Role and Function of Nucleotides in Infant Nutrition

• Nucleic acid precursors: nucleotides make up the monomeric units of DNA and RNA. • Energy-transfer molecules: adenosine triphosphate (ATP) is the major source of cellular chemical energy. • Physiologic mediators: cyclic adenosine monophosphate (cAMP) acts as second messenger; cyclic guanosine monophosphate (cGMP) regulates many cellular events; adenosine is known to be a potent vasodilator; guanosine triphosphate (GTP) is involved in signal transduction, etc. • Activated intermediates: for example, uridine diphosphoglucose (UDP glucose) is an intermediate in glycogen and glycoprotein synthesis, and other nucleotides are intermediates in the synthesis of phospholipids and serve as methyl sulfate donors. • Structural components of coenzymes: such as nicotinamide adenine dinucleotide (NAD), flavin adenine dinucleotide (FAD), and coenzyme A (CoA), involved in many metabolic pathways. • Allosteric effectors: controlling the regulatory steps of major metabolic pathways. • Cellular agonists: extracellular nucleotides trigger intracellular signal-transduction cascades including the cAMP and inositol-calcium pathways.