Millington W R, Wurtman R J
J Neurochem. 1982 Jun;38(6):1748-52. doi: 10.1111/j.1471-4159.1982.tb06658.x.
The phosphorylcholine concentration of rat brain rises and falls in response to parallel changes in the concentration of circulating choline. A single oral dose of choline chloride (20 mmol/kg) elevated whole-brain concentrations of both choline and phosphorylcholine 5 h after administration; a greater proportion of exogenously administered choline was retained by the brain in its phosphorylated form than as the free amine. Striatal phosphorylcholine concentrations were elevated within 2 h of choline administration and continued to be significantly greater than control values for up to 34 h after treatment. The response of striatal choline levels to exogenous choline was of shorter duration than that of phosphorylcholine and was correlated with a significant increase in striatal acetylcholine concentrations. The consumption of a choline-free diet for 7 days lowered both serum choline and striatal phosphorylcholine concentrations, but had no effect on striatal choline or acetylcholine. These results suggest that choline kinase is unsaturated by its substrate in vivo and may thus serve to modulate the response of brain choline concentrations to alterations in the supply of circulating choline.
大鼠脑中磷酸胆碱的浓度会随着循环胆碱浓度的平行变化而升高和降低。口服一剂氯化胆碱（20 mmol/kg）后5小时，全脑胆碱和磷酸胆碱的浓度均升高；与游离胺形式相比，脑以磷酸化形式保留的外源性胆碱比例更高。给药后2小时内纹状体磷酸胆碱浓度升高，治疗后长达34小时仍显著高于对照值。纹状体胆碱水平对外源性胆碱的反应持续时间比磷酸胆碱短，且与纹状体乙酰胆碱浓度的显著增加相关。食用7天无胆碱饮食会降低血清胆碱和纹状体磷酸胆碱浓度，但对纹状体胆碱或乙酰胆碱没有影响。这些结果表明，胆碱激酶在体内未被其底物饱和，因此可能有助于调节脑胆碱浓度对循环胆碱供应变化的反应。
