Turnover of Musculotendinous Collagen Following Exercise

描述（由申请人提供）：对于那些经常进行活动的人以及那些有工作相关伤害的人来说，过度使用伤害是很常见的。慢性过度使用性损伤的失败部位通常是肌肉肌腱结构。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，但人们对它的了解并不多，人们认为它是惰性的。然而，越来越多的证据表明胶原蛋白是动态的。本研究的目的是进一步阐明肌肉和肌腱胶原蛋白的合成和降解过程对机械负荷的响应及其在过度使用损伤中的不足。具体来说，我们假设：1)肌肉和肌腱胶原蛋白的合成在运动后增加，但这些速度并不遵循相同的时间过程；2)肌肉和肌腱胶原蛋白的降解速度在运动后增加；3)在肌腱过度使用损伤的受试者中，肌腱（而不是肌肉）的胶原蛋白合成速度在急性运动后短暂地低于健康肌腱。为此，我们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骨肌腱炎患者在剧烈运动后恢复过程中肌肉胶原蛋白的合成和降解及其调控。随着胶原蛋白合成和降解模式的阐明，以及受伤患者的缺陷在哪里，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.