Differential actions of corticosterone on luteinizing hormone and follicle-stimulating hormone biosynthesis and release in cultured rat anterior pituitary cells: interactions with estradiol.
Differential actions of corticosterone on luteinizing hormone and follicle-stimulating hormone biosynthesis and release in cultured rat anterior pituitary cells: interactions with estradiol.
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DOI：
10.1095/biolreprod44.6.1040
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发表时间：
1991-06
影响因子：
3.6
通讯作者：
D. M. Baldwin;P. Srivastava;L. Krummen
中科院分区：
文献类型：
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作者：
D. M. Baldwin;P. Srivastava;L. Krummen
我们实验室之前的体内研究表明，糖皮质激素可以拮抗雌激素依赖性的 LH 分泌作用。本研究调查了皮质酮 (B) 是否对体外促性腺激素生物合成和分泌具有类似的作用。将来自成年雌性大鼠的酶促分散的垂体前叶细胞在含有 10% 无类固醇马血清、含或不含 0.5 nM 雌二醇 (E2) 的 α 改良 Eagle 培养基中培养 48 小时。然后将细胞在存在或不存在E2的情况下在有或没有B的情况下培养24小时。为了评估激素释放，将 5 x 10(5) 细胞与不同剂量的 GnRH (0, 10(-11)-10(-7) M) 或脉冲 GnRH (10(-9) M；20 分钟/小时) 孵育 4 小时。通过RIA测量细胞和培养基LH和FSH。为了评估 LH 生物合成，将 5 x 10(6) 细胞与 10(-10) M GnRH、60 microCi 3H-葡萄糖胺 (3H-Gln)、20 microCi 35S-蛋氨酸 (35S-Met) 和适当的类固醇激素一起孵育另外 24 小时。通过免疫沉淀和 SDS-PAGE 测定放射性标记前体掺入 LH 亚基的情况。持续暴露于 GnRH 会以剂量依赖性方式刺激 LH 释放，并且 E2 会增强这种反应。 B本身对LH释放没有影响，但在低浓度GnRH（10(-10) M或更低）下抑制E2引发的细胞中LH的分泌。 GnRH 或类固醇治疗不会改变总 LH 含量。在接受脉动 GnRH 刺激的细胞中也观察到了 B 的类似作用。与 LH 相比，E2 或 B 在较高剂量的 GnRH 下增强 GnRH 刺激的 FSH 释放，而 E2 和 B 的组合增加基础并进一步增强 GnRH 刺激的释放。在 B 存在的情况下，总 FSH 含量也有所增加，但单独使用 E2 时则不会增加，并且在用两种类固醇处理的细胞中进一步增加。类固醇对响应 GnRH 脉冲的 FSH 释放量没有影响，但与对照组相比，E2 + B 组中 FSH 的累积释放量更大，表明基础释放增加。独立于 E2，B 将 3H-Gln 掺入 LH 的抑制率超过对照的 50%，对 35S-Met 的掺入仅产生微妙的影响。（摘要截断为 400 字）
Previous in vivo studies from our laboratory suggested that glucocorticoids antagonize estrogen-dependent actions on LH secretion. This study investigated whether corticosterone (B) may have similar actions on gonadotropin biosynthesis and secretion in vitro. Enzymatically dispersed anterior pituitary cells from adult female rats were cultured for 48 h in alpha-modified Eagle's medium containing 10% steroid-free horse serum with or without 0.5 nM estradiol (E2). The cells were then cultured for 24 h with or without B in the presence or absence of E2. To evaluate hormone release, 5 x 10(5) cells were incubated with varying doses of GnRH (0, 10(-11)-10(-7) M) or pulsatile GnRH (10(-9) M; 20 min/h) for 4 h. Cell and medium LH and FSH were measured by RIA. To evaluate LH biosynthesis, 5 x 10(6) cells were incubated for an additional 24 h with 10(-10) M GnRH, 60 microCi 3H-glucosamine (3H-Gln), 20 microCi 35S-methionine (35S-Met), and the appropriate steroid hormones. Radiolabeled precursor incorporation into LH subunits was determined by immunoprecipitation, followed by SDS-PAGE. Continuous exposure to GnRH stimulated LH release in a dose-dependent manner, and this response was enhanced by E2. B by itself had no effect on LH release, but inhibited LH secretion in E2-primed cells at low concentrations of GnRH (10(-10) M or less). Total LH content was not altered by GnRH or steroid treatment. Similar effects of B were observed in cells that were given a pulsatile GnRH stimulus. In contrast to LH, E2 or B enhanced GnRH-stimulated FSH release at the higher doses of GnRH, while the combination of E2 and B increased basal and further augmented GnRH-stimulated release. Total FSH content was also increased in the presence of B, but not E2 alone, and was further augmented in cells treated with both steroids. There were no effects of the steroids on the magnitude of FSH release in response to GnRH pulses, but the cumulative release of FSH was greater in the E2 + B group compared to controls, indicating an increased basal release. Independent of E2, B suppressed the incorporation of 3H-Gln into LH by more than 50% of control, with only subtle effects on the incorporation of 35S-Met.(ABSTRACT TRUNCATED AT 400 WORDS)