Impact of neonatal total parenteral nutrition and early glucose-enriched diet
on glucose metabolism and physical phenotypes in Guinea Pig
Neonatal exposure to oxidant molecules from total parenteral nutrition (TPN) alters future lipid and glucose metabolism, resulting in an energy deficient phenotype characterized by lower body weight and physical activity. Using a guinea-pig model, the hypothesis that early diet supplementation with glucose could overcome such symptoms at week 9 of age was tested in a two-factor full-factorial ANOVA design (p<0:05): TPN day 3-7, chow thereafter (TPN+) vs: chow from day 3 (TPN-), combined with glucose-enriched diet from week 3 (G+) vs: plain chow throughout (G-). The growth rate, physical activity, phosphofructose kinase-1 and glucose kinase (GK) activities, glucose-6-phosphate (G6P), glycogen and pyruvate concentrations, relative liver weight, fasting blood glucose, glucose tolerance, hepatic and plasma triacylglyceride and cholesterol levels, individual glutathione levels and GSH/GSSG-based redox potential were determined at 9 weeks. Glucose supplementation (vs: the lack thereof) resulted in a lower growth rate, higher GK activity, and higher G6P concentration at week 9. Plasma triacylglycerides at week 9 were lower in TPN+ (vs: TPN-) subjects. Hepatic GSH=GSSG-derived redox potential shifted to a more reduced state in G+ (vs: G-) subjects. No other parameters showed significant differences. Independently of TPN, an early glucose-rich diet stimulated the glycolysis pathway, shifted the redox potential towards a more reduced status ; however, it did not overcome the effects of TPN on future physical and metabolic phenotype.
Neonates total parenteral nutrition glucose metabolism redox potential metabolic programming guinea pig long-term impact