Post-Graduation Medical Sciences Program, Medical School/Universidade Federal do Rio Grande do Sul (UFRGS), Brazil.
Nitric Oxide. 2009 Nov-Dec;21(3-4):157-63. doi: 10.1016/j.niox.2009.08.002. Epub 2009 Aug 12.
The muscle wound healing occurs in three overlapping phases: (1) degeneration and inflammation, (2) muscle regeneration, and (3) fibrosis. Simultaneously to injury cellular infiltration by neutrophils and macrophages occur, as well as cellular 'respiratory burst' via activation of the enzyme NADPH oxidase. When skeletal muscle is stretched or injured, myogenic satellite cells are activated to enter the cell cycle, divide, differentiate and fuse with muscle fibers to repair damaged regions and to enhance hypertrophy of muscle fibers. This process depends on nitric oxide (NO) production, metalloproteinase (MMP) activation and release of hepatocyte growth factor (HGF) from the extracellular matrix. Generation of a fibrotic scar tissue, with partial loss of function, can also occur, and seems to be dependent, at least in part, on local TGF-beta expression, which can be downregulated by NO. Hence, regeneration the muscle depends on the type and severity of the injury, the appropriate inflammatory response and on the balance of the processes of remodeling and fibrosis. It appears that in all these phases NO exerts a significant role. Better comprehension of this role, as well as of the participation of other important mediators, may lead to development of new treatment strategies trying to tip the balance in favor of greater regeneration over fibrosis, resulting in better functional recovery.
（1）变性和炎症，（2）肌肉再生，和（3）纤维化。同时，中性粒细胞和巨噬细胞浸润细胞，以及通过 NADPH 氧化酶的激活发生细胞“呼吸爆发”。当骨骼肌伸展或受伤时，成肌卫星细胞被激活进入细胞周期，分裂，分化并与肌肉纤维融合，以修复受损区域并增强肌肉纤维的肥大。这个过程依赖于一氧化氮（NO）的产生，金属蛋白酶（MMP）的激活以及肝细胞生长因子（HGF）从细胞外基质中的释放。部分功能丧失的纤维疤痕组织的生成也可能发生，并且似乎至少部分依赖于局部 TGF-β表达，NO 可以下调 TGF-β表达。因此，肌肉的再生取决于损伤的类型和严重程度，适当的炎症反应以及重塑和纤维化过程的平衡。似乎在所有这些阶段，NO 都发挥了重要作用。更好地理解这种作用以及其他重要介质的参与，可能会导致开发新的治疗策略，试图使平衡有利于更大的再生而不是纤维化，从而实现更好的功能恢复。
