Cocaine- and amphetamine-regulated transcript (CART) peptide immunoreactivity in myenteric plexus neurons of the rat ileum and co-localization with choline acetyltransferase.
Cocaine and amphetamine regulated transcript (CART) encodes a novel brain-enriched protein whose features are reminiscent of a neurotransmitter propeptide. We have now localized CART peptide(s) in the gastrointestinal tract by immunohistochemical methods. Polyclonal antisera raised to CART peptide 106-129 stained neuronal cell bodies and fibers in rat ileum myenteric plexus-longitudinal muscle tissue preparations. Electron microscopic analysis of thin sections showed immunopositive axon terminals in close apposition to CART-labelled and unlabelled neuronal cell bodies as well as to the longitudinal muscle. CART peptide-immunoreactive terminals contained numerous ovoid electron-lucent vesicles and a few dark-stained dense-core vesicles. Light microscopic double labelling studies revealed CART peptide immunoreactivity in a subpopulation of choline acetyltransferase (ChAT)-immunoreactive neurons. This combined light microscopic and ultrastructural examination of CART peptides in the gastrointestinal tract suggests a role of CART peptides as transmitters or neuromodulators in the peripheral nervous system.
Division of Neuroscience, Yerkes Regional Primate Research Center and Emory University, Atlanta, Georgia 30329, USA. pastorc@rmy.emory.edu
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P
Couceyro
M
M
Paquet
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E
Koylu
M J
MJ
Kuhar
Y
Y
Smith
D000818:Animals; D000906:Antibodies; D002795:Choline O-Acetyltransferase / Q000032:analysis*; D007082:Ileum / Q000294:innervation*; D007150:Immunohistochemistry; D008297:Male; D016253:Microscopy, Immunoelectron; D009130:Muscle, Smooth / Q000294:innervation*; D009197:Myenteric Plexus / Q000166:cytology*; D009419:Nerve Tissue Proteins / Q000032:analysis*; D009474:Neurons / Q000166:cytology*; D017729:Presynaptic Terminals / Q000201:enzymology / Q000648:ultrastructure*; D051381:Rats; D017207:Rats, Sprague-Dawley; D000098882:Cocaine- and Amphetamine-Regulated Transcript Protein
D000906:Antibodies; D009419:Nerve Tissue Proteins; D000098882:Cocaine- and Amphetamine-Regulated Transcript Protein; D002795:Choline O-Acetyltransferase