短暂性新生儿甲状腺功能减退对大鼠不同中枢听觉区域游离天冬氨酸、谷氨酸和γ-氨基丁酸含量的影响。

Effect of transient neonatal hypothyroidism on the free aspartic acid, glutamic acid, and GABA content of different central auditory regions in the rat.

作者信息

Hébert R, Poulin R, Barden N, Dussault J H

出版信息

Can J Physiol Pharmacol. 1987 Mar;65(3):424-7. doi: 10.1139/y87-071.

Abstract

The aspartic acid, glutamic acid, and gamma-aminobutyric acid (GABA) contents were determined in four central auditory system regions in rats with transient neonatal hypothyroidism compared with control ones: the ventral and dorsal parts of the cochlear nucleus, the central nucleus of the inferior colliculus, the auditory cortex, and in an extra-auditory structure, the substantia nigra pars reticulata. The animals were sacrificed at 50 days of age, brain tissue samples were taken out by microdissection, and the free amino acids were extracted. The amino acid content was assessed by double-isotope labelling following two-dimensional thin-layer chromatography separation. GABA content was significantly decreased in both cochlear nucleus regions and glutamic acid was elevated in the inferior colliculus. Neonatal hypothyroidism had no significant effect on the aspartic acid levels in the regions studied. The results suggest an effect of neonatal hypothyroidism on regional contents of free amino acids known as candidate neurotransmitters in the auditory system.

摘要

与对照组相比，测定了短暂性新生儿甲状腺功能减退大鼠四个中枢听觉系统区域中的天冬氨酸、谷氨酸和γ-氨基丁酸（GABA）含量：耳蜗核的腹侧和背侧部分、下丘中央核、听觉皮层，以及一个听觉外结构——黑质网状部。在动物50日龄时将其处死，通过显微切割取出脑组织样本，并提取游离氨基酸。在二维薄层色谱分离后，通过双同位素标记评估氨基酸含量。两个耳蜗核区域的GABA含量均显著降低，而下丘中的谷氨酸含量升高。新生儿甲状腺功能减退对所研究区域的天冬氨酸水平没有显著影响。结果表明，新生儿甲状腺功能减退对听觉系统中作为候选神经递质的游离氨基酸区域含量有影响。