Epipregnanolone, also known as 3β-hydroxy-5β-pregnan-20-one, 3β,5β-tetrahydroprogesterone, or 3β,5β-THP, is an

endogenous Endogenous substances and processes are those that originate from within a living system such as an organism, tissue, or cell. In contrast, exogenous substances and processes are those that originate from outside of an organism. For example, es ...

neurosteroid. It acts as a

negative allosteric modulator In pharmacology and biochemistry, allosteric modulators are a group of substances that bind to a receptor to change that receptor's response to stimulus. Some of them, like benzodiazepines, are drugs. The site that an allosteric modulator binds t ...

of the GABA_A receptor and reverses the effects of

potentiator In clinical terms, a potentiator is a reagent that enhances sensitization of an antigen. Potentiators are used in the clinical laboratory for performing blood banking procedures that require enhancement of agglutination to detect the presence of ...

s like allopregnanolone. Epipregnanolone is

biosynthesized Biosynthesis is a multi-step, enzyme-catalyzed process where substrates are converted into more complex products in living organisms. In biosynthesis, simple compounds are modified, converted into other compounds, or joined to form macromolecules. ...

from

progesterone Progesterone (P4) is an endogenous steroid and progestogen sex hormone involved in the menstrual cycle, pregnancy, and embryogenesis of humans and other species. It belongs to a group of steroid hormones called the progestogens and is the m ...

by the actions of 5β-reductase and 3β-hydroxysteroid dehydrogenase, with 5β-dihydroprogesterone as the intermediate in this two-step transformation. Epipregnanolone is not a

progestogen Progestogens, also sometimes written progestagens or gestagens, are a class of natural or synthetic steroid hormones that bind to and activate the progesterone receptors (PR). Progesterone is the major and most important progestogen in the body. ...

itself, but via metabolization into other steroids, behaves indirectly as one. The

sulfate The sulfate or sulphate ion is a polyatomic anion with the empirical formula . Salts, acid derivatives, and peroxides of sulfate are widely used in industry. Sulfates occur widely in everyday life. Sulfates are salts of sulfuric acid and many ar ...

of epipreganolone, epipregnanolone sulfate, is a negative allosteric modulator of the

NMDA ''N''-methyl--aspartic acid or ''N''-methyl--aspartate (NMDA) is an amino acid derivative that acts as a specific agonist at the NMDA receptor mimicking the action of glutamate, the neurotransmitter which normally acts at that receptor. Unlike ...

and GABA_A receptors and also acts as a

TRPM3 Transient receptor potential cation channel subfamily M member 3 is a protein that in humans is encoded by the ''TRPM3'' gene. Function The product of this gene belongs to the family of transient receptor potential (TRP) channels. TRP channels ...

channel activator.

Chemistry

References

{{Progesterone receptor modulators 5β-Pregnanes GABAA receptor negative allosteric modulators Neurosteroids Pregnanes

Chemistry

See also

References