Stimulation of CDP-choline synthesis by uridine or cytidine in PC12 rat pheochromocytoma cells


Richardson U., Watkins C., Pierre C., Ulus I., Wurtman R.

BRAIN RESEARCH, vol.971, no.2, pp.161-167, 2003 (Journal Indexed in SCI) identifier identifier identifier

  • Publication Type: Article / Article
  • Volume: 971 Issue: 2
  • Publication Date: 2003
  • Doi Number: 10.1016/s0006-8993(03)02333-3
  • Title of Journal : BRAIN RESEARCH
  • Page Numbers: pp.161-167

Abstract

Oral administration of CDP-choline to rats raises plasma and brain cytidine levels and increases brain levels of phosphatidylcholine (PC). In contrast, in humans oral CDP-choline increases plasma levels of uridine. To determine whether uridine can also enhance PC synthesis, we developed an assay for CDP-choline, an immediate and rate-limiting precursor in PC synthesis, and measured this intermediate in clonal PC12 rat pheochromocytoma cells incubated with various concentrations of uridine or cytidine. Addition of uridine (50-100 muM) to the incubation medium caused significant elevations in UTP, CT, USAP and CDP-choline levels in PC12 cells. Uridine had no effect on the synthesis of diacylglycerol (DAG) or the activity of the phosphotransferase which catalyzes the synthesis of PC from DAG and CDP-choline. Hence uridine treatment was unlikely to inhibit the conversion of endogenous CDP-choline to PC. These results suggest the possibility that uridine may also enhance PC synthesis in intact brain. (C) 2003 Elsevier Science B.V. All rights reserved.