植物雌激素对雄性山羊幼崽血浆睾酮和三碘甲状腺原氨酸（T3）水平的影响。

Effects of dietary phytoestrogens on plasma testosterone and triiodothyronine (T3) levels in male goat kids.

机构信息

Department of Molecular Biology, Umeå University, S-901 87 Umeå, Sweden.

出版信息

Acta Vet Scand. 2009 Dec 10;51(1):51. doi: 10.1186/1751-0147-51-51.

DOI:10.1186/1751-0147-51-51

PMID:20003293

原文链接:https://pmc.ncbi.nlm.nih.gov/articles/PMC2803173/

Abstract

BACKGROUND

Exposure to xenoestrogens in humans and animals has gained increasing attention due to the effects of these compounds on reproduction. The present study was undertaken to investigate the influence of low-dose dietary phytoestrogen exposure, i.e. a mixture of genistein, daidzein, biochanin A and formononetin, on the establishment of testosterone production during puberty in male goat kids.

METHODS

Goat kids at the age of 3 months received either a standard diet or a diet supplemented with phytoestrogens (3-4 mg/kg/day) for approximately 3 months. Plasma testosterone and total and free triiodothyronine (T3) concentrations were determined weekly. Testicular levels of testosterone and cAMP were measured at the end of the experiment. Repeated measurement analysis of variance using the MIXED procedure on the generated averages, according to the Statistical Analysis System program package (Release 6.12, 1996, SAS Institute Inc., Cary, NC, USA) was carried out.

RESULTS

No significant difference in plasma testosterone concentration between the groups was detected during the first 7 weeks. However, at the age of 5 months (i.e. October 1, week 8) phytoestrogen-treated animals showed significantly higher testosterone concentrations than control animals (37.5 nmol/l vs 19.1 nmol/l). This elevation was preceded by a rise in plasma total T3 that occurred on September 17 (week 6). A slightly higher concentration of free T3 was detected in the phytoestrogen group at the same time point, but it was not until October 8 and 15 (week 9 and 10) that a significant difference was found between the groups. At the termination of the experiment, testicular cAMP levels were significantly lower in goats fed a phytoestrogen-supplemented diet. Phytoestrogen-fed animals also had lower plasma and testicular testosterone concentrations, but these differences were not statistically significant.

CONCLUSION

Our findings suggest that phytoestrogens can stimulate testosterone synthesis during puberty in male goats by increasing the secretion of T3; a hormone known to stimulate Leydig cell steroidogenesis. It is possible that feedback signalling underlies the tendency towards decreased steroid production at the end of the experiment.

摘要

背景

由于这些化合物对生殖的影响，人类和动物接触外源性雌激素的情况受到了越来越多的关注。本研究旨在探讨低剂量植物雌激素（即混合的染料木黄酮、大豆黄酮、大豆素和芒柄花素）暴露对雄性山羊青春期睾酮产生的影响。

方法

3 月龄山羊接受标准饮食或添加植物雌激素（3-4mg/kg/天）的饮食，时间约 3 个月。每周测定血浆睾酮和总三碘甲状腺原氨酸（T3）及游离三碘甲状腺原氨酸浓度。实验结束时测定睾丸睾酮和 cAMP 水平。采用统计分析系统程序包（SAS Institute Inc.，Cary，NC，USA，Release 6.12，1996）的 MIXED 程序对生成的平均值进行重复测量方差分析。

结果

前 7 周两组间血浆睾酮浓度无显著差异。然而，在 5 月龄（即 10 月 1 日，第 8 周）时，植物雌激素处理组的睾酮浓度明显高于对照组（37.5nmol/L 比 19.1nmol/L）。这种升高之前是血浆总 T3 的升高，发生在 9 月 17 日（第 6 周）。在同一时间点，植物雌激素组的游离 T3 浓度略高，但直到 10 月 8 日和 15 日（第 9 周和第 10 周）才发现两组间有显著差异。实验结束时，添加植物雌激素组的山羊睾丸 cAMP 水平显著降低。植物雌激素处理组的山羊血浆和睾丸睾酮浓度也较低，但无统计学意义。