title: Activation of caspase-9 and its influencing factors in beef during conditioning.
abstract: To study the activation of caspase-9 and its potential influence in conditioning, longissimus thoracis (LT), semitendinosus (STN) and psoas minor (PMi) muscles were used to analyze the ratio of pro-apoptotic bax to anti-apoptotic bcl-2 in fresh tissues and observe the changes in ATP, cytosolic cytochrome c and caspase-9 activity levels during storage at 4°C. Caspase-9 activity at 5 h is higher than the activity at 0 and 24 h in the muscles (P<0.001). The ATP content decreased between 0 and 3 h, between 8 and 14 h in the PMi and LT muscles (P<0.0001), whereas between 0 and 5 h, between 8 and 14 h in the STN muscle (P<0.0001). There is 60.2%, 55.3% and 43.1% available ATP in the STN, LT and PMi muscles at 5 h, respectively. The cytosolic cytochrome c level increased during 5 and 24 h storage in the LT and PMi muscles (P<0.0001), during 5 and 96 h in the STN muscle (P<0.0001). The cytosolic cytochrome c at 24 h (P<0.001) and ratio of bax to bcl-2 (P<0.05) was higher in the PMi than in other muscles. We concluded that the increase in cytosolic cytochrome c and available intracellular ATP should be responsible for the increase in caspase-9 activity; the activation of caspase-9 could be limited by the subsequent depletion of ATP; the postmortem release level of cytochrome c could be determined by the ratio of bax to bcl-2 in fresh tissues.
authors.affiliation: 1 Department of Food Science and Engineering, Ningbo University, Ningbo 315211, P. R. China.
authors.forename: J
authors.initials: J
authors.lastname: Cao
authors.affiliation: 2 National Center of Meat Quality and Safety Control, MOST, Nanjing Agricultural University, Nanjing 210095, P. R. China.
authors.forename: G
authors.initials: G
authors.lastname: Zhou
authors.affiliation: 3 College of Food Science and Technology, Shanghai Ocean University, Shanghai 201306, P. R. China.
authors.forename: Y
authors.initials: Y
authors.lastname: Liu
authors.affiliation: 4 College of Food Science and Technology, Yunnan Agricultural University, Kunming 650201, P. R. China.
authors.forename: G
authors.initials: G
authors.lastname: Liao
authors.affiliation: 2 National Center of Meat Quality and Safety Control, MOST, Nanjing Agricultural University, Nanjing 210095, P. R. China.
authors.forename: Q
authors.initials: Q
authors.lastname: Zhang
authors.affiliation: 2 National Center of Meat Quality and Safety Control, MOST, Nanjing Agricultural University, Nanjing 210095, P. R. China.
authors.forename: K
authors.initials: K
authors.lastname: Ye
authors.affiliation: 1 Department of Food Science and Engineering, Ningbo University, Ningbo 315211, P. R. China.
authors.forename: D
authors.initials: D
authors.lastname: Pan
authors.affiliation: 1 Department of Food Science and Engineering, Ningbo University, Ningbo 315211, P. R. China.
authors.forename: C
authors.initials: C
authors.lastname: Ou
mesh_terms: D000255:Adenosine Triphosphate / Q000032:analysis; D000818:Animals; D017209:Apoptosis; D051017:Apoptosis Regulatory Proteins / Q000032:analysis; D053453:Caspase 9 / Q000378:metabolism*; D002417:Cattle; D045304:Cytochromes c / Q000032:analysis; D004789:Enzyme Activation; D008460:Meat / Q000032:analysis*; D018482:Muscle, Skeletal / Q000737:chemistry* / Q000201:enzymology
chemical_list: D051017:Apoptosis Regulatory Proteins; D000255:Adenosine Triphosphate; D045304:Cytochromes c; D053453:Caspase 9