Characterization of CGRP receptors in various regions of gerbil brain.
The distribution of specific calcitonin gene-related peptide (CGRP) binding sites was investigated in gerbil brain regions such as cortex, cerebellum, hypothalamus, and hippocampus. The binding of [125I]CGRP to membranes prepared from these regions of the gerbil brain was rapid, saturable and specific with dissociation constants (Kd) between 10-40 pM and maximum binding (Bmax) between 10-30 fmol/mg protein. Human and rat CGRP and hCGRP8-37 competed for [125I]hCGRP binding in a concentration-dependent manner with a Ki of 10-100 pM. Salmon calcitonin was very weak in competing for [125I]hCGRP binding (ki > 10 microM). CGRP did not stimulate adenylate cyclase in these brain regions. Cross-linking of [125I] hCGRP to the brain membrane fractions with disuccinimidyl suberate revealed specific incorporation of [125I] hCGRP to a protein band of approximate molecular weight 52 kDa.
Aiyar
N
N
Department of Cardiovascular Pharmacology, SmithKline Beecham Pharmaceuticals, King of Prussia, PA 19406.
Baker
E
E
Nambi
P
P
Feuerstein
G
G
Willette
R
R
D000262:Adenylyl Cyclases / Q000378:metabolism; D000818:Animals; D001667:Binding, Competitive; D001921:Brain / Q000378:metabolism*; D002116:Calcitonin / Q000378:metabolism; D015740:Calcitonin Gene-Related Peptide / Q000378:metabolism; D002462:Cell Membrane / Q000378:metabolism; D003432:Cross-Linking Reagents; D004591:Electrophoresis, Polyacrylamide Gel; D005849:Gerbillinae; D007457:Iodine Radioisotopes; D051381:Rats; D018015:Receptors, Calcitonin Gene-Related Peptide / Q000378:metabolism*; D013388:Succinimides / Q000378:metabolism
D003432:Cross-Linking Reagents; D007457:Iodine Radioisotopes; D018015:Receptors, Calcitonin Gene-Related Peptide; D013388:Succinimides; C028815:salmon calcitonin; D002116:Calcitonin; D000262:Adenylyl Cyclases; D015740:Calcitonin Gene-Related Peptide; C019358:disuccinimidyl suberate