宰后鸭肉骨骼肌细胞中凋亡的发生及其影响因素研究

Study on the Apoptosis and Effect Facts of Duck Skeletal Muscle during Postmortem Ageing

探讨宰后鸭肉骨骼肌细胞中是否发生细胞凋亡以及哪些因素对其产生影响,为进一步用细胞凋亡机理阐明水禽类肉的成熟机理提供新的试验依据。分析检测宰后鸭胸肉和腿肉中Bcl-2、Bax、Caspase-3蛋白表达量和线粒体细胞色素-C含量变化、TUNEL法检测阳性凋亡细胞核数量变化以及宰后ATP代谢和pH值变化情况。结果显示,宰后鸭肉骨骼肌中Bax/Bcl-2蛋白表达量比值均显著上调(P<0.05),线粒体细胞色素-C含量均显著降低(P<0.05),Caspase-3酶原裂解为20 kDa左右的活化片断,宰后0.5～8 h骨骼肌中阳性凋亡细胞核数量均显著增多(P<0.05);ATP含量和pH值在宰后0.5～8 h均呈现显著下降趋势(P<0.05)。Bax促凋亡蛋白表达量的占优,线粒体细胞色素-C的快速释放,凋亡关键蛋白酶Caspase-3的活化和阳性凋亡细胞核数量的急剧增多,表明宰后鸭肉骨骼肌细胞中明显存在一个细胞凋亡的过程。ATP的大量消耗和pH值下调等因素为细胞凋亡提供一个必要的细胞内环境,且鸭肉骨骼肌凋亡程度可能于宰后8 h左右达到一个峰值。

This experiment investigate whether the duck skeletal muscle cells apoptosis occurs and what factors affect it and provide new experimental evidence for further use of the mechanism of apoptosis mature mechanism to clarify the water in poultry meat.Analysis detected after slaughter,the duck breast and thigh meat of Bcl-2,Bax in Caspase-3 protein expression and mitochondrial cytochrome-C content,TUNEL detect changes of the number of positive-apoptotic nuclei as well as post-mortem ATP metabolism and pH changes situation.The results showed that the duck skeletal muscle after slaughter Bax/Bcl-2 protein ratio were significantly raised（P0.05）,mitochondrial cytochrome-C content was significantly lower（P0.05）,Caspase-3 zymogen,respectively split into the activation of about 20 kDa fragment,0.5-8 h skeletal muscle after slaughter,the number of positive apoptotic nuclei were significantly increased（P0.05）;content of ATP and pH value in the postmortem 0.5-8 h showed a significant downward trend（P0.05）.The results of Bax pro-apoptotic protein expression levels was dominant,the quick emancipation of mitochondrial cytochrome-C,the activation of apoptosis key pro-Caspase-3 and the sharp increase of the number of positive apoptotic nuclei showed that there was a process of apoptosis postmortem in the duck skeletal muscle cells evidently.Consumption of ATP and the pH value reduction provide a necessary environment within the cell apoptosis and,the degree of apoptosis may reach a peak around 8 h postmortem in duck skeletal muscle.