Functional oxytocin receptors in bovine granulosa cells
Functional oxytocin receptors in bovine granulosa cells
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DOI：
10.1095/biolreprod56.3.625
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发表时间：
1997-03-01
影响因子：
3.6
通讯作者：
Kimura, T
中科院分区：
文献类型：
--
作者：
Okuda, K;Uenoyama, Y;Kimura, T
本研究的目的是确定牛颗粒细胞上功能性催产素（OT）受体的存在。通过放射受体测定法，对来自小卵泡（直径3-5 mm）或排卵前（成熟）卵泡的新鲜制备的牛颗粒细胞进行OT受体检查。Scatchard分析表明，小卵泡颗粒细胞的结合容量和亲和力均显著高于成熟卵泡颗粒细胞（P < 0.01）。用逆转录聚合酶链反应分析，OT受体mRNA的表达检测颗粒细胞从小和成熟的卵泡。小卵泡颗粒细胞在含10%小牛血清的Dulbecco改良Eagle培养基和Ham F-12培养基（1：1 [v：v]）中培养72 h后，随着培养时间的延长，颗粒细胞中OT受体的浓度逐渐降低，而孕酮和OT释放量则逐渐增加。然而，在培养72 h期间，结合亲和力没有改变。当牛卵泡卵母细胞与卵丘卵母细胞培养24小时，在组织培养介质-199与10%胎牛血清和OT（0-10 nM），卵母细胞达到最大卵丘扩张的百分比显着增加，在0.5，1，和10 nM OT，虽然核成熟的卵丘细胞包围的卵母细胞不受影响的添加OT。与OT拮抗剂共暴露阻断了OT对卵丘扩张的刺激作用，证实了该作用的特异性。抗OT兔血清对卵母细胞卵丘扩展率的影响显著低于正常兔血清组（p < 0.05）。总体结果表明，牛颗粒细胞中存在功能性OT受体，并支持OT在卵泡生长过程中作为自分泌因子调节颗粒细胞功能的假设。
The aim of this study was to identify the presence of functional oxytocin (OT) receptors on bovine granulosa cells. Freshly prepared bovine granulosa cells from small (3-5 mm in diameter) or preovulatory (mature) follicles were examined for OT receptors by a radioreceptor assay. Scatchard analysis revealed that both binding capacity and affinity in granulosa cells from small follicles were significantly higher than those in granulosa cells from mature follicles (p < 0.01). With use of a reverse transcriptase polymerase chain reaction analysis, expression of OT receptor mRNA was detected in granulosa cells obtained from both small and mature follicles. When the granulosa cells obtained from small follicles were cultured in Dulbecco's Modified Eagle's Medium and Ham's F-12 medium (1:1 [v:v]) with 10% calf serum up to 72 h, as the period of culture was prolonged, the concentration of OT receptor decreased with increases of progesterone and OT release in the medium. However, the binding affinity was not changed during culture for 72 h. When bovine follicular oocytes with cumulus oophorus were cultured for 24 h in tissue culture Medium-199 with 10% fetal calf serum and OT (0-10 nM), the percentages of oocytes reaching maximum cumulus expansion were significantly increased at 0.5, 1, and 10 nM OT, although nuclear maturation in oocytes surrounded by compact cumulus cells was not affected by the addition of OT. Coexposure with OT antagonist blocked the stimulatory effect of OT on cumulus expansion, confirming the specificity of the effect. Furthermore, anti-OT rabbit serum inhibited the percentages of oocytes with expanded cumulus compared to those supplemented with normal rabbit serum (p < 0.05). The overall results indicate the presence of functional OT receptors in bovine granulosa cells and support the hypothesis that OT plays a role (or roles) in regulating the function of granulosa cells as an autocrine factor during follicular growth.