Uptake and Utilization of Amino Acids by Splanchnic Bed

Splanchnic uptake and metabolism contributes significantly to the differences in flux seen between the intravenous and intragastric ingestion of certain indispensable amino acids. This is the third in a series of studies designed to increase the investigators knowledge of the metabolism of two indispensable amino acids, threonine and lysine, by the splanchnic bed. In the initial two studies the investigators established the neonatal parenteral requirement of threonine and lysine. In the current study, the investigators will be examining the differences in uptake and metabolism of threonine and lysine across the splanchnic bed.