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+).
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+).
Entities:
Keywords:
Parkinson’s disease; heavy metal; nicotinamideN-methyltransferase; sulfhydryl group
Authors: Y Mizuno; S Ohta; M Tanaka; S Takamiya; K Suzuki; T Sato; H Oya; T Ozawa; Y Kagawa Journal: Biochem Biophys Res Commun Date: 1989-09-29 Impact factor: 3.575
Authors: A H Schapira; V M Mann; J M Cooper; D Dexter; S E Daniel; P Jenner; J B Clark; C D Marsden Journal: J Neurochem Date: 1990-12 Impact factor: 5.372