MR Center of Excellence, Medical University of Vienna, Vienna, Austria.
Magn Reson Med. 2012 Apr;67(4):898-905. doi: 10.1002/mrm.23095. Epub 2011 Aug 12.
Alternate methods to quantify mitochondrial activity or function have been extensively used for studying insulin resistance and type 2 diabetes mellitus, namely saturation transfer and phosphocreatine (PCr) recovery. As these methods are in fact determining different parameters, this study aimed to compare saturation transfer results to PCr recovery measurements within the same group. Fifteen subjects underwent saturation transfer and ischemic exercise-recovery experiments. PCr decrease during ischemia (Q), induced by cuff inflation, served as an additional measure of resting ATP (adenosine triphosphate) production. ATP synthetic rate (fATP) measured by saturation transfer (0.234 ± 0.043 mM/s) was greater than (Q = 0.0077 ± 0.0011 mM/s), but correlated well with Q (r = 0.63 P = 0.013). Parameters of PCr recovery correlated well with fATP (Q(max,lin) : r = 0.71, P = 0.003, Q(max,ADP) : r = 0.66, P = 0.007) and Q (Q(max,lin) : r = 0.92, P = 0.000002, Q(max,ADP) : r = 0.76, P = 0.001). In conclusion, although saturation transfer yields higher ATP synthetic rates than PCr decrease during ischemia, their significant correlation indicates that fATP can be used as a marker of mitochondrial activity. The finding that both Q and fATP correlate with PCr recovery kinetics suggests that skeletal muscle with greater maximal aerobic ATP synthetic rates is also metabolically more active at rest. Magn Reson Med, 2011. © 2011 Wiley-Liss, Inc.
交替方法来量化线粒体的活性或功能已被广泛用于研究胰岛素抵抗和 2 型糖尿病，即饱和转移和磷酸肌酸（PCr）恢复。由于这些方法实际上是确定不同的参数，本研究旨在比较饱和转移的结果到 PCr 恢复测量在同一组。15 例受试者接受饱和转移和缺血运动恢复实验。PCr 减少在缺血（Q），由袖口充气诱导，作为休息时的 ATP （三磷酸腺苷）产生的额外措施。通过饱和转移测量的 ATP 合成率（fATP）（0.234 ± 0.043 mM/s）大于（Q = 0.0077 ± 0.0011 mM/s），但与 Q 相关性良好（r = 0.63，P = 0.013）。PCr 恢复的参数与 fATP （Q（max，lin）：r = 0.71，P = 0.003，Q（max，ADP）：r = 0.66，P = 0.007）和 Q （Q（max，lin）：r = 0.92，P = 0.000002，Q（max，ADP）：r = 0.76，P = 0.001）相关性良好。总之，尽管饱和转移产生比在缺血过程中 PCr 减少更高的 ATP 合成率，但它们的显著相关性表明，fATP 可作为线粒体活性的标志物。发现 Q 和 fATP 均与 PCr 恢复动力学相关，这表明具有更大最大有氧 ATP 合成率的骨骼肌在休息时也具有更高的代谢活性。磁共振医学，2011 年。© 2011 年威利-利希，公司。
