Peptide directoryGut, pancreas & liver

Cholecystokinin-22

A mid-length cholecystokinin found in gut and blood.

Where it comes from

Made in
I cells of the upper small intestine
Sent out by
Fat and protein after a meal
Acts on
  • Gallbladder
  • Pancreas
  • Vagus nerve

What it does

  • Everything CCK-8 does, through the sulfated end the whole family shares 1
  • One of the three main forms in human blood, beside CCK-33 and CCK-58 1
  • Cleared more slowly than CCK-8, so it carries more of the signal after a meal than its share of the total suggests

In medicine

  • Counted in “total CCK” assays; no medicine copies this form
  • Telling it from CCK-33 and CCK-58 needs chromatography before the assay, which is why no routine laboratory reports the forms separately 2

Beyond the body’s own use

  • Not studied on its own: no trial has given CCK-22 to a person, and no analogue of this length exists
  • The open question about it is a measurement one. Whether obesity blunts the CCK response at all depends on which forms an assay sees, and the assays do not agree, so published CCK levels are hard to compare 2

Sources

  1. Rehfeld et al., The predominant cholecystokinin in human plasma and intestine is cholecystokinin-33, Journal of Clinical Endocrinology and Metabolism 2001
  2. Rehfeld, Measurement of cholecystokinin in plasma, Nutrition Research 2020

This card describes what a medicine is for and what the evidence says; it recommends nothing. Talk to your clinician about anything you read here.