Grain dust exposure is a common cause of respiratory tract disorders in grain workers, feed mill employees, and farmers. Although grain dust is a heterogeneous substance, the endotoxin component has received the most attention as a possible cause of airway inflammation. In the February issue of American Journal of Physiology — Lung Cellular and Molecular Physiology, researchers from University of Iowa publish new evidence that endotoxin is important in the development of chronic airway disease.
Caroline George and colleagues evaluated physiological and airway inflammation parameters after an eight-week exposure to corn dust extract and again after a four-week recovery period in a strain of mice sensitive to endotoxin (C3H/HeBFeJ) and in one genetically hyporesponsive to (C3H/HeJ) endotoxin.
They found that airway hyperreactivity persisted after the recovery period only in the sensitive mice. These mice also showed significant inflammation of the lower airway but after the recovery period the inflammation subsided...