Mertani H C, Pechoux C, Garcia-Caballero T, Waters M J, Morel G
Centre National de la Recherche Scientifique Unité de Recherche Associée 1459, Pathologie des Fibroses, Institut Pasteur de Lyon, France.
J Clin Endocrinol Metab. 1995 Nov;80(11):3361-7. doi: 10.1210/jcem.80.11.7593452.
The increasing use of GH therapy has led to the description of its target cells in human tissues, but no data are yet available on the localization of the GH receptor in the human pituitary. In the present study, we used immunocytochemistry to detect the presence of GH receptor/binding protein (GHR/BP), and we examined its distribution among the different types of human anterior pituitary cells. Human pituitaries were taken from autopsies and were processed for embedding in paraffin wax. Immunocytochemistry was performed by using monoclonal antibody 263 raised against purified rat and rabbit GHR/BP, which cross-reacts with the human GH receptor. In order to determine the types of cells that display immunoreactivity for GHR/BP, adjacent pituitary sections were used to detect immunoreactivity for GH, PRL, ACTH, TSH, LH, and FSH. Several controls were carried out to verify the specificity of the immunostaining. Receptor immunoreactivity was found in the cytoplasm and nuclei of the somatotrophs, lactotrophs, and gonadotrophs but not in the thyrotrophs or corticotrophs. In order to demonstrate that the detected GHR/BP immunoreactivity was not caused solely by a cellular capture, we also investigated the cellular distribution of GHR gene expression. This was performed by in situ hybridization with use of complementary oligonucleotide radioactive probes encoding distinct domains of the GHR. Several tests were carried out to validate the detection of gene expression. In situ hybridization demonstrated the presence of GHR messenger RNAs in the anterior lobe of human pituitary, and examination of the signal strengthened the cell-specificity of GHR gene expression. These results demonstrate the presence of GHR/BP in discrete human pituitary cells and indicate a paracrine, autocrine, or intracrine role for GH in the pituitary.
生长激素（GH）疗法的使用日益增加，这使得人们对其在人体组织中的靶细胞进行了描述，但关于GH受体在人垂体中的定位尚无数据。在本研究中，我们使用免疫细胞化学方法检测生长激素受体/结合蛋白（GHR/BP）的存在，并研究其在不同类型人垂体前叶细胞中的分布。人垂体取自尸检标本，经处理后用石蜡包埋。使用针对纯化的大鼠和兔GHR/BP制备的单克隆抗体263进行免疫细胞化学，该抗体与人GH受体发生交叉反应。为了确定显示GHR/BP免疫反应性的细胞类型，相邻的垂体切片用于检测GH、PRL、ACTH、TSH、LH和FSH的免疫反应性。进行了多项对照以验证免疫染色的特异性。在生长激素细胞、催乳素细胞和促性腺激素细胞（促性腺细胞）的细胞质和细胞核中发现了受体免疫反应性，而在促甲状腺激素细胞或促肾上腺皮质激素细胞中未发现。为了证明检测到的GHR/BP免疫反应性并非仅由细胞捕获引起，我们还研究了GHR基因表达的细胞分布。这通过使用编码GHR不同结构域的互补寡核苷酸放射性探针进行原位杂交来完成。进行了多项测试以验证基因表达的检测。原位杂交证明人垂体前叶存在GHR信使核糖核酸（mRNA），对信号的检测加强了GHR基因表达的细胞特异性。这些结果证明离散的人垂体细胞中存在GHR/BP，并表明GH在垂体中具有旁分泌、自分泌或胞内分泌作用。
