血小板活化因子对大鼠黄体细胞孕酮分泌及血管内皮生长因子表达的作用

本文旨在研究血小板活化因子(platelet-activating factor,PAF)对大鼠黄体细胞孕酮分泌及血管内皮生长因子(vascularendothelial growth factor,VEGF)mRNA表达的作用.将未成年(25～28 d)Sprague-Dawley雌性大鼠颈部皮下注射50 IU孕马血清促性腺激素(pregnant mare serum gonadotrophin,PMSG),48 h后注射25 IU人绒毛膜促性腺激素(human chorionicgonadotrophin.hCG)诱导卵泡发育和黄体生成,第6天(hCG注射日为第1天)收集卵巢黄体细胞,体外培养24 h后,不加或加入不同剂量(0.1 μg/mL、1 μg/mL、10 μg/mL)PAF,37℃、5%CO2培养箱内培养24 h.用放射免疫方法测定培养液中孕酮的含量,流式细胞仪和RT-PCR方法检测黄体细胞凋亡以及VEGF mRNA的表达.结果显示,PAF促进黄体细胞孕酮分泌,1 μg/mL PAF作用最强(P<0.05);PAF促进黄体细胞凋亡无明显剂量依赖性,但10 μg/mL PAF显著促进大鼠黄体细胞凋亡(P<0.05):PAF刺激黄体细胞VEGF mRNA表达,1 μg/mL PAF效果最显著(P<0.01).结果提示,PAF可通过调节黄体细胞孕酮的分泌和VEGF mRNA的表达来促进黄体形成.

Role of platelet-activating factor in progesterone synthesis and vascular endothelial growth factor expression in rat luteal cells

The present study aimed to investigate the role of platelet-activating factor (PAF) in progesterone synthesis and vascular endothelial growth factor (VEGF) expression in rat luteal cells. Immature (25-28 days old) female Sprague-Dawley rats were injected subcutaneously with 50 IU pregnant mare serum gonadotrophin (PMSG), and 25 IU human chorionic gonadotrophin (hCG) 48 h later, to induce folliclular development and luteum formation. On day 6 after hCG administration (the day of hCG administration was the first day), the rats were killed by guillotine and the ovarian luteal cells were collected. After incubation for 24 h, luteal cells were incubated without or with different doses (0.1 mug/mL, 1 mug/mL, 10 mug/mL) of PAF at 37 degrees C (5% CO2) for 24 h, and then progesterone concentration was evaluated by radioimmunoassay (RIA); apoptotic rate and VEGF mRNA expression in luteal cells were assessed by flow cytometry and RT-PCR, respectively. The results showed that PAF promoted progesterone production, with a maximal effect at 1 mug/mL (P<0.05); PAF increased apoptotic rate but not in a dose-dependent manner, and 10 mug/mL PAF enhanced apoptotic rate significantly (P<0.05); furthermore, PAF stimulated VEGF mRNA expression in luteal cells, especially at 1 mug/mL (P<0.01). It is suggested that PAF regulates progesterone synthesis and VEGF mRNA expression in luteal cells to mediate corpus luteum formation in rat ovary.