Kawaguchi T, Murai S, Saito H
Department of Biochemistry, School of Dentistry, Iwate Medical University, Morioka, Japan.
Comp Biochem Physiol C Toxicol Pharmacol. 2000 Dec;127(3):281-90. doi: 10.1016/s0742-8413(00)00158-4.
Whether free choline levels are changeable in vivo in response to different types of autonomic agonists was examined in several mouse organs. Upon one subcutaneous injection of isoproterenol, phenylephrine and pilocarpine, choline levels in whole organ decreased, increased and decreased, respectively, in various organs within 30 min and returned to initial levels in a day. In the three major salivary glands, a delayed choline elevation also appeared on day 2 after one isoproterenol injection and subsided by day 6. Only in the three salivary glands more choline was accumulated after 10 once-a-day injections of isoproterenol than after one isoproterenol injection. Neither phenylephrine nor pilocarpine induced comparable choline accumulation in any organs examined. Isoproterenol injection repeated at a 2-day interval augmented the subsequent, delayed choline elevation. Examination with dobutamine and the adenylyl cyclase activator 6-(3-dimethylaminopropionyl)forskolin suggested that isoproterenol-induced immediate choline lowering was down-stream of cAMP synthesis and linked to cAMP more tightly than the choline accumulation, though both choline changes occurred via beta1-adrenergic receptors. Choline levels in the salivary glands also changed depending on the form of diet given and particularly in the parotid gland in parallel with gland weights. These results provide the first evidence for the autonomic control of intracellular choline levels; intracellular choline levels might be an integral part of the autonomic signalling pathway.
在多个小鼠器官中研究了体内游离胆碱水平是否会因不同类型的自主激动剂而发生变化。皮下注射异丙肾上腺素、去氧肾上腺素和毛果芸香碱后，30分钟内各器官的全器官胆碱水平分别下降、升高和下降，并在一天内恢复到初始水平。在三大唾液腺中，单次注射异丙肾上腺素后第2天也出现胆碱延迟升高，并在第6天消退。仅在三大唾液腺中，每天注射10次异丙肾上腺素后积累的胆碱比单次注射异丙肾上腺素后更多。去氧肾上腺素和毛果芸香碱在任何检测的器官中均未诱导出类似的胆碱积累。以2天为间隔重复注射异丙肾上腺素会增强随后的胆碱延迟升高。用多巴酚丁胺和腺苷酸环化酶激活剂6-(3-二甲基氨基丙酰)毛喉素进行检测表明，异丙肾上腺素诱导的胆碱立即降低是在cAMP合成的下游，并且与胆碱积累相比与cAMP的联系更紧密，尽管两种胆碱变化均通过β1-肾上腺素能受体发生。唾液腺中的胆碱水平也会根据所给饮食的形式而变化，特别是在腮腺中，胆碱水平与腺体重量平行变化。这些结果为自主神经对细胞内胆碱水平的控制提供了首个证据；细胞内胆碱水平可能是自主神经信号通路的一个组成部分。
