Blanco M, López M, García-Caballero T, Gallego R, Vázquez-Boquete A, Morel G, Señarís R, Casanueva F, Diéguez C, Beiras A
Department of Morphological Sciences, School of Medicine-University Clinical Hospital, University of Santiago de Compostela, E-15782 Santiago de Compostela, Spain.
J Clin Endocrinol Metab. 2001 Apr;86(4):1616-9.
Orexins-A and -B are hypothalamic peptides derived from a precursor called prepro-orexin and relationated with the stimulation of food intake. They act on G protein receptors named orexin receptor 1 (OX(1)R) and orexin receptor 2 (OX(2)R), respectively. In the present study, we used RT-PCR and immunohistochemical techniques to detect the presence of OX(1)R and OX(2)R in human pituitary. A band of the expected size for both OX(1)R and OX(2)R was shown in human pituitary by RT-PCR. The cellular localization of OX(1)R and OX(2)R was carried out using histological techniques. By consecutive sections we demonstrated that OX(1)R was present in acidophil, diffusely distributed cells, which represent the half of the total adenohypophysis cell population. As was expected, these cells were shown to coexpress GH. OX(2)R was found in the pars intermedia and in clusters of basophil cells of the anterior pituitary, which coexpress ACTH. These results were confirmed by double immunofluorescence techniques. We also found focal positivity in axon terminals of neurohypophysis, more intense for OX(2)R than for OX(1)R. In conclusion, these results demonstrated for the first time that OX(1)R and OX(2)R were expressed by somatotrope and corticotrope cells, respectively.
食欲素-A和食欲素-B是下丘脑肽，由一种名为前食欲素原的前体衍生而来，与食物摄入的刺激有关。它们分别作用于名为食欲素受体1（OX(1)R）和食欲素受体2（OX(2)R）的G蛋白受体。在本研究中，我们使用逆转录聚合酶链反应（RT-PCR）和免疫组织化学技术来检测人垂体中OX(1)R和OX(2)R的存在。通过RT-PCR在人垂体中显示出OX(1)R和OX(2)R预期大小的条带。使用组织学技术对OX(1)R和OX(2)R进行细胞定位。通过连续切片我们证明，OX(1)R存在于嗜酸性细胞中，这些细胞呈弥漫性分布，占腺垂体细胞总数的一半。正如预期的那样，这些细胞被证明共表达生长激素（GH）。OX(2)R在前叶垂体的中间部和嗜碱性细胞簇中被发现，这些细胞共表达促肾上腺皮质激素（ACTH）。这些结果通过双重免疫荧光技术得到证实。我们还在神经垂体的轴突终末发现了局灶性阳性，OX(2)R比OX(1)R更明显。总之，这些结果首次证明OX(1)R和OX(2)R分别由生长激素细胞和促肾上腺皮质激素细胞表达。
