Guanidinoacetic acid regulated postmortem muscle glycolysis associated with AMPK signaling and protein acetylation.

Objective: Antemortem stress accelerated muscle energy consumption in postmortem muscle. The objective of our study was to investigate the regulation of guanidinoacetic acid (GAA) administration on the postmortem glycolysis and protein acetylation in postmortem muscle of antemortem stress.

Methods: Forty C57BL/6 male mice were chosen and randomly assigned to four treatment groups (A, B, C and D), each treatment consisted of 10 replicates. Mice in group B, C and D were treated with 0.05% GAA oral administration for 6 days. On the 7th day of the experiment, the mice in group A and B were injected with saline, and mice in group C and D were injected with 5-aminoimidazole-4-carboxamide1-β-D-ribofuranoside (AICAR,50 μg/g body weight) and a combined injection with AICAR (50 μg/g body weight) and histone acetylase inhibitor Ⅱ (HAT Ⅱ,185 μg/g body weight), respectively.

Results: The results showed that the values of pH45min and pH24h of postmortem muscle in GAA administration were higher than those in the control group. However, the opposite result was observed in AICAR group. Moreover, the activities of acetone kinase, hexokinase and fruc-tose-2,6-diphosphatase, combined with the protein abundance of phosphorylated liver kinase, phosphorylated AMPKα2 and total acetylated protein were all decreased by GAA administration and HAT Ⅱ treatment.

Conclusion: Taken together, AMPK signaling and protein acetylation could mediate the regulation of GAA administration on postmortem glycolysis of antemortem stress-muscle.