Department of Physiology and Toxicology of Reproduction, Chair of Animal Physiology, Institute of Zoology, Jagiellonian University, Cracow, Poland.
J Physiol Pharmacol. 2012 Apr;63(2):195-9.
Ghrelin, a hormone predominantly found in the stomach, was described as a factor that controls female reproductive function. Using real time PCR and western blot, we measured gene and protein expression of ghrelin and its receptor. Enzyme-like immunoassay (ELISA) was used to measure the concentration of acylated (Ac) and unacylated (UnAc) forms of ghrelin as well as levels of estradiol (E2) in follicular fluid. For all analyses, we compared small, medium and large ovarian follicles collected from ovaries of prepubertal and estrous cycling pigs. We demonstrated that the gene expression levels of ghrelin significantly increased in ovarian follicles from cycling animals, with the maximum expression in large follicles, without any change in prepubertal. However, the protein expression of ghrelin and its concentration was increased with increasing follicle size both in prepubertal and cycling animals and it was positively correlated with E2 levels in follicular fluid. In addition, both receptor growth hormone secretagogue receptor (GHSR) and GHSR type GHSR-1a expression were significantly higher in ovarian follicles from cycling animals than prepubertal. Results of this study suggest the possibility of local synthesis of ghrelin in the ovarian follicles and point to important modulatory functions for ghrelin before puberty and during the estrous cycle.
胃激素（Ghrelin）主要存在于胃中，被描述为控制女性生殖功能的因素。我们使用实时 PCR 和 Western blot 测量了 Ghrelin 和其受体的基因和蛋白表达。酶联免疫吸附测定（ELISA）用于测量卵泡液中酰化（Ac）和未酰化（UnAc）形式的 Ghrelin 以及雌二醇（E2）的浓度。对于所有分析，我们比较了从小猪卵巢中收集的小、中、大卵泡。我们证明，Ghrelin 的基因表达水平在发情周期动物的卵巢卵泡中显著增加，最大表达在大卵泡中，而在青春期前没有变化。然而，Ghrelin 的蛋白表达及其浓度随着卵泡大小的增加而增加，在青春期前和发情周期动物中都是如此，并且与卵泡液中的 E2 水平呈正相关。此外，生长激素促分泌素受体（GHSR）和 GHSR 型 GHSR-1a 的受体表达在发情周期动物的卵巢卵泡中均显著高于青春期前。本研究的结果表明，Ghrelin 可能在卵巢卵泡中进行局部合成，并指出了 Ghrelin 在青春期前和发情周期中的重要调节功能。
