McCluggage W G, Ashe P, McBride H, Maxwell P, Sloan J M
Department of Pathology, Royal Group of Hospitals Trust, Belfast, Northern Ireland.
Histopathology. 1998 Mar;32(3):252-6. doi: 10.1046/j.1365-2559.1998.00385.x.
Inhibin is a peptide hormone which is normally produced by ovarian granulosa cells and which inhibits the release of follicle stimulating hormone from the pituitary gland, thus acting as a modulator of folliculogenesis. Serum inhibin levels are higher during pregnancy than during the normal menstrual cycle and the placenta is thought to be a source of circulating inhibin. Previous studies have yielded conflicting results as to the cellular localization of inhibin in the placenta and the aim of the present study was to investigate the immunohistochemical localization of the hormone in placental tissue. We also wished to investigate whether inhibin could be demonstrated in choriocarcinoma and in non-gestational trophoblastic tissue.
Immunohistochemical staining was performed using a monoclonal antibody against the alpha subunit of human inhibin. Specimens included in the study were intrauterine products of conception (n = 36), extrauterine products of conception (n = 4), decidualized endometrium (n = 15), extrauterine decidualized tissue (n = 3), hydatidiform mole (n = 5), uterine choriocarinoma (n = 2) and testicular embryonal carcinoma with syncytiotrophoblast giant cells (n = 6). In cases of products of conception, including hydatidiform mole, there was consistent strong positive staining of syncytiotrophoblast but no staining of cytotrophoblast with anti-inhibin. Staining with anti-inhibin highlighted trophoblastic cells within the placental bed. In a small number of cases there was focal weak positive staining of decidua. There was positive staining of the two cases of uterine choriocarcinoma and of syncytiotrophoblast giant cells in the six cases of testicular embryonal carcinoma.
The study shows that immunohistochemically detectable inhibin alpha subunit in placental tissue is mainly localized within syncytiotrophoblast although in some cases there is also positive staining of decidua. Production of inhibin by these cells may account for raised serum levels during pregnancy. Inhibin can also be demonstrated in choriocarcinoma and in nongestational trophoblastic tissue. Inhibin is a sensitive marker of syncytiotrophoblast and staining with this antibody may prove useful in the diagnosis of choriocarcinoma and in the demonstration of trophoblastic cells in germ cell tumours.
抑制素是一种肽类激素，通常由卵巢颗粒细胞产生，可抑制垂体促卵泡激素的释放，从而作为卵泡发生的调节剂。孕期血清抑制素水平高于正常月经周期，胎盘被认为是循环抑制素的来源之一。以往关于抑制素在胎盘中细胞定位的研究结果相互矛盾，本研究旨在探讨该激素在胎盘组织中的免疫组化定位。我们还希望研究在绒毛膜癌和非妊娠滋养层组织中是否能检测到抑制素。
采用抗人抑制素α亚基的单克隆抗体进行免疫组化染色。研究标本包括宫内妊娠产物（n = 36）、宫外妊娠产物（n = 4）、蜕膜化子宫内膜（n = 15）、宫外蜕膜化组织（n = 3）、葡萄胎（n = 5）、子宫绒毛膜癌（n = 2）以及伴有合体滋养层巨细胞的睾丸胚胎癌（n = 6）。在包括葡萄胎在内的妊娠产物病例中，合体滋养层对抗抑制素呈一致的强阳性染色，而细胞滋养层无染色。抗抑制素染色突出了胎盘床内的滋养层细胞。少数病例中蜕膜有局灶性弱阳性染色。两例子宫绒毛膜癌以及六例睾丸胚胎癌中的合体滋养层巨细胞均呈阳性染色。
该研究表明，胎盘组织中免疫组化可检测到的抑制素α亚基主要定位于合体滋养层，尽管在某些情况下蜕膜也呈阳性染色。这些细胞产生抑制素可能是孕期血清水平升高的原因。在绒毛膜癌和非妊娠滋养层组织中也能检测到抑制素。抑制素是合体滋养层的敏感标志物，用该抗体染色可能有助于绒毛膜癌的诊断以及生殖细胞肿瘤中滋养层细胞的显示。
