PPADS does not block contraction-induced prostaglandin E2 synthesis in cat skeletal muscle

Jennifer L. McCord, Shawn G. Hayes, Marc P Kaufman

Research output: Contribution to journalArticle

9 Scopus citations

Abstract

Pyridoxal-phosphate-6-azophenyl-2′-4-disulfonate (PPADS), a purinergic 2 (P2) receptor antagonist, has been shown to attenuate the exercise pressor reflex in cats. In vitro, however, PPADS has been shown to block the production of prostaglandins, some of which play a role in evoking the exercise pressor reflex. Thus the possibility exists that PPADS blocks the exercise pressor reflex through a reduction in prostaglandin synthesis rather than through the blockade of P2 receptors. Using microdialysis, we collected interstitial fluid from skeletal muscle to determine prostaglandin E2 (PGE2) concentrations during the intermittent contraction of the triceps surae muscle before and after a popliteal arterial injection of PPADS (10 mg/kg). We found that the PGE2 concentration increased in response to the intermittent contraction before and after the injection of PPADS (both, P < 0.05). PPADS reduced the pressor response to exercise (P < 0.05) but had no effect on the magnitude of PGE2 production during contraction (P = 0.48). These experiments demonstrate that PPADS does not block the exercise pressor reflex through a reduction in PGE 2 synthesis. We suggest that PGE2 and P2 receptors play independent roles in stimulating the exercise pressor reflex.

Original languageEnglish (US)
JournalAmerican Journal of Physiology - Heart and Circulatory Physiology
Volume295
Issue number5
DOIs
StatePublished - Nov 2008
Externally publishedYes

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Keywords

  • Exercise pressor reflex
  • Groups III and IV muscle afferents
  • Muscle microdialysis
  • Neural control of the circulation
  • Pyridoxal-phosphate-6-azophenyl- 2′-4-disulfonate

ASJC Scopus subject areas

  • Physiology
  • Cardiology and Cardiovascular Medicine
  • Physiology (medical)

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