Transmurally differentiated measurement of ATP hydrolysis rates in the in vivo porcine hearts.

ABSTRACT: Compare the transmural distribution of forward creatine kinase reaction (kf,CK ) and ATP hydrolysis rate (kr,ATPase ) in the myocardium of normal porcine heart. Rate constants were extracted from partially relaxed spectra by applying the T1nom method, effectively reducing data acquisition time by up to an order of magnitude.T1nom method for double saturation of PCr and Pi is introduced and validated through simulations. Bioenergetics was measured in vivo utilizing one-dimensional chemical shift imaging (1D-CSI) magnetic resonance (31) P spectroscopy.At basal conditions, there was no significant difference between subepicardial layers (EPI) vs. the subendocardial layers (ENDO) for both fluxf,CK and fluxr,ATPase . At high cardiac workload (HWL), where the rate pressure product increased 2.6-fold, PCr/ATP ratio and fluxf,CK showed no significant change in both EPI and ENDO layers, while fluxr,ATPase increased significantly (baseline: 1.11?±?0.12 and 1.12?±?0.13??mol/g/s, EPI and ENDO, respectively; to HWL: 2.35?±?0.27 and 2.21?±?0.08??mol/g/s, EPI and ENDO, respectively, each P?

SUBMITTER: Jang A 

PROVIDER: S-EPMC4833513 | biostudies-literature | 2016 May

REPOSITORIES: biostudies-literature