Klibanski A, Deutsch P J, Jameson J L, Ridgway E C, Crowley W F, Hsu D W, Habener J F, Black P M
J Clin Endocrinol Metab. 1987 Mar;64(3):536-42. doi: 10.1210/jcem-64-3-536.
Although gonadotropin-secreting pituitary adenomas are increasingly recognized, tumors secreting only LH are rare. Since gonadotropin production by pituitary adenomas may reflect imbalanced glycoprotein biosynthesis, we studied tumor LH and subunit biosynthesis and secretion in a patient with a LH- and alpha-subunit-producing pituitary tumor. Northern blot analysis of RNA from the tumor revealed the presence of mRNAs encoding both alpha- and beta-subunits of LH with a marked excess of the mRNA encoding LH beta. Analysis of tumor extracts by gel filtration chromatography confirmed an excess of free LH beta relative to free alpha-subunit. Clinical studies demonstrated that the secretion of LH and alpha-subunit by the tumor increased in response to the acute administration of LHRH (100 micrograms, iv) and decreased during a 4-h dopamine infusion (4 micrograms/kg X min). During a 4-week course of LHRH analog (D-Trp6-Pro9-NEt-LHRH) administration, given as a daily sc dose (8 micrograms/kg X day), serum LH and alpha-subunit concentrations increased 7- and 3-fold, respectively, consistent with a chronic agonist effect. Chronic administration of bromocriptine resulted in reduction of serum LH and alpha-subunit levels to normal.
尽管分泌促性腺激素的垂体腺瘤越来越受到认可，但仅分泌促黄体生成素（LH）的肿瘤却很罕见。由于垂体腺瘤产生的促性腺激素可能反映糖蛋白生物合成失衡，我们研究了一例产生LH和α亚基的垂体肿瘤患者肿瘤中LH及其亚基的生物合成与分泌情况。对肿瘤RNA进行Northern印迹分析显示，存在编码LH的α和β亚基的mRNA，其中编码LHβ的mRNA明显过量。通过凝胶过滤色谱法分析肿瘤提取物证实，相对于游离α亚基，游离LHβ过量。临床研究表明，急性静脉注射促性腺激素释放激素（LHRH，100微克）后，肿瘤分泌的LH和α亚基增加，而在4小时多巴胺输注（4微克/千克×分钟）期间则减少。在给予促性腺激素释放激素类似物（D-色氨酸6-脯氨酸9-乙基-LHRH）为期4周的疗程中，每日皮下注射剂量为8微克/千克×天，血清LH和α亚基浓度分别增加了7倍和3倍，这与慢性激动剂作用一致。长期服用溴隐亭可使血清LH和α亚基水平降至正常。
