Immunohistochemical characterization of oxidative stress in the lungs of rats exposed to the humidifier disinfectant polyhexamethylene guanidine hydrochloride.

Immunohistochemical characterization of oxidative stress in the lungs of rats exposed to the humidifier disinfectant polyhexamethylene guanidine hydrochloride. J Toxicol Pathol. 2019 Oct;32(4):311-317 Authors: Lee YH, Seo DS, Lee MJ, Cha HG 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 d...
Source: Journal of Toxicologic Pathology - Category: Toxicology Tags: J Toxicol Pathol Source Type: research