Year: 2011
Type: article
Abstract: RATIONALE: ³¹P magnetization saturation transfer (MST) experiment is the most widely used method to study ATP metabolism kinetics. However, its lengthy data acquisition time greatly limits the wide biomedical applications in vivo, especially for studies requiring high spatial and temporal resolutions. OBJECTIVE: We aimed to develop a novel superfast MST method that can accurately quantify ATP production rate constants (k(f)) through creatine kinase (CK) or ATP synthase (ATPase) with 2 spectra. METHODS AND RESULTS: The T₁(nom) (T₁ nominal) method uses a correction factor to compensate the partially relaxed MST experiments, thus allowing measurement of enzyme kinetics with an arbitrary repetition time and flip angle, which consequently reduces the data acquisition time of a transmurally differentiated CK k(f) measurement by 91% as compared with the conventional method with spatial localization. The novel T₁(nom) method is validated theoretically with numeric simulation, and further verified with in vivo swine hearts, as well as CK and ATPase activities in rat brain at 9.4 Tesla. Importantly, the in vivo data from swine hearts demonstrate, for the first time, that within an observation window of 30 minutes, the inhibition of CK activity by iodoacetamide does not limit left ventricular chamber contractile function. CONCLUSIONS: A novel MST method for superfast examination of enzyme kinetics in vivo has been developed and verified theoretically and experimentally. In the in vivo normal heart, redundant multiple supporting systems of myocardial ATP production, transportation, and utilization exist, such that inhibition of one mechanism does not impair the normal left ventricular contractile performance.
Source: Circulation Research
Authors: Qiang Xiong, Fei Du, Xiaohong Zhu, Pengyuan Zhang, Piradeep Suntharalingam, Joseph Ippolito, Forum D. Kamdar, Wei Chen, Jianyi Zhang
Institutions: University of Minnesota, Harvard University, McLean Hospital
Language: English
Subfield: Radiology, Nuclear Medicine and Imaging
Field: Medicine
Domain: Health Sciences
Open Access status: bronze
Awards: G1572568198, Energetics in Hypertrophied and Remodeled Left Ventricle, G2684552280, G2697481014, G2703868037, Mycardial Repair Using Human iPSC Derived Cardiac Muscle Patch, G4437449955, G4653431608, Study of Brain Oxidative Metabolism by 17-0 imaging, Stem Cell Therapy for Myocardial Repair, NMR Imaging and Spectroscopy, Quantitative and Non-invasive Imaging of Oxygen Metabolism in Human Brain, G7446692246, Midwestern Progenitor Cell Consortium, Noninvasive Study of Cerebral ATP Metabolism, Bioenergetics and Brain Function, Neuroscience Cores For MR Studies of the Brain
OpenAlex ID: W2529927756