Mocchegiani E, Paolucci P, Balsamo A, Cacciari E, Fabris N
Department of Gerontologic Research, Italian National Research Centers on Ageing, Ancona, Italy.
Horm Res. 1990;33(6):248-55. doi: 10.1159/000181528.
The thymus produces humoral factors that induce the proliferation and differentiation of T cells which are responsible for cell-mediated immunity. Experimental data have suggested that this thymic hormone production is modulated by the neuroendocrine network and, in particular, by growth hormone (GH) and thyroid hormones. To study the role played by GH in thymic endocrine activity in humans, the circulating level of one of the best known thymic peptides, i.e. thymulin (Zn-FTS), has been determined, after a washout period of 2 weeks without GH treatment, in GH-deficient children before and after a single injection of GH. The basal thymulin level is consistently lower in GH-deficient children than in healthy age-matched controls. A single injection of GH induces a significant increment of the thymulin level for at least 48 h. Since thymulin activity may also depend on zinc bioavailability, on thyroid hormone turnover and on the eventual presence of thymulin-inhibitory substances, all these aspects have been checked. No supporting evidence regarding the existence of these kinds of interferences in GH-deficient children has been substantiated. A positive correlation has been found between the serum level of insulin-like growth factor I, but not of GH, and thymulin activity. These data suggest that GH may directly or indirectly modulate the thymic endocrine function in humans. Whether and to what extent such a modulation is relevant to the functioning of the immune system remains to be ascertained.
胸腺产生体液因子，可诱导负责细胞介导免疫的T细胞增殖和分化。实验数据表明，这种胸腺激素的产生受神经内分泌网络调节，特别是受生长激素（GH）和甲状腺激素调节。为了研究GH在人类胸腺内分泌活动中的作用，在对生长激素缺乏的儿童进行单次注射GH之前和之后，经过2周无GH治疗的洗脱期后，测定了最知名的胸腺肽之一即胸腺素（Zn-FTS）的循环水平。生长激素缺乏儿童的基础胸腺素水平始终低于年龄匹配的健康对照组。单次注射GH可使胸腺素水平至少在48小时内显著升高。由于胸腺素活性也可能取决于锌的生物利用度、甲状腺激素的周转以及胸腺素抑制物质的最终存在情况，因此对所有这些方面都进行了检查。在生长激素缺乏儿童中，没有证实存在这类干扰的支持性证据。已发现胰岛素样生长因子I（而非GH）的血清水平与胸腺素活性之间存在正相关。这些数据表明，GH可能直接或间接调节人类的胸腺内分泌功能。这种调节是否以及在何种程度上与免疫系统的功能相关，仍有待确定。
