Dietary Nucleotides Influence Lipoprotein Metabolism in Newborn Infants

Abstract

ABSTRACT. Nucleotide supplementation of adapted-milk formulas may be of interest for infant nutrition because nucleotides are involved in the synthesis of proteins and other macromolecules such as phospholipids, and thereby facilitate lipoprotein synthesis. To determine whether dietary nucleotides influence plasma lipoproteins in newborns, we have studied the plasma-lipoprotein concentrations and the composition of the major lipoprotein fractions during the first week of life in two groups of preterm infants fed formulas differing only in their nucleotide content. For comparison, two groups of term infants were studied under the same conditions. Lipoproteins were isolated by density ultracentrifugation, and the lipid and protein content were determined by standard methods; apolipoprotein A-I was determined immunologically. Nucleotide supplementation of formula in preterm infants increased all plasma lipoprotein concentrations. In addition, an increase in the plasma esterification rate was observed. However, total cholesterol concentrations were unchanged. The changes in lipoproteins concentrations were due mainly to an increase in apolipoprotein content. Nucleotides added to formulas affected term-infants' lipoproteins significantly less than to perterm infants. These findings suggest that dietary nucleotides may enhance the synthesis of lipoproteins during the early neonatal period, especially in preterm infants. 35: 112-116,1994) Abbreviations LCAT, lecithin/cholesterol-acyl transferase CMP, cytidine monophosphate UMP, uridine monophosphate IMP, inosine monophosphate PTI-NFF, preterm infants fed nucleotide-free formula PTI-NSF, preterm infants fed nucleotide-supplemented formula TI-NFF, term infants fed nucleotide-free formula TI-NSF, term infants fed nucleotide-supplemented formula Nucleotides are present in most food products as nucleic acids from which nucleotides are released after digestion (1). Nucleic acids as well as free nucleotides are found in human milk in significant amounts (2, 3), and the nutritional role of these components is currently under study. Dietary nucleotides seem to influence several aspects of neonatal development (4-9), but little is known about the influence of nucleotides in lipoprotein (Pcdiatr Rcs

Maturation status of small intestine epithelium in rats deprived of dietary nucleotides

“…Dietary nucleotides are known to play many biochemical and physiological roles, serving as precursors for nucleic acid synthesis, being involved in protein synthesis and influencing lipid and lipoprotein metabolism (24)(25)(26). Recently, we found that the levels of plasma apolipoprotein A-IV, which is of intestinal origin, was increased by dietary nucleotide supplementation in newborn infants (Pediatr.…”

Profile of Nucleotides and Nucleosides of Human Milk.

“…During the last decade, it has been indicated that dietary nucleotides may play some physiologically important role especially in infants (2)(3)(4)(5)(6)(7)(8)(9)(10)(11)(12)(13)(14)(15). In addition to nucleotides, it has been recently suggested that dietary nucleosides may also participate in the differentiation of intestinal cells (17).…”

“…It should be a great load for infants. Also some physiological roles of dietary nucleotides have been reported (2)(3)(4)(5)(6)(7)(8)(9)(10). So, it is quite reasonable to provide infant nucleotide and/or nucleoside from milk.…”

The Composition of Human Milk as a Model for the Design of Infant Formulas: Recent Findings and Possible Applications

“…Effects of dietary nucleotides on the gastrointestinal system and on hepatic growth and function have only been observed in animal studies (Uauy et al 1990;Bustamante et al 1994;Novak et al 1994). Nucleotide supplementation appeared significantly to increase all plasma lipoprotein concentrations in preterm, but not in term infants (Sanchez-Pozo et al 1994). A quite fascinating finding that warrants further study has been that dietary nucleotides increased indices of cell mediated immunity in infants without, however, influencing incidence and severity of infections (Carver et al 1991).…”