| Histamine | |
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| IUPAC name | 2-(3H-imidazol-4-yl)ethanamine |
| Identifiers | |
| CAS number | [51-45-6] |
| PubChem | |
| MeSH | |
| SMILES | C1=C(NC=N1)CCN |
| Properties | |
| Molecular formula | C5H9N3 |
| Molar mass | 111. IUPAC Nomenclature is a system of naming Chemical compounds and of describing the science of Chemistry in general CAS registry numbers are unique numerical identifiers for Chemical compounds Polymers biological sequences mixtures and Alloys They are also referred to PubChem is a Database of chemical Molecules The system is maintained by the National Center for Biotechnology Information (NCBI a component Medical Subject Headings ( MeSH) is a huge Controlled vocabulary (or metadata system for the purpose of indexing journal articles and books A chemical formula is a way of expressing information about the Atoms that constitute a particular Chemical compound, and how the relationship between those atoms changes Molar mass, symbol M, is the Mass of one mole of a substance ( Chemical element or Chemical compound) 145 |
| Melting point |
83. The melting point of a solid is the temperature range at which it changes state from solid to Liquid. 5 °C (182. 3 °F) |
| Boiling point |
209. The boiling point of a liquid is the temperature at which the Vapor pressure of the liquid equals the environmental pressure surrounding the liquid 5 °C (409. 1 °F) |
| Except where noted otherwise, data are given for materials in their standard state (at 25 °C, 100 kPa) Infobox disclaimer and references |
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Histamine is a biogenic amine involved in local immune responses as well as regulating physiological function in the gut and acting as a neurotransmitter. In Chemistry, the standard state of a material is its state at 1 bar (100 Kilopascals exactly A biogenic amine is a Biogenic substance with an Amine group Examples Some prominent examples of biogenic amines include Histamine An immune system is a collection of mechanisms within an Organism that protects against Disease by identifying and killing Pathogens and Tumor See Chemical synapse for an introduction to concepts and terminology used in this article [1] New evidence also indicates that histamine plays an important role in chemotaxis of white blood cells. Chemotaxis, a kind of Taxis, is the phenomenon in which bodily cells bacteria, and other single-cell or Multicellular organisms direct their movements
Contents |
Synthesis and metabolism
Histamine is derived from the decarboxylation of the amino acid histidine, a reaction catalyzed by the enzyme L-histidine decarboxylase. Decarboxylation is any Chemical reaction in which a Carboxyl group (-COOH is split off from a compound as Carbon dioxide (CO2 In Chemistry, an amino acid is a Molecule containing both Amine and Carboxyl Functional groups In Biochemistry, this Histidine (abbreviated as His or H) is one of the 20 standard Amino acids present in Proteins In the Nutritional sense in Catalysis is the process in which the rate of a Chemical reaction is increased by means of a Chemical substance known as a catalyst Enzymes are Biomolecules that catalyze ( ie increase the rates of Chemical reactions Almost all enzymes are Proteins Histidine decarboxylase ( HDC) is the Enzyme that catalyzes the reaction which produces Histamine from Histidine as follows C6H9N3O2 It is a hydrophilic vasoactive amine. Hydrophile, from the Greek (hydros "water" and φιλια (philia "friendship" refers to a physical property of a Molecule A hormone drug or chemical which is capable of eliciting Vasoconstrictive or Vasodilative action on the Vasculature. Amines are Organic compounds and Functional groups that contain a basic Nitrogen Atom with a Lone pair.
Once formed, histamine is either stored or rapidly inactivated. Histidine (abbreviated as His or H) is one of the 20 standard Amino acids present in Proteins In the Nutritional sense in Histidine decarboxylase ( HDC) is the Enzyme that catalyzes the reaction which produces Histamine from Histidine as follows C6H9N3O2 Histamine released into the synapses is broken down by acetaldehyde dehydrogenase. Chemical synapses are specialized junctions through which Neurons signal to each other and to non-neuronal cells such as those in Muscles or Glands Acetaldehyde dehydrogenase s ( are Dehydrogenase Enzymes which catalyze the conversion of Acetaldehyde into Acetic acid. It is the deficiency of this enzyme that triggers an allergic reaction as histamines pool in the synapses. Enzymes are Biomolecules that catalyze ( ie increase the rates of Chemical reactions Almost all enzymes are Proteins Histamine is broken down by histamine-N-methyltransferase and diamine oxidase. Histamine N-methyltransferase is an enzyme involved in the metabolism of Histamine. Amine oxidase is an enzyme involved in the metabolism of Histamine. Some forms of foodborne disease, so-called "food poisonings," are due to conversion of histidine into histamine in spoiled food, such as fish. Foodborne illness (also foodborne disease) is any Illness resulting from the consumption of food
Storage and release
