GROWTH MODULATORY AND PROMOTERS OF LIVER CANCER II

拟议项目旨在研究机制的各个方面 其中某些环境因素作为肝脏的促进剂 致癌作用 低水平的饮食苯巴比妥（PB），或喂养 饮食缺乏单一的营养因素，胆碱，都强烈促进 化学致癌物诱发大鼠肝肿瘤。 添加 低水平的PB到无胆碱（CD）饮食导致协同作用， 促进行动。 现有证据表明，发起人的行为， 基本上，通过影响肝脏靶细胞的增殖， 通过化学致癌物刺激它们的进化， 癌前病变和肿瘤病变。 这些影响可能是由于 启动子直接作用于启动的细胞，或通过 创造有利于扩散的局部微观环境， 启动细胞的进化。 正常大鼠肝脏含有 其分别刺激或抑制肝细胞增殖。 的 这些物质之间的平衡被认为参与了 调节肝脏正常生长。 本项目提出的研究 旨在更好地了解这些 内源性肝脏物质，并探讨是否和在多大程度上 PB和CD饮食的肝癌发生促进作用， 单独或组合，是通过改变的平衡， 这些物质。

The proposed project is aimed at studying aspects of the mechanism(s) whereby certain environmental factors act as promoters of liver carcinogenesis. Low levels of dietary phenobarbital (PB), or feeding a diet devoid of a single nutritive factor, choline, both strongly promote the induction of liver tumors by chemical carcinogens in rats. Addition of low levels of PB to the choline-devoid (CD) diet results in a synergistic promoting action. Available evidence indicates that the promoters act, basically, by affecting the proliferation of liver target cells, initiated by a chemical carcinogen, and by stimulating their evolution to preneoplastic and neoplastic lesions. These effects could result from the promoters acting directly on the initiated cells, or indirectly, by creating a local micro-environment conducive to the proliferation and evolution of the initiated cells. Normal rat liver contains substances which stimulate or inhibit, respectively, hepatic cell proliferation. The balance between these substances is thought to participate in the regulation of normal liver growth. The studies proposed in this project are designed to gain a better understanding of the nature of these endogenous hepatic substances, and to explore whether and to what extent the liver carcinogenesis promoting action of PB and of a CD diet, either alone or in combination, is mediated by an alteration of the balance of these substances.