South Bohemian Research Center of Aquaculture and Biodiversity of Hydrocenoses, Research Institute of Fish Culture and Hydrobiology, Faculty of Fisheries and Protection of Waters, University of South Bohemia, 389 25, Vodnany, Czech Republic.
Institute of Aquaculture, Hellenic Center for Marine Research, Thalassocosmos, P.O. Box 2214, 71003, Heraklion, Crete, Greece.
Fish Physiol Biochem. 2012 Dec;38(6):1655-1666. doi: 10.1007/s10695-012-9662-9. Epub 2012 Jun 5.
Spermiation and changes in androgen (testosterone, T and 11-ketotestosterone, 11-KT) levels were studied in sterlet (Acipenser ruthenus) treated with GnRH agonist implants (DAla(6)-Pro(9)-LHRHa) at 25 and 75 μg kg(-1) b.w. and compared with those males treated with 4 mg kg(-1) b.w. of carp pituitary extract (CPE) and 3 pellets of Ovopel kg(-1) b.w., which contains DAla(6)-Pro(9)NEt-mGnRH and metoclopramide. Sperm quality (sperm mass, spermatozoa concentration and sperm motility and velocity) was evaluated 24, 48 and 72 h after hormonal treatments. Males did not release sperm in the control group injected with physiological solution, while sperm could not be collected 7 days after treatments in all hormonally treated groups. Spermiation rates were 100 % in the CPE and Ovopel groups and 25-50 % in the GnRHa-treated groups. Sperm production was significantly lower in the GnRHa-treated groups than in the CPE and Ovopel groups and decreased 72 h after hormonal treatment. Sperm motility and velocity were higher in the Ovopel and GnRHa (75 μg) groups compared to the CPE and GnRHa (25 μg) groups and decreased 72 h after hormonal treatment. Androgens were only affected in spermiating males and changed in the Ovopel and GnRHa (75 μg) after hormonal treatment. Significant correlations were observed between sperm production, sperm motility and sperm velocity, but not androgens. The present study suggests involvement of dopamine in sturgeon spawning. Additionally, better sperm quality observed in the Ovopel group and particularly sperm motility in the GnRHa (75 μg) suggests enhancement of sperm quality in sturgeon treated with GnRHa. Therefore, further study is needed to induce fully spermiation using GnRHa implants in combination with a dopamine inhibitor.
在 25 和 75μg/kg 体重的 GnRH 激动剂植入物（DAla(6)-Pro(9)-LHRHa）处理的欧洲鳇（Acipenser ruthenus）中研究了精子发生和雄激素（睾酮，T 和 11-酮睾酮，11-KT）水平的变化，并与用 4mg/kg 体重的鲤鱼脑垂体提取物（CPE）和 3 个 Ovopel/kg 体重的雄性进行了比较，其中含有 DAla(6)-Pro(9)NEt-mGnRH 和甲氧氯普胺。在激素处理后 24、48 和 72 小时评估精子质量（精子质量、精子浓度和精子活力和速度）。在注射生理盐水的对照组中，雄性未释放精子，而在所有激素处理组中，处理后 7 天均无法收集精子。在 CPE 和 Ovopel 组中，精子发生率为 100%，在 GnRHa 处理组中为 25-50%。GnRHa 处理组的精子产量明显低于 CPE 和 Ovopel 组，且在激素处理后 72 小时下降。与 CPE 和 GnRHa（25μg）组相比，Ovopel 和 GnRHa（75μg）组的精子活力和速度更高，且在激素处理后 72 小时下降。只有在精子发生的雄性中雄激素受到影响，并且在激素处理后 Ovopel 和 GnRHa（75μg）中发生变化。观察到精子产量、精子活力和精子速度之间存在显著相关性，但与雄激素无关。本研究表明多巴胺参与了鲟鱼的产卵。此外，在 Ovopel 组中观察到的精子质量更好，特别是在 GnRHa（75μg）中观察到的精子活力增强，表明用 GnRHa 处理鲟鱼可提高精子质量。因此，需要进一步研究使用 GnRH 植入物与多巴胺抑制剂结合以完全诱导精子发生。
