SOMATOMEDINS
SOMATOMEDINS
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生长素
DOI：
10.5694/j.1326-5377.1975.tb82055.x
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发表时间：
1975
影响因子：
11.4
通讯作者：
L. Lazarus
中科院分区：
文献类型：
--
作者：
M. Stuart;L. Lazarus
长期以来，一个完整的能够分泌生长激素的脑垂体一直被认为是实现人类骨骼生长潜力的首要条件。最近的研究表明，生长激素的促生长作用是一种体内现象，不能通过在体外骨骼组织中添加激素来模仿。负责骨骼生长的体液制剂现已被确定为生长激素，这是肝脏在垂体生长激素刺激下产生的一种肽。在生物测定系统中，通过监测软骨对标记硫酸盐的摄取刺激来测量血清中生长激素的水平。生长激素缺乏和身材矮小的儿童血清中检测到低水平的生长激素活性；肢端肥大症患者的水平高，而肝硬化或慢性肾功能衰竭患者的水平低。营养不良儿童的生长激素水平也很低，尽管血清中生长激素水平升高；这表明存在一种抑制剂，可以降低促生长素分子的促生长活性。这些儿童的充足营养可使血清生长激素水平恢复正常。分离和纯化生长激素的尝试已经导致鉴定了一组对骨骼组织具有相似作用的物质。胰岛素也被证明具有这些促进生长的活性，但在器官特异性上有所不同。神经生长因子、表皮生长因子和胰岛素原是构成一大群促生长肽的分子，它们可能都与生长激素有关。
An intact pituitary gland capable of secreting growth hormone has long been considered the prime requirement for the achievement of skeletal growth potential in man. Recent studies have revealed that the growth‐promoting action of growth hormone is an in‐vivo phenomenon which cannot be mimicked by the addition of the hormone to skeletal tissue in vitro. The humoral agent responsible for skeletal growth has now been identified as somatomedin, a peptide produced in the liver under the stimulus of pituitary growth hormone. Serum levels of somatomedin are measured in a bioassay system by monitoring the stimulation of uptake of labelled sulphate by cartilage. Low levels of somatomedin activity are detected in the serum of children with growth hormone deficiency and short stature; the levels are high in acromegalics and low in patients with cirrhosis of the liver or chronic renal failure. Undernourished children also have low levels despite raised serum levels of growth hormone; this suggests the presence of an Inhibitor which lowers the growth‐promoting activity of the somatomedin molecule. Adequate nutrition in these children results in the restoration of serum somatomedin levels to normal. Attempts to isolate and purify somatomedin have led to the identification of a group of substances sharing similar actions on skeletal tissue. Insulin has also been demonstrated to share some of these growth‐promoting activities but varies In its organ specificity. Nerve growth factor, epidermal growth factor and proinsulin are other molecules which form a large group of growth promoting peptides which may all be related to the somatomedins.