Zetser A, Kisliouk T, Ivakin E, Lahav M
Bruce Rappaport Faculty of Medicine, Technion, Israel Institute of Technology, Haifa 31096, Israel.
Biol Reprod. 2001 Oct;65(4):1082-91. doi: 10.1093/biolreprod/65.4.1082.
Luteal regression is a multistep, prolonged process, and long-term luteal cultures are required for studying it in vitro. Cell suspensions from ovaries of superovulated rats were enriched with steroidogenic cells, seeded on laminin or fibronectin, and maintained in defined medium for up to 10 days. Progesterone secretion was much lower than that of 20alpha-dihydroprogesterone, a product of 20alpha-hydroxysteroid dehydrogenase (20alpha-HSD). Prolactin added throughout the incubation period gradually increased the percent progesterone out of total progestins to fourfold, while reducing 20alpha-HSD mRNA by 73%. Luteinizing hormone accelerated the establishment of higher percent progesterone by prolactin but by itself had no effect. Prolactin did not increase total progestin production or cytochrome P450 side-chain cleavage (P450(scc)) mRNA. Cell viability was unaffected by prolactin and/or LH. Prostaglandin F2alpha (PGF2alpha) was added 7-8 days after seeding. In prolactin-treated cells, PGF2alpha reduced steroidogenesis after 4-45 h, and at 45 h total progestins and P450(scc) mRNA were reduced by 45%. At 8-45 h PGF2alpha reduced the percent progesterone out of total progestins, and at 45 h 20alpha-HSD mRNA was doubled. In contrast, in prolactin-deprived cultures, PGF2alpha had little effect on total progestins or 20alpha-HSD mRNA but doubled P450(scc) mRNA. Phospholipase C activity was stimulated by PGF2alpha regardless of prolactin. Thus, when prolactin-treated, our cultures are a good model for mature corpora lutea challenged with PGF2alpha; the finding that without prolactin PGF2alpha has an alternative set of actions could help in identifying the signaling pathways of PGF2alpha responsible for its luteolytic effects.
黄体退化是一个多步骤的长期过程，需要进行长期的黄体培养以在体外对其进行研究。从超排卵大鼠的卵巢中获取的细胞悬液富含类固醇生成细胞，接种于层粘连蛋白或纤连蛋白上，并在限定培养基中培养长达10天。孕酮分泌量远低于20α-二氢孕酮，后者是20α-羟基类固醇脱氢酶（20α-HSD）的产物。在整个孵育期添加催乳素可使孕酮在总孕激素中的百分比逐渐增加至四倍，同时使20α-HSD mRNA减少73%。促黄体生成素加速了催乳素使孕酮百分比升高的过程，但自身并无作用。催乳素并未增加总孕激素的产生或细胞色素P450侧链裂解酶（P450(scc)）mRNA。细胞活力不受催乳素和/或促黄体生成素的影响。在接种后7 - 8天添加前列腺素F2α（PGF2α）。在经催乳素处理的细胞中，PGF2α在4 - 45小时后降低类固醇生成，在45小时时总孕激素和P450(scc) mRNA减少45%。在8 - 45小时，PGF2α降低了总孕激素中孕酮的百分比，在45小时时20α-HSD mRNA增加了一倍。相比之下，在未添加催乳素的培养物中，PGF2α对总孕激素或20α-HSD mRNA几乎没有影响，但使P450(scc) mRNA增加了一倍。无论是否有催乳素，PGF2α均可刺激磷脂酶C活性。因此，当用催乳素处理时，我们的培养物是PGF2α刺激成熟黄体的良好模型；在没有催乳素的情况下PGF2α具有另一组作用这一发现，可能有助于确定PGF2α导致其黄体溶解作用的信号通路。
