Abstract: A total of 90 30-day-old commercial broilers were divided randomly into three groups that were respectively treated with LPS (lipopolysaccharide from Salmonella typhimurium, 5 mg/kg), AG (aminoguanidine, 300 mg/kg)+LPS and saline (2 mL/kg). After the injection of drugs, livers were taken from 6 killed chicken per group at five time points, i.e. 1, 3, 5, 7 and 9 h. At every time point, the mitochondria were determined for the evaluations of the concentrations of complexⅠ. The results indicated that LPS decreased significantly the activity of complexⅠof mitochondria in liver in broilers from 1 to 9 h(P<0.05). After the injections of AG, at 1 h, AG didn’t change the activity of complexⅠ(P>0.05), and increased significantly the activity of complexⅠat 3 h(P<0.05), and didn’t change the activity of complexⅠfrom 5 to 7 h(P>0.05), and decreased significantly the activity of complexⅠat 9 h(P<0.05),of the mitochondria in liver in broilers. It might be concluded that the LPS induced the damnification of mitochondria, resulted the disfunction of energy metabolism, decreased the production of ATP energy, resulted the impediment of activity of complexⅠ. AG played an important role in the objection of LPS and the protection of broilers.

Key words: broilers; endotoxin; lipopolysaccharide; aminoguanidine; mitochondria; complexⅠ