Radiolabeled meta-iodobenzylguanidine and the adrenergic neurons of salivary glands

Journal Article · Wed Dec 31 23:00:00 EST 1986 · Am. J. Physiol. Imag.; (United States)

OSTI ID:6954309

Sisson, J C; Wieland, D M; Jaques, S Jr; Sherman, P; Fisher, S; Mallette, S; Meyers, L; Mangner, T J

The handling of radiolabeled meta-iodobenzylguanidine (MIBG) by salivary glands was evaluated. In the submaxillary glands of rats, the uptake of 125I-MIBG was decreased after 1) nerve injury induced by 6-hydroxydopamine, 2) inhibition of the uptake-1 pathway by desmethylimipramine, and 3) surgical denervation. However, the reduction in 125I-MIGB uptake was less than that of 3H-norepinephrine (3H-NE) and of the endogenous content of NE in the glands. Yet, the sympathomimetic phenylpropanolamine displaced about the same fraction of 125I-MIBG as 3H-NE. These results suggest that 40% or more of 125I-MIBG resides in extraneuronal sites but that at least 30% and possibly more lies in the adrenergic nerve terminals. Fasting and feeding rats produced changes in the rates of disappearance of 125I-MIBG and 3H-NE from the submaxillary gland that were different, and the rates of loss of 125I-MIBG cannot be used as an index of adrenergic nerve activity. In man, the concentrations of 123I-MIBG in the salivary glands, particularly the parotid gland, are readily visible and measureable. Imipramine reduced the uptake of 123I-MIBG into parotid glands little or not at all; some of the 123I-MIBG may enter neurons via an imipramine-insensitive pathway, but a substantial fraction probably arrives in intraneuronal locations. Thus, phenylpropanolamine displaced over 50% of the parotid pool of 123I-MIBG. However, in only the most severe case of generalized autonomic neuropathy was the uptake of 123I-MIBG reduced.

• Research Organization: Univ. of Michigan Medical Center, Ann Arbor (USA)
• OSTI ID: 6954309
• Journal Information: Am. J. Physiol. Imag.; (United States), Journal Name: Am. J. Physiol. Imag.; (United States) Vol. 2:1; ISSN AJPIE
• Country of Publication: United States
• Language: English

Related Subjects

550501* -- Metabolism-- Tracer Techniques
59 BASIC BIOLOGICAL SCIENCES
AMINES
ANIMAL CELLS
ANIMALS
ANTIDEPRESSANTS
BETA DECAY RADIOISOTOPES
BIOLOGICAL PATHWAYS
BODY
CARBONIC ACID DERIVATIVES
CENTRAL NERVOUS SYSTEM AGENTS
DAYS LIVING RADIOISOTOPES
DRUGS
ELECTRON CAPTURE RADIOISOTOPES
GLANDS
GUANIDINES
HETEROCYCLIC COMPOUNDS
HOURS LIVING RADIOISOTOPES
IMIPRAMINE
INHIBITION
INTERMEDIATE MASS NUCLEI
IODINE 123
IODINE 125
IODINE ISOTOPES
ISOTOPE APPLICATIONS
ISOTOPES
LABELLED COMPOUNDS
MAMMALS
METABOLISM
NERVE CELLS
NUCLEI
ODD-EVEN NUCLEI
ORGANIC COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
ORGANS
PSYCHOTROPIC DRUGS
RADIOISOTOPES
RATS
RODENTS
SALIVARY GLANDS
SOMATIC CELLS
TRACER TECHNIQUES
TRITIUM COMPOUNDS
UPTAKE
VERTEBRATES