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Cholecystokinin
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| Identifiers | ||
| Symbol(s) | CCK; MGC117187 | |
| External IDs | OMIM: 118440 MGI: 88297 HomoloGene: 583 | |
| RNA expression pattern | ||
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| 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] |
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. Greek (el ελληνική γλώσσα or simply el ελληνικά — "Hellenic" is an Indo-European language, spoken today by 15-22 million people mainly The gallbladder (or cholecyst sometimes gall bladder is a small organ whose function in the body is to store Bile and aid in the digestive process Peptide hormones are a class of peptides that are secreted into the blood stream and have Endocrine functions in living animals Digestion is the breaking down of chemicals in the body into a form that can be absorbed Fats consist of a wide group of compounds that are generally soluble in organic solvents and largely insoluble in water Proteins are large Organic compounds made of Amino acids arranged in a linear chain and joined together by Peptide bonds between the Carboxyl 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. In Anatomy of the Digestive system, the duodenum is a hollow jointed tube about 25-30 cm (10-12 in long connecting the Stomach to the Jejunum In Biology the small Intestine is the part of the Gastrointestinal tract (gut between the Stomach and the Large intestine, and comprises Enzymes are Biomolecules that catalyze ( ie increase the rates of Chemical reactions Almost all enzymes are Proteins Bile or gall is a bitter yellow or green Alkaline fluid secreted by Hepatocytes from the Liver of most Vertebrates In many species The pancreas is a Gland organ in the digestive and Endocrine system of Vertebrates. The gallbladder (or cholecyst sometimes gall bladder is a small organ whose function in the body is to store Bile and aid in the digestive process It also acts as a hunger suppressant. Note "Anorectic" is also a term for an anorexic person a person suffering from Anorexia nervosa Anorectics, anorexigenics 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. An opioid is a chemical Substance that has a Morphine -like action in the body Medical uses Morphine can be used as an analgesic in hospital settings to relieve pain in Myocardial infarction pain in Heroin ( INN: diacetylmorphine, BAN: diamorphine) is a semi-synthetic opioid synthesized from Morphine, a derivative Withdrawal, also known as withdrawal/abstinence syndrome, refers to the characteristic signs and symptoms that appear when a drug that causes Physical dependence is [1][2]
Contents |
Structure
CCK is composed of varying numbers of amino acids (e. In Chemistry, an amino acid is a Molecule containing both Amine and Carboxyl Functional groups In Biochemistry, this g. , CCK58, CCK33, CCK8) depending on post-translational modification of the CCK gene product, preprocholecystokinin. Posttranslational modification (PTM is the chemical modification of a Protein after its translation. 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 the same as those of gastrin. In humans gastrin is a Hormone that stimulates secretion of Gastric acid (HCl by the Parietal cells of the Stomach, as well as aiding in The gastrointestinal hormones (or gut hormones) constitute a group of Hormones secreted by Enteroendocrine cells in the Stomach, Pancreas CCK58 comprises a helix-turn-helix configuration.
