Altered nitric oxide production in the premature gut may increase susceptibility to intestinal damage in necrotizing enterocolitis.
OBJECTIVE
Nitric oxide (NO) mediates enteric smooth muscle relaxation and mucosal protection. The authors have identified an ontogenically determined pattern of enteric NO neural maturation that may render the distal gut of premature piglets susceptible to injury.


METHODS
NO synthase (cNOS and iNOS) activities were measured in the developing piglet gut wall and compared with gut from an intraluminal model of necrotizing enterocolitis (NEC) at different times.


RESULTS
In premature animals, iNOS activity was significantly higher 3 hours after NEC induction compared with similarly treated 3-day-old piglets. INOS levels continued to rise 6 hours after NEC induction in prematures. Premature animals (labor induced by prostaglandins) failed to show such a rise in iNOS. In 3 day olds, iNOS levels increased significantly 16 hours after injury compared with the 3-hour group.


CONCLUSIONS
iNOS production increases in premature piglets with NEC compared with full-term NEC animals and continues to rise in the presence of intestinal damage regardless of developmental status. Maternal administration of prostaglandins attenuates this rise in iNOS activity. Elevated NO production in premature gut may contribute to increased susceptibility to damage in NEC.
Di Lorenzo
M
M
Division of Pediatric General Surgery, Department of Surgery, Hôpital Sainte-Justine, University of Montreal, Montreal, Quebec, Canada.
Krantis
A
A
D000367:Age Factors; D000818:Animals; D000831:Animals, Newborn / Q000378:metabolism*; D004195:Disease Models, Animal; D004198:Disease Susceptibility; D020345:Enterocolitis, Necrotizing / Q000378:metabolism*; D005260:Female; D005865:Gestational Age; D007413:Intestinal Mucosa / Q000378:metabolism*; D009569:Nitric Oxide / Q000378:metabolism*; D019001:Nitric Oxide Synthase / Q000378:metabolism*; D007752:Obstetric Labor, Premature / Q000188:drug therapy / Q000378:metabolism*; D011247:Pregnancy; D011453:Prostaglandins / Q000627:therapeutic use; D013552:Swine; D013997:Time Factors
D011453:Prostaglandins; D009569:Nitric Oxide; D019001:Nitric Oxide Synthase