Second Department of Internal Medicine, Charles University Faculty of Medicine and Teaching Hospital in Hradec Králové, Sokolská 581, 50005, Hradec Králové, Czech Republic.
Pituitary. 2012 Jun;15(2):222-6. doi: 10.1007/s11102-011-0316-1.
Clinically non-functioning pituitary adenomas account for about one-third of pituitary tumors. The majority of them are pathologically classified as gonadotropinomas or null-cell adenomas without hormonal expression. The rest represent silent corticotroph adenomas and plurihormonal tumors. Conservative therapy with dopamine agonists is effective in some cases only depending on the expression of dopamine 2 receptors (D2R). The aim of this study was to quantitatively estimate D2R expression in clinically non-functioning pituitary adenomas and correlate the results with adenoma type according to pathological classification. Out of the 87 adenomas investigated, 63 expressed gonadotropins, 7 were silent corticotroph adenomas, 7 were plurihormonal tumors, and only 6 did not express any pituitary hormone on immunohistochemical investigation. With the use of the reverse transcriptase PCR technique, D2R mRNA was expressed in all adenomas with very heterogeneous quantity. The expression was very low in corticotroph adenomas (relative median quantity after normalization to housekeeping gene 0.01) and lower in plurihormonal tumors (median 0.4) than in gonadotroph (median 1.3) and null-cell adenomas (median 1.9). The difference between corticotroph adenomas and plurihormonal tumors in comparison with other pathological types was statistically significant. The expression of D2R did not depend on the presence or absence of gonadotropins. We conclude that D2R expression is very low in corticotroph adenomas and significantly lower in plurihormonal tumors. The positivity of gonadotropins does not predict the D2R quantity.
临床上无功能的垂体腺瘤约占垂体肿瘤的三分之一。它们中的大多数在病理上被归类为促性腺激素瘤或无激素表达的无细胞腺瘤。其余的代表沉默的促皮质激素腺瘤和多激素肿瘤。仅根据多巴胺 2 受体 (D2R) 的表达，多巴胺激动剂的保守治疗在某些情况下才有效。本研究的目的是定量估计临床上无功能的垂体腺瘤中的 D2R 表达，并将结果与根据病理分类的腺瘤类型相关联。在研究的 87 个腺瘤中，63 个表达促性腺激素，7 个是沉默的促皮质激素腺瘤，7 个是多激素肿瘤，只有 6 个在免疫组织化学检查中不表达任何垂体激素。使用逆转录聚合酶链反应技术，所有腺瘤均表达 D2R mRNA，但数量非常不同。在促皮质激素腺瘤中表达非常低（相对于管家基因归一化后的相对中位数 0.01），在多激素肿瘤中（中位数 0.4）比在促性腺激素瘤（中位数 1.3）和无细胞腺瘤（中位数 1.9）中低。与其他病理类型相比，促皮质激素腺瘤和多激素肿瘤之间的表达差异具有统计学意义。D2R 的表达不依赖于促性腺激素的存在与否。我们得出结论，D2R 在促皮质激素腺瘤中的表达非常低，在多激素肿瘤中显著降低。促性腺激素的阳性并不能预测 D2R 的数量。
