Fig. 6.

Phenylalanine and tyrosine kinetics were monitored during total parenteral nutrition (TPN) in piglets of advancing gestational age. The flux rate of phenylalanine (A) and tyrosine (B) was greatest in full-term piglets (*P < 0.05). Phenylalanine hydroxylation to tyrosine was not affected by gestational age (C). Nonhydroxylative disposal, a measure of protein synthesis (D), was associated with gestational age (*P < 0.05). Data analyzed by one-way ANOVA and Tukey’s post hoc test. NS, not significant.