Talbot R J, Morgan A, Moores S R, Matulionis D H
Int J Radiat Biol Relat Stud Phys Chem Med. 1987 Jun;51(6):1101-10. doi: 10.1080/09553008714551391.
Our current experiments were designed to show whether 12 months' exposure to cigarette smoke enhances the incidence of lung tumours in mice that had previously inhaled 239PuO2. These periods of smoke exposure are almost complete. After death their lungs will be cleared and any nodules found will be sectioned for histopathology. This paper reports the results of two preliminary experiments conducted earlier. The first study showed that mice could tolerate the proposed smoking regime for 3 months, with no sign of ill health in any animal throughout. The major difference found was a reduced growth rate in both smoke- and sham-exposed mice relative to that of cage controls. After 3 months of treatment, histopathology and morphometry of lung sections found only slight smoke-induced changes. These included a reduced proportion of alveolar space and an increased number of pulmonary alveolar macrophages (PAM) per unit area. Bronchopulmonary lavage showed that the PAM from smoke-exposed mice were larger than those from sham-exposed or control mice and that an increased proportion of cells were binucleate. All mice in the second study were initially exposed to 239PuO2, then subsequently divided into three treatment groups as above. Cigarette smoke exposure was shown to inhibit the removal of 239Pu from the lung whilst sham exposure had no effect. Smoke exposure also produced an increase and sham exposure a decrease in lung weights relative to those of cage controls. The latter was probably as a result of their lower growth rate. In our current experiments it is likely that the group receiving 239PuO2, then smoke, will receive a higher radiation dose to lung than those receiving 239PuO2 only. Any increased tumour incidence found will be considered in conjunction with this evidence.
我们目前的实验旨在表明，让此前吸入过239PuO2的小鼠暴露于香烟烟雾12个月，是否会增加其肺部肿瘤的发生率。这些烟雾暴露期已基本结束。小鼠死后，将对其肺部进行清理，对发现的任何结节进行切片以进行组织病理学检查。本文报告了早期进行的两项初步实验的结果。第一项研究表明，小鼠能够耐受提议的吸烟方案3个月，在此期间所有动物均未出现健康问题。发现的主要差异是，与笼养对照小鼠相比，烟雾暴露组和假暴露组小鼠的生长速度均有所降低。治疗3个月后，对肺切片进行组织病理学和形态学测量发现，烟雾仅引起了轻微变化。这些变化包括肺泡空间比例降低，单位面积内肺泡巨噬细胞（PAM）数量增加。支气管肺泡灌洗显示，烟雾暴露组小鼠的PAM比假暴露组或对照组小鼠的更大，且双核细胞的比例增加。第二项研究中的所有小鼠最初均暴露于239PuO2，然后像上述那样分为三个治疗组。结果显示，香烟烟雾暴露会抑制肺部对239Pu的清除，而假暴露则没有影响。与笼养对照小鼠相比，烟雾暴露还导致肺重量增加，假暴露则使其降低。后者可能是由于它们的生长速度较低。在我们目前的实验中，先接受239PuO2然后再接受烟雾暴露的组，其肺部可能会比仅接受239PuO2的组接受更高的辐射剂量。发现的任何肿瘤发生率增加都将结合这一证据进行考虑。