Release and Function
CCK mediates a number of physiological processes, including digestion and satiety. Physiology (from Greek grc φύσις physis, "nature origin" and grc -λογία -logia) is the study of the mechanical physical Digestion is the breaking down of chemicals in the body into a form that can be absorbed Cholecystokinin ( CCK; from Greek chole, "bile" cysto, "sac" kinin, "move" hence move the bile-sac
Digestion
Secretion of CCK by the duodenal and intestinal mucosa is stimulated by fat- or protein-rich chyme entering the duodenum. Chyme is the semifluid mass of partly digested food expelled by the stomach into the duodenum In Anatomy of the Digestive system, the duodenum is a hollow jointed tube about 25-30 cm (10-12 in long connecting the Stomach to the Jejunum It then inhibits gastric emptying and gastric acid secretion and mediates digestion in the duodenum. Gastric acid is one of the main Secretions of the Stomach, together with several Enzymes and Intrinsic factor. It stimulates acinar cell of pancreas to produce water, ion and stimulates the secretion of a juice rich in pancreatic digestive enzymes. The pancreas is a Gland organ in the digestive and Endocrine system of Vertebrates. Digestion enzymes are Enzymes that break down Polymeric Macromolecules into their smaller building blocks 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. Somatostatin (also known as growth hormone inhibiting hormone ( GHIH) or somatotropin release-inhibiting factor ( SRIF) is a Peptide hormone
CCK also causes the increased production of hepatic bile, and stimulates the contraction of the gall bladder 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. The gallbladder (or cholecyst sometimes gall bladder is a small organ whose function in the body is to store Bile and aid in the digestive process The Sphincter of Oddi, also called the hepatopancreatic sphincter or Glisson's sphincter, controls secretions from the Liver, Pancreas, and Bile or gall is a bitter yellow or green Alkaline fluid secreted by Hepatocytes from the Liver of most Vertebrates In many species Bile salts form amphipathic micelles that emulsify fats, aiding in their digestion and absorption. Bile acids (also known as bile salts are Steroid Acids found predominantly in the Bile of Mammals. A micelle (rarely micella, plural micelles) is an aggregate of Surfactant molecules dispersed in a liquid Colloid. An emulsion ( IPA: /ɪˈmʌlʃən/ is a mixture of two Immiscible (unblendable liquids
Neurobiology
As a neuropeptide, CCK mediates satiety by acting on the CCK receptors distributed widely throughout the central nervous system. A neuropeptide is any of the variety of Peptides found in Neural tissue; e Cholecystokinin receptors or CCK receptors are a group of G-protein coupled receptors which bind the peptide hormones Cholecystokinin (CCK or Gastrin In Vertebrates the central nervous system ( CNS) is the part of the Nervous system which is enclosed in the Meninges. 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. Nausea ( Latin: Nausea, Greek:, " Sea-sickness " also called wamble) is the sensation of unease and discomfort Anxiety is a physiological and psychological state characterized by Cognitive, Somatic, Emotional and Behavioral components 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 cholecystokinin tetrapeptide fragment CCK-4 (Trp-Met-Asp-Phe-NH2) reliably causes anxiety when administered to humans, and is commonly used in scientific research to induce panic attacks for the purpose of testing new anxiolytic drugs. Cholecystokinin tetrapeptide ( CCK-4, Trp - Met - Asp - Phe -NH2) is a Peptide fragment derived from Tryptophan (abbreviated as Trp or W) is one of the 20 standard amino acids, as well as an Essential amino acid in the Human diet Methionine ( abbreviated as Met or M) is an α- Amino acid with the Chemical formula HO2CCH(NH2CH2CH2SCH3 Aspartic acid (abbreviated as Asp or D; Asx or B represent either aspartic acid or Asparagine) is an α- Amino acid Phe redirects here For the BitTorrent feature see PHE. For the constellation see Phoenix (constellation. Panic attacks are sudden discrete periods of intense anxiety mounting Physiological arousal fear stomach problems and discomfort that are associated with a variety of An anxiolytic is a drug prescribed for the treatment of Symptoms of Anxiety. [5]
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. Rats are various medium sized long-tailed Rodents of the superfamily Muroidea The hunger-suppressive effects of CCK also are reduced in obese rats. [6]
See also
References
- ^ Kissin I, Bright CA, Bradley EL (2000). Antianalgesia is the ability of some endogenous chemicals (notably Cholecystokinin and Neuropeptide Y) to counter the effects of exogenous Analgesics A Cholecystokinin antagonist is a specific type of Receptor antagonist which blocks the receptor sites for the Peptide Hormone Cholecystokinin Proglumide ( Milid) is a drug which inhibits gastrointestinal motility and reduces gastric secretions "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:. A digital object identifier ( DOI) is a permanent identifier given to an Electronic document. 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:. A digital object identifier ( DOI) is a permanent identifier given to an Electronic document. 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:. A digital object identifier ( DOI) is a permanent identifier given to an Electronic document. 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.
- ^ Bradwejn J. Neurobiological investigations into the role of cholecystokinin in panic disorder. Journal of Psychiatry and Neuroscience. 1993 Jul;18(4):178-88. PMID 8104032
- ^ 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:. A digital object identifier ( DOI) is a permanent identifier given to an Electronic document. PMID 9835394.
External links
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