Anandamide induces cardiovascular and respiratory reflexes via vasosensory nerves in the anaesthetized rat

PJW Smith*, DS McQueen

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

Abstract

1 We tested the hypothesis that sensory nerves innervating blood vessels play a role in the local and systemic regulation of the cardiovascular and respiratory (CVR) systems. We measured CVR reflexes evoked by administration of anandamide (86 - 863 nmoles) and capsaicin (0.3 - 10 nmoles) into the hindlimb vasculature of anaesthetized rats.

2 Anandamide and capsaicin each caused a rapid dose-dependent reflex fall in blood pressure and an increase in ventilation when injected intra-arterially into the hindlimb.

3 Action of both agonists at the vanilloid receptor (VR1) on perivascular sensory nerves was investigated using capsazepine (1 mg kg(-1) i.a.) a competitive VR1 antagonist, ruthenium red (1 mg kg(-1) i.a.), a non-competitive antagonist at VR1, or a desensitizing dose of capsaicin (200 nmoles i.a.). The cannabinoid receptor antagonist SR141716 (1 mg kg(-1) i.a.) was used to determine agonist activity at the CB, receptor.

4 Capsazepine, ruthenium red, or acute VR1 desensitization by capsaicin-pretreatment, markedly attenuated the reflex CVR responses evoked by anandamide and capsaicin (P

5 Local sectioning of the femoral and sciatic nerves attenuated CVR responses to anandamide and capsaicin (P

6 These data demonstrate that both the endogenous cannabinoid, anandamide, and the vanilloid, capsaicin, evoke CVR reflexes when injected intra-arterially into the rat hindlimb. These responses appear to be mediated reflexly via VR1 located on sensory nerve endings within the hindlimb vasculature.

Original languageEnglish
Pages (from-to)655-663
Number of pages9
JournalBritish Journal of Pharmacology
Volume134
Issue number3
DOIs
Publication statusPublished - Oct 2001

Keywords

  • anandamide
  • capsaicin
  • sensory nerves
  • cardiovascular-respiratory reflexes
  • vanilloid receptor
  • SENSORY NERVES
  • CANNABINOID RECEPTORS
  • VANILLOID RECEPTORS
  • ANESTHETIZED RATS
  • CAPSAICIN
  • PAIN
  • BIOSYNTHESIS
  • MECHANISMS
  • RELAXATION
  • INJECTION

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