Hess Monna F, Roser Janet F
Department of Animal Science, University of California, Davis, CA 95616, USA.
Anim Reprod Sci. 2005 Oct;89(1-4):7-19. doi: 10.1016/j.anireprosci.2005.06.014.
There are several hormones and local testicular factors involved in the initiation and control of steroidogenesis and spermatogenesis during puberty. GH and its mediator, IGF-I, increase substantially during puberty, and in addition to LH, these growth-promoting hormones can have direct effects upon testicular function. The objective of this work was to investigate the effects of eLH, eGH and hrIGF-I upon Leydig cells derived from testes of colts and stallions representing different stages of development. Testes were obtained from 48 light horse colts and stallions at the time of routine castration, horses were categorized according to age group (prepubertal, pubertal and postpubertal) and a Leydig cell enriched preparation was utilized for cell culture. Cells derived from all 48 horses were treated with doses of eLH, and a subset of 21 horses received doses of eGH and hrIGF-I. Cells were plated at a concentration of 1 x 10(6) cells/ml and incubated for 24 h at 32 degrees C. Production of testosterone and estradiol was measured by validated RIA. Leydig cells from prepubertal colts secreted greater basal amounts of testosterone but lesser basal amounts of estradiol compared with the other age groups (p < 0.001). Pubertal stallions exhibited the greatest relative response to eLH (p < 0.05). Neither eGH nor hrIGF-I elicited a steroidogenic response over baseline concentrations in any of the three age groups.
在青春期，有几种激素和睾丸局部因子参与类固醇生成和精子发生的启动与调控。生长激素（GH）及其介质胰岛素样生长因子-I（IGF-I）在青春期显著增加，除了促黄体生成素（LH）外，这些促进生长的激素可对睾丸功能产生直接影响。本研究的目的是调查重组人促黄体生成素（eLH）、重组人生长激素（eGH）和重组人胰岛素样生长因子-I（hrIGF-I）对来自不同发育阶段马驹和成年种马睾丸的睾丸间质细胞的影响。在常规去势时从48匹轻型马驹和成年种马获取睾丸，根据年龄组（青春期前、青春期和青春期后）对马进行分类，并使用富含睾丸间质细胞的制剂进行细胞培养。用不同剂量的eLH处理来自所有48匹马的细胞，21匹马的细胞亚群接受不同剂量的eGH和hrIGF-I处理。细胞以1×10⁶个细胞/毫升的浓度接种，在32℃孵育24小时。通过经过验证的放射免疫分析法（RIA）测定睾酮和雌二醇的生成量。与其他年龄组相比，青春期前马驹的睾丸间质细胞分泌的基础睾酮量更多，但基础雌二醇量更少（p<0.001）。青春期成年种马对eLH的相对反应最大（p<0.05）。在三个年龄组中的任何一组，eGH和hrIGF-I均未引起超过基线浓度的类固醇生成反应。
