Prohormone

A prohormone is a committed precursor of a hormone consisting of peptide hormones synthesized together that has a minimal hormonal effect by itself because of its expression-suppressing structure, often created by protein folding and binding additional peptide chains to certain ends, that makes hormone receptor binding sites located on its peptide hormone chain segments inaccessible.[1][2] Prohormones can travel the blood stream as a hormone in an inactivated form, ready to be activated later in the cell by post-translational modification.[1][3]

The body naturally produces prohormones as a way to regulate hormone expression, making them an optimal storage and transportation unit for inactive hormones. Once prohormones are needed to be expressed, prohormone convertase, a protein, cleaves the prohormones and separates them into one or more active hormones.[4] Often in nature, this cleaving process happens immediately, and a prohormone is quickly converted to a set of one or more peptide hormones.[5]

Examples of natural, human prohormones include proinsulin and pro-opiomelanocortin, but the most widespread prohormones in use are synthetic and labeled as anabolic steroid precursors, used as ergogenic or anabolic agents for muscle growth.[6] A commonly consumed example of said precursors are androstenedione and androstenediol, both of which are currently banned substances in the United States.[6][7] However, several illegal steroids, such as 1-testosterone, are still being produced legally under different chemical names, and the majority have not undergone clinical studies.[6][8]

  1. ^ a b Friedman, Theodore C.; Cool, David R. (2004-01-01), "Prohormones", in Martini, Luciano (ed.), Encyclopedia of Endocrine Diseases, New York: Elsevier, pp. 91–98, doi:10.1016/b0-12-475570-4/01074-x, ISBN 978-0-12-475570-3, retrieved 2021-12-04
  2. ^ Cite error: The named reference :8 was invoked but never defined (see the help page).
  3. ^ Miller, Benjamin Frank; Claire Brackman Keane (1997). Miller-Keane Encyclopedia & dictionary of medicine, nursing & allied health (6th ed.). Philadelphia: Saunders. ISBN 0-7216-6278-1. OCLC 36465055.
  4. ^ Dhanvantari, Savita; Cawley, Niamh X.; Loh, Y. Peng (2004-01-01), "Prohormone Convertases", in Martini, Luciano (ed.), Encyclopedia of Endocrine Diseases, New York: Elsevier, pp. 84–90, ISBN 978-0-12-475570-3, retrieved 2021-12-09
  5. ^ Alarcon, Cristina; Wicksteed, Barton; Rhodes, Christopher J. (2003-01-01), "Insulin Processing", in Henry, Helen L.; Norman, Anthony W. (eds.), Encyclopedia of Hormones, New York: Academic Press, pp. 359–368, doi:10.1016/b0-12-341103-3/00175-3, ISBN 978-0-12-341103-7, retrieved 2021-12-09
  6. ^ a b c Powers, Michael E. (2002). "The Safety and Efficacy of Anabolic Steroid Precursors: What is the Scientific Evidence?". Journal of Athletic Training. 37 (3): 300–305. ISSN 1062-6050. PMC 164360. PMID 16558675.
  7. ^ Pitts, Joseph R. (2014-12-18). "Text - H.R.4771 - 113th Congress (2013-2014): Designer Anabolic Steroid Control Act of 2014". www.congress.gov. Retrieved 2021-12-09.
  8. ^ Parr, Maria K.; Opfermann, Georg; Geyer, Hans; Westphal, Folker; Sönnichsen, Frank D.; Zapp, Josef; Kwiatkowska, Dorota; Schänzer, Wilhelm (2011-02-01). "Seized designer supplement named "1-Androsterone": identification as 3β-hydroxy-5α-androst-1-en-17-one and its urinary elimination". Steroids. 76 (6): 540–547. doi:10.1016/j.steroids.2011.02.001. ISSN 1878-5867. PMID 21310167. S2CID 4942690.