Key Laboratory of Meat Processing and Quality Control, Ministry of Education China, Synergetic Innovation Center of Food Safety and Nutrition, College of Food Science and Technology, Nanjing Agricultural University, Nanjing 210095, China.
Key Laboratory of Meat Processing and Quality Control, Ministry of Education China, Synergetic Innovation Center of Food Safety and Nutrition, College of Food Science and Technology, Nanjing Agricultural University, Nanjing 210095, China.
Meat Sci. 2015 Jan;99:25-31. doi: 10.1016/j.meatsci.2014.08.010. Epub 2014 Aug 27.
The objective of this study was to investigate the biochemical changes of nitric oxide synthase (NOS) in pork skeletal muscles during postmortem storage. Longissimus thoracis (LT), psoas major (PM) and semimembranosus (SM) muscles of pork were removed immediately after slaughter and stored under vacuum condition at 4°C for 0, 1 and 3d. Results showed that all three muscles exhibited NOS activity until 1d while SM muscle retained NOS activity after 3d of storage. The content of nNOS in SM muscle was stable across 3d of storage while decreased intensity of nNOS was detected at 1 and 3d of aging in PM and LT muscles due to the degradation of calpain. Immunostaining showed that nNOS was located at not only sarcolemma but also cytoplasm at 0 and 1d of storage. Our data suggest that postmortem muscles possess NOS activity and nNOS expression depends on muscle type.
本研究旨在探讨宰后贮藏过程中猪骨骼肌中一氧化氮合酶（NOS）的生化变化。宰后立即从猪的背最长肌（LT）、腰大肌（PM）和半膜肌（SM）中取出肌肉，并在 4°C 下真空储存 0、1 和 3d。结果表明，所有三种肌肉在 1d 内均表现出 NOS 活性，而 SM 肌肉在储存 3d 后仍保持 NOS 活性。SM 肌肉中的 nNOS 含量在 3d 的储存过程中保持稳定，而 PM 和 LT 肌肉中的 nNOS 强度在 1 和 3d 的老化过程中由于钙蛋白酶的降解而降低。免疫染色显示，nNOS 不仅位于肌膜上，而且在储存 0 和 1d 时也位于细胞质中。我们的数据表明，宰后肌肉具有 NOS 活性，nNOS 的表达取决于肌肉类型。
