The role of dopamine D2 receptor in the maintenance of pregnancy

Luteinization hormone和prolactin由pituitary扮演一个重要的角色，尤其是早期怀孕期间的维护。众所周知，多巴胺抑制剂（多巴胺D2受体刺激剂）是可以抑制从氯胺酮中释放催乳素的。要研究多巴胺D2受体在luteal功能和怀孕的维护中的作用，我们调查了Cabergolin（CAB）的影响，是一种长期的多巴胺抑制剂，关于培养大鼠Granulosa细胞和porcine luteal细胞的类固醇发生。此外，小鼠卵巢中多巴胺D2受体mRNA的表达是通过RT-PCR进行的。CAB inhibited the FSH-stimulated production of progesterone by cultured rat granulosa cell at concentrations ranging from 10年D1-8年D1 to 10年D1-4年D1M。At high concentrations （10年D1-5年D1 and 10年D1-4年D1M）， CAB inhibited the production of estradiol by cultured rat granulosa cell。The production of progesterone by cultured luteal cell prepared from porcine corpus luteum was also inhibited by CAB at concentrations ranging from 10-D1-8]在D1-4中D1M in the both condition with or without LH。Ovary from control， under inducing（注射PMSG后48小时），预热器（HCG注射后6小时），蒸发器（hCG后注射12小时）、后静脉注射（hCG后注射24小时和48小时）小鼠被测试用于多巴胺D2受体mRNA表达的小鼠。However，多巴胺D2受体的信息在任何血管循环中都没有检测到这些结果，即多巴胺D2受体刺激直接抑制了体外颗粒细胞和荧光细胞的类固醇生成，建议多巴胺D2受体可能参与到荧光功能和怀孕的维护中。

Luteinization hormone and prolactin secreted by pituitary play an important role in the maintenance of luteal function especially at early pregnancy. It is well known that dopamine agonist (dopamine D2 receptor stimulant) is able to inhibits prolactin release from the pituitary gland. To study the role of dopamine D2 receptor in the maintenance of luteal function and pregnancy, we investigated the effect of cabergoline (CAB), a long-acting dopaminergic agonist , on the steroidogenesis of cultured rat granulosa cells and porcine luteal cells. Also the expression of dopamine D2 receptor mRNA in the mouse ovary was examined by RT-PCR. CAB inhibited the FSH-stimulated production of progesterone by cultured rat granulosa cell at concentrations ranging from 10ィイD1-8ィエD1 to 10ィイD1-4ィエD1M. At high concentrations (10ィイD1-5ィエD1 and 10ィイD1-4ィエD1M), CAB inhibited the production of estradiol by cultured rat granulosa cell. The production of progesterone by cultured luteal cell prepared from porcine corpus luteum was also inhibited by CAB at concentrations ranging from 10ィイD1-8]ィエD1 to 10ィイD1-4ィエD1M in the both condition with or without LH.Ovary from control, under inducing (48 h after injection of PMSG), preovulatory (6h after injection of hCG), ovulatory (12h after injection of hCG), postovulatory(24 and 48 h after injection of hCG) mice was examined for the expression of dopamine D2 receptor mRNA. However, the message of dopamine D2 receptor was not detected in the ovary at any ovulatory cycle These results, that dopamine D2 receptor stimulant directly inhibits the steroidogenesis of granulosa cells and luteal cells in vitro, suggest that dopamine D2 receptor may participate in the maintenance of luteal function and pregnancy.