Low and high concentrations of gonadotropins differentially regulate hormone production by theca interna and granulosa cells from bovine preovulatory follicles.
Low and high concentrations of gonadotropins differentially regulate hormone production by theca interna and granulosa cells from bovine preovulatory follicles.
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低浓度和高浓度的促性腺激素不同地调节牛排卵前卵泡的内膜细胞和颗粒细胞产生的激素。
DOI：
10.1095/biolreprod52.6.1334
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发表时间：
1995
影响因子：
3.6
通讯作者：
Fortune,JE
中科院分区：
文献类型：
--
作者：
Berndtson,AK;Vincent,SE;Fortune,JE
哺乳动物排卵前卵泡在排卵前促性腺激素激增之前主要产生雌二醇和雄激素。在牛中，LH/FSH 激增会引发雌二醇和雄激素产量的迅速下降，以及黄体酮和催产素生物合成的急剧增加。目前尚不清楚体内促性腺激素浓度的变化如何调节激素产生的卵泡/黄体相移。为了解决这个问题，在 LH/FSH 激增的预期时间前约 24 小时，从荷斯坦小母牛的排卵前卵泡中分离出内膜细胞和颗粒细胞，并在含有胰岛素（1 微克/ml）和不同剂量的 LH 或 FSH（0、1、2、4、8、16、32、64 或 128 ng/ml）的确定成分培养基中培养。每 24 小时收集并更换培养基，持续 3 天，并测定内膜培养物中的雄烯二酮和孕酮，以及颗粒细胞培养物中的雌二醇、孕酮和催产素。培养第一天（24-72小时）后，只有极低剂量的LH（2或4ng/ml）增强（p<0.05）内膜培养物的雄烯二酮分泌，高于对照水平，而黄体酮分泌随着各种LH浓度而增加（p<0.05），在高剂量的LH下黄体酮分泌达到最大。同样，培养第一天（24-72 小时）后，颗粒细胞的雌二醇分泌仅受到低剂量 FSH 的刺激，并且相对于对照培养物在较高浓度下受到抑制（p < 0.05），而催产素和黄体酮的产生则通过高浓度 FSH 得到最大增强（p < 0.05）。（摘要截断为 250 字）
Mammalian preovulatory follicles produce primarily estradiol and androgens before the preovulatory gonadotropin surge. In cattle, the LH/FSH surge triggers a rapid decrease in estradiol and androgen production and a dramatic increase in progesterone and oxytocin biosynthesis. It is unclear how changes in gonadotropin concentrations in vivo regulate this follicular/luteal phase shift in hormone production. To address this question, theca interna and granulosa cells were isolated from preovulatory follicles of Holstein heifers approximately 24 h before the expected time of the LH/FSH surge and cultured in defined medium containing insulin (1 microgram/ml), with varying doses of LH or FSH (0, 1, 2, 4, 8, 16, 32, 64, or 128 ng/ml). Media were collected and replaced every 24 h for 3 days, and assayed for androstenedione and progesterone in theca interna cultures, and for estradiol, progesterone and oxytocin in granulosa cell cultures. After the first day of culture (24-72 h), only very low doses of LH (2 or 4 ng/ml) enhanced (p< 0.05) androstenedione secretion by theca interna cultures above control levels, whereas progesterone secretion was increased by a wide range of LH concentrations (p< 0.05), with maximal progesterone secretion at high doses of LH. Likewise, after the first day of culture (24-72 h), estradiol secretion by granulosa cells was stimulated only by low doses of FSH and was inhibited at higher concentrations relative to control cultures (p< 0.05), whereas the production of oxytocin and progesterone was enhanced maximally by high concentrations of FSH (p< 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)