Immunohistochemical characterization of oxidative stress in the lungs of rats exposed to the humidifier disinfectant polyhexamethylene guanidine hydrochloride | 2021.06.30 | ||
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저자: Yong-Hoon Lee, Dong-Seok Seo, Mi Ju Lee, Hyo-Geun Cha (원문 바로가기) ABSTRACT Polyhexamethylene guanidine hydrochloride (PHMG-HCl), an antimicrobial additive in humidifier disinfectants, was associated with the pulmonary disease outbreak in South Korea. However, PHMG-mediated oxidative stress has only been studied in vitro. Here, we evaluated PHMG-induced oxidative stress in the lungs of rats exposed to PHMG-HCl. Male F344 rats were exposed to different concentrations of PHMG-HCl for 13-weeks via whole-body inhalation. Histopathological examination of the exposed rats showed the presence of lung lesions, including alveolar/interstitial fibrosis with inflammatory cell infiltration, bronchioalveolar hyperplasia, bronchiolar/alveolar squamous metaplasia, bronchial/bronchiolar epithelial detachment, and alveolar hemorrhage. Immunohistochemical analysis showed that 4-hydroxynonenal (4-HNE) was expressed in the bronchiolar epithelium, mainly in Clara cells and macrophages of the fibrotic tissue. The number of 4-HNE-positive cells increased significantly in a dose-dependent manner. This is the first in vivo study to report PHMG-induced oxidative stress. Our study provides clues to elucidate the mechanisms underlying PHMG-induced damage in patients affected by humidifier disinfectants. Keywords 4-hydroxynonenal (4-HNE); humidifier disinfectants; immunohistochemistry; inhalation toxicity; oxidative stress; polyhexamethylene guanidine hydrochloride (PHMG-HCl). |