iPedia Free Information Center

Information about Cholecystokinin

CCK identified at bottom right.
Cholecystokinin
Identifiers
SymbolCCK
Entrez885
HUGO1569
OMIM118440
RefSeqNM_000729
UniProtP06307
Other data
LocusChr. 3 pter-p21
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 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.

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, CCK administration causes nausea and anxiety, and weakly decreases the desire to eat.[1] The mechanism for this hunger suppression is thought to be a decrease in the rate of gastric emptying.[2]

The effects of CCK vary between individuals. For example, in rats, CCK administration significantly reduces hunger in young males, but is less effective in older subjects, and even less effective in females. The hunger-suppressive effects of CCK also diminish in obese rats.[3]

See also

References

1. ^ 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. PMID 9855480. 
2. ^ Shillabeer G, Davison J (1987). "Proglumide, a cholecystokinin antagonist, increases gastric emptying in rats". Am J Physiol 252 (2 Pt 2): R353-60. PMID 3812772. 
3. ^ Fink H, Rex A, Voits M, Voigt J (1998). "Major biological actions of CCK--a critical evaluation of research findings". Exp Brain Res 123 (1-2): 77-83. PMID 9835394. 

External links

 •  • [ e]
Endocrine system: hormones/endocrine glands (Peptide hormones, Steroid hormones)
Hypothalamic-pituitary Hypothalamus: TRH, CRH , GnRH, GHRH, somatostatin, dopamine - Posterior pituitary: vasopressin, oxytocin - Anterior pituitary: α (FSH, LH, TSH), GH, prolactin, POMC (ACTH, MSH, endorphins, lipotropin)
Adrenal axis Adrenal medulla: epinephrine, norepinephrine - Adrenal cortex: aldosterone, cortisol, DHEA
Thyroid axis Thyroid: thyroid hormone (T3 and T4) - calcitonin - Parathyroid: PTH
Gonadal axisTestis: testosterone, AMH, inhibin - Ovary: estradiol, progesterone, inhibin/activin, relaxin (pregnancy)
Other end. glands Pancreas: glucagon, insulin, somatostatin - Pineal gland: melatonin
Non-end. glands Placenta: hCG, HPL, estrogen, progesterone - Kidney: renin, EPO, calcitriol, prostaglandin - Heart atrium: ANP - Stomach: gastrin, ghrelin - Duodenum: CCK, GIP, secretin, motilin, VIP - Ileum: enteroglucagon - Adipose tissue: leptin, adiponectin, resistin - Thymus: Thymosin - Thymopoietin - Liver/other: Insulin-like growth factor (IGF-1, IGF-2)
Target-derivedNGF, BDNF, NT-3
 •  • [ e]
Digestive system, physiology: gastrointestinal physiology
Enteric nervous systemMeissner's plexus - Auerbach's plexus
ExocrineChief cells (Pepsinogen) - Parietal cells (Gastric acid, Intrinsic factor) - Goblet cells (Mucus)
Endocrine/paracrineG cells (gastrin), D cells (somatostatin) - ECL cells (Histamine) - enterogastrone: I cells (CCK), K cells (GIP), S cells (secretin)
BorderBrunner's glands - Paneth cells - Enterocytes
FluidsSaliva - Bile - Intestinal juice - Gastric juice - Pancreatic juice
ProcessesSwallowing - Vomiting - Peristalsis (Interstitial cell of Cajal) - Migrating motor complex - Borborygmus - Gastrocolic reflex - Segmentation contractions - Defecation
 •  • [ e]
Peptides: neuropeptides
HypothalamicSomatostatin - CRH - GnRH - GHRH - Orexins - TRH - POMC (ACTH, MSH, Lipotropin)
Gastrointestinal hormonesCholecystokinin - Gastric inhibitory polypeptide - Gastrin - Motilin - Secretin - Vasoactive intestinal peptide
Other hormonesVasopressin - Calcitonin -
OtherAngiotensin - 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
 •  • [ e]
Hormones: gastrointestinal hormones
CCK - EGF - GIP - Gastrin releasing peptide - Gastrins - Proglucagon - Motilin - Peptide YY -Prokineticin - Secretin - VIP
The Entrez Global Query Cross-Database Search System is a powerful federated search engine, or web portal that allows users to search many discrete health sciences databases at the National Center for Biotechnology Information (NCBI) website.
..... Click the link for more information.
Hugo is a male given name, a latinized form of the name Hugh, a German/Teutonic name meaning "Bright in Mind and Spirit".

Hugo is one of the most popular names in Europe ranking as high as #2 in France, #6 in Spain, and #7 in Belgium in 2006.
..... Click the link for more information.
The National Center for Biotechnology Information (NCBI) is part of the United States National Library of Medicine (NLM), a branch of the National Institutes of Health. The NCBI is located in Bethesda, Maryland and was founded in 1988.
..... Click the link for more information.
Swiss-Prot is a manually curated biological database of protein sequences. Swiss-Prot was created in 1986 by Amos Bairoch during his PhD and developed by the Swiss Institute of Bioinformatics and the European Bioinformatics Institute.
..... Click the link for more information.
locus (plural loci) is a fixed position on a chromosome, such as the position of a gene or a biomarker (genetic marker). A variant of the DNA sequence at a given locus is called an allele. The ordered list of loci known for a particular genome is called a genetic map.
..... Click the link for more information.
Greek}}} 
Writing system: Greek alphabet 
Official status
Official language of:  Greece
 Cyprus
 European Union
recognised as minority language in parts of:
 European Union
 Italy
 Turkey
Regulated by:
..... Click the link for more information.
The gallbladder (or cholecyst, sometimes gall bladder) is a pear-shaped organ that stores about 50 ml of bile (or "gall") until the body needs it for digestion.
..... Click the link for more information.
Peptide hormones are a class of peptides that are secreted into the blood stream and have endocrine functions in living animals.

