Analgesic, heart rate, and temperature effects of delta8-THC during acute and chronic administration to conscious rats

Pharmacology. 1977;15(1):63-72.


Acute and chronic effects of delta8-THC on tail-flick, heart rate, and rectal temperature responses in conscious, unrestrained male rats were studied. In the acute experiment unidirectional dose-dependent analgesic, hypothermic, and negative chronotropic cardiac effects were observed within the dose range employed. Of the three variables, heart-rate decreases were most sensitive to the effects of THC, reaching significance at 2 mg/kg. Rapid development of tolerance occurred for all three measures, with complete tolerance developing within 13 days only to the heart-rate decreases. The results discussed in the context of previous data.

MeSH terms

  • Analgesics, Opioid*
  • Animals
  • Body Temperature / drug effects*
  • Depression, Chemical
  • Dose-Response Relationship, Drug
  • Dronabinol / administration & dosage
  • Dronabinol / pharmacology*
  • Drug Tolerance
  • Heart Rate / drug effects*
  • Male
  • Rats


  • Analgesics, Opioid
  • Dronabinol