Effects of cardiac sympathetic nervous system on the stunned myocardium experimental study with 123I-metaiodobenzylguanidine.
123I-Metaiodobenzylguanidine (123I-MIBG) uptake in the stunned myocardium was investigated in open chest dogs. 123I-MIBG is a tracer taken up in presynaptic adrenergic vesicles and reflects the function of the myocardial sympathetic nervous system. This study revealed that in the stunned myocardium without infarct, 123I-MIBG uptake was normal up to 40 minutes of ischemia and that exogenous noradrenaline improved deteriorated regional wall motion with increased uptake of 123I-MIBG. However, uptake of 123I-MIBG per flow decreased with infarct in ischemic areas, and it showed a linear relation with regional wall motion. Thus, in the absence of infarction 123I-MIBG is a tracer to differentiate stunning from more severe ischemia with persistent wall motion abnormality. Normal uptake and storage of 123I-MIBG in the stunned condition suggests that catecholamine release or second effector mechanism may relate to the mechanism.
Nohara
R
R
Third Division of Internal Medicine, Kyoto University Hospital, Japan.
Kambara
H
H
Okuda
K
K
Ono
S
S
Tamaki
N
N
Konishi
J
J
Kawai
C
C
D019797:3-Iodobenzylguanidine; D000818:Animals; D001794:Blood Pressure; D004285:Dogs; D004452:Echocardiography; D005260:Female; D006321:Heart / Q000000981:diagnostic imaging / Q000294:innervation*; D006339:Heart Rate; D007457:Iodine Radioisotopes / Q000493:pharmacokinetics; D007462:Iodobenzenes / Q000493:pharmacokinetics; D008297:Male; D009200:Myocardial Contraction; D009203:Myocardial Infarction / Q000503:physiopathology; D009206:Myocardium / Q000378:metabolism; D011877:Radionuclide Imaging; D013564:Sympathetic Nervous System / Q000502:physiology*
D007457:Iodine Radioisotopes; D007462:Iodobenzenes; D019797:3-Iodobenzylguanidine