EFFECTS OF POLYAROMATIC COMPOUNDS ON PLACENTAL PROTEINS

我们的研究已经证明了不同的诱导 小鼠组织中细胞色素P-450单加氧酶的研究 多环芳香族化合物β-萘黄酮对大鼠胎盘的影响 (BnF)和3-甲基胆蒽(3mc)。进一步研究与 分离的胎盘组织的外植体显示， 分泌蛋白中的(~3H)-亮氨酸掺入在 经BetaNF/3mc处理后的基底带和卵黄囊组织 动物。这项拟议的研究将寻求识别这些蛋白质 β-核因子/3mc的影响及生化特性 与其相关的细胞内过程的改变 各自的合成和分泌。调查的第一线 将研究一种新的主要40,000(40K)分子量 卵黄囊外植体培养上清液中存在(M/R)蛋白质 是BetaNF所特有的，或者，更确切地说，是由 BetaNf/3mc。β-核因子/3mc对血管内皮细胞掺入的影响 放射性标记氨基酸合成40K蛋白和甲胎蛋白 卵黄囊的主要分泌产物(法新社)将是 在培养基和组织中使用2维 聚丙烯酰胺凝胶电泳法和免疫印迹法 程序。卵黄囊mRNA的特征是无细胞 易位系统，以及通过Northern杂交分析 大鼠甲胎蛋白基因探针。如果一个共同的机制牵涉到 与BetaNF/3mc相关的40K蛋白的存在，进一步 研究将确定40K蛋白的合成是否 从数量上和时间上都与……的诱导有关 乙基二氢呋喃-O-脱乙基酶(EROD)的活性 和TCDD。下一个目标将是评估 β-核因子/3mc-处理降低了卵黄分泌甲胎蛋白 翻译后糖基化改变引起的SAC 机械装置。甲胎蛋白分子的不均一性将被表征 经ConA-Sepharose层析和2D-PAGE鉴定。一个单独的 调查线将研究基底带组织的外植体 确定BetaNF/3mc治疗是否选择性地改变 大鼠胎盘催乳素(PL)或a的合成与分泌 其他20-30K M/r蛋白的复合体。最终目标是 确定母体血清中AFP和AP的浓度 血清被BetaNF/3mc改变，而且与 胎盘和胎儿体重。综上所述，拟议的研究 将表征合成过程中的生化变化 β-核因子/3MC处理后胎盘组织中的分泌蛋白 老鼠。这些结果将有助于进一步阐明归纳 是反映心脏功能毒性的一个指标。

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.