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Event: 1756

Key Event Title

A descriptive phrase which defines a discrete biological change that can be measured. More help

Decreased, plasma 11-ketotestosterone level

Short name
The KE short name should be a reasonable abbreviation of the KE title and is used in labelling this object throughout the AOP-Wiki. More help
Decreased, 11KT
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Biological Context

Structured terms, selected from a drop-down menu, are used to identify the level of biological organization for each KE. More help
Level of Biological Organization

Organ term

The location/biological environment in which the event takes place.The biological context describes the location/biological environment in which the event takes place.  For molecular/cellular events this would include the cellular context (if known), organ context, and species/life stage/sex for which the event is relevant. For tissue/organ events cellular context is not applicable.  For individual/population events, the organ context is not applicable.  Further information on Event Components and Biological Context may be viewed on the attached pdf. More help
Organ term
blood plasma

Key Event Components

The KE, as defined by a set structured ontology terms consisting of a biological process, object, and action with each term originating from one of 14 biological ontologies (Ives, et al., 2017; Biological process describes dynamics of the underlying biological system (e.g., receptor signalling).Biological process describes dynamics of the underlying biological system (e.g., receptor signaling).  The biological object is the subject of the perturbation (e.g., a specific biological receptor that is activated or inhibited). Action represents the direction of perturbation of this system (generally increased or decreased; e.g., ‘decreased’ in the case of a receptor that is inhibited to indicate a decrease in the signaling by that receptor).  Note that when editing Event Components, clicking an existing Event Component from the Suggestions menu will autopopulate these fields, along with their source ID and description.  To clear any fields before submitting the event component, use the 'Clear process,' 'Clear object,' or 'Clear action' buttons.  If a desired term does not exist, a new term request may be made via Term Requests.  Event components may not be edited; to edit an event component, remove the existing event component and create a new one using the terms that you wish to add.  Further information on Event Components and Biological Context may be viewed on the attached pdf. More help
Process Object Action
androgen biosynthetic process 11-Keto-testosterone decreased

Key Event Overview

AOPs Including This Key Event

All of the AOPs that are linked to this KE will automatically be listed in this subsection. This table can be particularly useful for derivation of AOP networks including the KE.Clicking on the name of the AOP will bring you to the individual page for that AOP. More help
AOP Name Role of event in AOP Point of Contact Author Status OECD Status
PPARa Agonism Impairs Fish Reproduction KeyEvent Arthur Author (send email) Open for citation & comment
11β-hydroxylase inhibition, infertility in fish KeyEvent Allie Always (send email) Under development: Not open for comment. Do not cite Under Development
11βHSD inhibition, decreased population trajectory KeyEvent Agnes Aggy (send email) Under development: Not open for comment. Do not cite Under Development

Taxonomic Applicability

Latin or common names of a species or broader taxonomic grouping (e.g., class, order, family) that help to define the biological applicability domain of the KE.In many cases, individual species identified in these structured fields will be those for which the strongest evidence used in constructing the AOP was available in relation to this KE. More help
Term Scientific Term Evidence Link
teleost fish teleost fish High NCBI
Order carcharhiniformes carcharhiniformes Moderate NCBI
mammals mammals Low NCBI

Life Stages

An indication of the the relevant life stage(s) for this KE. More help
Life stage Evidence
Juvenile Moderate
Adult, reproductively mature High
Larvae Moderate

Sex Applicability

An indication of the the relevant sex for this KE. More help
Term Evidence
Male High
Female High

Key Event Description

A description of the biological state being observed or measured, the biological compartment in which it is measured, and its general role in the biology should be provided. More help

11-ketotestosterone (11KT; CAS 564-35-2 | DTXSID8036499) is an oxygenated steroidal androgen with a keto group at the C11 position (Pretorius et al. 2017). 

11-ketotestosterone is a dominant androgen in teleost fish (Borg 1994). It is synthesized from testosterone using the enzymes CYP11b1 and HSD11b (Yazawa et al., 2008; Swart et al., 2013). Zebrafish studies also show that cyp17a1 and cyp11c1 knockouts have dramatically reduced levels of 11KT (Shu et al., 2020; Zhang et al., 2020)

11KT is also produced by other vertebrates, although the site of its biosynthesis and physiological signficance in different taxa can vary widely. In humans, 11KT is primarily synthesized in the adrenal glands (Pretorius et al. 2017; Turcu et al. 2018). 

