Study on the apoptosis mediated by apoptosis-inducing-factor and influencing factors of bovine muscle during postmortem aging.

This study investigated the apoptosis pathway mediated by apoptosis-inducing factors (AIF) and internal factors that influence the release of AIF. The results indicated that the AIF expression was decreased in mitochondria and increased in nucleus (P < 0.05). However, no significant differences were observed in the AIF expression in mitochondria with caspase inhibitor treatment. The optical density of nucleus and mitochondrial swelling was significant increased (P < 0.05). Reactive oxygen species (ROS) fell gradually within the first 6 h and increased in the next 24 h. Calpain I activity was decreased, Ca2+ concentration, cathepsin B and D activities was increased (P < 0.05). The results demonstrated that AIF-mediated caspase-dependent pathway was a new mitochondrial apoptosis pathway and that mitochondrial swelling, ROS content, Ca2+ concentration, calpain I, cathepsin B and cathepsin D activities are the key influencing factors in apoptosis in postmortem bovine muscle.