POTENTIAL FETOPROTECTANTS FROM ETOH-INDUCED STRESS

摄取EtOH可导致多种自由基种类的产生。如果EtOH消耗是大量和慢性的，体内的器官开始恶化。一些器官损伤是由于EtOH消耗造成的，可能是由自由基的产生和随后的脂质过氧化（LPO）引起的。现在的理论认为，LPO的普遍和毒性作用可能有助于胎儿酒精综合征（FAS）的表达。水飞蓟素（SY）是一种植物衍生的黄酮，已被确定为一种有效的抗氧化剂，目前在欧洲销售的商品名为Legalon(R)，是一种保护肝脏的药物。我们已经进行了几项动物研究，研究了SY对母亲和胎儿脑和肝组织中乙氧化酶诱导的酶活性的保肝和保胎作用。我们现在想测试SY和其他四种抗氧化类黄酮的抗氧化作用；槲皮素、杨梅素、(+)-儿茶素和芹菜素对暴露于etoh的胎鼠大脑和肝脏组织的影响。测试额外的生物类黄酮化合物是基于研究结果，其中证明这些类黄酮也抑制乙醇诱导的自由基产生。为了比较抗氧化效果，还将测试n -乙酰半胱氨酸（NAC）和S-腺苷甲硫酮（SAM）。在先前的体外研究中已经证明，胚胎大鼠肝细胞（FRH）线粒体在EtOH中孵育会增加氧化应激的迹象。进一步证实，在暴露于EtOH 24小时之前和期间，用NAC或SAM处理FRH线粒体可以防止谷胱甘肽（GSH）的减少，恢复细胞复制，并减缓丙二醛（MDA）的产生。我们将把这种体外模型扩展到体内模型，以验证一种或所有类黄酮与NAC或SAM一样有效地正常化et0h诱导的胎儿大脑和肝脏组织氧化应激的一般假设。大坝将在12小时内插管6次EtOH。按照Henderson， Devi, Perez, & Schencker（1995）中描述的程序，在妊娠12、13和14天的间隔时间内进行检查。用于评估预后的依赖指标将是：胎儿生存能力、胎儿体重、肝脏组织学、胎儿脑和肝组织谷胱甘肽水平、α生育酚水平、丙二醛水平和GGTP活性。此外，为了继续我们实验室目前的研究，我们将建立平行组，在这些组中饲养大鼠幼仔进行后续的行为测试。

The ingestion of EtOH can lead to the creation of a variety of free radical species. If EtOH consumption is heavy and chronic, organs within the body begin to deteriorate. Some of the organ damage sustained as a consequence of EtOH consumption might be caused by free radical generation and subsequent lipid peroxidation (LPO). It is now theorized that the pervasive and toxic effects of LPO may contribute to the expression of fetal alcohol syndrome (FAS). Silymarin (SY), a plant-derived flavone, has been identified as an effective antioxidant and is currently marketed in Europe wider the trade name Legalon(R) as a hepatoprotective medication. We have conducted several animal studies of the hepatoprotective and fetoprotective effects of SY against EtOH-induced enzyme activity in maternal and fetal brain and liver tissue. We now want to test the antioxidant effects of SY and four other antioxidant flavonoids; quercetin, myricetin, (+)-catechin, and apigenin on EtOH-exposed fetal rat brain and liver tissue. Testing of the additional bioflavonoid compounds is predicated on the results of studies in which it was demonstrated that these flavonoids also inhibited EtOH-induced free radical production. For purposes of comparison of antioxidant efficacy, N-acetylcysteine (NAC) and S- adenosylmethione (SAM) will also be tested. It has been demonstrated in previous in vitro studies that the incubation of fetal rat hepatocyte (FRH) mitochondria in EtOH increased indications of oxidative stress. It was further established that the treatment of the FRH mitochondria with NAC or SAM before and during the 24-hr exposure to EtOH prevented the decrease in glutathione (GSH), restored cell replication, and moderated malondialdehyde (MDA) production. We will extend this in vitro model to an in vivo model to test the general hypothesis that one or all of the flavonoids will be as effective as NAC or SAM at normalizing Et0H-induced oxidative stress in fetal brain and liver tissue. Dams will be intubated with EtOH six times at 12-hr. intervals over days 12, 13, and 14 of gestation following the procedures described in Henderson, Devi, Perez, & Schencker (1995). The dependent measures used to assess outcome will be: fetal viability, fetal weight, liver histology, fetal brain and liver tissue glutathione levels, alpha tocopherol levels, MDA levels, and GGTP activity. In addition, to continue with current studies in our lab, we will establish parallel groups in which rat pups will be raised for subsequent behavioral testing.