RESUMO
OBJECTIVES: The purpose of the present study was to determine if protecting parenteral nutrition solutions from ambient light and supplementing with N-acetylcysteine (NAC) improves mesenteric blood flow, gut morphology, and oxidative status of parenterally fed neonates. METHODS: Neonatal Yucatan miniature piglets (nâ=â23, 7-11 days old) were surgically fitted with central venous catheters and an ultrasonic blood flow probe around the superior mesenteric artery. Piglets were fed continuously for 7 days either light-protected (LP) or light-exposed (LE) complete parenteral nutrition that was enriched with either NAC or alanine (ALA). RESULTS: There were no differences in body weight or overall gut morphology among groups after 7 days. Plasma concentrations of NAC were greater and total homocysteine lower in NAC- versus ALA-supplemented pigs on day 7 (N-acetylcysteine: 94 vs 7âµmol/L; Pâ<â0.001; homocysteine: 14 versus 21âµmol/L; Pâ<â0.005); plasma total glutathione was not affected. Hepatic lipid peroxidation was reduced by 25% in piglets that received LP parenteral nutrition (Pâ<â0.05). The mesenteric artery blood flow decreased in all pigs between days 2 and 6 (Pâ<â0.001) because of parenteral feeding. Photoprotection alone (LP-ALA) attenuated the decrease in mesenteric blood flow to 66% of baseline on day 6 compared with LE-ALA (37%; Pâ<â0.05) and LP-NAC pigs (43%; Pâ=â0.062); LE-NAC piglets had intermediate reductions in blood flow (55%). CONCLUSIONS: Photoprotection of parenteral nutrition solutions is a simple, effective method to attenuate decline in blood flow to the gut and hepatic lipid peroxidation, which are both commonly associated with parenteral feeding.