Preferential recruitment of neutrophils by endothelin-1 in acute lung inflammation induced by lipopolysaccharide or cigarette smoke

Tapan Bhavsar, Xing Jian Liu, Hardik Patel, Ralph Stephani, Jerome O CantorSt John’s University, School of Pharmacy and Allied Health Sciences, New York, USAAbstract: This study examined the role of endothelin-1 (ET-1) in recruiting inflammatory cells to the lung after induction of injury with either lipopolysaccharide (LPS) or cigarette smoke. Hamsters injected with either ET-1 or its precursor peptide (Big ET-1) prior to treatment with LPS or cigarette smoke had markedly increased concentrations of neutrophils in bronchoalveolar lavage fluid (BALF) despite a reduction in total numbers of BALF leukocytes. Furthermore, the effect of ET-1 on smoke-exposed animals was reversed by addition of an endothelin-A receptor antagonist. These results are consistent with preferential recruitment of neutrophils by ET-1, and suggest that inhibition of this proinfl ammatory mediator may decrease acute pulmonary inflammation associated with cigarette smoke and other pulmonary toxins.Keywords: endothelin, lipopolysaccahride, cigarette smoke, neutrophils, lung