Most histamine in body tissue is found in granules in mast cells (see figure) or basophils. A mast cell (or mastocyte) is a resident cell of several types of tissues and contains many granules rich in Histamine and Heparin Mast cells are especially numerous at sites of potential injury - the nose, mouth, and feet; internal body surfaces; and blood vessels. Non-mast cell histamine is found in several tissues, including the brain, where it functions as a neurotransmitter. The brain is the center of the Nervous system in animals All Vertebrates and the majority of Invertebrates have a brain Another important site of histamine storage and release is the enterochromaffin-like (ECL) cell of the stomach. Enterochromaffin-like cells or ECL cells are a type of Neuroendocrine cells found in the gastric glands of the Gastric mucosa beneath the Epithelium In Human anatomy, the stomach is a J-shaped hollow muscular organ of the Gastrointestinal tract involved in the second phase of Digestion, following
The most important pathophysiologic mechanism of mast cell and basophil histamine release is immunologic. An immune system is a collection of mechanisms within an Organism that protects against Disease by identifying and killing Pathogens and Tumor These cells, if sensitized by IgE antibodies attached to their membranes, degranulate when exposed to the appropriate antigen. In Biology, Immunoglobulin E ( IgE) is a class of Antibody (or Immunoglobulin " Isotype " that has only been found in Antibodies (also known as immunoglobulins, abbreviated Ig) are Gamma globulin Proteins that are found in Blood or other Bodily The cell membrane (also called the plasma membrane, plasmalemma, or "phospholipid bilayer" is a Selectively permeable Lipid bilayer Degranulation is a cellular process that releases Antimicrobial Cytotoxic molecules from secretory vesicles called granules found inside An antigen (from antibody-generating) or immunogen is a substance that prompts the generation of Antibodies and can cause an immune response Certain amines, including such drugs as morphine and tubocurarine, can displace histamine in granules and cause its release. Amines are Organic compounds and Functional groups that contain a basic Nitrogen Atom with a Lone pair. Medical uses Morphine can be used as an analgesic in hospital settings to relieve pain in Myocardial infarction pain in Tubocurarine chloride is an antagonist of Nicotinic neuromuscular acetylcholine receptors that is used to paralyse patients undergoing Anaesthesia.
Mechanism of action
Histamine exerts its actions by combining with specific cellular histamine receptors. The histamine receptors are a class of G-protein coupled receptors with Histamine as their Endogenous Ligand. The four histamine receptors that have been discovered are designated H1 through H4.
| Type | Location | Function |
| H1 histamine receptor | Found on smooth muscle, endothelium, and central nervous system tissue | Causes vasodilation, bronchoconstriction, smooth muscle activation, separation of endothelial cells (responsible for hives), and pain and itching due to insect stings; the primary receptors involved in allergic rhinitis symptoms and motion sickness. The H1 receptor is a Histamine receptor, and thus an important target for clinically important drugs and is likely one of the most important receptors for modulating Smooth muscle is a type of non- Striated muscle, found within the Tunica media layer of large and small Arteries and Veins, the bladder The endothelium is the thin layer of cells that line the interior surface of Blood vessels forming an interface between circulating Blood in the In Vertebrates the central nervous system ( CNS) is the part of the Nervous system which is enclosed in the Meninges. Bronchoconstriction is the constriction of the airways in the Lungs due to the tightening of surrounding Smooth muscle, with consequent Coughing, Wheezing Smooth muscle is a type of non- Striated muscle, found within the Tunica media layer of large and small Arteries and Veins, the bladder The endothelium is the thin layer of cells that line the interior surface of Blood vessels forming an interface between circulating Blood in the Pain, in the sense of physical pain, is a typical sensory experience that may be described as the unpleasant awareness of a noxious stimulus or bodily harm Itch ( Latin: pruritus) is an unpleasant Sensation that evokes the desire or Reflex to scratch Hay Fever is a comic play written by Noel Coward in 1924 and first produced in 1925 with Marie Tempest as the first Judith Bliss Motion sickness or kinetosis is a condition in which a disagreement exists between visually perceived movement and the Vestibular system 's sense of movement |
| H2 histamine receptor | Located on parietal cells | Primarily stimulate gastric acid secretion |
| H3 histamine receptor | - | Decreased neurotransmitter release: histamine, acetylcholine, norepinephrine, serotonin |
| H4 histamine receptor | Found primarily in the thymus, small intestine, spleen, and colon. H2 receptors positively coupled to Adenylate cyclase via Gs. It is a potent stimulant of cAMP production Parietal cells (also called oxyntic cells) are the Stomach Epithelium cells that secrete Gastric acid and Intrinsic factor Gastric acid is one of the main Secretions of the Stomach, together with several Enzymes and Intrinsic factor. Histamine H3 receptors are expressed in the Central nervous system and to a lesser extent the Peripheral nervous system, where they act as Autoreceptors See Chemical synapse for an introduction to concepts and terminology used in this article The Chemical compound acetylcholine (often abbreviated ACh) is a Neurotransmitter in both the Peripheral nervous system (PNS and Central Norepinephrine ( INN) (abbreviated norepi or NE) or noradrenaline ( BAN) (abbreviated NA or NAd) is a Serotonin (ˌsɛrəˈtoʊnən ( 5-hydroxytryptamine, or 5-HT) is a Monoamine Neurotransmitter synthesized in serotonergic Neurons The histamine H4 receptor is like the other three Histamine receptors, a member of the G protein-coupled receptor superfamily In Human anatomy, the thymus is an organ located in the upper Anterior portion of the chest cavity just behind the Sternum. In Biology the small Intestine is the part of the Gastrointestinal tract (gut between the Stomach and the Large intestine, and comprises The spleen is an organ found in all Vertebrate animals In humans the spleen is located in the abdomen of the body where it functions in the destruction of redundant Red The colon is a storage tube for solid wastes The main function of the colon appears to be extraction of Water and salts from Feces. It is also found on basophils and in the bone marrow. Bone marrow is the flexible tissue found in the hollow interior of Bones In adults marrow in large bones produces new Blood cells It constitutes 4% of | Unknown physiological role. |
