Zhou Shi-Sheng, Zhou Yi-Ming, Li Da, Ma Qiang
Institute of Basic Medical Sciences, Medical College, Dalian University, Dalian 116622, China.
Autism Res Treat. 2013;2013:963697. doi: 10.1155/2013/963697. Epub 2013 Mar 4.
Autism, a neurodevelopmental disorder that affects boys more than girls, is often associated with altered levels of monoamines (serotonin and catecholamines), especially elevated serotonin levels. The monoamines act as both neurotransmitters and signaling molecules in the gastrointestinal and immune systems. The evidence related to monoamine metabolism may be summarized as follows: (i) monoamine neurotransmitters are enzymatically degraded/inactivated by three mechanisms: oxidative deamination, methylation, and sulfation. The latter two are limited by the supply of methyl groups and sulfate, respectively. (ii) A decrease in methylation- and sulfation-mediated monoamine inactivation can be compensated by an increase in the oxidative deamination catalyzed by monoamine oxidase, an X-linked enzyme exhibiting higher activity in females than in males. (iii) Vitamins can, on one hand, facilitate the synthesis of monoamine neurotransmitters and, on the other hand, inhibit their inactivation by competing for methylation and sulfation. Therefore, we postulate that excess multivitamin feeding in early infancy, which has become very popular over the past few decades, may be a potential risk factor for disturbed monoamine metabolism. In this paper, we will focus on the relationship between excess multivitamin exposure and the inactivation/degradation of monoamine neurotransmitters and its possible role in the development of autism.
自闭症是一种神经发育障碍，男孩比女孩更易受其影响，常与单胺（血清素和儿茶酚胺）水平改变有关，尤其是血清素水平升高。单胺在胃肠道和免疫系统中既是神经递质又是信号分子。与单胺代谢相关的证据可总结如下：（i）单胺神经递质通过三种机制被酶促降解/失活：氧化脱氨、甲基化和硫酸化。后两种机制分别受甲基和硫酸盐供应的限制。（ii）甲基化和硫酸化介导的单胺失活减少可通过单胺氧化酶催化的氧化脱氨增加来补偿，单胺氧化酶是一种X连锁酶，在女性中比在男性中具有更高的活性。（iii）维生素一方面可促进单胺神经递质的合成，另一方面可通过竞争甲基化和硫酸化来抑制其失活。因此，我们推测在婴儿早期过量喂养多种维生素（在过去几十年中这种情况变得非常普遍）可能是单胺代谢紊乱的一个潜在风险因素。在本文中，我们将重点关注过量接触多种维生素与单胺神经递质失活/降解之间的关系及其在自闭症发展中的可能作用。
