Enhancement of brain choline levels by nicotinamide: mechanism of action

Neurosci Lett. 1998 Jun 19;249(2-3):111-4. doi: 10.1016/s0304-3940(98)00418-2.

Abstract

Following the subcutaneous (s.c.) administration of nicotinamide (10 mmol/kg), the brain and CSF levels of nicotinamide were increased to millimolar concentrations, but the concentrations of N-methylnicotinamide (NMN) in the CSF, and of NMN and NAD+ in brain tissue were not significantly altered. Concomitantly, nicotinamide caused increases of the choline levels in the venous brain blood. In hippocampal slices, nicotinamide (1-10 mM) induced choline release in a calcium- and mepacrine-sensitive manner and, in [3H]choline-labelled slices, increased the levels of [3H]lyso-phosphatidylcholine and [3H]glycerophosphocholine. We conclude that nicotinamide enhances brain choline concentrations by mobilising choline from choline-containing phospholipids, presumably via activation of phospholipase A2, while the formation of NMN does not contribute to this effect.

MeSH terms

  • Animals
  • Brain / drug effects
  • Brain / metabolism*
  • Choline / cerebrospinal fluid
  • Choline / metabolism*
  • Hippocampus / metabolism
  • In Vitro Techniques
  • Injections, Subcutaneous
  • Liver / metabolism
  • Male
  • NAD / metabolism
  • Niacinamide / analogs & derivatives
  • Niacinamide / cerebrospinal fluid
  • Niacinamide / metabolism
  • Niacinamide / pharmacology*
  • Rats
  • Rats, Wistar
  • Time Factors

Substances

  • NAD
  • Niacinamide
  • Choline
  • N-methylnicotinamide