A critical role for fibroblast growth factor-7 during early alveolar formation in the neonatal rat.

Mesenchymal cell-derived FGF-7 (fibroblast growth factor-7) induces proliferation in both epithelial and endothelial cells. We found FGF-7 to be expressed in the lungs of neonatal rats from birth to d 14 of age. A role for FGF-7 in early postnatal lung growth and alveolar formation, by an action on type II pneumocytes, has been excluded by the work of others.

Hepatocyte growth factor is required for alveologenesis in the neonatal rat.

Rationale: Our core hypothesis is that growth factors that have dysregulated expression during experimental neonatal lung injury are likely to be involved in normal postnatal lung growth and alveologenesis.

Objectives: To determine if hepatocyte growth factor (HGF) is upregulated in neonatal lung injury and is essential for postnatal alveologenesis.

Methods: A neonatal lung injury, in which there were patchy areas of interstitial thickening with a relative increase in the proportion of epithelial cells, was induced in newborn rats by exposing them to 60% oxygen for 14 days.