Effect of CDP-choline on brain acetylcholinesterase and Na+,K+-ATPase in adult rats

Objective: 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 Mg2+-ATPase activities in homogenates of adult rat whole brain and in pure (nonmembrane bound) enzymes. Design and Methods: Tissues were homogenized, centrifuged at 1000 ×g for 10 min, and in the supernatant AChE activity and Na+,K+-ATPase, Mg2+-ATPase activities were determined according to Ellman’s method and Bowler’s and Tirri’s, respectively. Results: 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 Mg2+-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. Conclusions: 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.