The hydrolysis of glycerophosphocholine by rat brain microsomes: activation and inhibition.

Experiments with glycerophosphocholine phosphodiesterase (GPC diesterase, EC 3.1.4.2.) in rat brain microsomes suggest that, although its activity is inhibited by low concentrations of calmidazolium, its dependence on Ca2+ ions is not modulated by calmodulin. The activity of glycerophosphocholine choline phosphodiesterase (choline phosphohydrolase, EC 3.1.4.38) was much lower than that of the GPC diesterase. A relatively inexpensive method for the preparation of sn-glycero-3-phospho [Me-14C]choline is described.