Objective To investigate whether thyroitoxicosis would induce changes of plasma ghrelin concentrations in mice and the influencing factors. Methods C57B1/6 mice were treated with thyroxin to induce thyroitoxicosis in experimental group,and then they were further divided into ad libtum, mild and server food restricted groups. Serum glucose,lipid,leptin,GH,IGF-1 and insulin were measured. Plasma ghrelin and Desacyl ghrelin were also detected by EDSA. Results Although the thyroid hormone was in the same level,plasma ghrelin levels showed opposite changes between ad libtum and food restricted thyroitoxicosis mice. Comparing with the control group, Desacyl ghrelin was significantly lower in ad libtum thyroitoxicosis mice,and acylated ghrelin was significantly higher in food restricted thyroitoxicosis mice (P < 0.05). Plasma ghrelin showed a positive correlation with blood glucose and a negative correlation with final body weight,serum insulin,leptin and HOMA-IR index (P < 0.05). Multiple regression analysis showed that glucose and leptin were the predictors for acylated ghrelin levels in thyroid dysfunction. Conclusion These results suggested that thyroid hormone might not be the primary factor regulating ghrelin secretion. The combination of altered metabolic parameters related to glucose metabolic and insulin resistance might be responsible for the alteration of ghrelin concentrations in the situation of thyroid dysfunction.%目的 探讨甲状腺毒症小鼠循环中Ghrelin水平变化及其影响因素.方法 实验组C57BL6小鼠给予左旋甲状腺激素,每日皮下注射,连续2周诱发小鼠甲状腺毒症,对照组仅注射生理盐水.检测小鼠给药前后体质量、摄食量并采血和留尿.测定空腹血糖、血脂、胰岛素、瘦素水平和甲状腺功能等.实验组小鼠进一步分为自由摄食组、轻度限制摄食组及重度限制摄食组.ELISA方法测定血浆辛酰化和去辛酰化Ghrelin水平.结果 与对照组比较,自由摄食组甲状腺毒症小鼠的非辛酰化Ghrelin 水平明显降低,而摄食控制的甲状腺毒症小鼠的辛酰化Ghrelin水平明显升高(P＜0.05).实验组血浆辛酰化、非辛酰化Ghrelin 水平与血糖水平呈正相关(r值分别为0.417,0.32,P＜0.01),而与个体的终体质量、血清胰岛素、瘦素水平及HOMA-IR指数呈负相关(辛酰化Ghrelin:r值分别为-0.419,-0.511,-0.501,-0.363,P＜0.05；非辛酰化Ghrelin:r值分别为-0.5,-0.609,-0.687,-0.448,P＜0.01).回归分析显示,血糖及瘦素可预测辛酰化Ghrelin水平.结论 甲状腺激素本身可能不是调节Ghrelin分泌的主要因素.甲状腺毒症时Ghrelin水平的变化可能与机体的糖代谢及胰岛素抵抗指数的变化有关.
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