Open-chest 31P magnetic resonance spectroscopy of mouse heart at 4.7 Tesla.
OBJECTIVE
To develop a rapid, robust, and accurate method for assessing myocardial energetics in mice and demonstrate its applicability to mouse models of acquired and genetic heart disease.


METHODS
We combined surface coil localization (10-mm diameter, tunable between (1)H and (31)P, using adiabatic half-passage radiofrequency pulses) and surgery (electrocautery removal of anterior chest wall) to create an open-chest method for acquiring in vivo (31)P nuclear magnetic resonance (NMR) cardiac spectra from mice at 4.7T within 12 minutes. Normal BALB/c mice, BALB/c with myocardial infarction (MI), cardiomyocyte-restricted peroxisome proliferator-activated receptor-delta knockout (KO) (CR-PPARd(-/-)) and control loxP-flanked Ppard (Ppard(flox/flox)) mice were examined.


RESULTS
The mean phosphocreatine (PCr)/adenosine triphosphate (ATP) ratios in control BALB/c mice, BALB/c MI mice, Ppard(flox/flox) mice, and PPAR-delta KO mice were 2.13 +/- 0.09 (N = 11), 1.35 +/- 0.07 (N = 9, P < 0.001 vs. BALB/c control), 1.92 +/- 0.09 (N = 5), and 1.31 +/- 0.12 (N = 5, P < 0.005 vs. Ppard(flox/flox) control), respectively. The significant depression of myocardial PCr/ATP we observed in these genetic/acquired models of heart disease was in accord with previous data from analogous large animal models. No NMR signal contamination from chamber blood or adjacent skeletal muscle was identified.


CONCLUSIONS
This new technique provides cardiac (31)P spectra suitable for accurate quantitative analysis in a relatively short acquisition time, is suitable for terminal studies of mouse myocardial energy metabolism, and could be installed in virtually any NMR laboratory to study myocardial energetics in numerous mouse models of human heart disease.
Lee
Joseph
J
Department of Medicine, University of Minnesota Academic Health Center, Minneapolis, Minnesota 55455, USA.
Hu
Qingsong
Q
Nakamura
Yasuhiro
Y
Wang
Xiaohong
X
Zhang
Xiaoliang
X
Zhu
Xiaohong
X
Chen
Wei
W
Yang
Qinglin
Q
Zhang
Jianyi
J
D000255:Adenosine Triphosphate / Q000032:analysis*; D000818:Animals; D009682:Magnetic Resonance Spectroscopy / Q000379:methods*; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D008822:Mice, Transgenic; D009203:Myocardial Infarction / Q000378:metabolism*; D009206:Myocardium / Q000378:metabolism*; D010725:Phosphocreatine / Q000032:analysis*; D010759:Phosphorus Isotopes
D010759:Phosphorus Isotopes; D010725:Phosphocreatine; D000255:Adenosine Triphosphate