Metaiodobenzylguanidine to map scintigraphically the adrenergic nervous system in man.
Metaiodobenzylguanidine (MIBG) localizes in adrenergic neurons; MIBG labeled with 123I then serves as an analog of norepinephrine, and concentrations of [123I]MIBG reflect sites of adrenergic neurons in organs. Movements of [123I]MIBG into and out of organs were measured by quantitative scintigraphy in man. We perturbed adrenergic neuron function in several ways, and [123I]MIBG concentrations in the heart were subsequently altered in patterns consistent with the concept that [123I]MIBG resides mostly in adrenergic neurons. Uptake of [123I]MIBG into the heart was inhibited by the tricyclic drug, imipramine, and this agent also accelerated the rate of loss of [123I]MIBG. Phenylpropanolamine, a sympathomimetic drug that acts by displacing norepinephrine from neurons, increased the rates of loss of [123I]MIBG from the heart. Exercise was followed by a movement of [123I]MIBG into blood and urine. Generalized autonomic neuropathies were associated with marked diminutions of [123I]MIBG uptake into the heart. We conclude that quantitative scintigraphy in patients will enable determinations of regional disturbances in integrity (by measuring uptake of [123I]MIBG) and function (by measuring rates of loss of [123I]MIBG) of the adrenergic nervous system in the heart.
Sisson
J C
JC
Department of Internal Medicine, University of Michigan Medical Center, Ann Arbor 48109-0028.
Shapiro
B
B
Meyers
L
L
Mallette
S
S
Mangner
T J
TJ
Wieland
D M
DM
Glowniak
J V
JV
Sherman
P
P
Beierwaltes
W H
WH
D019797:3-Iodobenzylguanidine; D000320:Adrenergic Fibers / Q000000981:diagnostic imaging* / Q000187:drug effects; D000328:Adult; D000368:Aged; D001342:Autonomic Nervous System Diseases / Q000000981:diagnostic imaging; D005260:Female; D006321:Heart / Q000000981:diagnostic imaging / Q000294:innervation*; D006801:Humans; D007099:Imipramine / Q000494:pharmacology; D007457:Iodine Radioisotopes; D007462:Iodobenzenes; D008297:Male; D008875:Middle Aged; D010665:Phenylpropanolamine / Q000494:pharmacology; D005082:Physical Exertion; D011877:Radionuclide Imaging
D007457:Iodine Radioisotopes; D007462:Iodobenzenes; D010665:Phenylpropanolamine; D019797:3-Iodobenzylguanidine; D007099:Imipramine