Immunocytochemical localization of prolactin-releasing peptide in the rat brain.
Immunocytochemical localization of prolactin-releasing peptide in the rat brain.
复制标题
大鼠脑中催乳素释放肽的免疫细胞化学定位。
作者：
M. Maruyama;H. Matsumoto;Ken Fujiwara;C. Kitada;S. Hinuma;H. Onda;Masahiko Fujino;Kinji Inoue
最近发现的一种刺激催乳素释放的下丘脑肽是一种孤儿受体的配基，命名为催乳素释放肽(PrRP)。PrRP及其受体主要分布在下丘脑和脑垂体部。其特性提示PrRP是一种新的促垂体素，可刺激垂体前叶PRL细胞；然而，这一点仍有待于形态上的证实。因此，我们进行了免疫细胞化学研究，利用识别PrRP C末端和内部序列的区域特异性单抗P2L-1C和P2L-1T来定位PrRP在大鼠脑内的位置。结果表明，下丘脑室旁核、视上核、丘脑旁核、杏仁基底外侧核和终纹床核均有致密的免疫反应神经纤维网络。在垂体神经叶内也观察到少量的PrRP神经纤维。然而，在正中隆起的外部区域没有观察到免疫阳性纤维，这是已知的经典促垂体激素的释放部位。此外，PrRP在发情周期中的分布也没有变化。因此，我们得出结论，PrRP可能不同于经典的下丘脑释放激素。免疫反应阳性胞体主要分布在下丘脑背内侧核和孤束核的尾侧部。免疫细胞化学双重染色显示，部分PrRP阳性神经元与下丘脑室旁核内的催产素阳性神经元有突触接触，提示PrRP对催产素神经元的功能有调节作用。这是首次报道了新的下丘脑多肽PrRP的定位，因此我们认为它参与了多种脑功能。然而，目前还不知道PrRP是如何被转运到脑下垂体的，脑下垂体是这种新肽的受体浓度最高的部位。因此，需要额外的工作来解决配体和受体位置之间的差异。
A hypothalamic peptide that stimulates PRL release has recently been found as a ligand of an orphan receptor and named PRL-releasing peptide (PrRP). PrRP and its receptor were mainly detected in the hypothalamus and pituitary gland, respectively. Its characteristics suggested PrRP to be a novel hypophysiotropic peptide that stimulates the anterior pituitary PRL cell; however, this remained to be confirmed morphologically. We therefore performed an immunocytochemical study to locate PrRP in the rat brain using the region-specific monoclonal antibodies, P2L-1C and P2L-1T, which recognize the C-terminal and the internal sequence of PrRP, respectively. Our results clearly show that dense immunoreactive nerve fiber networks are present in the paraventricular hypothalamic nucleus, supraoptic nucleus, paratenial thalamic nucleus, basolateral amygdaloid nucleus, and bed nucleus of the stria terminalis. A small number of PrRP nerve fibers was also observed in the neural lobe of the hypophysis. However, no immunopositive fiber was observed in the external region of the median eminence, which is known to be the release site of the classical hypophysiotropic hormones. Also, the distribution of PrRP was not changed during the estrous cycle. We therefore concluded that PrRP probably differs from classical hypothalamic releasing hormones. We found the immunoreactive cell bodies to be mainly in the caudal portion of the dorsomedial hypothalamic nucleus and solitary nucleus. A double immunocytochemical procedure revealed that some PrRP-positive neurons showed synaptic contact with oxytocin-positive cell bodies in the paraventricular hypothalamic nucleus, which suggests that PrRP regulates the function of oxytocin neurons. This is the first report to demonstrate the localization of the novel hypothalamic peptide, PrRP, and we therefore suggest that it takes part in a variety of brain functions. However, it is not yet known how PrRP is transported to the pituitary gland, which is the site that contains the greatest concentration of receptors to this new peptide. Therefore, additional work will be required to resolve this discrepancy between ligand and receptor site location.
影响因子：
4.8
作者：
LECHAN, RM;JACKSON, IMD
通讯作者：
JACKSON, IMD
催产素在控制催乳素分泌中的生理作用的证据。
影响因子：
4.8
作者：
Samson,WK;Lumpkin,MD;McCann,SM
通讯作者：
McCann,SM