Sympathetic activation triggers endogenous opioid release and analgesia within peripheral inflamed tissue.

@article{Binder2004SympatheticAT,
  title={Sympathetic activation triggers endogenous opioid release and analgesia within peripheral inflamed tissue.},
  author={Waltraud Binder and Shaaban A Mousa and Nicolle Sitte and Myriam Kaiser and Christoph Stein and Michael Schaefer},
  journal={The European journal of neuroscience},
  year={2004},
  volume={20 1},
  pages={92-100}
}
Stress induces analgesia by mechanisms within and outside the brain. Here we show that the sympathetic nervous system is an essential trigger of intrinsic opioid analgesia within peripheral injured tissue. Noradrenaline, injected directly into inflamed hind paws of male Wistar rats, produced dose-dependent antinociception, reversible by alpha(1)-, alpha(2)- and beta(2)-antagonists. alpha(1)-, alpha(2)- and beta(2)-adrenergic receptors were demonstrated on beta-endorphin-containing immune cells… CONTINUE READING