A nucleoside mixture and its sparing effect on de novo purine nucleotide synthesis.

Abstract

Total parenteral nutrition (TPN) is a well-accepted method of managing patients to protect body composition and stimulate recover from lean body mass. While amino acids, carbohydrates and fats are essential to nutrition, nucleic acid precursors such as bases, nucleosides and nucleotides are considered less important because they are endogenously synthesized to meet the bodily requirements. However, these precursors may be necessary when the de novo synthesis of nucleotides is inadequate. This inadequate situation may occur during periods of severe surgical stress, infection, or long-term TPN treatment.1 The use of nucleic acid components in TPN was investigated in rats by Ogoshi et al., using OG-VI comprising inosine, 5’-sodium guanylate, cytidine, uridine and thymidine.2, 3 Several effects of OG-VI, including a protein sparing effect in hepatectomized rats4, have been reported as a result of the provision of nucleotide precursors.4–7 Yet, it is not fully clear whether the OG-VI ends up sufficiently being utilized to spare the de novo synthesis of nucleotides in response to bodily need. The aim of this study was to investigate whether parenteral administration of OG-VI spares the de novo purine nucleotide synthesis which is closely associated with protein metabolism. Two experimental rat models were used which were stimulated for the de novo synthesis by continuous infusion of glucagon (glucagon model)8 or by 70% hepatectomy (hepatectomized model).9 KeywordsTotal Parenteral NutritionPurine NucleotidePurine SynthesisNucleic Acid ComponentTotal Parenteral Nutrition SolutionThese keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.