7.0T MR代谢与功能成像对延迟性肌肉酸痛及PI3K/AKt/mTOR信号通路作用研究

Delayed onset muscle soreness (DOMS), also called muscle fever, is the pain and stiffness felt in muscles several hours to days after unaccustomed or strenuous exercise. The soreness is felt most strongly 24 to 72 hours after the exercise. It is caused by eccentric exercise. After such exercise, the muscle adapts rapidly to prevent muscle damage, and thereby soreness, if the exercise is repeated. DOMS is quite common in sports and exercises. Although is not threaten to life, DOMS make people feel inconvenient，uncomfortable and will affect their normal activities, training and competition. Therefore, exploring a simple and accurate diagnostic methods and revealing the mechanism of its occurrence, is very important for the prevention and treatment of DOMS. DOMS show a time delay and dynamic changes as its character, thereby an in vivo tracking study in the same individual become particularly important. Molecular imaging is the best way to detect skeletal muscle microstructure and energy metabolism in vivo. This study plan to test the dynamic changes of microstructure, damage repair and energy metabolism in vivo skeletal muscle of rat after eccentric exercise through animal special 7T MRI/31-MRS imaging system, the results will be verified by pathology and mitochondrial research methods; PI3K/AKt/mTOR signaling pathways associated protein changes during DOMS will be analysis by western blot and immunohistochemistry; Investigate the role of this pathway in the development process of DOMS by injection of inhibitors and activators；Providing reliable experimental evidence for DOMS prevention and treatment as well as clarify the mechanism eventually.

延迟性肌肉酸痛（DOMS）的诊治和发生机制是运动医学的研究热点，发展在体动态追踪的研究方法意义重大。本研究旨在采用超高场强7T MRI/31P-MRS成像系统，动态在体检测DOMS肌组织不同时间细胞水肿、损伤修复和能量代谢的变化；采用离体研究方法探讨肌纤维病理结构改变和骨骼肌能量代谢（ATP生成率，呼吸控制率，呼吸链还原酶活性），与MRI/MRS结果进行相关分析；western-blot及免疫组化检测PI3K/AKt/mTOR信号通路相关蛋白在DOMS发生中的变化；分别注射抑制剂和激活剂研究通路相关作用；探讨7T MR代谢及功能成像在早期诊断评估DOMS中的可行性，阐述PI3K/AKt/mTOR通路在DOMS发展过程中的作用；为阐明DOMS发生机理提供可靠的理论依据。

延迟性肌肉酸痛（DOMS）的诊治和发生机制是运动医学的研究热点，发展在体动态追踪的研究方法意义重大。本研究采用7T MR研究DOMS发生发展转归，结果发现：（1）MR代谢成像显示Pi、PCr和β-ATP各代谢物峰下面积在损伤后24h至3day降低随后恢复；Pi/PCr变化与肌肉损伤变化趋势一致，PCr/ATP和PCr/(PCr+Pi)比值在损伤后24h至5day均升高至7天恢复。（2）MR成像显示T1加权成像、T2加权成像、DWI成像ADC值均提示DOMS骨骼肌损伤在运动后24h开始出现，72h左右达到顶峰，随后下降至运动后7day到9day恢复正常。（3）分子生物学实验显示PI3K/AKt/mTOR信号通路相关蛋白在DOMS不同时程表达存在差异，但抑制该信号通路对DOMS肌细胞结构和功能变化不具有显著性影响，该信号通路与DOMS发生发展之间的关系有待进一步研究。（4）生物力学检测显示DOMS不同阶段肌纤维最大拉伸率和最大拉伸强度呈现规律性改变，且与MR研究结果及病理实验结果相一致。（5）肌组织细胞线粒体呼吸链功能检测提示DOMS发展的24小时阶段线粒体功能显著性降低，氧化应激增加，组织ATP含量下降，72小时后逐渐恢复至正常。总之，7TMR代谢和功能成像能够反映DOMS发生发展过程中肌组织能量代谢和结构变化特点，与相关的分子生物学、组织病理学及生物力学变化特征具有显著相关性，提示该技术可作为DOMS临床诊断和康复评定的有效手段。

内容获取失败，请点击重试