Effect Of Melatonin On Lung Injury Induced By Lipopolysaccharide In Rats And Its Elementary Mechanism

Objective: Acute lung injury (ALI) is a common disease induced by many factors including infection in clinic, it can result in diffuse pulmonary parenchyma injury. ALI is also a typical appearance in lung for systemic inflammatory response syndrome (SIRS) or multiple organ dysfunction syndrome (MODS). The pathogenesis of ALI is very complicated, which has remained unclear. The majority of scholars thought that the unbalance of oxidation/antioxidation played an important role in body, especially in lung. When lung tissues were demolished by all kinds of etiological factors (trauma, shock, infection, et al), then severe oxidative stress was generated in lung and it also caused ALI accordingly. In addition, many scholars reported that a great quantity of polymorphonuclear neutrophil (PMN) sequestrated in intrapulmonary were the important cells, which could result in inflammatory reaction of ALI. Activated PMN in lung were in state of respiratory burst and oxygen consumption increased significantly. At the same time, excessive oxygen free radicals were generated, like superoxide anion and hydroxy radical, et al. Oxygen free radical might participate in the occurrence of ALI through destroying lung tissues directly and...