Possible Role of Oestrogen in Pubertal Increase of Kiss1/Kisspeptin Expression in Discrete Hypothalamic Areas of Female Rats
Possible Role of Oestrogen in Pubertal Increase of Kiss1/Kisspeptin Expression in Discrete Hypothalamic Areas of Female Rats
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DOI：
10.1111/j.1365-2826.2009.01868.x
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发表时间：
2009-06-01
影响因子：
3.2
通讯作者：
Maeda, K.-I.
中科院分区：
文献类型：
--
作者：
Takase, K.;Uenoyama, Y.;Maeda, K.-I.
Kisspeptin是由Kiss 1基因编码的一种肽，被认为是触发青春期开始的潜在候选因子，并且在啮齿动物模型中发现其在青春期前后在下丘脑中的表达增加。本研究旨在阐明雌激素调节青春期前后前腹侧室周核（AVPV）和下丘脑弓状核（ARC）中Kiss 1 mRNA表达的变化，并确定哪些kisspeptin神经元的表达与青春期前后促黄体生成激素（LH）脉冲的变化平行。定量逆转录-聚合酶链反应和免疫组化显示，在ARC Kiss 1 mRNA表达和kisspeptin免疫反应性的时间周围的阴道开口在完整的雌性大鼠明显增加。AVPV Kiss 1 mRNA水平在第26天也增加，但在第31天下降，然后在第36/41天增加。在卵巢切除（OVX）大鼠，ARC Kiss 1 mRNA的表达并没有表现出围青春期的变化，并保持在一个高水平的整个围青春期期间。在这些青春期前OVX大鼠中发现明显的LH脉冲。雌二醇替代抑制ARC Kiss 1 mRNA表达在OVX青春期前大鼠，但不是在成年。同样，LH脉冲在青春期前（第21天和第26天）被雌二醇抑制，但在成年期发现有规律的脉冲。目前的研究表明，青春期增加Kiss 1/kisspeptin表达的ARC和AVPV参与青春期的开始。这些结果也表明，LH脉冲和ARC Kiss 1的表达更负调控的雌激素在青春期前的雌性大鼠相比，成年大鼠。
Kisspeptin, a peptide encoded by the Kiss1 gene, has been considered as a potential candidate for a factor triggering the onset of puberty, and its expression in the hypothalamus was found to increase during peripubertal period in rodent models. The present study aimed to clarify the oestrogenic regulation of peripubertal changes in Kiss1 mRNA expression in the anteroventral periventricular nucleus (AVPV) and hypothalamic arcuate nucleus (ARC), and to determine which population of kisspeptin neurones shows a change in kisspeptin expression parallel to that in luteinising hormone (LH) pulses at the peripubertal period. Quantitative reverse transcriptase-polymerase chain reaction and immunohistochemistry revealed an apparent increase in the ARC Kiss1 mRNA expression and kisspeptin immunoreactivity around the time of vaginal opening in intact female rats. The AVPV Kiss1 mRNA levels also increased at day 26, but decreased at day 31, and then increased at day 36/41. In ovariectomised (OVX) rats, ARC Kiss1 mRNA expression did not show peripubertal changes and was kept at a high level throughout peripubertal periods. Apparent LH pulses were found in these prepubertal OVX rats. Oestradiol replacement suppressed ARC Kiss1 mRNA expression in OVX prepubertal rats, but not in adults. Similarly, LH pulses were suppressed by oestradiol in the prepubertal period (days 21 and 26), but regular pulses were found in adulthood. The present study suggests that a pubertal increase of Kiss1/kisspeptin expression both in the ARC and AVPV is involved in the onset of puberty. These results also suggest that both LH pulses and ARC Kiss1 expression are more negatively regulated by oestrogen in prepubertal female rats compared to adult rats.