Antibodies raised against a synthetic decapeptide corresponding to a specific sequence of G(i3)-α protein (an inhibitory guanine nucleotide-binding protein) were used to analyze G(i3)-α-like immunoreactivity in brain sections from colchicine-treated rats by indirect immunofluorescence histochemistry. G(i3)-α-peptide-positive cell bodies were found in the ventral tegmental area and substantia nigra, and these cells were also cholecystokinin (CCK)- and tyrosine 3-hydroxylase-positive. G(i3)-α-peptide staining was observed in perikarya in the hippocampus and in fibers in the nucleus accumbens, tuberculum olfactorium, bed nucleus of stria terminalis, and a spino-thalamic tract, where it coexisted with CCK-like immunoreactivity as well. No coexistence with CCK occurred in C(i3)-α-peptide-positive ependymal cells outlining the aqueduct and ventricles. Preadsorption of G(i3)-α antibodies with CCK-8 or CCK-33 did not alter G(i3)-α-peptide staining. The occurrence of G(i3)-α-peptide-like immunoreactivity in CCK-containing neurons may indicate the presence of G(i3)-α protein and in CCK/dopamine neurons may indicate an association of this G(i) protein with dopamine autoreceptors.
|Original language||English (US)|
|Number of pages||5|
|Journal||Proceedings of the National Academy of Sciences of the United States of America|
|State||Published - Jan 1 1988|
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