Like other proteins, peptide hormones are synthesized from amino acids according to an mRNA template, which is itself synthesized from a DNA
..... Click the link for more information.
gastrointestinal tract (GI tract), also called the digestive tract, or the alimentary canal, is the system of organs within multicellular animals that takes in food, digests it to extract energy and nutrients, and expels the remaining waste.
..... Click the link for more information.
Digestion is the process of metabolism whereby a biological entity processes a substance in order to chemically and mechanically convert the substance for the body to use.

Overview

Digestion occurs at the multicellular, cellular, and sub-cellular levels, usually in animals.
..... Click the link for more information.

Fat

Fat may refer to:
  • Fat, a group of compounds that are generally soluble in organic solvents and largely insoluble in water
  • Adipose tissue, an anatomical term for loose connective tissue composed of adipocytes

..... Click the link for more information.
Proteins are large organic compounds made of amino acids arranged in a linear chain and joined together by peptide bonds between the carboxyl and amino groups of adjacent amino acid residues.
..... Click the link for more information.
In anatomy of the digestive system, the duodenum is a hollow jointed tube about 25-30 cm long connecting the stomach to the jejunum. It is the first and shortest part of the small intestine and it is where most chemical digestion takes place.
..... Click the link for more information.
In biology the small intestine is the part of the gastrointestinal tract (gut) between the stomach and the large intestine and includes the duodenum, jejunum, and ileum. It is where the vast majority of digestion takes place.
..... Click the link for more information.
Enzymes are proteins that catalyze (i.e. accelerate) chemical reactions.[1] In enzymatic reactions, the molecules at the beginning of the process are called substrates, and the enzyme converts them into different molecules, the products.
..... Click the link for more information.
Bile (or gall) is a bitter, yellow or green alkaline fluid secreted by hepatocytes from the liver of most vertebrates. In many species, it is stored in the gallbladder between meals and upon eating is discharged into the duodenum
..... Click the link for more information.
The pancreas is a gland organ in the digestive and endocrine systems of vertebrates<ref name="New Standard" />. It is both exocrine (secreting pancreatic juice containing digestive enzymes) and endocrine (producing several important hormones, including
..... Click the link for more information.
The gallbladder (or cholecyst, sometimes gall bladder) is a pear-shaped organ that stores about 50 ml of bile (or "gall") until the body needs it for digestion.
..... Click the link for more information.
Hunger is a feeling experienced when the glycogen level of the liver falls below a threshold, usually followed by a desire to eat. The usually unpleasant feeling originates in the hypothalamus and is released through receptors in the liver.
..... Click the link for more information.
Discrimination

Major forms
Racism
Sexism
Homophobia
Ageism
Antisemitism
Islamophobia
Ableism

Manifestations
Slavery · Racial profiling
Hate speech · Hate crime
Genocide · Ethnocide · Holocaust
..... Click the link for more information.
An opioid is a chemical substance that has a morphine-like action in the body. The main use is for pain relief. These agents work by binding to opioid receptors, which are found principally in the central nervous system and the gastrointestinal tract.
..... Click the link for more information.
Morphine (INN) (IPA: [ˈmɔ(ɹ)fin]) is a highly potent opiate analgesic drug and is the principal active agent in opium and the prototypical opioid. Like other opiates, e.g.
..... Click the link for more information.
Heroin (INN: diacetylmorphine, BAN: diamorphine) is a semi-synthetic opioid synthesized from morphine, a derivative of the opium poppy, Papaver somniferum.
..... Click the link for more information.
For other meanings, see Withdrawal (disambiguation).


Withdrawal, also known as withdrawal syndrome, refers to the characteristic signs and symptoms that appear when a drug that causes physical dependence is regularly used for a long time and then
..... Click the link for more information.
amino acid is a molecule that contains both amine and carboxyl functional groups. In biochemistry, this term refers to alpha-amino acids with the general formula H2NCHRCOOH, where R is an organic substituent.
..... Click the link for more information.
Protein synthesis is the creation of proteins using DNA and RNA. Biological and artificial methods for creation of proteins differ significantly.
  • For biological protein synthesis, see protein biosynthesis.
  • For artificial protein synthesis, see peptide synthesis.

..... Click the link for more information.
In humans, gastrin is a hormone that stimulates secretion of gastric acid by the parietal cells of the stomach. It is released by G cells in the stomach and duodenum.

Physiology

Genetics

The GAS
..... Click the link for more information.
The gastrointestinal hormones (or gut hormones) constitute a group of hormones secreted by enteroendocrine cells in the stomach, pancreas, and small intestine that control various functions of the digestive organs.
..... Click the link for more information.
Physiology (from Greek: φυσις, physis, “nature, origin”; and λόγος, logos, "knowledge") is the study of the mechanical, physical, and biochemical functions of living organisms.
..... Click the link for more information.
Digestion is the process of metabolism whereby a biological entity processes a substance in order to chemically and mechanically convert the substance for the body to use.

Overview

Digestion occurs at the multicellular, cellular, and sub-cellular levels, usually in animals.
..... Click the link for more information.


This article is copied from an article on Wikipedia.org - the free encyclopedia created and edited by online user community. The text was not checked or edited by anyone on our staff. Although the vast majority of the wikipedia encyclopedia articles provide accurate and timely information please do not assume the accuracy of any particular article. This article is distributed under the terms of GNU Free Documentation License.
Herod_Archelaus


page counter