Metaiodobenzylguanidine as an index of the adrenergic nervous system integrity and function

Journal Article · Thu Oct 01 04:00:00 EDT 1987 · J. Nucl. Med.; (United States)

OSTI ID:5628200

Sisson, J C; Wieland, D M; Sherman, P; Mangner, T J; Tobes, M C; Jacques, S Jr

The radiopharmaceutical, metaiodobenzylguanidine (MIBG) acts as an analog of norepinephrine (NE). Experiments in rats were carried out to determine how closely the movements of (/sup 125/I)MIBG in the heart mimicked those of (/sup 3/H)NE, and if the changes (/sup 125/I) MIBG concentrations would reflect injury to, and function of, adrenergic neurons in the heart. Injury to adrenergic neurons by 6-hydroxydopamine substantially reduced the uptake of (/sup 125/I) MIBG into the left ventricle, but the effect was less than that on uptake of (/sup 3/H)NE uptake and concentration of endogenous NE. Similarly, when desmethylimipramine was given to inhibit the uptake-1 pathway of neurons, the reduction in uptake of (/sup 125/I)MIBG was statistically significant but less than that of (/sup 3/H)NE; part of this difference may be attributable to partial uptake of (/sup 125/I)MIBG into neurons by a diffusion pathway. Substantial fractions of (/sup 125/I)MIBG and (/sup 3/H)NE were displaced from the heart by the sympathomimetic drug, phenylpropanolamine. When adrenergic neurons of the heart were stimulated by feeding of rats, the disappearance rates of (/sup 3/H)NE and (/sup 125/I)MIBG from the heart were significantly increased. Although not a perfect analog of (/sup 3/H)NE, (/sup 125/I)MIBG appears to enter and leave the heart in patterns similar to those of (/sup 3/H)NE. Thus, movements of (/sup 125/I)MIBG give indices of adrenergic neuron injury and function in the heart.

• Research Organization: Univ. of Michigan Medical Center, Ann Arbor
• OSTI ID: 5628200
• Journal Information: J. Nucl. Med.; (United States), Journal Name: J. Nucl. Med.; (United States) Vol. 28:10; ISSN JNMEA
• Country of Publication: United States
• Language: English

Related Subjects

550601* -- Medicine-- Unsealed Radionuclides in Diagnostics
62 RADIOLOGY AND NUCLEAR MEDICINE
ADRENAL HORMONES
ANIMAL CELLS
ANIMALS
AUTONOMIC NERVOUS SYSTEM AGENTS
BETA DECAY RADIOISOTOPES
BIOLOGICAL PATHWAYS
BODY
CARDIOTONICS
CARDIOVASCULAR AGENTS
CARDIOVASCULAR SYSTEM
DAYS LIVING RADIOISOTOPES
DRUGS
DYNAMIC FUNCTION STUDIES
ELECTRON CAPTURE RADIOISOTOPES
HEART
INTERMEDIATE MASS NUCLEI
IODINE 125
IODINE ISOTOPES
ISOTOPES
LABELLED COMPOUNDS
MAMMALS
NERVE CELLS
NEUROREGULATORS
NORADRENALINE
NUCLEI
ODD-EVEN NUCLEI
ORGANS
RADIOISOTOPES
RADIOPHARMACEUTICALS
RATS
RODENTS
SOMATIC CELLS
SYMPATHOMIMETICS
TRITIUM COMPOUNDS
UPTAKE
VERTEBRATES