Effects of protein S-nitrosylation on the glycogen metabolism in postmortem pork

The aim of this study was to investigate the effects of protein S-nitrosylation on the glycogen metabolism in postmortem pork. The pork samples were incubated with control (0.9% NaCl), nitric oxide synthase (NOS) inhibitor, or NO donor for 4 and 12 h at 4 °C. Results indicate that NOS inhibitor treatment led to significantly lower level of glycogen and higher lactate content at 24 h compared those of control and NO donor treatments (P < 0.05). The pH of NOS inhibitor treatment was significantly lower than other treatments, which indicates the fast glycolysis during postmortem aging (P < 0.05). In addition, the activities of glycolytic enzymes including GP, GAPDH and PK were significantly different among three treatments (P < 0.05) possibly due to the different modification of protein S-nitrosylation. These results suggest that NO could regulate the glycogen metabolism through modulating the activities of glycolytic enzymes by protein S-nitrosylation.