Lipotropin

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pro-opiomelanocortin
Identifiers
Symbol POMC
Entrez 5443
HUGO 9201
OMIM 176830
RefSeq NM_000939
UniProt P01189
Other data
Locus Chr. 2 p23

Lipotropin is a hormone produced by the cleavage of pro-opiomelanocortin (POMC). The anterior pituitary gland produces the pro-hormone POMC, which is then cleaved again to form adrenocorticotropin (ACTH) and β-lipotropin (β-LPH).

β-Lipotropin[edit]

β-Lipotropin is a 90-amino acid polypeptide that is the carboxy-terminal fragment of POMC.

It stimulates melanocytes to produce melanin, and can also be cleaved into smaller peptides. In humans, γ-lipotropin, α-MSH, β-MSH, γ-MSH, α-endorphin, β-endorphin, γ-endorphin, and met-enkephalin are all possible fragments of β-lipotropin.[1]

β-Lipotropin also performs lipid-mobilizing functions such as lipolysis and steroidogenesis. β-Lipotropin is the predominant opiod of the anterior human and rat pituitary gland. It is found in essentially equimolar concentrations to that of corticotropin. Evidence shows that β-Lipotropin is metabolized into endorphins that can greatly affect mood and behavior and is thus regarded as a prohormone.[2]

γ-Lipotropin[edit]

γ-lipotropin is the amino-terminal peptide fragment of β-lipotropin. In humans, it has 56 amino acids. Gamma lipotropin is identical to the first 56 amino acid sequences of β-lipotropin.

Use in sport[edit]

Lipotropin has also, under its alternate name AOD-9604 (Anti-Obesity Drug-9604),[3] been connected with controversies in Australian Rules Football. Allegations have arisen around the use of the drug and its administration to players of the Essendon Football Club as a supplement, including weekly administration to players in the 2012 season. The matters are currently under investigation due to the relationship between Lipotropin and growth hormones, as noted by club medical staff.[4]

References[edit]

  1. ^ Joachim Spiess, Charles D. Mount, Wendell E. Nicholson, David N. Orth (1982), NH2-Terminal amino acid sequence and peptide mapping of purified human β-lipotropin: Comparison with previously proposed sequences, Proc. Natl. Acad. Sci. USA 79 (16): 5071–5, Bibcode:1982PNAS...79.5071S, doi:10.1073/pnas.79.16.5071, PMC 346829, PMID 6956916 
  2. ^ Lazarus, L H; Ling, Guillemin (June 1, 1976). "beta-Lipotropin as a prohormone for the morphinomimetic peptides endorphins and enkephalins". Proceedings of the National Academy of Sciences of the United States of America PNAS, Proceedings of the National Academy of Sciences 73 (6): 2156–2159. doi:10.1073/pnas.73.6.2156. 
  3. ^ Peptides Direct information page, accessed 26 August 2013
  4. ^ AFL Statement of Charges against James Hird and Essendon Football Club, accessed 26 August 2013 [1]

External links[edit]