Although mutations in the mettl3 gene usually cause embryonic lethality, one particular mutation in non-lethal and causes significantly reduced 11KT levels in zebrafish (Xia et al., 2018)

How It Is Measured or Detected

A description of the type(s) of measurements that can be employed to evaluate the KE and the relative level of scientific confidence in those measurements.These can range from citation of specific validated test guidelines, citation of specific methods published in the peer reviewed literature, or outlines of a general protocol or approach (e.g., a protein may be measured by ELISA). Do not provide detailed protocols. More help

11KT production can be measured in an ex vivo steroidogenesis assay using the organism's gonad after it has been exposed to a compound.

The concentration of 11KT can be measured in a radioimmunoassay or enzyme-linked immunosorbent assay (ELISA). 

Several papers show that in fish, 11KT is correlated with testosterone levels (Spanò et al., 2004; Maclatchy & Vanderkraak, 1995; Lorenzi et al., 2008). 

Domain of Applicability

A description of the scientific basis for the indicated domains of applicability and the WoE calls (if provided).  More help

Taxanomic Applicability: Most understand of 11KT comes from studies involving teleost fish as it is their dominant androgen. Some studies have measured 11KT in sharks of the order carcharhiniformes, but there is less research in this area (Manire et al., 1999; Garnier et al. 1999; Mills et al. 2010). Many mammals possess the genes necessary to produce 11KT (NCBI), but 11KT may not be as relevant when it’s not the dominant androgen.

Sex Applicability: Males and females use the same biological processes to produce steroids. However, sexual dimorphism in 11KT production varies between species. In humans, plasma levels of 11KT do not differ between sexes (Imamichi et al., 2016). In Zebrafish, gonad levels of 11KT are approximately two magnitudes higher in males than females (Wang & Orban, 2007). Of the 30 other fish species sampled by Lokman et al. (2002), 11KT levels are typically dramatically lower in females than in males, but a few species of the order Perciformes show no sexual dimorphism.

Life Stage Applicability: 11KT can be measured in fish larvae however individuals must be pooled for sufficient sample size (Hattori et al., 2009). Lokman et al. (2002) measured plasma levels of 11-KT in several species of juvenile and adult fish. 11KT levels tend to be higher in males although some fish species don’t show sexual dimorphism. Levels of 11KT in juveniles are similar to levels in females regardless of if the species shows sexual dimorphism in 11KT levels. In males, 11KT increases for spawning and decreases afterwards (Kindler et al., 1989; Páll et al., 2002). Because of it’s involvement in reproduction, 11KT levels may not be meaningful in juveniles.


List of the literature that was cited for this KE description. More help

Borg, B. (1994). Androgens in teleost fishes. Comparative Biochemistry and Physiology Part C: Pharmacology, Toxicology and Endocrinology109(3), 219-245.

Fraz, S. et al. (2018) “Gemfibrozil and carbamazepine decrease steroid production in zebrafish testes (Danio rerio)”, Aquatic Toxicology, Vol. 198, Elsevier, pp. 1-9. 

Golshan, M. & S.M.H. Alvai (2019) “Androgen signaling in male fishes: Examples of anti-androgenic chemicals that cause reproductive disorders”, Theriogenology, Vol. 139, Elsevier, pp. 58-71. 

Hattori, R.S. et al. (2009) “Cortisol-induced masculinization: Does thermal stress affect gonadal fate in pejerrey, a teleost fish with temperature-dependent sex determination?”, PLoS ONE, Vol. 4(8), pp. 1-7. doi:10.1371/journal.pone.0006548

Imamichi, Y. et al. (2016) “11-Ketotestosterone is a major androgen produced in human gonads”, The Journal of Clinical Endocrinology & Metabolism, Vol. 101(10), Oxford Academic, pp. 3582-3591.

Kindler, P. M. et al. (1989) “Serum 11-ketotestosterone and testosterone concentrations associated with reproduction in male bluegill (Lepomis macrochirus: Centrarchidae)”, General and Comparative Endocrinology, Vol. 75(3), Elsevier, pp. 446-453.

Lee, G. et al. (2019) “Effects of gemfibrozil on sex hormones and reproduction related performances of Oryzias latipes following long-term (155 d) and short-term (21 d) exposure”, Ecotoxicology and Environmental Safety, Vol. 173, Elsevier, pp. 174-181.

Lokman, P.M. et al. (2002) “11-Oxygenated androgens in female teleosts: prevalence, abundance, and life history implications”, General and Comparative Endocrinology, Vol. 129, Academic Press, pp. 1-12. doi: 10.1016/s0016-6480(02)00562-2

Lorenzi, V. et al. (2008) “Diurnal patterns and sex differences in cortisol, 11-ketotestosterone, testosterone, and 17β-estradiol in the bluebanded goby (Lythrypnus dalli)”, General and Comparative Endocrinology, Vol. 155(2)., Elsevier, pp. 438-446.

