Endothelial nitric oxide synthase in hypoxic newborn porcine pulmonary vessels

Academic Article


  • Aims-To determine if the failure of neonatal pulmonary arteries to dilate is due to a lack of nitric oxide synthase (NOS). Methods-A monoclonal antibody to endothelial NOS was used to demonstrate the distribution and density of NOS in the developing porcine lung after a period in hypobaric hypoxia. Newborn piglets were made hypertensive by exposure to hypobaric hypoxia (50.8 kPa) from < 5 minutes of age to 2.5 days of age, 3-6 days of age or 14-17 days of age. A semiquantitative scoring system was used to assess the distribution of endothelial NOS by light microscopy. Results-NOS was present in the arteries in all hypoxic animals. However, hypoxia from birth caused a reduction in NOS compared with those lungs normal at birth and those normal at 3 days. Hypoxia from 3-6 days led to a high density of NOS compared with normal lungs at 6 days. Hypoxia from 14-17 days had little effect on the amount of NOS. On recovery in room air after exposure to hypoxia from birth there was a transient increase in endothelial NOS after three days of recovery, mirroring that seen at three days in normal animals. Conclusions-Suppression of NOS production in the first few days of life may contribute to pulmonary hypertension in neonates.
  • Digital Object Identifier (doi)

    Author List

  • Hislop AA; Springall DR; Oliveira H; Pollock JS; Polak JM; Haworth SG
  • Volume

  • 77
  • Issue

  • 1