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Hyperglycaemia, a morphine-like effect produced by naloxone in the cat
The Journal of Physiology
|July 1, 1983
Summary
Naloxone blocks morphine-induced hyperglycemia in cats but can also cause hyperglycemia and morphine-like behaviors itself. These effects occur regardless of naloxone
Area of Science:
- Neuropharmacology
- Endocrinology
Background:
- Opioid drugs like morphine can induce hyperglycemia.
- Naloxone is a known opioid antagonist used to reverse opioid effects.
Purpose of the Study:
- To investigate the effects of naloxone on morphine-induced hyperglycemia in unanesthetized cats.
- To explore whether naloxone possesses intrinsic hyperglycemic or morphine-like properties.
Main Methods:
- Intravenous and intracerebroventricular/cisternal magna administration of morphine and naloxone in cats.
- Observation and measurement of hyperglycemia and behavioral changes.
Main Results:
- Intravenous naloxone inhibited morphine-induced hyperglycemia.
- Higher doses of naloxone alone caused hyperglycemia.
- Central administration of naloxone or morphine resulted in hyperglycemia resistant to intravenous naloxone.
- Naloxone also induced behavioral effects similar to morphine.
Conclusions:
- Naloxone's interaction with opioid-induced hyperglycemia is complex, involving both antagonistic and agonistic properties.
- Central administration of naloxone can lead to hyperglycemia, suggesting central mechanisms.
- Naloxone may have direct effects on glucose regulation and behavior beyond simple opioid antagonism.
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