Roles in the body
Sleep regulation
Histamine is released as a neurotransmitter. The cell bodies of neurons which release histamine are found in the posterior hypothalamus, in various tuberomammillary nuclei. The hypothalamus links the Nervous system to the Endocrine system via the Pituitary gland (hypophysis The tuberomammillary nucleus is a subnucleus of the Posterior third of the Hypothalamus. From here, these histaminergic neurons project throughout the brain, to the cortex through the medial forebrain bundle. The brain is the center of the Nervous system in animals All Vertebrates and the majority of Invertebrates have a brain The Medial forebrain bundle (MFB is a complex bundle of axons coming from the basal olfactory regions the periamygdaloid region and the Septal nuclei, and passing to the Histaminergic action is known to modulate sleep. Sleep is a Natural state of bodily rest observed throughout the animal kingdom Classically, antihistamines (H1 histamine receptor antagonists) produce sleep. Likewise, destruction of histamine releasing neurons, or inhibition of histamine synthesis leads to an inability to maintain vigilance. Alertness is the state of paying close and continuous Attention. Finally, H3 receptor antagonists (which stimulate histamine release) increase wakefulness.
It has been shown that histaminergic cells have the most wakefulness-related firing pattern of any neuronal type thus far recorded. They fire rapidly during waking, fire more slowly during periods of relaxation/tiredness and completely stop firing during REM and NREM (non-REM) sleep. The Sleep stages 1 through 4 are collectively referred to as NREM (non-rapid eye movement sleep Histaminergic cells can be recorded firing just before an animal shows signs of waking.
Sexual response
Research has shown that histamine is released as part of the human orgasm from mast cells in the genitals. An orgasm (sexual climax is the conclusion of the plateau phase of the sexual response cycle, and may be experienced by both males and females If this response is lacking this may be a sign of histapenia (histamine deficiency). In such cases, a doctor may prescribe diet supplements with folic acid and niacin (which used in conjunction can increase blood histamine levels and histamine release), or L-histidine. Folic acid (also known as Vitamin M and Folacin) and Folate (the Anionic form are forms of the water-soluble Vitamin B9 Niacin, also known as vitamin B3, is a water-soluble vitamin which prevents the deficiency disease Pellagra. Conversely, men with high histamine levels may suffer from premature ejaculations. Premature ejaculation (PE also known as rapid ejaculation, rapid climax, premature climax or early ejaculation, is the most common sexual
Schizophrenia
It has been found that about half the patients classified as suffering from schizophrenia have low histamine levels in the blood. Schizophrenia ( from the Greek roots schizein (σχίζειν "to split" and phrēn [2] This may be because of antipsychotics that have unwanted effect on histamine, such as quetiapine. Antipsychotics are a group of Psychoactive drugs commonly but not exclusively used to treat Psychosis, which is typified by Schizophrenia. Quetiapine ( kwe-TYE-a-peen marketed by AstraZeneca as Seroquel and by Orion Pharma as Ketipinor, is an Atypical antipsychotic Although, in these cases, as histamine levels were increased, their health improved.
Disorders
High or low histamine levels are considered by some of the alternative medicine community to be health issues; this is not accepted by the mainstream medical community. However, as an integral part of the immune system it may be involved in immune system disorders and allergies. Autoimmunity is the failure of an organism to recognize its own constituent parts as self, which results in an immune response against its own cells and tissues Allergy is a disorder of the Immune system often also referred to as Atopy.
Nomenclature
"H substance" or "substance H" are occasionally used in medical literature for histamine or a hypothetical histamine-like diffusible substance released in allergic reactions of skin and in the responses of tissue to inflammation.
See also
References
- ^ Template:Tte book
- ^ What is Schizophrenia?
External links
Scombroid food poisoning is a foodborne Illness that results from eating spoiled (decayed Fish. The DrugBank database available at the University of Alberta is a unique Bioinformatics and Cheminformatics resource that combines detailed drug (iDictionary
histamine
-noun
- (biochemistry) An amine, C5H9N3, formed by decarboxylation of histidine, that causes dilatation of capillaries, contraction of smooth muscle, and stimulation of gastric acid secretion; it is released during allergic reactions.
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