Kutlu Esra, Ozgen Lker Tolga, Bulut Huri, Kocyigit Abdurrahim, Ustunova Savas, Hüseyinbas Onder, Torun Emel, Cesur Yasar
Health Sciences University Istanbul Umraniye Training and Research Hospital, Department of Pediatrics, Division of Pediatric Endocrinology, Umraniye, Istanbul, Turkey.
Bezmialem Vakif University, Faculty of Medicine, Department of Pediatrics, Division of Pediatric Endocrinology, Fatih, Istanbul, Turkey.
Peptides. 2023 May;163:170976. doi: 10.1016/j.peptides.2023.170976. Epub 2023 Feb 14.
The timing of pubertal development is closely related to metabolic status and energy reserves. It is thought that irisin, which is involved in the regulation of energy metabolism and is shown to be present in the hypothalamo-pituitary-gonadal (HPG) axis, may play a role in this process. In our study, we aimed to investigate the effect of irisin administration on pubertal development and HPG axis in rats.
DESIGN-METHODS: 36 female rats were included in the study were divided into 3 groups: 100 ng/kg/day irisin treatment group (irisin-100), 50 ng/kg/day irisin treatment group (irisin-50), and control group. On the 38th day, serum samples were taken to determine levels of luteinizing hormone (LH) and follicle stimulating hormone (FSH), estradiol and irisin. Brain hypothalamus samples were taken to determine levels of pulsatile gonadotropin-releasing hormone (GnRH), kisspeptin, neurokinin-B, dynorphin (Dyn), and makorin ring finger protein-3 (MKRN3).
Vaginal opening and estrus were seen firstly in the irisin-100 group. At the end of the study, the highest rate of vaginal patency was found in the irisin-100 group. Hypothalamic protein expression levels of GnRH, NKB and Kiss1 in homogenates; serum FSH, LH, and estradiol levels were the highest in the irisin-100 group, followed by the irisin-50 and control groups, respectively. Ovarian sizes were significantly greater in the irisin-100 group compared to the other groups. The hypothalamic protein expression levels of MKRN3 and Dyn were the lowest in the irisin-100 group.
In this experimental study, irisin triggered the onset of puberty in a dose-dependent manner. Irisin administration caused the excitatory system to dominate in the hypothalamic GnRH pulse generator.
青春期发育的时间与代谢状态和能量储备密切相关。据认为，参与能量代谢调节且已证实在下丘脑-垂体-性腺（HPG）轴中存在的鸢尾素可能在此过程中发挥作用。在我们的研究中，我们旨在研究给予鸢尾素对大鼠青春期发育和HPG轴的影响。
设计-方法：本研究纳入36只雌性大鼠，分为3组：100 ng/kg/天鸢尾素治疗组（鸢尾素-100）、50 ng/kg/天鸢尾素治疗组（鸢尾素-50）和对照组。在第38天，采集血清样本以测定黄体生成素（LH）、卵泡刺激素（FSH）、雌二醇和鸢尾素的水平。采集脑下丘脑样本以测定脉冲性促性腺激素释放激素（GnRH）、亲吻素、神经激肽B、强啡肽（Dyn）和泛素连接酶3（MKRN3）的水平。
鸢尾素-100组首先出现阴道开口和发情。在研究结束时，鸢尾素-100组的阴道通畅率最高。匀浆中下丘脑GnRH、NKB和Kiss1的蛋白表达水平；血清FSH、LH和雌二醇水平在鸢尾素-100组中最高，其次分别是鸢尾素-50组和对照组。与其他组相比，鸢尾素-100组的卵巢尺寸明显更大。鸢尾素-100组下丘脑MKRN3和Dyn的蛋白表达水平最低。
在本实验研究中，鸢尾素以剂量依赖性方式触发青春期开始。给予鸢尾素导致下丘脑GnRH脉冲发生器中的兴奋系统占主导地位。
