Consequences of Brief Exposure to High Concentrations of Carbon Monoxide in Conscious Rats
Source: Inhalation Toxicology, Volume 17, Number 13, December 1 2005 , pp. 755-764(10)
Publisher: Informa Healthcare
Abstract:Exposure to high-concentration carbon monoxide (CO) is of concern in military operations. Experimentally, the physiologic manifestations of a brief exposure to elevated levels of CO have not been fully described. This study investigated the development of acute CO poisoning in conscious male Sprague-Dawley rats (220–380 g). Animals were randomly grouped ( n = 6 ) and exposed to either air or 1 of 6 CO concentrations (1000, 3000, 6000, 10,000, 12,000, or 24,000 ppm) in a continuous air/CO dynamic exposure chamber for 5 min. Respiration was recorded prior to and during exposures. Mixed blood carboxyhemoglobin (COHb) and pH were measured before and immediately after exposure. Before exposure the mean baselines of respiratory minute volumes (RMVs) were 312.6 ± 43.9, 275.2 ± 40.8, and 302.3 ± 39.1 ml/min for the 10,000, 12,000 and 24,000 ppm groups, respectively. In the last minute of exposure RMVs were 118.9 ± 23.7, 62.1 ± 10.4, and 22.0 ± 15.1% ( p 82%. Blood pH was unaltered and no death occurred in rats exposed to CO at concentrations 10,000 ppm for brief periods as short as 5 min may change RMV, resulting in acute respiratory failure, acidemia, and even death.
Document Type: Research Article
Affiliations: 1: Department of Respiratory Research, Walter Reed Army Institute of Research, Silver Spring, Maryland, USA 2: Division of Pathology, Walter Reed Army Institute of Research, Silver Spring, Maryland, USA 3: Division of Biometrics, Walter Reed Army Institute of Research, Silver Spring, Maryland, USA
Publication date: 2005-12-01