title: Cholecystokinin octapeptide in rat central nervous system: Immunocytochemical studies using a monoclonal antibody that does not react with CGRP.
abstract: The biological activity of the important neuropeptide cholecystokinin octapeptide (CCK8) resides at the C-terminus. Antibodies with C-terminal specificity have been reported to cross-react with a different neuropeptide, calcitonin gene related peptide (CGRP) and this has frustrated the interpretation of immunohistochemical studies. We describe here the properties of a monoclonal antibody to the CCK-related peptide, caerulein, that reacts with the C-terminal region of CCK8, but does not react with CGRP in radioimmunoassay or immunohistochemistry. The distribution of CCK-like activity revealed by immunohistochemistry using this antibody broadly resembles that described previously with a single major exception: in the dorsal horn of the spinal cord. The results support the suggestion that apparent CCK activity in the terminals of rat primary sensory neurones is due to cross-reactivity with CGRP.
authors.affiliation: Department of Physiology and Pharmacology, Medical and Biological Sciences Building, University of Southampton, Southampton, SO9 3TU, U.K.; MRC Secretory Control Group, Physiological Laboratory, University of Liverpool, U.K.
authors.forename: R G
authors.initials: RG
authors.lastname: Williams
authors.forename: R
authors.initials: R
authors.lastname: Dimaline
authors.forename: A
authors.initials: A
authors.lastname: Varro
authors.forename: A M
authors.initials: AM
authors.lastname: Isetta
authors.forename: D
authors.initials: D
authors.lastname: Trizio
authors.forename: G J
authors.initials: GJ
authors.lastname: Dockray