Affordable Access

Opioid receptor mediation of the hypothermic response to caffeine.

Authors
  • Durcan, M J1
  • Morgan, P F
  • 1 Laboratory of Neurogenetics, DICBR, National Institute on Alcohol Abuse and Alcoholism, Bethesda, MD 20892.
Type
Published Article
Journal
European Journal of Pharmacology
Publisher
Elsevier
Publication Date
Dec 02, 1992
Volume
224
Issue
2-3
Pages
151–156
Identifiers
PMID: 1334837
Source
Medline
License
Unknown

Abstract

Caffeine and other methylxanthines induce a dose-dependent reduction in core body temperature in mice. These experiments investigated the effects of neurotransmitter and neuromodulator antagonists on caffeine-induced hypothermia. Pretreatment with the alpha 2-adrenoceptor antagonist, atipamezole; the beta-adrenoceptor antagonist, propranolol; the dopamine antagonist, haloperidol; or the benzodiazepine receptor antagonist, flumazenil had no intrinsic effects on core body temperature nor did they interact significantly with the hypothermic effects of caffeine. The alpha 1-adrenoceptor antagonist, prazosin and the 5-HT receptor antagonist, metergoline significantly enhanced the hypothermic effects of caffeine, probably involving a combined effect with their intrinsic hypothermic actions. Pretreatment with the opiate receptor antagonist, naloxone (3 mg/kg i.p.), had no intrinsic effect on core body temperature but attenuated the hypothermic effect of caffeine reflected in a parallel shift to the right in the caffeine dose-effect curve. The naloxone-induced attenuation of the hypothermic effects of caffeine was also seen to be dose-dependent. The results reveal that opiate receptors (but not adrenoceptors, 5-HT, dopamine or benzodiazepine receptors) may play a role in modulating the hypothermic action of caffeine and possibly other methylxanthines.

Report this publication

Statistics

Seen <100 times