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Substance P releases and augments the morphine-evoked release of adenosine from spinal cord

C M Cahill1, T D White, J Sawynok

  • 1Department of Pharmacology, Dalhousie University, Halifax, Nova Scotia, Canada.

Brain Research
|June 20, 1997
PubMed

Insights

Substance P influences adenosine release, augmenting morphine-induced release at specific concentrations. This release is calcium-dependent and originates from capsaicin-sensitive nerve terminals.

Area of Science:

  • Neuropharmacology
  • Neurotransmitter Release

Background:

  • Adenosine plays a role in neurotransmission.
  • Substance P is a neuropeptide involved in pain and inflammation.
  • Morphine is an opioid analgesic.

Purpose of the Study:

  • To investigate the effects of Substance P on adenosine release.
  • To determine if Substance P modulates morphine-evoked adenosine release.

Main Methods:

  • Examined the effects of various concentrations of Substance P on adenosine release.
  • Investigated the role of calcium and capsaicin-sensitive nerve terminals in Substance P-mediated adenosine release.

Main Results:

  • Substance P alone induced multiphasic adenosine release at nanomolar and micromolar concentrations.
  • An inactive dose of Substance P enhanced morphine-evoked adenosine release.
  • Adenosine release by Substance P and Substance P/morphine was calcium-dependent and from capsaicin-sensitive nerve terminals.

Conclusions:

  • Substance P modulates adenosine release.
  • Substance P can enhance opioid-induced adenosine release.
  • Capsaicin-sensitive nerve terminals and calcium are critical for these effects.

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