Effect of postnatal nutrition restriction on the oxidative status of neonates with intrauterine growth restriction in a pig model

Abstract

Objective: In offspring with intrauterine growth restriction (IUGR), where oxidative stress may play an important role in inducing metabolic syndrome, nutrition restriction has been shown to improve oxidative status. In this study, we aimed to investigate the effect of postnatal nutrition restriction on the oxidative status of IUGR neonates.

Methods: A total of twelve pairs of piglets, of normal birth-weight (NBW) and with IUGR (7 days old), respectively, were randomly allocated to have adequate nutritional intake (ANI) and restricted nutritional intake (RNI) for a period of 21 days, respectively. This design produced 4 experimental groups: NBW-ANI, IUGR-ANI, NBW-RNI and IUGR-RNI (n = 6 per group). Serum, ileum and liver samples were analyzed for antioxidant parameters and the mRNA expression of genes with regard to oxidative status. The data were subjected to general linear model analysis and Duncan's test with a 5% significance level.

Results: Irrespective of nutritional intake, the IUGR pigs had markedly lower activity of glutathione peroxidase (GPX), gene expressions of liver mitochondrial manganese superoxide dismutase (Mn-SOD) and ileum cytoplasmic copper/zinc (CuZn)-SOD and, accordingly, there was a markedly higher malondialdehyde concentration in the liver of these pigs compared to in the NBW pigs. Irrespective of body weight, pigs receiving ANI treatment had significantly lower activities of antioxidant enzymes in the serum (total antioxidative capability, CuZn-SOD and GPX) and liver (total SOD and glutathione reductase) and decreased gene expression of liver CuZn-SOD and Mn-SOD compared to the pigs receiving RNI. In addition, the IUGR pigs had a markedly lower concentration of liver reduced glutathione (GSH), ratio of GSH to oxidized glutathione, gene expression of ileum CuZn-SOD and extracellular SOD than the NBW pigs when receiving ANI, but not all of these differences were observed in those receiving RNI.

Conclusion: IUGR neonates may have poor antioxidant defense systems, and postnatal nutrition restriction has the potential to prevent oxidative stress.