EFFECTS OF POLYAROMATIC COMPOUNDS ON PLACENTAL PROTEINS

我们的研究表明， 细胞色素P-450单加氧酶在组织中的作用 多环芳烃化合物β-萘啶酮对大鼠胎盘的影响 (BNF)和3-甲基胆蒽（3 MC）。 的进一步研究 分离的胎盘组织的外植体显示， （3 H）-亮氨酸掺入分泌蛋白质的改变， 来自BetaNF/3 MC处理的基底区和卵黄囊组织 动物 这项拟议中的研究将寻求识别这些蛋白质 受betaNF/3 MC影响并表征生化特征 参与其细胞内过程的改变 分别合成和分泌。 调查的第一线 将研究一个新的主要40，000（40 K）分子量 （M/r）卵黄囊外植体培养基中存在的蛋白质 是betaNF所特有，或者更确切地说，是Ah诱导的标志物， β NF/3MC。 betaNF/3 MC对细胞因子掺入的影响 放射性标记的氨基酸转化为40 K蛋白和甲胎蛋白 (AFP)卵黄囊的主要分泌产物， 在培养基和组织中使用二维 聚丙烯酰胺凝胶电泳和免疫印迹 程序. 卵黄囊mRNA将在无细胞培养中表征。 易位系统，以及通过北方印迹分析， 大鼠AFP cDNA探针。 如果有一个共同的机制 40 K蛋白的BetaNF/3 MC相关存在，进一步 研究将确定40 K蛋白的合成是否是 在数量上和时间上， Ethocyresorufin-O-脱乙基酶（EROD）活性（BetaNF，3 MC） 和TCDD。 下一个目标将是评估是否 BetaNF/3 MC处理降低了蛋黄的AFP分泌 通过翻译后糖基化的改变 机制等 AFP分子异质性将被表征 ConA-Sepharose层析和2D-PAGE。 单独的 研究将研究基底区组织的外植体， 确定BetaNF/3 MC治疗是否选择性地改变 大鼠胎盘催乳素（PL）或a合成与分泌 其他20- 30 K M/r蛋白的复合物。 最终目标是 确定孕妇体内AFP和AP的浓度 血清被BetaNF/3 MC改变，此外，与 胎盘和胎儿重量。 总之，拟议的研究 将表征合成中的生物化学改变， β NF/3 MC处理的胎盘组织中的分泌蛋白 大鼠 这一结果将有助于进一步阐明诱导是否 Ah的含量是胎盘功能毒性的指标。

Our studies have demonstrated the differential induction of cytochrome P-450 monooxygenase enzymes in the tissues of the rat placenta by the polyaromatic compounds beta-naphthoflavone (BNF) and 3-methlcholanthrene (3MC). Further studies with explants of isolated placental tissues show that the profile of (3H)-leucine incorporation into secreted proteins is altered in basal zone and yolk sac tissues from BetaNF/3MC-treated animals. The proposed research will seek to identify the proteins affected by betaNF/3MC as well as characterize biochemical alterations in the intracellular processes involved in their respective synthesis and secretion. The first line of investigation will examine whether a new major 40,000 (40K) molecular weight (M/r) protein present in the culture media from yolk sac explants is unique to betaNF or, rather, is a marker for Ah inductin by betaNF/3MC. Effects of betaNF/3MC on the incorporation of radiolabeled amino acids into 40K protein and alpha-fetoprotein (AFP), the main secretory product of the yolk sac, will be examined in culture media and tissues using 2-dimensional polyacrylamide gel electrophoresis (2D-PAGE) and immunoblot procedures. Yolk sac mRNA will be characterized in cell-free translocation system, as well as by Northern blot analysis using a rat AFP cDNA probe. If a common mechanism is implicated in the BetaNF/3MC-related presence of the 40K protein, further studies will determine whether the synthesis of the 40K protein is realted, quantitatively and temporally, to the induction of ethocyresorufin-O-deethylase (EROD) activity by BetaNF, 3MC and TCDD. The next aim will be to evaluate whether BetaNF/3MC-treatments have decreased AFP secretion from yolk sac through alterations in post-translational glycosylation mechanisms. AFP molcular heterogeneity will be characterized by Con A-Sepharose chromatography and 2D-PAGE. A separate line of investigation will study explants of basal zone tissue to determine if BetaNF/3MC treatments selectively alter the synthesis and secretion of rat placental lactogen (PL) or a complex of other 20-30K M/r proteins. The final goal is to establish whether concentrations of AFP and AP in maternal serum are altered by BetaNF/3MC and, moreover, correlate with placental and fetal weight. In summary, the proposed research will characterize biochemical alterations in the synthesis of secretory proteins in placental tissue from betaNF/3MC-treated rats. The results wil further help to elucidate whether induction of Ah is an indicator of toxicity in palcental function.