Plataras C, Tsakiris S, Angelogianni P
Department of Experimental Physiology, University of Athens, Medical School, Athens, Greece.
Clin Biochem. 2000 Jul;33(5):351-7. doi: 10.1016/s0009-9120(00)00084-9.
The aim of this work was to investigate the effect of different cytidine-5'-diphosphocholine (CDP-choline) concentrations (0.1-1 mM) on acetylcholinesterase (AChE), (Na(+),K(+))-ATPase and Mg(2+)-ATPase activities in homogenates of adult rat whole brain and in pure (nonmembrane bound) enzymes.
Tissues were homogenized, centrifuged at 1000 xg for 10 min, and in the supernatant AChE activity and Na(+),K(+)-ATPase, Mg(2+)-ATPase activities were determined according to Ellman's method and Bowler's and Tirri's, respectively.
After a 1-3 h CDP-choline preincubation, this substance induced a maximal stimulation of 20%-25% (p < 0.001) for AChE and 50-55% (p < 0.001) for Na(+), K(+)-ATPase, but it did not influence Mg(2+)-ATPase activity. One mM acetylcholine (ACh) resulted in an approximately 18% (p < 0.001) AChE inhibition by excess substrate in the brain homogenate, while 0. 01 mM noradrenaline did not influence Na(+),K(+)-ATPase activity.
CDP-choline can stimulate brain AChE and Na(+), K(+)-ATPase independently of ACh and noradrenaline. This enzymatic stimulation may be due to the transformation of CDP-choline to membrane phophatidylcholine. The above data could explain in part the clinical effects of this substance in some neuronal disturbances.
