Developmental delay in hypoxia-induced HO-1 expression predisposes to gut injury.

Aims: Necrotizing enterocolitis (NEC) is an often fatal disease that affects 5-8% of preterm newborn infants but does not occur in older infants and children. As carbon monoxide (CO) may exert protective effects against NEC, we assessed patterns of intestinal injury and investigated the expression of the CO-producing enzyme heme oxygenase-1 (HO-1) in mature and immature rat guts in response to hypercapnia and reoxygenation (H/R).

Methods: Gut barrier failure (increased permeability for dextran) was assessed in immature (newborn rats) and mature rats (weanling rats) subjected to H/R.