Over-the-counter drugs block heart accumulation of MIBG

Conference · Wed May 01 00:00:00 EDT 1985 · J. Nucl. Med.; (United States)

OSTI ID:6644530

Sherman, P S; Fisher, S J; Wieland, D M; Sisson, J C

Previous work in the authors' laboratory using chemically sympathectomized animals showed that > 50% of meta-iodobenzyl-guanidine (MIBG) in the heart is localized in adrenergic nerves. In the present study, commonly used drugs known to alter the uptake and/or release of norepinephrine by adrenergic neurons have been evaluated for their effect on the biodistribution of MIBG. Pseudoephedrine (Sudafed), phenylpropanolamine (Dexatrim) and phenylephrine (Neosynephrine) were administered (5 mg/kg, i.p.) to rats; amphetamine was also evaluated (0.8mg/kg, i.p.). Thirty minutes later I-125-MIBG (0.2-0.4 Ci/mm) was injected i.v.; animals (N=3) were sacrificed 2 h following radiotracer. Compared to controls (N = 3), drug pretreatments resulted in large decreases in radiotracer concentration in adrenergic-rich tissues such as left atrium, left ventricle, spleen and parotid glands. Pseudoephedrine caused decreases (%) of 78, 57, 48 and 35 in the four tissues, respectively. Each of the four drugs caused a greater decrease in I-125-MIBG concentration in the left atrium than in the left ventricle. Comparative studies using H-3-norepinephrine are in progress. Entex, a nasal decongestant containing both phenylephrine and phenylpropanolamine, markedly diminished the heart and salivary gland accumulation of I-123-MIBG in a normal male volunteer. These preliminary studies suggest that commonly used sympathomimetic agents, including some over-the-counter preparations, decrease the accumulation of MIBG in adrenergic neurons. These results also suggest that patients should be carefully screened for drug usage prior to MIBG scintigraphy of the heart.

• Research Organization: Univ. of Michigan, Ann Arbor, MI
• OSTI ID: 6644530
• Report Number(s): CONF-850611-
• Journal Information: J. Nucl. Med.; (United States), Journal Name: J. Nucl. Med.; (United States) Vol. 26:5; ISSN JNMEA
• Country of Publication: United States
• Language: English

Related Subjects

550501 -- Metabolism-- Tracer Techniques
550601* -- Medicine-- Unsealed Radionuclides in Diagnostics
59 BASIC BIOLOGICAL SCIENCES
62 RADIOLOGY AND NUCLEAR MEDICINE
ADRENAL HORMONES
ANIMAL CELLS
AUTONOMIC NERVOUS SYSTEM AGENTS
BETA DECAY RADIOISOTOPES
BIOCHEMICAL REACTION KINETICS
BIOCHEMISTRY
BIOLOGICAL LOCALIZATION
BODY
CARDIOTONICS
CARDIOVASCULAR AGENTS
CARDIOVASCULAR SYSTEM
CHEMICAL PREPARATION
CHEMISTRY
COUNTING TECHNIQUES
DIAGNOSTIC TECHNIQUES
DISTRIBUTION
DRUGS
ELECTRON CAPTURE RADIOISOTOPES
EVALUATION
FUNCTIONS
HEART
HORMONES
HOURS LIVING RADIOISOTOPES
INTERMEDIATE MASS NUCLEI
IODINE 123
IODINE ISOTOPES
ISOTOPES
KINETICS
LABELLED COMPOUNDS
LABELLING
METABOLISM
MIBG
NERVE CELLS
NEUROREGULATORS
NORADRENALINE
NUCLEI
ODD-EVEN NUCLEI
ORGANS
PERFORMANCE
RADIOISOTOPE SCANNING
RADIOISOTOPES
RADIONUCLIDE KINETICS
RADIOPHARMACEUTICALS
REACTION KINETICS
RETENTION FUNCTIONS
SCINTISCANNING
SOMATIC CELLS
SPLEEN
STEROID HORMONES
SYMPATHOLYTICS
SYMPATHOMIMETICS
SYNTHESIS
TISSUE DISTRIBUTION
UPTAKE