Corbani M, Counis R, Wolinska-Witort E, d'Angelo-Bernard G, Moumni M, Jutisz M
Laboratoire des Hormones Polypeptidiques, CNRS, Gif-sur-Yvette, France.
J Mol Endocrinol. 1990 Apr;4(2):119-25. doi: 10.1677/jme.0.0040119.
The effects of oestradiol and progesterone on LH-subunit mRNA levels were investigated in ovariectomized rats. Four weeks after ovariectomy, rats were implanted with silicone elastomer capsules containing oestradiol and/or injected daily with progesterone in oil (5 mg/rat) for 8 days. The levels of pituitary mRNA encoding alpha and LH-beta were determined using direct hybridization with specific [32P]cDNA probes. After oestradiol implantation in ovariectomized rats, both alpha and LH-beta mRNA decreased with time, with maximum inhibition after 6-8 days of treatment. Progesterone injected alone did not show any effect on alpha and LH-beta mRNA. Cytosolic progesterone receptors, determined using [3H]methyl-17 alpha-progesterone as ligand, were undetectable in control ovariectomized rats. In contrast, 2 days after oestradiol implantation, the number of receptors increased to 287.5 +/- 35.4 (S.E.M.) fmol/pituitary and reached a plateau of 400 +/- 21.8 fmol/pituitary after 4 days. The effects of progesterone were therefore examined by first implanting ovariectomized rats with oestradiol to induce progesterone receptors and then injecting progesterone daily for a further period of 6 days. As a result of this treatment, progesterone induced a decrease in the pituitary gland contents of both alpha and LH-beta mRNAs, and LH release was significantly greater than that observed in the group receiving oestradiol alone. Moreover, the mRNA levels in the animals treated with oestradiol plus progesterone were lower after 8 days of treatment than those observed in ovariectomized rats treated with a tenfold higher dose of oestradiol alone.(ABSTRACT TRUNCATED AT 250 WORDS)
在去卵巢大鼠中研究了雌二醇和孕酮对促黄体生成素亚基mRNA水平的影响。去卵巢4周后，给大鼠植入含雌二醇的硅橡胶弹性体胶囊，和/或每天注射溶于油中的孕酮（5mg/只），持续8天。使用与特异性[32P]cDNA探针直接杂交的方法测定垂体中编码α亚基和促黄体生成素β亚基的mRNA水平。在去卵巢大鼠中植入雌二醇后，α亚基和促黄体生成素β亚基的mRNA均随时间下降，在治疗6 - 8天后抑制作用最大。单独注射孕酮对α亚基和促黄体生成素β亚基的mRNA没有任何影响。以[3H]甲基-17α-孕酮作为配体测定的胞质孕酮受体，在对照去卵巢大鼠中未检测到。相反，在植入雌二醇2天后，受体数量增加到287.5±35.4（标准误）fmol/垂体，并在4天后达到400±21.8 fmol/垂体的平台期。因此，通过先给去卵巢大鼠植入雌二醇以诱导孕酮受体，然后再连续6天每天注射孕酮来研究孕酮的作用。这种治疗的结果是，孕酮导致垂体中α亚基和促黄体生成素β亚基的mRNA含量均下降，并且促黄体生成素的释放明显高于仅接受雌二醇治疗的组。此外，在接受雌二醇加孕酮治疗8天后，动物体内的mRNA水平低于单独接受高10倍剂量雌二醇治疗的去卵巢大鼠。（摘要截短至250字）
