Hashimoto Y, Furukawa S, Omae F, Miyama Y, Hayashi K
Institute of Biological Science, Mitsui Pharmaceuticals Inc., Chiba, Japan.
J Neurochem. 1994 Jul;63(1):326-32. doi: 10.1046/j.1471-4159.1994.63010326.x.
Effects of thyroxine (T4) on nerve growth factor (NGF) level and choline acetyltransferase (ChAT) activity of rat brains were investigated. Repetitive intraperitoneal administration of T4 caused increases in both NGF level and ChAT activity in the frontal cortex, septum, hippocampus, and striatum and decreases in the cerebellum in 2-day-old rats. Only ChAT activity was elevated in the olfactory bulb, and the NGF level remained unchanged there. No changes were observed in the midbrain and pons/medulla. Furthermore, T4 was effective on the postnatal rats only up to day 11. These results suggest that T4 plays a role in the developmental regulation of NGF level and ChAT activity in rat brain in a region- and/or stage-specific manner. That (1) changes in NGF level and ChAT activity occurred in regions nearly identical to those that contained NGF-responding neurons, and (2) the change in NGF level in the hippocampus and frontal cortex was followed by the change of ChAT activity after a single injection of T4 suggest that the effects of T4 on cholinergic differentiation are, at least in part, mediated via NGF, which itself is quantitatively regulated by T4.
研究了甲状腺素（T4）对大鼠脑内神经生长因子（NGF）水平和胆碱乙酰转移酶（ChAT）活性的影响。对2日龄大鼠反复腹腔注射T4，导致额叶皮质、隔区、海马和纹状体内的NGF水平和ChAT活性均升高，而小脑中的NGF水平和ChAT活性降低。嗅球中仅ChAT活性升高，而NGF水平保持不变。中脑和脑桥/延髓未观察到变化。此外，T4仅在出生后11天内对大鼠有效。这些结果表明，T4以区域和/或阶段特异性方式在大鼠脑内NGF水平和ChAT活性的发育调节中发挥作用。（1）NGF水平和ChAT活性的变化发生在与含有NGF反应性神经元的区域几乎相同的区域，以及（2）单次注射T4后，海马和额叶皮质中NGF水平的变化随后是ChAT活性的变化，这表明T4对胆碱能分化的影响至少部分是通过NGF介导的，而NGF本身受T4的定量调节。
