Concomitant Effect of Chlorpyrifos and Intranasal Endotoxin Administration on Apoptosis Related Protein Expression in Lung of Mice

Abstract

Pesticides and bacterial endotoxin have been implicated in variety of respiratory dysfunctions. In present study, mice were administered chlorpyrifos at 3 mg/Kg BW/day for 30 days (by oral gavage) and/or challenged with bacterial endotoxin at 80 μg/mice by intranasal route to investigate expression of apoptosis related proteins such as p53, Bax and caspase-3 in lung. The results of immunohistochemistry of lung showed significant increase in number of p53 expressing cells in chlorpyrifos treated mice as compared to control while endotoxin and chlorpyrifos+endotoxin treated mice showed increased number of p53 expressing cells as compared to control and chlorpyrifos treated mice. Chlorpyrifos or endotoxin administration resulted in increased expression of Bax and Caspase-3 while chlorpyrifos treated and endotoxin challenged mice showed synergistic effect on expression of these proteins. From these results, it is concluded that chlorpyrifos and/or endotoxin increased critical apoptosis related proteins such as p53, Bax and Caspase-3 in lung of mice, which may play pivotal role in pathophysiology of pulmonary dysfunctions resulting from exposure to pesticides and endotoxin.