Ethanol exposure induces oxidative stress and impairs nitric oxide availability in the human placental villi: A possible mechanism of toxicity
Ethanol exposure induces oxidative stress and impairs nitric oxide availability in the human placental villi: A possible mechanism of toxicity
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DOI：
10.1067/mob.2000.104201
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发表时间：
2000-03-01
影响因子：
9.8
通讯作者：
Magness, RR
中科院分区：
文献类型：
--
作者：
Kay, HH;Grindle, KM;Magness, RR
目的：我们进行了这项调查，以探讨乙醇暴露对一氧化氮合酶水平和一氧化氮释放的影响。我们的假设是，乙醇暴露修改一氧化氮的活性在胎盘内的氧化stress.Study设计：四个10克的长期正常人胎盘绒毛组织的样本进行灌注nonrecycling Dulbecco的修改鹰的培养基和25 mmol/L N-[2-羟乙基]哌嗪-N '-[2-乙磺酸]与0-，50-，100-，或200 mmol/L乙醇。暴露2小时后，取出组织，固定并冷冻用于分析。对亚型I或神经元型一氧化氮合酶（nNOS）、亚型II或诱导型一氧化氮合酶（iNOS）和亚型III或内皮型一氧化氮合酶（eNOS）定位进行免疫组织化学分析。进行Western印迹分析用于eNOS定量。环磷酸鸟苷和铜锌超氧化物歧化酶水平分别采用电免疫分析法和动力学分析法测定。结果：免疫组化证实，只有eNOS定位于合体滋养细胞。乙醇暴露后，eNOS蛋白表达增加2.5- 3.0倍，超过对照组。组织环磷酸鸟苷含量和一氧化氮释放到流出物中减少，而超氧化物歧化酶水平在较高的乙醇水平下增加（P < .05）。乙醇暴露似乎会诱导氧化应激，这可能是一氧化氮释放减少的原因，因为一氧化氮可能会转向清除自由基，eNOS蛋白表达增加可能是对一氧化氮需求增加的反应。一氧化氮可用性降低可能会对胎盘血流调节产生不利影响，这反过来又可能导致暴露于乙醇的胎儿生长受限。
OBJECTIVE: We undertook this investigation to explore the effects of ethanol exposure on nitric oxide synthase levels and nitric oxide release. Our hypothesis was that ethanol exposure modifies nitric oxide activity within the placenta as a result of oxidative stress.STUDY DESIGN: Four 10-g samples of term normal human placental villous tissue were perifused with nonrecirculating Dulbecco's modified Eagle's medium and 25-mmol/L N-[2-hydroxyethyl]piperazine-N'-[2-ethanesulfonic acid] with 0-, 50-, 100-, or 200-mmol/L ethanol. After 2 hours of exposure, tissue was removed, fixed, and frozen for analysis. immunohistochemical analysis was performed for subtype I or neuronal nitric oxide synthase (nNOS), subtype II or inducible nitric oxide synthase (iNOS), and subtype III or endothelial nitric oxide synthase (eNOS) localization. Western blot analysis was performed for eNOS quantitation. Cyclic guanosine monophosphate and copper-zinc superoxide dismutase levels were measured by electroimmunoassay and kinetic assay, respectively. Nitric oxide release was analyzed by a Sievers nitric oxide analyzer.RESULTS: Immunohistochemical examination confirmed that only eNOS was localized to the syncytiotrophoblasts. After ethanol exposure, eNOS protein expression increased 2.5- to 3.0-fold over that of the control. Tissue cyclic guanosine monophosphate content and nitric oxide release into the effluent were decreased, whereas superoxide dismutase levels were increased at higher ethanol levels (P < .05).CONCLUSION: Ethanol exposure appears to induce oxidative stress, which may account for the decreased nitric oxide release, because nitric oxide may be shunted toward scavenging free radicals, Increased eNOS protein expression may be a response to the increased demand for nitric oxide. Decreased nitric oxide availability could adversely affect placental blood flow regulation, which could, in turn, account for the growth restriction seen in ethanol-exposed fetuses.