RESPIRATORY CARCINOGENESIS BY CHEMICAL AND PHYSICAL FACTORS

诱导呼吸道肿瘤发生机制的研究 化学和物理因素，单独或以各种组合， 在适当的动物模型中进行。 两名叙利亚人最近在 金黄仓鼠群（近交系15：16/EHS：CR和远交系Syrian/CR：RGH） 用于颗粒物上吸附的致癌物的气管内滴注 载体单独或组合，全身与局部治疗，和 与致癌物和辅助因子联合治疗。 F-344大鼠 用于二氧化硅致癌机制的研究， 纤维化 呼吸道上皮组织反应的特征在于： 组织学、超微结构、组织化学和生物化学方法，以及 通过他们对器官和细胞培养条件的研究。 二乙基亚硝胺诱发金黄地鼠呼吸道肿瘤的实验研究 当使用致癌物质时， 从一日龄开始比在4或8周，但诱导 气管乳头状瘤不受年龄因素的影响。 组合暴露方案已被用于研究 N-甲基硝基脲、苯并[a]芘（BP）、3-甲基吲哚和 二甲亚砜 对物理因素作用的研究仍在继续， 包括微创生理盐水和微粒物质 本文比较研究了BP在金黄地鼠气管、支气管和 单次或重复滴注BP氧化铁后的肺部 粒子 致癌的靶部位（气管和支气管） 显示出最高水平的新陈代谢和DNA结合。 研究二氧化硅诱导的肺上皮增生性病变， 它们与肉芽肿细胞反应、 活性氧和炎症细胞介质的作用。

Studies on the mechanisms of respiratory tract carcinoma induction by chemical and physical factors, alone or in various combinations, are pursued in the appropriate animal models. Two recently established Syrian golden hamster colonies (inbred 15:16/EHS:CR and outbred Syrian/CR:RGH) are used for intratracheal instillation of carcinogens adsorbed on particulate carriers alone or in combinations, systemic versus topical treatments,a nd combined treatments with carcinogens and cofactors. F-344 rats are also used for studies on mechanisms of silica-indued carcinogenesis and fibrogenesis. Respiratory epithelial tissue responses are characterized by histological, ultrastructural, histochemical and biochemical methods, and by their study in organ and cell culture conditions. Induction of respiratory tract carcinomas by diethylnitrosamine in hamster was found to be much more effective when the carcinogen was administered starting at one day of age than at 4 or 8 weeks, but the induction of tracheal papillomas is not affected by this age factor. Combined exposure protocols have been used to study the effects of N-methylnitro-sourea, benzo[a]pyrene (BP), 3-methylindole and dimethylsulfoxide. Studies on the role of physical factors are continuing, with protocols involving microtrauma, saline and particulate materials. Metabolism of BP was comparatively studies in hamster trachea, bronchi and lung after single or repeated instillation of BP with ferric oxide particles. The target sites for carcinogenesis (trachea and bronchi) showed the highest level of metabolism and of DNA binding. Silica-induced pulmonary epithelial proliferative lesions are studied for their pathogenetic relationship to granulomatous cell reactions, to the role fo reactive oxygen and cellular mediators of inflammation.