【摘要】 本文目的在于探讨甲状腺低功大鼠下丘脑神经递质的变化及其对血清 TSH 水平的影响。结果表明:低甲大鼠下丘脑神经递质的代谢比较活跃,NE 及5-HIAA 较对照组增高;下丘脑 NE、5-HIAA、5-HIAA/5-HT 与血清 TSH 呈线性正相关,NE 与 T₄,5-HIAA 与 T₃、T₄均呈线性负相关。由此推测,NE 及5-HT 系统能够促进 TSH 的分泌和释放。甲状腺激素对腺垂体 TSH的负反馈调节作用可能由两方面的参与,其一是甲状腺激素对腺垂体 TSH 的直接负反馈调节作用,其二是甲状腺激素可能通过神经递质的改变发挥其对 TSH 的负反馈调节作用。更多还原

【Abstract】 The purpose of this study was to determine the specific roles of hypothalamicDA,NE and 5-HT in controlling the release of TSH and to observe the effect ofthyroid hormone on neurotransmitters in hypothyroid and euthyroid status in therat.The experimental rats were treated with NaClO₄（1%）in their drinking waterand control rats were maintained on normal。After 60 day treatmet,the animalswere killed and trunk blood was collected.The brains were immediately removedand the media basal hypothalamus was dissected,weighed and homogenized.Serum T₃,T₄ and TSH were measured by RIA。Hypothalamic concentration ofNE,DA,5-HT and 5-HIAA was measured by fluospectorometry。In hypothyroid rats an increase in TSH secretion was associated with significantincreases in hypothalamic NE and 5-HIAA concentration。Concentration of DAand 5-HT was not different from controls。There was a positive correlation betw-een serum TSH and the concentration of NE,5-HIAA and ratio 5-HIAA to 5-HT（r=0.55,0.67,0.62 P<0.05）。The hypothesis that NE and the high 5-HTactivity were driving TSH release in hypothyroid rats。A negative correlation be-tween T₄ and the concentration of NE,5-HIAA in hypothalamus（r=-0.5,-0.57 P<0.05）could be seen。There was no specific relationship between hypo-thalamic DA and TSH secretion in this experiment。The experimental results indicated that NE and 5-HIAA in hypothalamus weresignificantly increased in hypothyroidism rats and the secretion of TSH wasstimulated by NE and 5-HT neuronal activity。A negative feedback effect ofhypothyroid hormone on TSH was probably processing with hypothalamicneurotransmitters.更多还原