MacLatchy, D.L. and G.J. Vanderkraak (1995) “The phytoestrogen β-sitosterol alters the reproductive endocrine status of goldfish”, Toxicology and Applied Pharmacology, Vol. 134(2), Elsevier, pp. 305-312.

Manire, C.A., L.E. Rasmussen & T.S. Gross (1999) “Serum steroid hormones including 11-ketotestosterone, 11-ketoandrostenedione, and dihydroprogesterone in juvenile and adult bonnethead sharks, Sphyrna tiburo”, Journal of Experimental Zoology, Vol. 284(5), Wiley-Blackwell, pp. 595-603. DOI: 10.1002/(sici)1097-010x(19991001)284:5<595::aid-jez15> 

Páll, M. K., I. Mayer and B. Borg (2002) “Androgen and behavior in the male three-spined stickleback, Gasterosteus aculeatus I. – Changes in 11-ketotestosterone levels during nesting cycle”, Hormones and Behavior, Vol. 41(4), Elsevier, pp. 377-383.

Pretorius, E, Arlt, W & Storbeck, K-H 2016, 'A new dawn for androgens: novel lessons from 11-oxygenated C19 steroids', Molecular and Cellular Endocrinology.

Shu, T. et al. (2020) “Zebrafish cyp17a1 knockout reveals that androgen-mediated signaling is important for male brain sex differentiation”, General and Comparative Endocrinology, Vol. 295. doi:10.1016/j.ygcen.2020.113490 

Singh, P.B. & V. Singh (2008) “Cypermethrin induced histological changes in gonadotrophic cells, liver, gonads, plasma levels of estradiol-17beta and 11-ketotestosterone, and sperm motility in Heteropneustes fossilis (Bloch)”, Chemosphere, Vol. 72(3), Elsevier, pp. 422-431. DOI: 10.1016/j.chemosphere.2008.02.026 

Spanó, L. et al. (2004) “Effects of atrazine on sex steroid dynamics, plasma vitellogenin concentration and gonad development in adult goldfish (Carassius auratus)”, Aquatic Toxicology, Vol. 66(4), Elsevier, pp. 369-379.

Swart, A.C. et al. (2013) “11β-hydroxyandrostenedione, the product of androstenedione metabolism in the adrenal, is metabolized in LNCaP cells by 5α-reductase yielding 11β-hydroxy-5α-androstanedione”, The Journal of Steroid Biochemistry and Molecular Biology, Vol 138, Elsevier, pp. 132-142.

Turcu AF, Nanba AT, Auchus RJ. The Rise, Fall, and Resurrection of 11-Oxygenated Androgens in Human Physiology and Disease. Horm Res Paediatr. 2018;89(5):284-291. doi: 10.1159/000486036. Epub 2018 May 9. PMID: 29742491; PMCID: PMC6031471.

Velasco-Santamaría, Y.M. et al. (2011) “Bezafibrate, a lipid-lowering pharmaceutical, as a potential endocrine disruptor in male zebrafish (Danio rerio)”, Aquatic Toxicology, Vol. 105, Elsevier, pp. 107-118. doi:10.1016/j.aquatox.2011.05.018

Wang, X.G. and L. Orban (2007) “Anti-Müllerian hormone and 11β-hydroxylase show reciprocal expression to that of aromatase in the transforming gonad of zebrafish males”, Developmental Dynamics, Vol 236(5), Wiley-Liss, pp. 1329-1338.

Xia, H. et al. (2018) “Mettl3 mutation disrupts gamete maturation and reduced fertility in zebrafish”, Genetics, Vol. 208(2), Genetics Society of America, pp. 729-743. DOI: 10.1534/genetics.117.300574 

Yazawa, T. (2008) “Cyp11b1 is induced in the murine gonad by luteinizing hormone/human chorionic gonadotropin and involved in the production of 11-ketotestosterone, a major fish androgen: Conservation and evolution of the androgen metabolic pathway”, Endocrinology, Vol. 149(4), Oxford Academy, pp. 1786-1792.

Zheng, Q. et al. (2020) “Loss of cyp11c1 causes delayed spermatogenesis due to the absence of 11-ketotestosterone", Journal of Endocrinology, Vol. 244(3), Bioscientifica, pp. 487-499.