Lopot Magdalena, Ciechanowska Magdalena, Malewski Tadeusz, Mateusiak Krystyna, Misztal Tomasz, Przekop Franciszek
The Kielanowski Institute of Animal Physiology and Nutrition, Polish Academy of Sciences, 05-110 Jabłonna n. Warsaw, Poland.
Reprod Biol. 2008 Jul;8(2):149-61. doi: 10.1016/s1642-431x(12)60010-2.
In the present paper the role of GnRH in the ultrashort loop of the negative feedback action on GnRH secretion was evaluated on the molecular level by the Real-time PCR technique. Specifically, the effect of GnRH infused into the third cerebral ventricle on the expression of GnRH and GnRH receptor (GnRH-R) genes was analyzed in the hypothalamic-pituitary unit of anestrous ewes. GnRH did not significantly affect GnRH mRNA levels in the preoptic/anterior hypothalamic area but drastically increased its level in the ventromedial hypothalamus. In addition, GnRH infusion augmented GnRH-R mRNA level in the entire hypothalamus. In the GnRH-treated animals, anterior pituitary GnRH-R mRNA level and plasma LH concentration were also elevated. The changes in GnRH mRNA and GnRH-R mRNA levels in the hypothalamus in response to treatment with GnRH suggest that GnRH acts differently on the stability of these transcripts. On the basis of presented results it seems that GnRH may affect GnRH and GnRH-R biosynthesis and, consequently, GnRH/LH release.
在本研究中，通过实时PCR技术在分子水平评估了促性腺激素释放激素（GnRH）在对GnRH分泌的负反馈作用的超短反馈环路中的作用。具体而言，分析了向第三脑室注入GnRH对处于乏情期母羊下丘脑 - 垂体单元中GnRH和GnRH受体（GnRH-R）基因表达的影响。GnRH对视前区/下丘脑前部区域的GnRH mRNA水平没有显著影响，但显著提高了腹内侧下丘脑的GnRH mRNA水平。此外，注入GnRH增加了整个下丘脑的GnRH-R mRNA水平。在接受GnRH治疗的动物中，垂体前叶的GnRH-R mRNA水平和血浆促黄体生成素（LH）浓度也升高。下丘脑GnRH mRNA和GnRH-R mRNA水平对GnRH治疗的反应变化表明，GnRH对这些转录本的稳定性有不同的作用。根据所呈现的结果，似乎GnRH可能影响GnRH和GnRH-R的生物合成，从而影响GnRH/LH的释放。
