吸入奈米等級之二氧化鈦顆粒對於鼠肺功能影響的研究

Background and objective: Environmental nano particles exposure is a risk factor for health, in which different exposure routes or different amount accumulated produce different influences on the individuals. Since the surface effect and mass effect of nano particles they will change the physical or chemical properties of the bio-materials so that organisims will be injuried. Nano particles used widely in the daily life. For architecture, nano particles used in the coating and photocatalyst painting with anti-bacteria effect. Amazing functions of nano particles are over emphasized in recent decade. However, the reverse effects were ignored. Therefore, the effects of nano particles on lung function will be studied.
Methods: In this study dry powder injector is used for titanium dioxide nano particles exposure after Sprague Dawley rats were anesthetized with Isoflurane. Different groups are included: control group, low doses of titanium dioxide nano particles (4 mg/kg), medium dose (10 mg/kg) and high dose (20 mg/kg) group. The duration of exposures is eight hours. During exposure period, body weight, behavior and appearance of SD rats are recorded. The pulmonary function tests including Non Invasive Airway Mechanics and BUXCO Pulmonary Function Testing. The parameters of lung injury included airway resistance, peak flow, functional residual capacity and lung compliance. Blood concentrations of lactate dehydrogenase were also measured.
Results: Preliminary result showed that exposure to titanium dioxide nano particles, the respiratory resistance, functional residual capacity and compliance increased significantly. Peak flow decreased significantly. Lactate dehydrogenase level increased. Conclusions: Through this study, exposure of titanium dioxide nano particles can induce airway inflammation, lung hyperinflation and lung injury. There were not significant differences among different exposure doses suggests that even low dose of titanium exposure could induce lung inflammation and lung injury.