Cholecystokinin octapeptide in rat central nervous system: Immunocytochemical studies using a monoclonal antibody that does not react with CGRP.
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.
Williams
R G
RG
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.
Dimaline
R
R
Varro
A
A
Isetta
A M
AM
Trizio
D
D
Dockray
G J
GJ