Local hormonesare a large group ofsignaling moleculesthat do not circulate within the blood. Localhormonesare produced by nerve and glandcellsand bind to either neighboring cells or the same type of cell that produced them. Local hormones are activated and inactivated quickly.[1]They are released during physical work and exercise. They mainly controlsmoothandvascularmuscle dilation.[2]Strength of response is dependent upon the concentration of receptors of target cell and the amount of ligand ( the specific local hormone).[3]
Eicosanoids(ī′kō-să-noydz;eicosa= twenty,eidos= formed) are a primary type of local hormone. These local hormones are polyunsaturated fatty acid derivatives containing 20 carbon atoms andfatty acidsderived fromphospholipidsin thecell membraneor from diet. Eicosanoids initiate eitherautocrine stimulationorparacrine stimulation.There are two main types of eicosanoids: prostaglandins and leukotrienes, which initiate eitherautocrine stimulationorparacrine stimulation.Eicosanoids are the result of a ubiquitous pathway which first produces arachidonic acid, and then the eicosanoid product.
Prostaglandinsare the most diverse category of eicosanoids and are thought to be synthesized in most tissues of the body. This type of local hormone stimulatespain receptorsand increases theinflammatory response.Nonsteroidal anti-inflammatory drugsstop the formation of prostaglandins, thus inhibiting these responses.
Leukotrienesare a type of eicosanoids that are produced in leukocytes and function in inflammatory mediation.[4]
Paracrines(para- = beside or near) are local hormones that act on neighboring cells.[1]This type of signaling involves the secretion of paracrine factors, which travel a short distance in the extracellular environment to affect nearby cells. These factors can be excitatory or inhibitory. There are a few families of factors that are very important in embryo development including fibroblast growth factorsecretedthem.[1]
Juxtacrines(juxta = near) are local hormones that require close contact and act on either the cell which emitted them or on adjacent cells.[5]
Classification
editAccording to structural and functional similarity, many local hormones fall into either thegastrinor thesecretinfamily.[6]
Gastrin family
editTheGastrin familyis a group of peptides evolutionarily similar in structure and function. Commonly synthesized in antroduodenal G-cells. Regulate gastric function along with gastric acid secretion and mucosal growth.[7]
- Gastrin
- Cholecystokinin(CCK)
Secretin family
editTheSecretin familyare peptides that act as local hormones which regulate activity ofG-protein coupled receptors.Most often found in the pancreas and the intestines. Secretin was discovered in 1902 by E. H. Starling. It was later linked to chemical regulation and was the first substance to be deemed a hormone.[8]
Others
editReferences
edit- ^abc"The Endocrine System 2"(PDF).
- ^"Classification of Hormones".
- ^Haynes, William G.; Webb, David J. (1997), "The Endothelins",Molecular and Cellular Endocrinology,Elsevier, pp. 543–572,doi:10.1016/s1569-2582(97)80171-7,ISBN9781559388153
- ^Salmon, John A; Higgs, Gerald A (April 1987). "Prostaglandins and leukotrienes as inflammatory mediators".British Medical Bulletin.43(2): 285–296.doi:10.1093/oxfordjournals.bmb.a072183.ISSN1471-8391.PMID2825898.
- ^Grubb, B. J. (2006-06-06)."Developmental Biology, Eighth Edition. Scott F. Gilbert, editor".Integrative and Comparative Biology.46(5): 652–653.doi:10.1093/icb/icl011.ISSN1540-7063.
- ^Joshi, Vijaya D. (2006).Anatomy and Physiology for Nursing and Health Care.BI Publications Pvt Ltd. p. 293.ISBN9788172252359.
- ^Jens F. Rehfeld; Lennart Friis-Hansen; Jens P. Goetze; Thomas V. O. Hansen (2007-06-01). "The Biology of Cholecystokinin and Gastrin Peptides".Current Topics in Medicinal Chemistry.7(12): 1154–1165.doi:10.2174/156802607780960483.ISSN1568-0266.PMID17584137.
- ^J. H. Henriksen, O. B. Schaffalitzk (January 2000). "Secretin, its discovery, and the introduction of the hormone concept".Scandinavian Journal of Clinical and Laboratory Investigation.60(6): 463–472.doi:10.1080/003655100448446.ISSN0036-5513.PMID11129062.S2CID218987888.
- Mark H. Whitnall, William G. Haynes, David J. Webb (1997). Principles of Medical Biology.
- Salmon JA, Higgs GA (April 1987). "Prostaglandins and leukotrienes as inflammatory mediators".Br. Med. Bull.43(2): 285–96.doi:10.1093/oxfordjournals.bmb.a072183.PMID2825898.
- SF Gilbert. (2000). Developmental Biology 6th Edition.
- Jan M. Keppel Hesselink.(2016). "Autacoids: A New Fundament for Pain Medicine of the 21th Century".
- McKinley, Michael P., et al.Anatomy & Physiology: an Integrative Approach.McGraw-Hill Higher Education, 2012
- Rehfeld JF1, Friis-Hansen L, Goetze JP, Hansen TV. (2007). "The biology of cholecystokinin and gastrin peptides". Curr Top Med Chem. 2007;7(12):1154-65.
- Henriksen JH, de Muckadell OB. (2000). "Secretin, its discovery, and the introduction of the hormone concept.". Scand J Clin Lab Invest. 2000 Oct;60(6):463-71.