Galanin gene expression in radiothyroidectomy-induced thyrotroph adenomas.
Galanin gene expression in radiothyroidectomy-induced thyrotroph adenomas.
复制标题
放射性甲状腺切除术诱导的促甲状腺素腺瘤中甘丙肽基因的表达。
DOI：
10.1152/ajpendo.1996.271.1.e24
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发表时间：
1996
期刊：
影响因子：
--
通讯作者：
Morrison,DG
中科院分区：
文献类型：
--
作者：
Hyde,JF;MooreJr,JP;Drake,KW;Morrison,DG
甘丙肽基因表达在雌激素处理的大鼠（促乳细胞增生）以及人生长激素释放激素转基因小鼠（促生长细胞增生）的垂体前叶中显著增加。本研究的目的是检查甘丙肽在促甲状腺激素腺瘤形成的小鼠模型。通过使用碘-131（131 I）对雄性小鼠进行放射性甲状腺切除术，并在下丘脑-垂体轴中评估甘丙肽水平。放射性甲状腺切除术后3、6、9和12个月，131 I治疗小鼠垂体前叶中的免疫反应性甘丙肽浓度下降80%。在这些时间，下丘脑中的甘丙肽水平降低20-25%。用雌二醇或3，3 '，5-三碘-L-甲状腺原氨酸治疗增加了131 I治疗小鼠垂体前叶中甘丙肽的浓度，但两种治疗都不能恢复甘丙肽的浓度。放射性甲状腺切除术后1年甘丙肽mRNA水平下降> 80%。我们的结论是，不同的动物模型的催乳激素和促生长激素细胞增生，甘丙肽基因的表达被抑制在整个发展的促甲状腺激素腺瘤，这表明甘丙肽没有刺激作用的促甲状腺激素细胞的增殖。此外，这些数据表明，甲状腺激素是小鼠甘丙肽基因表达的重要正调控因子，在甲状腺激素缺乏的情况下，雌激素可能会刺激甘丙肽基因表达。
Galanin gene expression is markedly increased in the anterior pituitary glands of estrogen-treated rats (lactotroph hyperplasia) as well as human growth hormone-releasing hormone transgenic mice (somatotroph hyperplasia). The objective of this study was to examine galanin in a mouse model of thyrotroph adenoma formation. Male mice were radiothyroidectomized by use of iodine-131 (131I), and galanin peptide levels were assessed in the hypothalamic-pituitary axis. Immunoreactive galanin concentrations in the anterior pituitaries of 131I-treated mice were decreased 80% at 3, 6, 9, and 12 mo after radiothyroidectomy. Galanin peptide levels in the hypothalamus were decreased 20-25% at these times. Treatment with either estradiol or 3,3',5-triiodo-L-thyronine increased galanin peptide concentrations in the anterior pituitaries of 131I-treated mice, but neither treatment restored galanin concentrations. Galanin mRNA levels were decreased > 80% 1 yr after radiothyroidectomy. We conclude that, unlike animal models of lactotroph and somatotroph hyperplasia, galanin gene expression is suppressed throughout the development of thyrotroph adenomas, suggesting that galanin does not have a stimulatory role in the proliferation of thyrotrophs. Moreover, these data show that thyroid hormones are important positive regulators of galanin gene expression in the mouse and that estrogen may stimulate galanin gene expression in the absence of thyroid hormones.