The effect of hypothyroidism on growth, serum growth hormone, the growth hormone-dependent somatomedin, insulin-like growth factor, and its carrier protein in rats.
The effect of hypothyroidism on growth, serum growth hormone, the growth hormone-dependent somatomedin, insulin-like growth factor, and its carrier protein in rats.
复制标题
甲状腺功能减退症对大鼠生长、血清生长激素、生长激素依赖性生长调节素、胰岛素样生长因子及其载体蛋白的影响。
作者：
P. Burstein;B. Draznin;C. J. Johnson;D. Schalch
为了研究甲状腺功能减退症相关的生长迟缓的可能机制，测定了甲状腺功能减退症大鼠及其年龄匹配对照组的血清T4、GH、GH依赖性生长调节素、胰岛素样生长因子（IGF）及其载体蛋白（CP）。三组大鼠进行了研究：婴儿，未成熟的，和成年。通过向实验动物提供含有0.05%丙基硫氧嘧啶的饮用水，使其产生明显的甲状腺功能减退症（血清T4，低于1微克/分升）。婴儿和未成熟的甲状腺功能减退症大鼠体重明显低于正常对照组，血清GH，IGF和CP水平显着降低。正常成年大鼠，丙基硫氧嘧啶治疗60天，体重也大大低于对照组动物，并表现出显着下降，血清GH，IGF，CP在此期间。牛生长激素甲状腺功能减退症成年大鼠7天的管理没有恢复IGF或CP水平正常，表明他们在血清中的减少，部分，甲状腺功能减退症本身的直接结果。这些结果表明，血清GH，IGF和CP水平至少部分地在甲状腺激素控制下。此外，这些研究表明，与甲状腺功能减退症相关的生长迟缓可能是通过生长调节素活性介导的。
To study the possible mechanisms involved in growth retardation associated with hypothyroidism, serum T4, GH, the GH-dependent somatomedin, insulin-like growth factor (IGF), and its carrier protein (CP) were measured in hypothyroid rats and their age-matched controls. Three groups of rats were studied: infant, immature, and adult. Marked hypothyroidism (serum T4, less than 1 microgram/dl) was produced in experimental animals by providing them with drinking water containing 0.05% propylthiouracil. Infant and immature hypothyroid rats weighed markedly less than normal controls and had significantly reduced serum levels of GH, IGF, and CP. Normal adult rats, treated with propylthiouracil for 60 days, also weighed considerably less than control animals and exhibited a significant drop in serum GH, IGF, and CP during this period. The administration of bovine GH to hypothyroid adult rats for 7 days did not restore either IGF or CP levels to normal, indicating that their decrease in serum was, in part, a direct result of hypothyroidism per se. These results indicate that serum levels of GH, IGF, and CP are at least partly under thyroid hormone control. Furthermore, these studies suggest that the growth retardation associated with hypothyroidism may be mediated through somatomedin activity.