Thyroid hormone and apotransferrin regulation of growth hormone secretion by GH1 rat pituitary tumor cells in iron restricted serum-free defined medium.
Thyroid hormone and apotransferrin regulation of growth hormone secretion by GH1 rat pituitary tumor cells in iron restricted serum-free defined medium.
复制标题
甲状腺激素和脱铁转铁蛋白对铁限制性无血清成分确定培养基中 GH1 大鼠垂体肿瘤细胞生长激素分泌的调节。
DOI：
10.1007/bf02631081
复制
发表时间：
1992
期刊：
影响因子：
--
通讯作者：
Eby,JE
中科院分区：
文献类型：
--
作者：
Sirbasku,DA;Pakala,R;Sato,H;Eby,JE
生长激素（GH）的生产GH 1大鼠垂体瘤细胞在铁限制性无血清限定培养基中需要脱铁转铁蛋白（apoTf）和三碘甲状腺原氨酸（T3）。通过放射免疫测定，apoTf + T3诱导的GH水平是对照组的2 - 4倍。apoTf或T3缺失均抑制GH分泌。ApoTf/T3确定培养基与全血清一样有效地调节GH的产生。由于糖皮质激素在含血清的培养物中增强GH分泌，因此在apoTf/T3限定培养基中评价地塞米松的作用。除非在apoTf/T3确定的培养基中孵育之前将细胞暴露于血清，否则类固醇激素没有显示出增强作用。即使在这些条件下，对地塞米松的反应仍然依赖于T3。这些观察结果表明，除了apoTf之外，还有一种尚待鉴定的血清因子调节对类固醇激素的反应。这是第一次报告的甲状腺激素调节生长激素分泌的大鼠垂体瘤细胞在完全无血清化学定义的条件下。
Growth hormone (GH) production by GH1rat pituitary tumor cells in iron restricted serum-free defined medium requires apotransferrin (apoTf) and triiodothyronine (T3). As measured by radioimmunoassay, apoTf plus T3induced GH levels 2 to 4-fold above controls. Deletion of either apoTf or T3arrested GH secretion. ApoTf/T3defined medium regulated GH production as effectively as whole serum. Because glucocorticoids enhance GH secretion in serum containing cultures, the effects of dexamethasone were evaluated in apoTf/T3defined medium. The steroid hormone showed no enhancing effects unless the cells were exposed to serum prior to incubation in apoTf/T3defined medium. Even under these conditions, the response to dexamethasone remained T3dependent. These observations indicate that a yet to be characterized serum factor(s), other than apoTf, regulates the reponse to the steroid hormone. This is the first report of thyroid hormone regulation of GH secretion by rat pituitary tumor cells under completely serum-free chemically defined conditions.