Abstract
Oxidative stress is common in the whole process of broiler production, and breast muscle is one of the target organs most vulnerable to oxidative attack. When broilers are subjected to oxidative stress, the regulation of adenosine 5-monophosphate activated protein kinase (AMPK) is a critical path to maintain the dynamic balance of intracellular energy. However, whether calcium/calmodulin-dependent protein kinase (CaMKK) and liver kinase B1 (LKB1) are involved in the regulation of AMPK activation in broiler breast muscle under oxidative stress has not been elucidated. In this study, a total of 144 one-day-old male Ross 308 chicks were selected, with an average body weight of 43.44 ± 0.04 g. The broilers were divided into 3 groups with 6 replicates of 8 broilers each (control group, intraperitoneal injection of physiological saline group, and intraperitoneal injection of hydrogen peroxide [H2O2] group), the injection time was selected on the 16th and 37th day of the experimental period, the injection volumes were 1.0 mL/kg broiler body weight. The results of this experiment showed that H2O2 exposure reduced the average daily gain (ADG) and increased the feed to gain ratio (F/G), the level of corticosterone (CORT) and the activity of lactate dehydrogenase (LDH) in serum were increased after H2O2 exposure. H2O2 exposure also increased the contents of reactive oxygen species (ROS) and protein carbonyl, but decreased the activities of catalase (CAT), total antioxidant capacity (T-AOC), total superoxide dismutase (T-SOD) and glutathione peroxidase (GSH-Px) in breast muscle. After H2O2 exposure, the activity of pyruvate dehydrogenase (PDH) was decreased, the content of glycogen was reduced, and the contents of adenosine monophosphate (AMP) and lactate were increased in breast muscle. In addition, H2O2 exposure increased the content of Ca2+, upregulated the protein expression levels of CaMKK1 and p-AMPK, and increased the activities of hexokinase (HK) and LDH in breast muscle. These findings suggested that the activation of CaMKK/LKB1/AMPK signaling pathway would be associated with the accelerated glycolysis of broiler breast muscle under oxidative stress.