Inositol 1,4,5-trisphosphate receptor binding: autoradiographic localization in rat brain.
Inositol 1,4,5-trisphosphate is a second messenger generated by stimulation of the phosphoinositide cycle, thought to release calcium from intracellular stores. We have mapped the distribution of 3H-inositol 1,4,5-trisphosphate receptor binding sites in rat brain by autoradiographic techniques. The cerebellum contains the highest level of inositol 1,4,5-trisphosphate binding sites in brain, which appear to be selectively localized to Purkinje cells. Moderate levels of binding sites are present in the hippocampus, cerebral cortex, caudate, and substantia nigra. Lesion studies indicate that binding in the hippocampus is restricted to intrinsic neuronal elements and in the nigra is found on terminals of the striatonigral projection. Overall, the autoradiographic distribution of inositol 1,4,5-trisphosphate receptors resembles the distribution of phorbol ester binding sites associated with protein kinase C. However, the inositol 1,4,5-trisphosphate receptor has a more restricted distribution since it is not detectable in the spinal cord or olfactory bulb, regions with substantial levels of protein kinase C.
Worley
P F
PF
Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, Maryland 21205.
Baraban
J M
JM
Snyder
S H
SH
D000818:Animals; D001345:Autoradiography; D001665:Binding Sites; D001921:Brain / Q000378:metabolism* / Q000473:pathology; D015220:Calcium Channels; D005576:Colforsin / Q000378:metabolism; D053496:Inositol 1,4,5-Trisphosphate Receptors; D008297:Male; D051379:Mice; D008818:Mice, Neurologic Mutants / Q000378:metabolism; D011493:Protein Kinase C / Q000378:metabolism; D051381:Rats; D011919:Rats, Inbred Strains; D011956:Receptors, Cell Surface / Q000378:metabolism*; D018160:Receptors, Cytoplasmic and Nuclear; D014018:Tissue Distribution
D015220:Calcium Channels; D053496:Inositol 1,4,5-Trisphosphate Receptors; D011956:Receptors, Cell Surface; D018160:Receptors, Cytoplasmic and Nuclear; D005576:Colforsin; D011493:Protein Kinase C