These tools will no longer be maintained as of December 31, 2024. Archived website can be found here. PubMed4Hh GitHub repository can be found here. Contact NLM Customer Service if you have questions.


Pubmed for Handhelds

PUBMED FOR HANDHELDS

Search MEDLINE/PubMed

  • Title: Full and partial agonist activity of C-terminal cholecystokinin peptides at the cloned human CCK-A receptor expressed in Chinese hamster ovary cells.
    Author: Dunlop J, Zhang Y, Evans N.
    Journal: Peptides; 1997; 18(6):865-8. PubMed ID: 9285936.
    Abstract:
    The agonist activities of the C-terminal cholecystokinin peptides sulfated cholecystokinin octapeptide (CCK-8S), non-sulfated cholecystokinin octapeptide (CCK-8NS), pentagastrin and CCK-4 at the cloned human CCK-A receptor expressed in Chinese hamster ovary cells were evaluated in two functional assays of receptor activation. [125I]-CCK-8S displacement studies employing membranes derived from these cells revealed the expected rank order of affinity for a number of CCK receptor ligands. CCK-8S was a potent agonist in (i) stimulating the mobilization of intracellular free Ca2+, measured with the Ca2+ sensitive fluorescent indicator FURA-2, and (ii) stimulating increases in extracellular acidification rates, measured by microphysiometry. Consistent with their lower affinities for CCK-A receptors, CCK-8NS, pentagastrin and CCK-4 were weaker agonists in both functional assays. In addition, these peptides exhibited partial agonist activity relative to the maximum response observed with CCK-8S in both assays. These results demonstrate that CCK-8S represents the minimum ligand requirement for both high affinity and full agonist activity at the human CCK-A receptor subtype.
    [Abstract] [Full Text] [Related] [New Search]