Di Yorio M P, Delgadin T H, Pérez Sirkin D I, Vissio P G
Laboratorio de Neuroendocrinología del Crecimiento y la Reproducción, DBBE, FCEN-UBA, Ciudad Universitaria, C1428EHA, Buenos Aires, Argentina.
Fish Physiol Biochem. 2015 Aug;41(4):843-52. doi: 10.1007/s10695-015-0051-z. Epub 2015 Apr 14.
Neuropeptide Y (NPY) is considered the most potent orexigenic peptide, increasing before meal time and during fasting. In teleost, most studies on NPY action upon growth hormone (GH) and luteinizing hormone (LH) were conducted in females or group of animals without sex discrimination. The aim of this study was to evaluate whether NPY modulates the expression and release of GH and gonadotropins in both sexes of Cichlasoma dimerus. By double-label immunofluorescence, we first determined the association between NPY fibers and pituitary cells. In addition, we performed in vitro studies to evaluate the effect of NPY on GH and gonadotropins expression by real-time PCR, and release by Western blot, in males and females separately. Contacts between NPY fibers and GH and follicle-stimulating hormone (FSH)-producing cells were detected, indicating possible functional relationships. We observed an increase in GH release in the culture medium at 2 nM for males (p = 0.043) and 20 nM for females (p = 0.028). Pituitary FSH release was stimulated at 20 nM (p = 0.026) and 200 nM (p = 0.033) for males and females, respectively. Finally, NPY only increased β-LH mRNA expression at 20 nM in females (p = 0.028) and its release at 2 nM (p = 0.049) and 200 nM for males (p = 0.005) and 200 nM for females (p = 0.018). In conclusion, NPY acts as a GH-, LH- and FSH-releasing factor, in a dose- and sex-dependent way.
神经肽Y（NPY）被认为是最有效的促食欲肽，在进餐前和禁食期间会增加。在硬骨鱼中，大多数关于NPY对生长激素（GH）和促黄体生成素（LH）作用的研究是在雌性或未区分性别的动物群体中进行的。本研究的目的是评估NPY是否调节双须丽鱼两性中GH和促性腺激素的表达与释放。通过双重标记免疫荧光，我们首先确定了NPY纤维与垂体细胞之间的关联。此外，我们进行了体外研究，分别评估NPY对雄性和雌性GH和促性腺激素表达（通过实时PCR）以及释放（通过蛋白质免疫印迹法）的影响。检测到NPY纤维与GH以及产生促卵泡激素（FSH）的细胞之间存在接触，表明可能存在功能关系。我们观察到，在雄性中，2 nM的NPY使培养基中GH释放增加（p = 0.043），在雌性中，20 nM的NPY使GH释放增加（p = 0.028）。垂体FSH释放分别在雄性20 nM（p = 0.026）和雌性200 nM（p = 0.033）时受到刺激。最后，NPY仅在雌性中使β-LH mRNA表达在20 nM时增加（p = 0.028），在雄性中使β-LH释放在2 nM（p = 0.049）和200 nM时增加（p = 0.005），在雌性中使β-LH释放在200 nM时增加（p = 0.018）。总之，NPY以剂量和性别依赖性方式作为GH、LH和FSH释放因子发挥作用。
