Related Experiment Videos
Cross-tolerance to metkephamid (LY127623) produced by morphine solution ingestion by mice
Alcohol and Drug Research
|January 1, 1987
Abstract:
The effects of morphine and metkephamid were determined on the writhing test in drug-naive mice and mice that had been exposed to morphine solutions as their sole fluid source for a 5- or 7-day period. The average dose of morphine consumed was 435 mg/kg, using either 0.5 mg/ml solution for 7 days or a 1 mg/ml solution for 5 days. The ingestion of these morphine solutions produced a marked tolerance to the analgesic effects of morphine and cross-tolerance to the analgesic effects of metkephamid.
Insights
Mice exposed to morphine solutions developed tolerance to morphine
Area of Science:
- Pharmacology
- Neuroscience
Background:
- Opioid analgesics like morphine are widely used for pain management.
- Understanding the development of tolerance is crucial for effective pain therapy.
Purpose of the Study:
- To investigate the development of tolerance to morphine and cross-tolerance to metkephamid.
- To assess the impact of chronic morphine solution ingestion on analgesic responses.
Main Methods:
- The writhing test was employed to evaluate analgesic effects in mice.
- Mice were administered morphine solutions as their sole fluid source for 5 or 7 days.
- Drug-naive mice served as a control group.
Main Results:
- Morphine ingestion led to significant tolerance to its own analgesic effects.
- Cross-tolerance to the analgesic effects of metkephamid was observed.
- Mice consumed an average dose of 435 mg/kg of morphine.
Conclusions:
- Chronic exposure to morphine solutions induces substantial tolerance to opioid analgesics.
- Metkephamid shares cross-tolerance with morphine, indicating overlapping mechanisms of action.
- These findings have implications for managing pain and understanding opioid dependence.