Turnover of Musculotendinous Collagen Following Exercise

描述（由申请人提供）：过度使用伤害是常见的那些经常进行活动，以及那些与工作有关的伤害。慢性过度使用损伤的失效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。尽管胶原蛋白组织普遍存在，但人们对它的了解并不充分，而且认为它是相当惰性的。然而，越来越多的证据表明胶原蛋白是非常动态的。本提案的目的是进一步阐明肌肉和肌腱胶原蛋白的合成和降解的过程中响应机械负荷及其不足之处，在过度使用损伤。具体地，假设1）肌肉和肌腱胶原蛋白响应于运动而增加合成，但这些速率不遵循相同的时间过程，2）肌肉和肌腱胶原蛋白降解速率响应于运动而增加，3）在过度使用肌腱损伤的受试者中，在剧烈运动后，与健康肌腱相比，肌腱（而不是肌肉）中胶原蛋白合成的速率暂时降低。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受试者在剧烈运动后恢复期间肌肉胶原蛋白的合成和降解及其调节。随着胶原蛋白合成和降解模式的阐明，以及受伤者的缺陷所在，然后将有可能设计特定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.