Dehnel J M, Hamblen D L
J Endocrinol. 1977 Mar;72(3):361-9. doi: 10.1677/joe.0.0720361.
Somatomedins are the intermediaries through which growth hormone acts on the epiphyseal growth plate to effect linear skeletal growth. Rat epiphyseal chondrocytes were isolated and cultured in vitro in the presence of somatomedin. Two sources of somatomedin were used, foetal calf serum and rat liver perfusates. The chondrocytes proliferated and synthesized sulphated glycosaminoglycans when grown in the presence of somatomedin from either source, but were not metabolically active in chemically defined medium alone. Some differences in the growth patterns in response to serum or liver somatomedins are reported and discussed. Chondrocyte metabolic activity in the presence of somatomedin in vitro showed a graded response to alterations in the atmospheric oxygen, being greatest at low oxygen pressure, and almost completely inhibited at 95% oxygen. A gradient of local oxygen tension has been reported to exist across the epiphyseal plate in vivo. The effects of somatomedin combined with changing oxygen levels may help to explain the divergence of cell proliferation and matrix synthesis seen in the various regions of the growth plate.
生长调节素是生长激素作用于骨骺生长板以实现骨骼线性生长的中介物质。分离大鼠骨骺软骨细胞，并在体外于生长调节素存在的情况下进行培养。使用了两种生长调节素来源，即胎牛血清和大鼠肝脏灌流液。当在来自任一来源的生长调节素存在下生长时，软骨细胞会增殖并合成硫酸化糖胺聚糖，但在单独的化学成分确定的培养基中无代谢活性。报告并讨论了对血清或肝脏生长调节素反应的生长模式中的一些差异。体外在生长调节素存在下软骨细胞的代谢活性对大气氧的变化呈现分级反应，在低氧压力下最大，在95%氧气时几乎完全被抑制。据报道，体内骨骺板存在局部氧张力梯度。生长调节素与变化的氧水平相结合的作用可能有助于解释生长板不同区域中细胞增殖和基质合成的差异。
