Evaluation of post-ischemic myocardial metabolism by 1H-magnetic resonance spectroscopy in the rabbit heart.
To assess myocardial metabolism during ischemia and reperfusion, 36 rabbits were divided into 4 groups; a control group (Control), an ischemia group in which the circumflex branch was ligated for 30 min (Ischemia), a 5 min reperfusion group (5-RP) and a 30 min reperfusion group (30-RP). The concentrations of metabolites (lactate, alanine and free-carnitine) in the myocardium determined by 1H-magnetic resonance spectroscopy (MRS). The concentration of free carnitine was lower in Ischemia than in Control (2.0 +/- 0.4 vs 5.2 +/- 1.4 mumol/wet.g, p < 0.01), and remained reduced in 30-RP (3.0 +/- 0.6 mumol/wet.g, p < 0.01). On the other hand, the concentration of lactate and alanine were higher in Ischemia than in those of Control (54.9 +/- 8.5 vs 8.8 +/- 0.8, 6.5 +/- 1.0 vs 2.5 +/- 0.5 mumol/wet.g, respectively; p < 0.01), and remained elevated in 30-RP. These findings indicate that recovery from an ischemia-induced disturbance in myocardial metabolism to the pre-ischemic level apparently requires a prolonged period after reperfusion, and that 1H-MRS is a useful new method for evaluating myocardial ischemia.
First Department of Internal Medicine, Fukui Medical School, Japan.
M
M
Yamamoto
J D
JD
Lee
H
H
Shimizu
N
N
Kawasaki
A
A
Hara
Y
Y
Ishii
T
T
Nakamura
D000409:Alanine / Q000378:metabolism; D000818:Animals; D002331:Carnitine / Q000378:metabolism; D006859:Hydrogen; D007773:Lactates / Q000378:metabolism; D019344:Lactic Acid; D009682:Magnetic Resonance Spectroscopy; D017202:Myocardial Ischemia / Q000378:metabolism*; D015425:Myocardial Reperfusion; D009206:Myocardium / Q000378:metabolism*; D011817:Rabbits
D007773:Lactates; D019344:Lactic Acid; D006859:Hydrogen; D000409:Alanine; D002331:Carnitine