title: The effect of heavy metals on nicotinamideN-methyltransferase activityin vitro relating to Parkinson's disease.
abstract: OBJECTIVE
  The aims of this study were to determine the effects of heavy metals such as manganese on nicotinamideN-methyltransferase (EC 2.1.1.1) (NNMT) activity and to consider the possibility of involvement of NNMT activation in the pathogenesis of heavy metal induced Parkinson's disease.
  
  
  METHODS
  NNMT activity in supernatants separated from brain, liver and kidney homogenates of 5 elderly male Wistar rats by centrifugation were measured by high performance liquid chromatography system with fluorescence. NNMT activity under the conditon of 0.5 or 5.0 mM Mn(2+), Fe(2+), Cu(2+) or Cd(2+) was compared with control (no metal ion existence).
  
  
  RESULTS
  NNMT activities in rat brain, liver and kidneys were significantly decreased by Cu(2+), and those in the liver and kidneys were significantly decreased by Cd(2+). Mn(2+) reduced NNMT activity only in the liver. Fe(2+) had no effect on NNMT activity.
  
  
  CONCLUSIONS
  No metal increased NNMT activity in this study, contrary to our hypothesis. Further study is needed to clarify the reason why the effects of Mn(2+) and Fe(2+) which have a high relevance to Parkinson's disease on NNMT activity differ from those of Cu(2+) and Cd(2+).
authors: Department of Hygiene & Preventive Medicine, Fukushima Medical University School of Medicine, 1 Hikarigaoka, 960-1295, Fukushima, Japan.
authors: Akiko
authors: A
authors: Sugawara
authors: Hiroko
authors: H
authors: Yokoyama
authors: Mitsuhiro
authors: M
authors: Ohta
authors: Takafumi
authors: T
authors: Maeda
authors: Kazuko
authors: K
authors: Tanaka
authors: Tetsuhito
authors: T
authors: Fukushima