Components of the opioid withdrawal syndrome in mice are thermoregulatory responses

John Belknap

Research output: Contribution to journalArticle

9 Citations (Scopus)

Abstract

C57BL/6J mice were rendered physically dependent on morphine by giving them ad lib access to a drinking fluid containing 0.2% saccharin and morphine for 14 days at 20-22°C. Core body temperatures were monitored by radio telemetry, which obviated the need for restraint, handling, or otherwise disturbing the animals. Consistent hyperthermia was present throughout the morphine intoxication phase, followed by hypothermia after the withdrawal syndrome had been precipitated by naloxone challenge (2.0 mg/kg, IP) at 22.5°C. The hypothermia could be blocked by exposing the animals to a 34.5°C ambient temperature, which also prevented the occurrence of tremor and "wet dog shakes." In contrast, the other withdrawal signs monitored were not significantly affected. In a second experiment, mice were given the same morphine-saccharin drinking fluid as before, except that a choice was provided between two interconnected home cages (23°C vs. 35°C) throughout the experiment. A marked preference for the 35°C cage was seen during intoxication, which served to enhance the hyperthermia due to morphine. Following withdrawal, when hypothermia is evident, the preference for the 35°C cage declined to control levels. These results suggest that hypothermia is both a consequence and a contributor to the opioid withdrawal syndrome.

Original languageEnglish (US)
Pages (from-to)241-245
Number of pages5
JournalPharmacology, Biochemistry and Behavior
Volume34
Issue number2
DOIs
StatePublished - 1989

Fingerprint

Hypothermia
Morphine
Opioid Analgesics
Saccharin
Drinking
Animals
Fever
Telemetry
Fluids
Level control
Tremor
Telemetering
Naloxone
Body Temperature
Radio
Inbred C57BL Mouse
Experiments
Dogs
Temperature

Keywords

  • C57BL/6J mice
  • Hypothermia
  • Morphine
  • Opioids
  • Physical dependence Body temperature by radio telemetry
  • Thermoregulation
  • Withdrawal syndrome

ASJC Scopus subject areas

  • Biochemistry
  • Behavioral Neuroscience
  • Pharmacology

Cite this

Components of the opioid withdrawal syndrome in mice are thermoregulatory responses. / Belknap, John.

In: Pharmacology, Biochemistry and Behavior, Vol. 34, No. 2, 1989, p. 241-245.

Research output: Contribution to journalArticle

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