Eicosatetraynoic and eicosatriynoic acids, lipoxygenase inhibitors, block meiosis via antioxidant action
Eicosatetraynoic and eicosatriynoic acids, lipoxygenase inhibitors, block meiosis via antioxidant action
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DOI：
10.1152/ajpcell.2000.278.4.c646
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发表时间：
2000-04-01
影响因子：
5.5
通讯作者：
Behrman, HR
中科院分区：
文献类型：
--
作者：
Takami, M;Preston, SL;Behrman, HR
我们以前表明，去甲二氢愈创木酸（NDGA）和其他抗氧化剂抑制卵母细胞卵丘复合体（OCC）和裸露卵母细胞（DO）减数分裂的恢复。由于NDGA是众所周知的是一种脂氧合酶（LOX）的抑制剂，我们评估了其他LOX抑制剂是否会影响OCC和DO中自发性生发泡破裂（GVBD）。最小有效剂量的5，8，11，14-二十碳四炔酸（ETYA）和5，8，11-二十碳三炔酸（ETI）分别能显著和可逆地抑制大鼠排卵前卵泡OCC的自发性GVBD。在DO中，100 μ M ETYA或ETI显著抑制GVBD。在OCC或DO中抑制GVBD的ETYA和ETI的最小有效浓度类似于在完整细胞中抑制50% LOX活性所需的浓度的30- 50倍。因为我们之前发现NDGA和其他抗氧化剂抑制减数分裂的自发恢复，我们评估了ETYA和ETI是否可以类似地作为活性氧（ROS）的清除剂。鲁米诺放大的化学发光显示，50 μ M的ETYA或ETI显著且显著地减少了用10 mM 2，2 '-偶氮二（2-脒基丙烷）二盐酸盐（AAPH）产生的ROS。此外，用30 mm AAPH孵育DO可逆转100 μ M ETYA或ETI对GVBD的抑制作用。这些发现支持ETYA和ETI通过充当抗氧化剂而不是通过抑制LOX来抑制卵母细胞成熟的结论。
We previously showed that nordihydroguaiaretic acid (NDGA) and other antioxidants inhibit the resumption of meiosis in oocyte-cumulus complexes (OCC) and denuded oocytes (DO). Because NDGA is well known to be an inhibitor of lipoxygenases (LOX), we assessed whether other LOX inhibitors influence spontaneous germinal vesicle breakdown (GVBD) in OCC and DO. Spontaneous GVBD in rat OCC obtained from preovulatory follicles was significantly and reversibly inhibited by the minimum effective doses of 80 and 100 mu M 5,8,11,14-eicosatetraynoic acid (ETYA) and 5,8,11-eicosatriynoic acid (ETI), respectively. In DO, GVBD was significantly inhibited by 100 mu M ETYA or ETI. The minimum effective concentrations of ETYA and ETI for inhibition of GVBD in either OCC or DO are similar to 30- to 50-fold higher than the concentrations necessary to inhibit LOX activity by 50% in intact cells. Because re previously showed that NDGA and other antioxidants inhibit the spontaneous resumption of meiosis, we assessed whether ETYA and ETI may act similarly as scavengers of reactive oxygen species (ROS). Luminol-amplified chemiluminescence showed that 50 mu M of either ETYA or ETI markedly and significantly reduced ROS generated with 10 mM 2,2'-azobis(2-amidinopropane)dihydrochloride (AAPH). Moreover, incubation of DO with 30 mm AAPH reversed the inhibition of GVBD produced by 100 mu M ETYA or ETI. These findings support the conclusion that ETYA and ETI inhibit oocyte maturation by acting as antioxidants rather than by inhibiting LOX.