Ethanol-induced hypothermia. Cross tolerance with morphine

Area of Science:

• Neuroscience
• Pharmacology
• Addiction Research

Background:

• Ethanol (alcohol) consumption can lead to tolerance, a reduced response to its effects.
• Morphine, an opiate, also induces tolerance and shares some physiological effects with ethanol.

Purpose of the Study:

• To investigate the development of tolerance to ethanol-induced hypothermia and hypnosis.
• To examine cross-tolerance between ethanol and morphine in mice and rats.
• To explore the potential opiate-like mechanisms of ethanol action.

Main Methods:

• Rodents (rats and mice) were administered ethanol to assess hypothermic and hypnotic effects.
• Chronic ethanol administration was used to induce tolerance.
• Morphine pellets were implanted to assess cross-tolerance.
• Body temperature and hypnosis duration were measured.

Main Results:

• Ethanol significantly reduced body temperature in both rats and mice.
• Chronic ethanol administration led to tolerance to ethanol's hypothermic effects and cross-tolerance to morphine's hypothermic effects.
• Morphine pellet implantation induced cross-tolerance to ethanol-induced hypothermia in rats, but not in mice.
• Ethanol's hypnotic effect duration was reduced in chronically alcoholized rats, but not in morphine-implanted rats or mice.

Conclusions:

• The findings support the hypothesis that ethanol may exert some of its effects through an opiate-like mechanism.
• Species-specific differences in cross-tolerance development between ethanol and morphine were observed.