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: Akiko Sugawara, Hiroko Yokoyama, Mitsuhiro Ohta, Takafumi Maeda, Kazuko Tanaka, Tetsuhito Fukushima
• Journal: Environmental health and preventive medicine (Environ Health Prev Med) Vol. 10 Issue 4 Pg. 180-3 (Jul 2005) ISSN: 1342-078X [Print] Japan
• PMID: 21432137 (Publication Type: Journal Article)