Harris D A, Van Vliet G, Egli C A, Grumbach M M, Kaplan S L, Styne D M, Vainsel M
J Clin Endocrinol Metab. 1985 Jul;61(1):152-9. doi: 10.1210/jcem-61-1-152.
To explore further the relationship of gonadal sex steroids to the rise in somatomedin-C (Sm-C) during puberty, we studied a group of children with true precocious puberty before and after treatment which suppressed sex steroid output. Plasma estradiol and testosterone and serum acid-ethanol-extractable Sm-C were determined by specific RIAs in 7 boys and 12 girls with true precocious puberty before and at regular intervals during treatment with a potent LHRH-agonist (LHRH-A), D-Trp6-Pro9-NEt-LHRH. For comparison, Sm-C and sex steroid concentrations were determined in 266 normal adolescents and 37 normal prepubertal children, 1-9 yr of age. The mean +/- SEM Sm-C levels in normal male individuals peaked at 15 yr (2.46 +/- 0.23 U/ml) and at pubertal (genital) stage III (2.29 +/- 0.19 U/ml), and those in normal females reached their highest concentration at 12-15 yr of age and at pubertal (breast) stage III (2.47 +/- 0.15 U/ml). Sm-C concentrations correlated better with pubertal (genital or breast) stage than with chronological age for both sexes and better with testosterone levels in males than with estradiol levels in females. The mean +/- SEM Sm-C concentrations in both males and females with true precocious puberty were 2.07 +/- 0.16 U/ml before therapy and decreased significantly to 1.52 +/- 0.13 U/ml after 6 months of therapy. The mean Sm-C level of the patients remained significantly elevated for chronological age, but decreased into the normal range for bone age after 6-12 months of therapy. Sm-C correlated significantly with testosterone and estradiol levels, but not with growth rate. Mean nighttime GH secretion decreased significantly after 6 months of LHRH-A therapy. In summary, children with true precocious puberty have Sm-C elevations typical of normal puberty. The decrease in Sm-C levels after suppression of gonadal sex steroid output with LHRH-A is evidence that sex steroids are necessary to induce this elevation in Sm-C concentration. The decrease in GH secretion during LHRH-A therapy suggests that the effect of sex steroids on Sm-C levels during normal puberty is mediated, at least in part, through stimulation of GH secretion.
为了进一步探究性腺甾体激素与青春期生长介素C（Sm-C）升高之间的关系，我们对一组真性性早熟儿童在抑制性甾体激素分泌的治疗前后进行了研究。采用特异性放射免疫分析法（RIAs）测定了7名患真性性早熟男孩和12名患真性性早熟女孩在使用强效促性腺激素释放激素激动剂（LHRH-A）D-色氨酸6-脯氨酸9-乙基-LHRH治疗前及治疗期间定期的血浆雌二醇、睾酮以及血清酸乙醇可提取的Sm-C水平。作为对照，测定了266名正常青少年以及37名1至9岁正常青春期前儿童的Sm-C和性甾体激素浓度。正常男性个体的Sm-C平均水平±标准误在15岁时达到峰值（2.46±0.23U/ml），在青春期（生殖器）Ⅲ期时为（2.29±0.19U/ml）；正常女性个体的Sm-C平均水平在12至15岁以及青春期（乳房）Ⅲ期时达到最高浓度（2.47±0.15U/ml）。对于男女两性而言，Sm-C浓度与青春期（生殖器或乳房）分期的相关性优于与实际年龄的相关性，并且在男性中与睾酮水平的相关性优于在女性中与雌二醇水平的相关性。患真性性早熟的男性和女性在治疗前的Sm-C平均水平±标准误为2.07±0.16U/ml，在治疗6个月后显著降至1.52±0.13U/ml。患者的Sm-C平均水平相对于实际年龄仍显著升高，但在治疗6至12个月后降至骨龄对应的正常范围内。Sm-C与睾酮和雌二醇水平显著相关，但与生长速率无关。在LHRH-A治疗6个月后，夜间生长激素（GH）平均分泌量显著下降。总之，患真性性早熟的儿童具有正常青春期典型的Sm-C升高。用LHRH-A抑制性腺甾体激素分泌后Sm-C水平下降，这证明性甾体激素是诱导Sm-C浓度升高所必需的。LHRH-A治疗期间GH分泌下降表明，在正常青春期，性甾体激素对Sm-C水平的影响至少部分是通过刺激GH分泌介导的。
