Saccomanno K, Gil del Alamo P, Bassetti M, Reza-Elahi F, Spada A
Istituto di Scienze Endocrine, Ospedale Maggiore IRCCS, Milano, Italy.
J Endocrinol Invest. 1993 Feb;16(2):109-15. doi: 10.1007/BF03347659.
This study, carried out on 9 nonfunctioning pituitary adenomas, was undertaken in order to evaluate the ability of these tumors to synthesize and release gonadotropins and/or free alpha-subunit (alpha-SU) of glycoproteins. The morphological study included electron microscopy and immunofluorescence analysis while hormone release was evaluated by the reverse hemolytic plaque assay (RHPA) and measurements in culture media. By electron microscopy in all tumors (6 null cell adenomas and 3 oncocytomas), it was possible to identify rough endoplasmic reticulum, Golgi apparatus and secretory granules. By immunofluorescence, 5 of 6 tumors were immunoreactive for one or more gonadotropin subunits; in particular, 5 adenomas were positive for alpha-SU and LH-beta, and 3 for FSH-beta. By the RHPA, about 1% of cells obtained from one single tumor formed plaques for LH-beta and alpha-SU while the remaining tumors were negative. Similarly, the study of media concentrations of LH, FSH and alpha-SU in 2 h culture revealed very low amounts of released hormones. In these experimental conditions no modification was observed after the addition of stimulatory agents such as TRH, GnRH and VIP. The present study clearly indicates that although the large majority of nonfunctioning tumors are positive for gonadotropins their secretory capacity is very low in both basal and stimulated conditions.
本研究对9例无功能垂体腺瘤进行，旨在评估这些肿瘤合成和释放促性腺激素及/或糖蛋白游离α亚基（α-SU）的能力。形态学研究包括电子显微镜检查和免疫荧光分析，而激素释放则通过反向溶血空斑试验（RHPA）和培养基测量进行评估。通过电子显微镜观察，在所有肿瘤（6例无分泌颗粒细胞腺瘤和3例嗜酸性细胞瘤）中，均可识别出粗面内质网、高尔基体和分泌颗粒。通过免疫荧光检测，6例肿瘤中有5例对一种或多种促性腺激素亚基呈免疫反应性；具体而言，5例腺瘤对α-SU和LH-β呈阳性，3例对FSH-β呈阳性。通过RHPA，从单个肿瘤获得的约1%的细胞形成了LH-β和α-SU的空斑，而其余肿瘤均为阴性。同样，对2小时培养物中LH、FSH和α-SU的培养基浓度研究显示，释放的激素量非常低。在这些实验条件下，添加TRH、GnRH和VIP等刺激剂后未观察到变化。本研究清楚地表明，尽管绝大多数无功能肿瘤对促性腺激素呈阳性，但在基础和刺激条件下其分泌能力都非常低。
