Background: β-APP is induced in adults after hypoxic injury or head trauma. We investigated whether β-APP induction followed neonatal HII.

Subjects and Interventions: β-APP expression in the brains of day 14 rats following unilateral carotid artery ligation and 30 minutes in an 8% oxygen environment was assessed at defined time points by immunohistochemistry (IHC) and Western blotting. β-APP expression in 10 term human infants dying between 12 hours and 16 months after HII was also assessed by IHC.

Results: In rats increased β-APP expression was detectable by 2 hours post injury, peaked around 24 hours and declined to near basal levels by 5 days. Induction was seen bilaterally but was greater on the side of injury. In human term infants increased β-APP was detected by 12 hours after birth, the earliest time histological damage was identifible, was maximal in infants dying 2-3 days after HII and was similar to control levels by 10 days. Induction was seen in areas with and without histological evidence of damage.

Conclusion: We conclude that β-APP induction is part of the cerebral acute phase response to HII in the newborn.