Androgens play important roles in male sexual differentiation, development, and reproductive development and function. 11-Ketotestosterone (11-KT) is the primary and most potent androgen in teleost fish. 11-KT stimulates the development of secondary sexual characteristics and the expression of male reproductive behavior in various teleost fish.

Structure

11-KT is an oxidized form of testosterone that contains a keto group at position-11. 

Properties

Molecular formula: C19H26O3, Mr: 302 g/mol. Melting point: 181–184°C. Appearance: white crystalline powder.

Synthesis and release 

In some teleosts,itwas reported that 11-KTis synthesized in the gonads.11-KT is synthesized from testosterone by the action of steroidogenic enzymes, 11β-hydroxylase (P45011β), 11β-hydroxysteroid dehydrogenase (11β-HSD), and 17β-hydroxysteroid dehydrogenase (17β-HSD). Recent analyses showed the presence of 11KT in other species, including early branching actinopterygian fish (sturgeon),urodele amphibians (Necturus maculosus),and humans,indicating the significant role of 11KT as an androgen in these species.

Plasma concentration(ng/mL) 

Coho salmon (male) spawning season, 80–150 ng/mL (65–97 nmol/L), coho salmon (female) spawning season 4–12 ng/mL (13–40 nmol/L).7 Men (234± 47 pg/mL), women (250± 66 pg/mL).

Regulation of synthesis and release 

Gonadotropins stimulate the production of 11-KT.

Biological functions 

Target cells/tissues and functions 11-Ketotestosterone(11-KT) has important roles in spermatogenesis, male secondary sexual characteristics, behavior, and nuptial coloration.