Pharmacological identification of delta and mu opiate receptors on bulbar respiratory neurons

Eur J Pharmacol. 1984 Feb 17;98(2):241-7. doi: 10.1016/0014-2999(84)90595-8.


The opiate receptors of central neurons related to the generation of the respiratory rhythm were identified using microiontophoresis of the synthetic opioid peptides DSLET (Tyr-D-Ser-Gly-Phe-Leu-Thr) and TRIMU-4 (Tyr-D-Ala-Gly-NH-CH (CH3)-CH2-CH(CH3)2), exhibiting a high selectivity for delta and mu receptors respectively. Both agonists induced depressions of spontaneous and L-glutamate-induced discharges; the effects were antagonized by naloxone and not mimicked by a related almost inactive peptide DSLLET (Tyr-D-Ser-Gly-Leu-Leu-Thr). The effect of DSLET had a faster time course than that of TRIMU-4 and persisted after prolonged applications of TRIMU-4. It is concluded that delta and mu receptors subtypes are distinct and are both present on central respiratory-related neurons.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Cats
  • Enkephalin, Leucine* / analogs & derivatives*
  • Glutamates / pharmacology
  • Glutamic Acid
  • Medulla Oblongata / drug effects
  • Medulla Oblongata / physiology*
  • Naloxone / pharmacology
  • Neurons / drug effects
  • Neurons / physiology*
  • Oligopeptides / pharmacology*
  • Receptors, Opioid / analysis*
  • Receptors, Opioid / drug effects
  • Receptors, Opioid / physiology
  • Respiratory Center / physiology*
  • Respiratory Function Tests


  • Glutamates
  • Oligopeptides
  • Receptors, Opioid
  • Naloxone
  • Glutamic Acid
  • Enkephalin, Leucine
  • tyrosyl-alanyl-N-(1,3-dimethylbutyl)glycinamide
  • enkephalin, Ser(2), Leu(5), Thr(6)-