【Objective】 To investigate the effect of ghrelin on lung nitrosative stress in septic rats. 【Methods】 Sepsis model was induced by cecal ligation and puncture (CLP). Twentyfour male SD rats were randomly divided into 3 groups according to randomized block design: shamoperated controls

sepsis (CLP) group

and ghrelin group. In ghrelin group

ghrelin was administered by intraperitoneal injection at 3 h and 15 h postoperation. Samples among each group were harvested at 20 h postoperation. We detected the activity of serum SOD

lung wet/dry weight

pulmonary iNOS and nitrotyrosine levels. 【Results】 The activity of serum SOD in sepsis group [(85.62 ±1.09)%] and ghrelin group [(88.71±0.86)%] was significantly decreased when compared with shamoperated controls [(93.17 ± 0.54)%]

P < 0.05. In ghrelin group

SOD activity was higher than that in sepsis group

but P > 0.05. There was no significant difference in lung wet/dry weight ratio between ghrelin group and sepsis group. Compared with sepsis group (1.08 ± 0.05)

pulmonary iNOS protein level in ghrelin group (0.87± 0.03) was reduced at 20 h postoperation. The result of immunohistochemistry revealed that the expression of nitrotyrosine in ghrelin group was lower than that in sepsis group

P < 0.05. 【Conclusion】 Ghrelin can downregulate pulmonary iNOS protein expression and decrease nitrosative stress in CLPinduced septic rats. Besides

it tended to increase serum SOD activity. However

lung wet/dry weight ratio did not show any improvement by ghrelin administration.