Foley T P, DePhilip R, Perricelli A, Miller A
J Pediatr. 1980 Mar;96(3 Pt 2):605-10. doi: 10.1016/s0022-3476(80)80874-2.
Somatomedin activity was determined by the simultaneous incorporation of 35S-sulfate and 3H-methyl thymidine into costal cartilage from hypophysectomized rats in cord sera from term and preterm infants and infants with intrauterine growth retardation. Mean Sm activity by sulfate incorporation was 0.49 +/- 0.04, 0.35 +/- 0.05, and 0.09 +/- 0.03 units/ml (+/- SE) in the term, preterm, and IGR cord sera, respectively. The levels for each group were significantly different from each of the other groups. There was no significant difference between the mean Sm activity by thymidine incorporation in cord sera from term (0.92 +/- 0.09 units/ml) and preterm (0.87 +/- 0.08 units/ml) infants. These levels were significantly higher, however, than the Sm activity by sulfate incorporation for the respective groups, P less than 0.001 for both groups. The mean Sm activity by thymidine incorporation in cord sera for IGR infants was 0.36 +/- 0.13 units/ml, and significantly lower than the levels in cord sera of term and preterm infants (P less than 0.01). Inhibition of Sm activity by mixing cord serum and pooled adult serum was found in one of the two cord specimens tested from IGR infants. The low levels of Sm activity in cord sera from IGR infants may reflect altered intrauterine nutrition. The discrepancy in the thymidine and sulfate incorporation by the costal cartilage bioassay for term and preterm cord sera might result from Sm-like factors in human fetal serum with greater mitogenic or thymidine transport activity compared to the activity for proteoglycan synthesis in cartilage.
通过将35S - 硫酸盐和3H - 甲基胸苷同时掺入来自垂体切除大鼠的肋软骨中，来测定足月、早产以及宫内生长迟缓婴儿脐带血清中的生长调节素活性。通过硫酸盐掺入法测得的足月、早产和宫内生长迟缓婴儿脐带血清中的平均生长调节素活性分别为0.49±0.04、0.35±0.05和0.09±0.03单位/毫升（±标准误）。每组的水平与其他组均有显著差异。足月（0.92±0.09单位/毫升）和早产（0.87±0.08单位/毫升）婴儿脐带血清中通过胸苷掺入法测得的平均生长调节素活性之间无显著差异。然而，这些水平显著高于相应组通过硫酸盐掺入法测得的生长调节素活性，两组的P值均小于0.001。宫内生长迟缓婴儿脐带血清中通过胸苷掺入法测得的平均生长调节素活性为0.36±0.13单位/毫升，显著低于足月和早产婴儿脐带血清中的水平（P小于0.01）。在检测的两份宫内生长迟缓婴儿脐带标本中的一份中，发现将脐带血清与混合的成人血清混合会抑制生长调节素活性。宫内生长迟缓婴儿脐带血清中生长调节素活性水平较低可能反映了宫内营养改变。对于足月和早产脐带血清，肋软骨生物测定法中胸苷和硫酸盐掺入的差异可能是由于人胎儿血清中存在与软骨中蛋白聚糖合成活性相比具有更强促有丝分裂或胸苷转运活性的生长调节素样因子。
