Abstract—In the early 2000s, it was shown that dopamine is synthesized not only by dopaminergic neurons that possess the necessary set of enzymes, tyrosine hydroxylase and aromatic L-amino acid decarboxylase (AAD), but also by non-dopaminergic (monoenzymatic) neurons containing one of the enzymes. In this case, L-3,4-dihydroxyphenylalanine (L-DOPA), which is synthesized in neurons containing tyrosine hydroxylase, is transferred to neurons containing AAD, where dopamine is synthesized. The evidence for cooperative dopamine synthesis in our previous studies was a decrease in the total dopamine synthesis during incubation of a suspension of neurons of the tuberoinfundibular system (TIS) of fetuses or TIS slices from adult rats in the presence of a neutral amino acid that is a competitive inhibitor of the membrane L-DOPA carrier. In this work, the previously applied methodological approach was improved by using only sections of TIS and 2-amino-2-norbornanecarboxylic acid, a synthetic non-metabolizable L-DOPA membrane carrier inhibitor. This made it possible to confirm the presence of cooperative dopamine synthesis in TIS in fetuses and adult rats, and to obtain additional evidence of this synthesis in the form of an increase in the intercellular content of L-DOPA during inhibition of its membrane carrier. In addition, using an improved method we quantitatively characterized the synthesis of dopamine by nondopaminergic neurons and compared it in fetuses and adult rats. It was shown that the proportion of cooperative dopamine synthesis from the total dopamine synthesis by monoenzymatic and dopaminergic neurons in TIS in rat fetuses is 1.8 times higher than in adult animals. A six-fold increase in the synthesis of dopamine by rat TIS monoenzymatic neurons from the end of the prenatal period to adulthood are of particular interest from the standpoint of the functional role of dopamine produced by monoenzymatic neurons. Thus, in ontogeny, the proportion of dopamine synthesis by nondopaminergic monoenzymatic neurons in the general synthesis of dopamine is significantly reduced and the absolute value of cooperative dopamine synthesis increases by many times.

中文翻译：

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大鼠肺漏斗系统非多巴胺能神经元发育过程中的多巴胺合成。

摘要—在2000年代初期，研究表明，多巴胺不仅由具有必要的一组酶，酪氨酸羟化酶和芳香族L-氨基酸脱羧酶（AAD）的多巴胺能神经元合成，而且还由含有下列物质的非多巴胺能（单酶）神经元合成：一种酶。在这种情况下，在含有酪氨酸羟化酶的神经元中合成的L-3,4-二羟基苯丙氨酸（L-DOPA）被转移到含有AAD的神经元中，在此合成多巴胺。我们以前的研究中合作多巴胺合成的证据是，在存在中性氨基酸的情况下，成年大鼠的胎儿肾小管系统（TIS）或TIS切片的神经元悬浮液的孵育过程中，总多巴胺合成减少。膜L-DOPA载体的竞争性抑制剂。在这项工作中 通过仅使用TIS的部分和2-氨基-2-降冰片烷羧酸（一种合成的不可代谢的L-DOPA膜载体抑制剂）改进了以前应用的方法。这使得有可能在胎儿和成年大鼠的TIS中证实协同多巴胺合成的存在，并以抑制L-DOPA膜载体期间细胞间含量增加的形式获得这种合成的其他证据。此外，使用改进的方法，我们定量表征了非多巴胺能神经元合成多巴胺的能力，并在胎儿和成年大鼠中进行了比较。结果表明，在大鼠胎儿中，TIS中由单酶和多巴胺能神经元合成的多巴胺占总多巴胺合成比例的比例是成年动物的1.8倍。从单酶神经元产生的多巴胺的功能作用的观点来看，从产前期到成年期，大鼠TIS单酶神经元的多巴胺合成增加了六倍。因此，在个体发育中，非多巴胺能单酶神经元合成多巴胺的比例在多巴胺的一般合成中显着降低，并且协同多巴胺合成的绝对值增加了很多倍。