Tetrahydrodeoxycorticosterone (abbreviated as THDOC; 3α,21-dihydroxy-5α-pregnan-20-one), also referred to as ''allotetrahydrocorticosterone'', 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 Neurosteroids, also known as neuroactive steroids, are endogenous or exogenous steroids that rapidly alter neuronal excitability through interaction with ligand-gated ion channels and other cell surface receptors. The term ''neurosteroid'' was coin ...

. It is synthesized from the adrenal hormone

deoxycorticosterone Deoxycorticosterone (DOC), or desoxycorticosterone, may refer to: * 11-Deoxycorticosterone (21-hydroxyprogesterone) * 21-Deoxycorticosterone (11β-hydroxyprogesterone) See also * Deoxycortisol * Deoxycortisone * 11-Hydroxyprogesterone {{Che ...

by the action of two enzymes, 5α-reductase type I and 3α-hydroxysteroid dehydrogenase. THDOC is a potent positive allosteric modulator of the GABA_A receptor, and has

sedative A sedative or tranquilliser is a substance that induces sedation by reducing irritability or excitement. They are CNS depressants and interact with brain activity causing its deceleration. Various kinds of sedatives can be distinguished, but t ...

, anxiolytic and

anticonvulsant Anticonvulsants (also known as antiepileptic drugs or recently as antiseizure drugs) are a diverse group of pharmacological agents used in the treatment of epileptic seizures. Anticonvulsants are also increasingly being used in the treatment of b ...

effects. Changes in the normal levels of this steroid particularly during pregnancy and

menstruation Menstruation (also known as a period, among other colloquial terms) is the regular discharge of blood and mucosal tissue from the inner lining of the uterus through the vagina. The menstrual cycle is characterized by the rise and fall of hor ...

may be involved in some types of epilepsy (

catamenial epilepsy Catamenial epilepsy is a form of epilepsy in women where seizures are exacerbated during certain phases of the menstrual cycle. In rare cases, seizures occur only during certain parts of the cycle; in most cases, seizures occur more frequently (b ...

) and

premenstrual syndrome Premenstrual syndrome (PMS) refers to emotional and physical symptoms that regularly occur in the one to two weeks before the start of each menstrual period. Symptoms resolve around the time menstrual bleeding begins. Different women experienc ...

, as well as stress, anxiety and depression.

Chemistry

References

Neurosteroids Anticonvulsants Hypnotics GABAA receptor positive allosteric modulators GABAA-rho receptor negative allosteric modulators Pregnanes {{Steroid-stub