Investigation of the critical amounts of inhaled particles in rat lung as a cause of fibrosis

大鼠肺中吸入颗粒的临界量作为纤维化原因的研究

• 批准号: 13670401
• 负责人: OYABU Takako
• 金额: $ 2.11万
• 依托单位: University of Occupational and Environmental Health
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 2001
• 资助国家: 日本
• 起止时间: 2001 至 2002
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-13670401/
• 关键词: Biopersiscentce; Respirable Particles; Fibrosis; Intratracheal instillation; Inhalation; 注入曝露法; 生体内滞留性; 気管内注入; チタン酸カリウム; クリアランス

The adverse health effect of respirable particles in working environment is thought to depend on the amounts and biopersistence of particles in lung. From the results of our rodent research, fiber amounts in lung over the critical amount (about 1 mg per lung) caused the prolongation of the biopersistence and fibrotic change.For the clarification of the critical amounts of fiber in lung, the quantitative relationship between particle amount in lung and biopersistence and pathological change were investigated using potassium octatitanate whisker by intratracheal instillation method and inhalation method. In intratracheal instillation method, 0.5, 1.0, 2.0, 5.0 mg of whisker were instilled to rat lungs. The biopersistence became longer and the pathological change became severe as the dose in lung increased. However the discrepancy between instillation results and inhalation results in the quantitative relation was observed. Then inhalation research in high concentration during 4 week was performed. The amount in lung was 1.5 mg which is almost critical amount in previous research but the prolongation in bioresistence was not observed. In order to clarify the critical amount, we need to conduct more inhalation experiments using fibers which have different physicochemical properties when the deposited amount is around 1 or 2 mg.furthermore the effect of particle shape on the adverse health effect was investigated. 2 mg of potassium octatitanate particle was instilled to rat lung and compared with the results of whisker. Particle was cleared faster and smaller pathological change than whisker. This results suggest that the particle shape is important index for adverse health effect.

作业环境中可吸入颗粒物对人体健康的影响与其在肺内的数量和生物持久性有关。本实验采用八钛酸钾晶须，分别采用气管内滴注法和吸入法，研究了肺内颗粒物数量与肺生物持久性和病理变化的定量关系，以明确肺内颗粒物数量与肺生物持久性和病理变化的关系。肺内滴注法：将晶须0.5、1.0、2.0、5.0mg分别滴入大鼠肺内。肺组织的生物持久性随剂量的增加而延长，肺组织的病理变化也随剂量的增加而加重。然而，滴注结果和吸入结果之间的定量关系存在差异。然后进行为期4周的高浓度吸入研究。肺中的量为1.5mg，这几乎是以前研究中的临界量，但未观察到生物耐受性的延长。为了阐明临界量，我们需要使用具有不同物理化学性质的纤维进行更多的吸入实验，当沉积量约为1或2 mg时。此外，研究了颗粒形状对不良健康影响的影响。将2mg八钛酸钾颗粒滴入大鼠肺内，并与晶须的结果进行比较。微粒比晶须清除快，病变小。这一结果表明，颗粒形状是不利健康影响的重要指标。