OBJECTIVETo investigate the roles of hypoxia-inducible factor-1α (HIF-1α), endothelin-1 (ET-1) and inducible nitric oxide synthase (iNOS) in the pathogenesis of hypoxia-induced pulmonary hypertension (HPH) of the newborn.

METHODSSeventy-five term hospitalized neonates with HPH (mild 29 cases, moderate 25 cases, severe 21 cases) and 22 term hospitalized neonates without HPH (control group) were enrolled between June 2006 and November 2009. Serum levels of HIF-1α, iNOS and ET-1 were measured using ELASA 1, 3 and 7 days after birth.

RESULTSSerum concentrations of HIF-1α and ET-1 in the mild, moderate and severe HPH groups were significantly higher than those in the control group (P<0.01) 1 day after birth, and were related to the severity of HPH. The serum iNOS concentrations in the moderate and severe HPH groups were also significantly higher than those in the control group (P<0.01). By 3 days after birth, serum ET-1 concentration in the moderate HPH group and serum concentrations of HIF-1α, ET-1 and iNOS in the severe HPH group reminded significantly higher than those in the control group (P<0.05). At 7 days after birth, serum ET-1 concentration in the severe HPH group still remained higher than that in the control group (P<0.05).

CONCLUSIONSSerum levels of HIF-1α, ET-1 and iNOS increase in neonates with HPH, resulting in an imbalance of ET-1 and NO. This may be of importance in the pathogenesis of neonatal HPH.