 0.01) and the ratio of pulmonary/systemic vascular resistance (p < 0.01). Systemic vascular resistance fell approximately 25% from hypoxic baseline (p < 0.01) while PVR decreased 54%. There were no differences between groups in mean systemic arterial pressure, cardiac output, pH, or PaCO2. In addition, pretreatment with FPL 57231 attenuated the hemodynamic response to hypoxia. These data suggest that leukotrienes may, in part, mediate hypoxic pulmonary vasoconstriction in piglets.
ASJC Scopus subject areas
- Pediatrics, Perinatology, and Child Health