目的：下丘脑-垂体-甲状腺轴可能影响瘦素的分泌和代谢。该研究探讨甲状腺功能减低和甲状腺功能亢进时甲状腺激素对血清瘦素水平和脂肪瘦素mRNA水平的影响。方法：应用他巴唑和优甲乐人工造成大鼠甲状腺功能减低和甲状腺功能亢进状态，分别于用药10天、停药10天检测用药组、停药组和正常对照大鼠血清瘦素、T3、T4、TSH浓度、体重和脂肪瘦素的mRNA水平。结果：甲减用药组、甲亢用药组和正常对照组大鼠血清瘦素与体重均有相关性(P<0.05)，相关系数分别0.84、0.83、0.94。去除体重因素，甲亢用药组、停药组血清瘦素和脂肪瘦素mRNA水平和正常对照组相比无明显差别(P>0.05)，而甲减用药组血清瘦素(0.68±0.07 ng/ml)和脂肪瘦素mRNA水平(0.39±0.02)显著低于停药组(1.98±0.09 ng/ml)(0.87±0.05)和正常对照组(2.14±0.46 ng/ml)(0.95±0.03)(P<0.05)。结论：甲状腺素可能对血清瘦素的稳定分泌起一定的作用。［中国当代儿科杂志，2004, 6(5): 369-372］

OBJECTIVE: The hypothalamus-hypophysis-thyroid axis may influence the secretion and metabolism of leptin. The aim of the study was to assess the effect of hypothyroidism and hyperthyroidism on serum leptin levels and adipocyte leptin mRNA expression. METHODS: Hypo-and hyperthyroidism were induced in rats by administering methimazole and L-thyroxine respectively. The serum levels of leptin, T3, T4 and TSH, body weight and adipocyte leptin mRNA expression were measured 10 days after methimazole or L-thyroxine administration and withdrawal respectively. Ten normal rats treated with normal saline served as the Control group. RESULTS: Serum leptin levels in rats with hypo- and hyperthyroidism and the Control group were correlated with body weight 10 days after administration (r= 0.84, 0.83, and 0.94 respectively; P< 0.05). After the effect of body weight had been factored out, serum leptin levels and adipocyte leptin mRNA expression in the rats with hyperthyroid 10 days after either administration or withdrawal were not different from the Control group. Ten days after administration, hypothyroid rats showed significantly decreased leptin levels and adipocyte leptin mRNA expression in comparison with those of 10 days after withdrawal ( 0.68± 0.07 ng/nl vs 1.98± 0.09 ng/ml and 0.39± 0.02 vs 0.87± 0.05, respectively; P< 0.05) and in comparison with the Control group ( 2.14± 0.46 ng/ml and 0.95± 0.03; P< 0.05). CONCLUSIONS: Thyroid hormone may play a role in maintaining a steady secretion of leptin.