In vivo cardiac 1H-MRS in the mouse.
The mouse is the predominant animal model to study the effect of gene manipulations. Imaging techniques to define functional effects on the heart caused by genomic alterations are becoming increasingly routine in mice, yet methods for in vivo investigation of metabolic phenotypes in the mouse heart are lacking. In this work, cardiac 1H-MRS was developed and applied in mouse hearts in vivo using a single-voxel technique (PRESS). In normal C57Bl/6J mice, stability and reproducibility achieved by dedicated cardiac and respiratory gating was demonstrated by measuring amplitude and zero-order phase changes of the unsuppressed water signal. Various cardiac metabolites, such as creatine, taurine, carnitine, or intramyocardial lipids were successfully detected and quantified relative to the total water content in voxels as small as 2 microl, positioned in the interventricular septum. The method was applied to a murine model of guanidinoacetate N-methyltransferase (GAMT) deficiency, which is characterized by substantially decreased myocardial creatine levels. Creatine deficiency was confirmed noninvasively in myocardium of anesthetized GAMT-/- mice. This is the first study to report the application of cardiac 1H-MRS in mice in vivo.
Schneider
Jürgen E
JE
Department of Cardiovascular Medicine, University of Oxford, UK. jurgen.schneider@cardiov.ox.ac.uk
Tyler
Damian J
DJ
ten Hove
Michiel
M
Sang
A Elizabeth
AE
Cassidy
Paul J
PJ
Fischer
Alexandra
A
Wallis
Julie
J
Sebag-Montefiore
Liam M
LM
Watkins
Hugh
H
Isbrandt
Dirk
D
Clarke
Kieran
K
Neubauer
Stefan
S
D000818:Animals; D002331:Carnitine / Q000378:metabolism; D003401:Creatine / Q000378:metabolism; D005240:Feasibility Studies; D005989:Glycerides / Q000378:metabolism; D009682:Magnetic Resonance Spectroscopy / Q000379:methods*; D051379:Mice; D008810:Mice, Inbred C57BL; D009206:Myocardium / Q000378:metabolism*; D013654:Taurine / Q000378:metabolism
D005989:Glycerides; D013654:Taurine; D003401:Creatine; D002331:Carnitine