Recovery from silver-nanoparticle-exposure-induced lung inflammation and lung function changes in Sprague Dawley rats

• Published in: Nanotoxicology 2013-03, Vol.7 (2), p.169-180
• Main Authors: Song, Kyung Seuk, Sung, Jae Hyuck, Ji, Jun Ho, Lee, Ji Hyun, Lee, Jong Seong, Ryu, Hyeon Ryol, Lee, Jin Kyu, Chung, Yong Hyun, Park, Hyun Min, Shin, Beom Soo, Chang, Hee Kyung, Kelman, Bruce, Yu, Il Je
• Format: Article
• Language: English
• Subjects: Animals; Biological and medical sciences; Chemical and industrial products toxicology. Toxic occupational diseases; Cross-disciplinary physics: materials science; rheology; Dose-Response Relationship, Drug; Drug toxicity and drugs side effects treatment; Exact sciences and technology; Female; Inflammation; inhalation exposure; Inhalation Exposure - adverse effects; Lung - drug effects; Lung - metabolism; Lung - pathology; Lung - physiopathology; lung function; Male; Materials science; Medical sciences; Metal Nanoparticles - toxicity; Metals and various inorganic compounds; Nanoscale materials and structures: fabrication and characterization; Particle Size; Peak Expiratory Flow Rate - drug effects; Pharmacology. Drug treatments; Physics; Pneumonia - chemically induced; Pneumonia - metabolism; Pneumonia - pathology; Pneumonia - physiopathology; Rats; Rats, Sprague-Dawley; recovery; Recovery of Function; Respiratory Rate - drug effects; Silver - pharmacokinetics; Silver - toxicity; Silver nanoparticle; subchronic; Tidal Volume - drug effects; Time Factors; Toxicity: respiratory system, ent, stomatology; Toxicology
• ISSN: 1743-5390; 1743-5404
• DOI: 10.3109/17435390.2011.648223

Abstract In a previous study, the lung function, as indicated by the tidal volume, minute volume, and peak inspiration flow, decreased during 90 days of exposure to silver nanoparticles and was accompanied by inflammatory lesions in the lung morphology. Therefore, this study investigated the recovery from such lung function changes in rats following the cessation of 12 weeks of nanoparticle exposure. Male and female rats were exposed to silver nanoparticles (14-15 nm diameter) at concentrations of 0.66 × 106 particles/cm3 (49 μg/m3, low dose), 1.41 × 106 particles/cm3 (117 μg/m3, middle dose), and 3.24 × 106 particles/cm3 (381 μg/m3, high dose) for 6 h/day in an inhalation chamber for 12 weeks. The rats were then allowed to recover. The lung function was measured every week during the exposure period and after the cessation of exposure, plus animals were sacrificed after the 12-week exposure period, and 4 weeks and 12 weeks after the exposure cessation. An exposure-related lung function decrease was measured in the male rats after the 12-week exposure period and 12 weeks after the exposure cessation. In contrast, the female rats did not show a consistent lung function decrease either during the exposure period or following the exposure cessation. The histopathology showed a gradual recovery from the lung inflammation in the female rats, whereas the male rats in the high-dose group exhibited persistent inflammation throughout the 12-week recovery period. Therefore, the present results suggest a potential persistence of lung function changes and inflammation induced by silver nanoparticle exposure above the no observed adverse effect level.