Ketamine and ketamine metabolites as novel estrogen receptor ligands: Induction of cytochrome P450 and AMPA glutamate receptor gene expression.
Ming-Fen Ho, Cristina Correia, James N Ingle, Rima Kaddurah‐Daouk, Liewei Wang, Scott H Kaufmann, Richard M Weinshilboum
Biochemical Pharmacology June 2018 DOI: 10.1016/j.bcp.2018.03.032 (opens in new tab)
Study at a glance
AI-extracted from the abstract| Characteristics | Laboratory study Peer reviewed |
|---|---|
| Interventions | Ketamine (2R 6R)-hydroxynorketamine (2S Estrogen |
| Topics | Ketamine Esketamine |
| Keywords | Ampa receptors Cyp2a6 Cyp2b6 Estrogens Ketamine metabolites |
| Key points | Estrogen plus ketamine or its active metabolites (2R,6R)-HNK and (2S,6S)-HNK additively induced AMPA receptor subunit expression and upregulated ERα. Ketamine bound ERα directly (KD 344.5 ± 13 nM), and ketamine and both metabolites showed similar ERα affinity (IC50 2.31 ± 0.1, 3.40 ± 0.2, and 3.53 ± 0.2 µM). AMPA receptor induction was lost when ERα was knocked down or silenced, suggesting a positive feedback loop involving CYP2A6 and CYP2B6. |
Abstract
Major depressive disorder (MDD) is the most common psychiatric illness worldwide, and it displays a striking sex-dependent difference in incidence, with two thirds of MDD patients being women. Ketamine treatment can produce rapid antidepressant effects in MDD patients, effects that are mediated-at least partially-through glutamatergic neurotransmission. Two active metabolites of ketamine, (2R,6R)-hydroxynorketamine (HNK) and (2S,6S)-HNK, also appear to play a key role in ketamine's rapid antidepressant effects through the activation of α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) glutamate receptors. In the present study, we demonstrated that estrogen plus ketamine or estrogen plus active ketamine metabolites displayed additive effects on the induction of the expression of AMPA receptor subunits. In parallel, the expression of estrogen receptor alpha (ERα) was also significantly upregulated. Even more striking, radioligand binding assays demonstrated that [3H]-ketamine can directly bind to ERα (KD: 344.5 ± 13 nM). Furthermore, ketamine and its (2R,6R)-HNK and (2S,6S)-HNK metabolites displayed similar affinity for ERα (IC50: 2.31 ± 0.1, 3.40 ± 0.2, and 3.53 ± 0.2 µM, respectively) as determined by [3H]-ketamine displacement assays. Finally, induction of AMPA receptors by either estrogens or ketamine and its metabolites was lost when ERα was knocked down or silenced pharmacologically. These results suggest a positive feedback loop by which estrogens can augment the effects of ketamine and its (2R,6R)-HNK and (2S,6S)-HNK metabolites on the ERα-induced transcription of CYP2A6 and CYP2B6, estrogen inducible enzymes that catalyze ketamine's biotransformation to form the two active metabolites. These observations provide novel insight into ketamine's molecular mechanism(s) of action and have potential implications for the treatment of MDD.
Comparable studies
Other experimental studies on ketamine, most cited first.
| Study | Year | Design | Participants |
|---|---|---|---|
| Ketamine activates psychosis and alters limbic blood flow in schizophrenia Schizophrenic individuals | 1995 | Experimental study | |
| The spectral exponent of the resting EEG indexes the presence of consciousness during unresponsiveness induced by propofol, xenon, and ketamine Healthy participants | 2019 | Controlled experimental study | n = 15 |
| Ketamine Increases Human Motor Cortex Excitability to Transcranial Magnetic Stimulation Normal human subjects | 2003 | Experimental study | n = 7 |
| Evidence that Subanesthetic Doses of Ketamine Cause Sustained Disruptions of NMDA and AMPA-Mediated Frontoparietal Connectivity in Humans Human participants | 2015 | Experimental study | |
| S(+)-ketamine Effect on Experimental Pain and Cardiac Output Healthy adult volunteers (10 men and 10 women) | 2009 | Pharmacokinetic-pharmacodynamic modeling study in healthy volunteers | n = 20 |
Citations in the library
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- Antidepressant-relevant concentrations of the ketamine metabolite (2R,6R)-hydroxynorketamine do not block NMDA receptor function Proceedings of the National Academy of Sciences February 22, 2019
- Repurposing Ketamine in Depression and Related Disorders: Can This Enigmatic Drug Achieve Success? Frontiers in Neuroscience April 30, 2021
- Beyond NMDA Receptors: A Narrative Review of Ketamine's Rapid and Multifaceted Mechanisms in Depression Treatment. International Journal of Molecular Sciences December 20, 2024
- Risk of manic switch and suicidal outcomes in bipolar depression treated with esketamine: A one-year retrospective cohort study of 2126 patients. European Neuropsychopharmacology August 6, 2025
- Effect of ketamine and esketamine on RNA expression and its relevance for depression: a systematic review. Pharmacological Research July 31, 2025
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Cites 6
- A Randomized Trial of an N-methyl-D-aspartate Antagonist in Treatment-Resistant Major Depression Archives of General Psychiatry August 1, 2006
- mTOR-Dependent Synapse Formation Underlies the Rapid Antidepressant Effects of NMDA Antagonists Science August 19, 2010
- NMDAR inhibition-independent antidepressant actions of ketamine metabolites Nature April 24, 2016
- Ketamine and Other NMDA Antagonists: Early Clinical Trials and Possible Mechanisms in Depression American Journal of Psychiatry October 1, 2015
- Simultaneous population pharmacokinetic modelling of ketamine and three major metabolites in patients with treatment‐resistant bipolar depression British Journal of Clinical Pharmacology February 1, 2012
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