Andersson K, Eneroth P
Acta Physiol Scand. 1985 Jan;123(1):105-19. doi: 10.1111/j.1748-1716.1985.tb07567.x.
The effects of thyroidectomy (4 weeks) on dopamine (DA) and noradrenaline (NA) turnover rates were determined by means of regression analysis. The disappearance of catecholamine (CA) fluorescence (using quantitative histofluorimetry) after tyrosine hydroxylase inhibition (alpha-methyl-DL-p-tyrosine methyl ester) has been investigated in discrete hypothalamic and forebrain DA and NA nerve terminal systems of the male rat. A time-dependent monophasic CA fluorescence disappearance was observed in all CA nerve terminal systems of the sham-operated and thyroidectomized rats. In the thyroidectomized rat, DA turnover in the anterior nucleus accumbens and in the medial and lateral palisade zones of the median eminence (ME) was reduced while DA turnover in the posterior nucleus accumbens was increased as compared to control rats. Furthermore, NA turnover was increased in the paraventricular hypothalamic nucleus (PA) and reduced in the dorsomedial hypothalamic nucleus (DM) and in the 'border zone' (lateral hypothalamus). Radioimmunoassay of hormones in serum demonstrated marked increases in TSH levels and reduced concentrations of GH, prolactin, corticosterone, triiodothyronine and thyroxine. The reduced DA turnover in the external layer of the ME and the increased NA turnover in the PA may indicate an inhibitory dopaminergic mechanism in the ME and a facilitatory noradrenergic mechanism in the PA in the regulation of TSH secretion. These mechanisms seem to interact with thyroid hormones. The reduced NA turnover demonstrated in the DM and in the border zone may be related to the lowering of growth hormone levels and pulsatility caused by thyroidectomy. Finally, the DA nerve terminal systems in the anterior and posterior parts of the nucleus accumbens are differently regulated by changes in the brain-pituitary-thyroid axis.
通过回归分析确定甲状腺切除术（4周）对多巴胺（DA）和去甲肾上腺素（NA）周转率的影响。在雄性大鼠离散的下丘脑和前脑DA和NA神经末梢系统中，研究了酪氨酸羟化酶抑制（α-甲基-DL-对酪氨酸甲酯）后儿茶酚胺（CA）荧光的消失情况（使用定量组织荧光测定法）。在假手术组和甲状腺切除组大鼠的所有CA神经末梢系统中均观察到随时间变化的单相CA荧光消失。与对照大鼠相比，甲状腺切除组大鼠伏隔核前部以及正中隆起（ME）内侧和外侧栅栏区的DA周转率降低，而伏隔核后部的DA周转率增加。此外，下丘脑室旁核（PA）中的NA周转率增加，而下丘脑背内侧核（DM）和“边界区”（下丘脑外侧）中的NA周转率降低。血清中激素的放射免疫分析表明促甲状腺激素水平显著升高，而生长激素、催乳素、皮质酮、三碘甲状腺原氨酸和甲状腺素的浓度降低。ME外层DA周转率降低和PA中NA周转率增加可能表明ME中存在抑制性多巴胺能机制，而PA中存在促进性去甲肾上腺素能机制参与促甲状腺激素分泌的调节。这些机制似乎与甲状腺激素相互作用。DM和边界区中NA周转率降低可能与甲状腺切除引起的生长激素水平降低和脉冲性有关。最后，伏隔核前后部的DA神经末梢系统受脑-垂体-甲状腺轴变化的调节方式不同。
