S Tsakiris1, P Angelogianni, K H Schulpis, J C Stavridis. 1. Department of Experimental Physiology, University of Athens, Medical School, P.O. Box 65257, GR-154 01, Athens, Greece. stsakir@cc.uoa.gr
Abstract
OBJECTIVE: To investigate whether the preincubation of brain homogenates with L-phenylalanine (Phe) could reverse the free radical effects on brain acetylcholinesterase (AChE) activity, since it has been reported that Phe binds hydroxyl radicals ((*)OH). DESIGN AND METHODS: Two well established systems were used for production of free radicals: (a) FeSO(4) (84 microM) plus ascorbic acid (400 microM), and (b) FeSO(4), ascorbic acid and H(2)O(2) (1 mM) at 37 degrees C in homogenates of adult rat whole brain. Changes in brain AChE activity were studied in the presence of each system separately. RESULTS: AChE was inhibited (18-28%) by both systems of free radicals. This inhibition was reversed when the brain homogenate was preincubated with Phe 1.8 mM. CONCLUSIONS: In accordance with our previous reports, Phe could protect against the direct action of (*)OH radicals on brain AChE and in this way it might be useful in the prevention of certain cholinergic neural dysfunctions.
OBJECTIVE: To investigate whether the preincubation of brain homogenates with L-phenylalanine (Phe) could reverse the free radical effects on brain acetylcholinesterase (AChE) activity, since it has been reported that Phe binds hydroxyl radicals ((*)OH). DESIGN AND METHODS: Two well established systems were used for production of free radicals: (a) FeSO(4) (84 microM) plus ascorbic acid (400 microM), and (b) FeSO(4), ascorbic acid and H(2)O(2) (1 mM) at 37 degrees C in homogenates of adult rat whole brain. Changes in brain AChE activity were studied in the presence of each system separately. RESULTS:AChE was inhibited (18-28%) by both systems of free radicals. This inhibition was reversed when the brain homogenate was preincubated with Phe 1.8 mM. CONCLUSIONS: In accordance with our previous reports, Phe could protect against the direct action of (*)OH radicals on brain AChE and in this way it might be useful in the prevention of certain cholinergic neural dysfunctions.
Authors: Francieli M Stefanello; Alexandra I Zugno; Clovis M D Wannmacher; Moacir Wajner; Angela T S Wyse Journal: Metab Brain Dis Date: 2003-09 Impact factor: 3.584
Authors: Angela T S Wyse; Francieli M Stefanello; Fábria Chiarani; Débora Delwing; Clóvis M D Wannmacher; Moacir Wajner Journal: Neurochem Res Date: 2004-02 Impact factor: 3.996