Endotracheal aerosolization of atropine sulfate protects against soman-induced acute respiratory toxicity in guinea pigs
Source: Inhalation Toxicology, Volume 23, Number 4, March 2011 , pp. 182-195(14)
Publisher: Informa Healthcare
Abstract:The efficacy of endotracheal aerosolization of atropine sulfate for protection against soman (GD)-induced respiratory toxicity was investigated using microinstillation technique in guinea pigs. GD (841 mg/m3, 1.3 LCt50 or 1121 mg/m3, 1.7 LCt50) was aerosolized endotracheally to anesthetized male guinea pigs that were treated with atropine sulfate (5.0 mg/kg) 30 s postexposure by endotracheal microinstillation. Animals exposed to 841 mg/m3 and 1121 mg/m3GD resulted in 31 and 13% while treatment with atropine sulfate resulted in 100 and 50% survival, respectively. Cholinergic symptoms and increased body weight loss were reduced in atropine-treated animals compared to GD controls. Diminished pulse rate and blood O2 saturation in GD-exposed animals returned to normal levels after atropine treatment. Increased cell death, total cell count and protein in the bronchoalveolar fluid (BALF) in GD-exposed animals returned to normal levels following atropine treatment. GD exposure increased glutathione and superoxide dismutase levels in BALF and that were reduced in animals treated with atropine. Respiratory parameters measured by whole-body barometric plethysmography revealed that treatment with atropine sulfate resulted in normalization of respiratory frequency, tidal volume, time of expiration, time of inspiration, end expiratory pause, pseudo lung resistance (Penh) and pause at 4 and 24 h post 841 mg/m3 GD exposure. Lung histopathology showed that atropine treatment reduced bronchial epithelial subepithelial inflammation and multifocal alveolar septal edema. These results suggest that endotracheal aerosolization of atropine sulfate protects against respiratory toxicity and lung injury induced by microinstillation inhalation exposure to lethal doses of GD.
Document Type: Research Article
Affiliations: 1: 1Medical/Analytical Toxicology, US Army Medical Research Institute of Chemical Defense, Aberdeen Proving Ground, USA 2: 2Closed Head Injury Branch, Walter Reed Army Institute of Research, Center for Military Psychiatry and Neurosciences, Silver Spring, MD, USA 3: 3Department of Pathology, Walter Reed Army Institute of Research, Silver Spring, MD, USA
Publication date: 2011-03-01