Effect of mu-, kappa-, and delta-selective opioid agonists on thermoregulation in the rat.

Abstract

The effect of selective mu-, kappa-, and delta-agonists on brain surface temperature (Tb), oxygen consumption (Vo2), and heat exchange (Q) was studied in unrestrained, male Sprague-Dawley rats using whole-body calorimetry. Hyperthermia, produced by PL-017 (1.86 nM) given ICV, resulted from increased Vo2 and reduced Q during the first 15-45 min postinjection. Tb returned to control levels due to a combination of increased Q and reduced Vo2. PL-017-induced hyperthermia was abolished by the mu-selective antagonist CTAP (0.75 nM). Dynorphin A1-17 (4.65 nM), a kappa-selective agonist, reduced both Vo2 and Q, resulting in hypothermia that was blocked by the kappa-selective antagonist nor-binaltorphimine (25 nM). The delta-selective agonist DPDPE (4.64 nM) caused no significant changes in Tb, Vo2, or Q. The data indicate that central stimulation of the mu- and kappa-opioid receptors affects both oxidative metabolism and heat exchange, which result in a change in Tb. These alterations can be prevented with selective opioid antagonist pretreatment.

• Authors: C M Handler, E B Geller, M W Adler
• Journal: Pharmacology, biochemistry, and behavior (Pharmacol Biochem Behav) Vol. 43 Issue 4 Pg. 1209-16 (Dec 1992) ISSN: 0091-3057 [Print] United States
• PMID: 1361992 (Publication Type: Journal Article, Research Support, U.S. Gov't, P.H.S.)

Chemical References

• Endorphins
• Enkephalins
• Indoles
• Morphinans
• Narcotic Antagonists
• Receptors, Opioid, delta
• Receptors, Opioid, kappa
• Receptors, Opioid, mu
• Naltrexone
• Dynorphins
• morphiceptin, N-Me-Phe(3)-
• Enkephalin, D-Penicillamine (2,5)-
• naltrindole

Topics

• Amino Acid Sequence
• Animals
• Body Temperature (drug effects)
• Body Temperature Regulation (drug effects)
• Brain (drug effects, physiology)
• Dose-Response Relationship, Drug
• Dynorphins (pharmacology)
• Endorphins (pharmacology)
• Enkephalin, D-Penicillamine (2,5)-
• Enkephalins (pharmacology)
• Indoles (pharmacology)
• Injections, Intraventricular
• Male
• Molecular Sequence Data
• Morphinans (pharmacology)
• Naltrexone (analogs & derivatives)
• Narcotic Antagonists (pharmacology)
• Oxygen Consumption (drug effects)
• Rats
• Rats, Sprague-Dawley
• Receptors, Opioid, delta (drug effects)
• Receptors, Opioid, kappa (drug effects)
• Receptors, Opioid, mu (drug effects)