Abstract

Aims

A number of studies have shown that neuropeptide Y (NPY) is considered to be one of the key regulators of hypothalamic-pituitary-gonadal (HPG) axis in the mammals. In addition, kisspeptin (encode by Kiss1 gene), neurokinin B (encode by Tac3 gene) and dynorphin (encode by Pdyn gene) (commonly known as KNDy secreting neurons) are a powerful upstream regulators of GnRH neuron in hypothalamus.

Materials and Methods

The present study aims to investigate the effects of the intracerebroventricular (icv) injection of NPY and BIBP3226 (NPY receptor antagonist (NPYRA)) on the male sexual behavioral. Additionally, in order to see whether NPY signals can be relayed through the pathway of kisspeptin/neurokinin B/dynorphin, the gene expression of these peptides along with Gnrh1 gene in the hypothalamus were measured.

Results

The icv injection of NPY decreased the latencies and increase the frequencies of sexual parameters of the male rats in a significant way. In this line, NPYRA antagonized the stimulative effects of NPY. Moreover, data from real-time quantitative PCR indicated that injection of NPY significantly increased the gene expression of Gnrh1, Kiss1 and Tac3 and decrease the Pdyn while treatment with NPYRA controlled the modulative effects of NPY on these gene expression.

Conclusions

In conclusion based on the results of this study, NPY can exert its impacts on the sexual behavior of male rats via modulation of the KNDy secreting neurons as an interneural pathway to GnRH neurons.

中文翻译：

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神经肽Y的中枢注射调节雄性大鼠的性行为：与GnRH和kisspeptin/神经激肽B/强啡肽的相互作用

摘要

宗旨

许多研究表明，神经肽 Y (NPY) 被认为是哺乳动物下丘脑-垂体-性腺 (HPG) 轴的关键调节因子之一。此外，kisspeptin（由Kiss1基因编码）、神经激肽 B（由Tac3基因编码）和强啡肽（由Pdyn基因编码）（俗称 KNDy 分泌神经元）是下丘脑 GnRH 神经元的强大上游调节因子。

材料和方法

本研究旨在研究脑室内 (icv) 注射 NPY 和 BIBP3226（NPY 受体拮抗剂 (NPYRA)）对男性性行为的影响。此外，为了观察 NPY 信号是否可以通过Kisspeptin/neurokinin B/dynorphin 通路传递，测量了这些肽与Gnrh1基因在下丘脑中的基因表达。

结果

NPY的icv注射显着降低了雄性大鼠的潜伏期并增加了性参数的频率。在这方面，NPYRA 拮抗了 NPY 的刺激作用。此外，来自实时定量 PCR 的数据表明，注射 NPY 显着增加了Gnrh1、Kiss1 和 Tac3的基因表达并降低了Pdyn，而用 NPYRA 处理控制了 NPY 对这些基因表达的调节作用。

结论

总之，基于本研究的结果，NPY 可以通过调节 KNDy 分泌神经元作为 GnRH 神经元的神经通路对雄性大鼠的性行为产生影响。