Cholecystokinin
You don't need to be Editor-In-Chief to add or edit content to WikiDoc. You can begin to add to or edit text on this WikiDoc page by clicking on the edit button at the top of this page. Next enter or edit the information that you would like to appear here. Once you are done editing, scroll down and click the Save page button at the bottom of the page.
| Cholecystokinin
| ||||||||||||||
| Identifiers | ||||||||||||||
| Symbol(s) | CCK; MGC117187 | |||||||||||||
| External IDs | OMIM: 118440 MGI: 88297 Homologene: 583 | |||||||||||||
| ||||||||||||||
| RNA expression pattern | ||||||||||||||
|
| ||||||||||||||
| Orthologs | ||||||||||||||
| Human | Mouse | |||||||||||||
| Entrez | 885 | 12424 | ||||||||||||
| Ensembl | ENSG00000187094 | ENSMUSG00000032532 | ||||||||||||
| Uniprot | P06307 | Q53WS9 | ||||||||||||
| Refseq | NM_000729 (mRNA) NP_000720 (protein) | NM_031161 (mRNA) NP_112438 (protein) | ||||||||||||
| Location | Chr 3: 42.27 - 42.28 Mb | Chr 9: 121.34 - 121.34 Mb | ||||||||||||
| Pubmed search | [1] | [2] | ||||||||||||
| |
| CCK identified at bottom right. | |
| Cholecystokinin
| |
| Identifiers | |
| Symbol | CCK |
| Entrez | 885 |
| HUGO | 1569 |
| OMIM | 118440 |
| RefSeq | NM_000729 |
| UniProt | P06307 |
| Other data | |
| Locus | Chr. 3 pter-p21 |
Editor-In-Chief: C. Michael Gibson, M.S., M.D. [3] Phone:617-525-6884
Please Take Over This Page and Apply to be Editor-In-Chief for this topic: There can be one or more than one Editor-In-Chief. You may also apply to be an Associate Editor-In-Chief of one of the subtopics below. Please mail us [4] to indicate your interest in serving either as an Editor-In-Chief of the entire topic or as an Associate Editor-In-Chief for a subtopic. Please be sure to attach your CV and or biographical sketch.
Overview
Cholecystokinin (CCK; from Greek chole, "bile"; cysto, "sac"; kinin, "move"; hence, move the bile-sac (gallbladder)) is a peptide hormone of the gastrointestinal system responsible for stimulating the digestion of fat and protein. Cholecystokinin, previously called pancreozymin, is synthesised by I-cells in the mucosal epithelium of the small intestine and secreted in the duodenum, the first segment of the small intestine, and causes the release of digestive enzymes and bile from the pancreas and gallbladder, respectively. It also acts as a hunger suppressant. Recent evidence has suggested that it also plays a major role in inducing drug tolerance to opioids like morphine and heroin, and is partly implicated in experiences of pain hypersensitivity during opioid withdrawal.[1][2]
Structure
CCK is composed of varying numbers of amino acids (e.g., CCK58, CCK33, CCK8) depending on post-translational modification of the CCK gene product, preprocholecystokinin. CCK is very similar in structure to gastrin, another of the gastrointestinal hormones, so much so that the last five C-terminal amino acids are same as those of gastrin. CCK58 comprises a helix-turn-helix configuration.
Release and Function
CCK mediates a number of physiological processes, including digestion and satiety.
Digestion
Secretion of CCK by the duodenal and intestinal mucosa is stimulated by fat- or protein-rich chyme entering the duodenum. It then inhibits gastric emptying and gastric acid secretion and mediates digestion in the duodenum. It acts on the pancreas to stimulate the secretion of a juice rich in pancreatic digestive enzymes. Together these enzymes catalyze the digestion of fat, protein, and carbohydrates. Thus the levels of the substances which stimulated the release of CCK drop and the concentration of the hormone drops as well. The release of CCK is also inhibited by somatostatin.
CCK also causes the increased production of hepatic bile, and stimulates the contraction of the gallbladder and the relaxation of the Sphincter of Oddi (Glisson's sphincter), resulting in the delivery of bile into the duodenal part of the small intestine. Bile salts form amphipathic micelles that emulsify fats, aiding in their digestion and absorption.
