Interaction between ketamine and ethanol in rats and mice

Area of Science:

• Neuroscience
• Pharmacology
• Addiction Research

Background:

• Ethanol and ketamine (KET) are widely used substances with analgesic properties.
• Understanding tolerance and cross-tolerance is crucial for managing substance use and pain.
• The role of endogenous systems in the effects of these drugs requires further investigation.

Purpose of the Study:

• To investigate the development of tolerance to the analgesic effects of ethanol and ketamine.
• To examine cross-tolerance between ethanol and ketamine.
• To assess the impact of ketamine on ethanol abstinence symptoms.

Main Methods:

• Chronic administration of ethanol or ketamine to mice and rats.
• Assessment of analgesic effects using established nociceptive tests.
• Evaluation of ethanol withdrawal symptoms (head shakes, audiogenic seizures) and the effect of ketamine.
• Naloxone pretreatment was used to explore opioid system involvement.

Main Results:

• Chronic ethanol treatment reduced ethanol's analgesic effects, indicating tolerance.
• Chronic ketamine treatment induced tolerance to its own analgesic effects.
• Significant cross-tolerance was observed between ethanol and ketamine for analgesic actions.
• Ketamine administration attenuated key ethanol abstinence symptoms in both species.
• Naloxone blocked ketamine's inhibitory effect on ethanol withdrawal in rats.

Conclusions:

• Ethanol and ketamine exhibit similar pharmacological profiles regarding tolerance and cross-tolerance.
• Ketamine effectively mitigates symptoms associated with ethanol withdrawal.
• The findings suggest a potential involvement of the endogenous opioid system in the actions of both ethanol and ketamine.