Growth responses in a mutant dwarf rat to human growth hormone and recombinant human insulin-like growth factor I.
Growth responses in a mutant dwarf rat to human growth hormone and recombinant human insulin-like growth factor I.
复制标题
突变侏儒大鼠对人生长激素和重组人胰岛素样生长因子 I 的生长反应。
作者：
A. Skottner;R. Clark;L. Fryklund;I. Robinson
一种新的突变 GH 缺陷型侏儒大鼠已被用于研究静脉输注人 GH (hGH) 和重组人胰岛素样生长因子 I (hIGF-I) 的效果。这种动物的垂体 GH 含量仅为正常的 5% 左右，循环 GH 水平较低，并且没有规律的 GH 激增。该缺陷似乎是 GH 特有的。以 180 微克/天的剂量输注 hIGF-I，持续 9 天，血清 IGF-I 浓度显着高于输注盐水的对照组（713 +/- 20 ng/ml vs. 395 +/- 31 ng/ml）； hGH 输注不会显着提高 IGF-I 水平 (435 +/- 20 ng/ml)。血清样品的凝胶过滤显示，高剂量hIGF-I输注增加了游离IGF浓度，但没有明显改变IGF-I结合模式，而hGH输注增加了高mol wt IGF-I结合蛋白的量。 IGF-I 和 hGH 输注均不会影响侏儒大鼠垂体中存在的少量大鼠 GH。与注射盐水的侏儒大鼠（1.2+/-0.3g/天和43+/-3微米/天）相比，连续静脉注射hGH（200mU/天，持续9天）显着刺激体重增加（2.1+/-0.2g/天）和骨骼生长（96+/-9微米/天）。 180微克/天的hIGF-I输注产生的体重增加（2.1+/-0.5克/天）与hGH输注组相似，但对骨生长的刺激明显较小（63+/-3微米/天）。输注低 5 倍剂量的 hIGF-I（36 微克/天，持续 9 天）对体重或骨骼生长没有影响。食物摄入量不受 hGH 或 hIGF-I 输注的影响。 hGH 和 IGF-I 输注对组织生长模式的影响不同，但总体体重增加相同。 hGH 诱导大多数研究器官相对成比例的生长，而 hIGF-I 180 微克/天的输注则刺激肾脏、肾上腺和脾脏的不成比例的更大生长。在一些动物中，提取组织用于 IGF-I 的 RIA；对照组、hGH 或 IGF-I 输注动物的肝脏中 IGF-I 含量相似，而 IGF-I 输注动物的肾脏和肾上腺比 hGH 治疗大鼠的组织含有更多的免疫反应性 IGF-I。因此，hGH和hIGF-I都可以促进突变侏儒大鼠的生长，但它们的作用模式在数量和质量上都不同。
A new mutant GH-deficient dwarf rat has been used to study the effects of iv infusions of human GH (hGH) and recombinant human insulin-like growth factor I (hIGF-I). This animal has only about 5% of normal pituitary GH content, low circulating GH levels, and no regular GH surges. The defect seems to be specific for GH. Infusions of hIGF-I at 180 micrograms/day for 9 days elevated serum IGF-I concentrations significantly over those in the saline-infused controls (713 +/- 20 ng/ml vs. 395 +/- 31 ng/ml); hGH infusions did not raise IGF-I levels significantly (435 +/- 20 ng/ml). Gel filtration of serum samples showed that the high-dose hIGF-I infusions increased free IGF concentrations, without apparently altering the pattern of IGF-I binding whereas hGH infusions increased the amount of high mol wt IGF-I binding protein. Neither IGF-I nor hGH infusions affected the small amounts of rat GH present in the dwarf rat pituitary glands. Continuous iv infusions of hGH (200 mU/day for 9 days) stimulated body wt gain (2.1 +/- 0.2 g/day) and bone growth (96 +/- 9 microns/day) significantly compared to saline-infused dwarf rats (1.2 +/- 0.3 g/day and 43 +/- 3 microns/day). Infusions of hIGF-I at 180 micrograms/day produced a body wt gain (2.1 +/- 0.5 g/day) similar to that seen in the hGH-infused group but a significantly smaller stimulation of bone growth (63 +/- 3 microns/day). Infusion of a 5-fold lower dose of hIGF-I (36 micrograms/day for 9 days) had no effect on body wt or bone growth. Food intake was unaffected by either hGH or hIGF-I infusions. The pattern of tissue growth was affected differentially by hGH and IGF-I infusions that produced the same overall body wt gain. hGH induced a relatively proportional growth in most of the organs studied, whereas hIGF-I infusion at 180 micrograms/day stimulated a disproportionately greater growth of the kidney, adrenals, and spleen. In some of the animals, tissues were extracted for RIA of IGF-I; the amounts of IGF-I in the liver were similar in control, hGH, or IGF-I-infused animals, whereas kidney and adrenals from IGF-I infused animals contained larger amounts of immunoreactive IGF-I than did those tissues from hGH-treated rats. Thus, both hGH and hIGF-I can promote growth in the mutant dwarf rat, but they differ both quantitatively and qualitatively in their pattern of actions.
生长激素刺激大鼠生长时血清和组织生长调节素水平的不一致。
影响因子：
4.8
作者：
Orlowski,CC;Chernausek,SD
通讯作者：
Chernausek,SD
DOI：
10.1073/pnas.81.3.935
发表时间：
1984-01-01
期刊：
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA-BIOLOGICAL SCIENCES
影响因子：
--
作者：
DERCOLE, AJ;STILES, AD;UNDERWOOD, LE
通讯作者：
UNDERWOOD, LE