Neurobiology
As a neuropeptide, CCK mediates satiety by acting on the CCK receptors distributed widely throughout the central nervous system. In humans, it has been suggested that CCK administration causes nausea and anxiety, and weakly decreases the desire to eat is the reason for CCK administration to induce a satiating effect. Some studies have given a strong correlation for the satiating effect, but have not proven or disproven that CCK administration causes nauseau or anxiety Benoit et al (2003).[3] The mechanism for this hunger suppression is thought to be a decrease in the rate of gastric emptying.[4]
The effects of CCK vary between individuals. For example, in rats, CCK administration significantly reduces hunger in young males, but is slightly less effective in older subjects, and even slightly less effective in females. The hunger-suppressive effects of CCK also are reduced in obese rats.[5]
See also
References
- ↑ Kissin I, Bright CA, Bradley EL (2000). "Acute tolerance to continuously infused alfentanil: the role of cholecystokinin and N-methyl-D-aspartate-nitric oxide systems". Anesth. Analg. 91 (1): 110–6. doi:10.1097/00000539-200007000-00021. PMID 10866896.
- ↑ Fukazawa Y, Maeda T, Kiguchi N, Tohya K, Kimura M, Kishioka S (2007). "Activation of spinal cholecystokinin and neurokinin-1 receptors is associated with the attenuation of intrathecal morphine analgesia following electroacupuncture stimulation in rats". J. Pharmacol. Sci. 104 (2): 159–66. doi:10.1254/jphs.FP0070475. PMID 17558184.
- ↑ Greenough A, Cole G, Lewis J, Lockton A, Blundell J (1998). "Untangling the effects of hunger, anxiety, and nausea on energy intake during intravenous cholecystokinin octapeptide (CCK-8) infusion". Physiol. Behav. 65 (2): 303–10. doi:10.1016/S0031-9384(98)00169-3. PMID 9855480.
- ↑ Shillabeer G, Davison JS (1987). "Proglumide, a cholecystokinin antagonist, increases gastric emptying in rats". Am. J. Physiol. 252 (2 Pt 2): R353–60. PMID 3812772.
- ↑ Fink H, Rex A, Voits M, Voigt JP (1998). "Major biological actions of CCK--a critical evaluation of research findings". Exp Brain Res 123 (1-2): 77–83. doi:10.1007/s002210050546. PMID 9835394.
External links
Digestive system, physiology: gastrointestinal physiology | |
|---|---|
| Enteric nervous system | Meissner's plexus - Auerbach's plexus |
| Exocrine | Chief cells (Pepsinogen) - Parietal cells (Gastric acid, Intrinsic factor) - Goblet cells (Mucus) |
| Endocrine/paracrine | G cells (gastrin), D cells (somatostatin) - ECL cells (Histamine) - enterogastrone: I cells (CCK), K cells (GIP), S cells (secretin) |
| Border | Brunner's glands - Paneth cells - Enterocytes |
| Fluids | Saliva - Bile - Intestinal juice - Gastric juice - Pancreatic juice |
| Processes | Swallowing - Vomiting - Peristalsis (Interstitial cell of Cajal) - Migrating motor complex - Borborygmus - Gastrocolic reflex - Segmentation contractions - Defecation |
Peptides: neuropeptides | |
|---|---|
| Hypothalamic | Somatostatin - CRH - GnRH - GHRH - Orexins - TRH - POMC (ACTH, MSH, Lipotropin) |
| Gastrointestinal hormones | Cholecystokinin - Gastric inhibitory polypeptide - Gastrin - Motilin - Secretin - Vasoactive intestinal peptide |
| Other hormones | Vasopressin - Calcitonin - |
| Other | Angiotensin - Bombesin/Neuromedin B - Calcitonin gene-related peptide - Carnosine - Delta sleep-inducing peptide - FMRFamide - Galanin - Gastrin releasing peptide - Kinins (Bradykinin, Tachykinins ) - Neuromedin (B, N, U) - Neuropeptide Y - Neurophysins - Neurotensin - Opioid peptide - Pancreatic polypeptide - Pituitary adenylate cyclase activating peptide |
Hormones: gastrointestinal hormones |
|---|
| CCK - EGF - GIP - Gastrin releasing peptide - Gastrins - Proglucagon - Motilin - Peptide YY -Prokineticin - Secretin - VIP |
Acknowledgement and Attribution Regarding Sources of Content
Some of the initial content on this page may be incorporated in part from copyleft sources in the public domain including wikis such as Wikipedia and AskDrWiki. Drug information for patients came from the The National Library of Medicine. Infectious disease information may have come from the Centers for Disease Control (CDC). Differential Diagnoses are drawn from clinicians as well as an amalgamation of 3 sources: 1.The Disease Database; 2. Kahan, Scott, Smith, Ellen G. In A Page: Signs and Symptoms. Malden, Massachusetts: Blackwell Publishing, 2004:3; 3. Sailer, Christian, Wasner, Susanne. Differential Diagnosis Pocket. Hermosa Beach, CA: Borm Bruckmeir Publishing LLC, 2002:7 .
de:Cholecystokinin fr:Cholécystokinine it:Colecistochinina nl:Cholecystokininesr:Холецистокинин fi:Kolekystokiniini sv:Cholecystokinin
