Turnover of Musculotendinous Collagen Following Exercise

描述(由申请人提供)：过度使用伤害是经常进行活动的人以及与工作有关的受伤的人常见的。在慢性过度使用损伤中，失败的部位通常是肌腱结构。肌腱组织中最丰富的成分是胶原蛋白。尽管胶原蛋白组织无处不在，但人们对其了解不多，而且被认为是相当惰性的。然而，越来越多的证据表明，胶原蛋白是非常动态的。这项建议的目的是进一步阐明肌肉和肌腱胶原合成和降解的过程，以响应机械负荷及其在过度使用损伤中的不足。具体地说，假设1)肌肉和肌腱胶原蛋白的合成随着运动的增加而增加，但这些速度并不遵循相同的时间进程，2)肌肉和肌腱胶原的降解率随着运动的反应而增加，3)过度使用肌腱损伤的受试者，在急性运动后肌腱(而不是肌肉)的胶原合成速度与健康肌腱相比一过性地降低。为此，将结合稳定同位素示踪剂、组织取样、微透析和分子生物学技术，研究健康受试者和髌腱炎者在剧烈运动后的恢复过程中肌肉胶原的合成和降解及其调节。随着胶原合成和降解模式的阐明，以及损伤患者的缺陷所在，随后将有可能设计具体的干预措施来帮助重建。

DESCRIPTION (provided by applicant): Overuse injuries are common to those regularly performing activity as well as those with job related injuries. The site of failure in chronic overuse injuries are often musculotendinous structures. The most abundant component of musculotendinous tissue is collagen. Despite its ubiquity, collagen tissue is not well understood and is perceived to be rather inert. However, evidence is accumulating that collagen is quite dynamic. The purpose of this proposal is to further elucidate the processes of muscle and tendon collagen synthesis and degradation in response to mechanical loading and its deficiencies in overuse injuries. Specifically it is hypothesized that, 1) muscle and tendon collagen increase synthesis in response to exercise but these rates do not follow the same time course, 2) rates of muscle and tendon collagen degradation increase in response to exercise, 3) in subjects with an overuse tendon injury, rates of collagen synthesis in tendon (but not muscle) are transiently decreased compared to healthy tendon after an acute bout of exercise. To this end muscle collagen synthesis and degradation and its regulation will be studied with a combination of stable isotope tracers, tissue sampling, microdialysis, and molecular biology techniques during recovery from a strenuous bout of exercise in healthy subjects and those with patellar tendonitis. With elucidation of the patterns of collagen synthesis and degradation and where deficiencies lie in those with injuries, it will then be possible to design specific interventions to aid in restructuring.