Oral uridine-5'-monophosphate (UMP) increases brain CDP-choline levels in gerbils

Brain Res. 2005 Oct 5;1058(1-2):101-8. doi: 10.1016/j.brainres.2005.07.054. Epub 2005 Aug 29.

Abstract

We examined the biochemical pathways whereby oral uridine-5'-monophosphate (UMP) increases membrane phosphatide synthesis in brains of gerbils. We previously showed that supplementing PC12 cells with uridine caused concentration-related increases in CDP-choline levels, and that this effect was mediated by elevations in intracellular uridine triphosphate (UTP) and cytidine triphosphate (CTP). In the present study, adult gerbils received UMP (1 mmol/kg), a constituent of human breast milk and infant formulas, by gavage, and plasma samples and brains were collected for assay between 5 min and 8 h thereafter. Thirty minutes after gavage, plasma uridine levels were increased from 6.6 +/- 0.58 to 32.7 +/- 1.85 microM (P < 0.001), and brain uridine from 22.6 +/- 2.9 to 89.1 +/- 8.82 pmol/mg tissue (P < 0.001). UMP also significantly increased plasma and brain cytidine levels; however, both basally and following UMP, these levels were much lower than those of uridine. Brain UTP, CTP, and CDP-choline were all elevated 15 min after UMP (from 254 +/- 31.9 to 417 +/- 50.2, [P < 0.05]; 56.8 +/- 1.8 to 71.7 +/- 1.8, [P < 0.001]; and 11.3 +/- 0.5 to 16.4 +/- 1, [P < 0.001] pmol/mg tissue, respectively), returning to basal levels after 20 and 30 min. The smallest UMP dose that significantly increased brain CDP-choline was 0.05 mmol/kg. These results show that oral UMP, a uridine source, enhances the synthesis of CDP-choline, the immediate precursor of PC, in gerbil brain.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Administration, Oral
  • Animals
  • Brain / drug effects*
  • Brain / metabolism
  • Cytidine Diphosphate Choline / biosynthesis*
  • Dose-Response Relationship, Drug
  • Gerbillinae
  • Male
  • Membrane Lipids / biosynthesis
  • Phosphatidylcholines / biosynthesis
  • Up-Regulation / drug effects*
  • Up-Regulation / physiology
  • Uridine / blood
  • Uridine Monophosphate / metabolism
  • Uridine Monophosphate / pharmacology*

Substances

  • Membrane Lipids
  • Phosphatidylcholines
  • Cytidine Diphosphate Choline
  • Uridine Monophosphate
  • Uridine