title: Pharmacological identification of delta and mu opiate receptors on bulbar respiratory neurons.
abstract: 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.
mesh_terms: D000818:Animals; D002415:Cats; D004743:Enkephalin, Leucine / Q000031:analogs & derivatives*; D005971:Glutamates / Q000494:pharmacology; D018698:Glutamic Acid; D008526:Medulla Oblongata / Q000187:drug effects / Q000502:physiology*; D009270:Naloxone / Q000494:pharmacology; D009474:Neurons / Q000187:drug effects / Q000502:physiology*; D009842:Oligopeptides / Q000494:pharmacology*; D011957:Receptors, Opioid / Q000032:analysis* / Q000187:drug effects / Q000502:physiology; D012125:Respiratory Center / Q000502:physiology*; D012129:Respiratory Function Tests
chemical_list: D005971:Glutamates; D009842:Oligopeptides; D011957:Receptors, Opioid; D009270:Naloxone; D018698:Glutamic Acid; D004743:Enkephalin, Leucine; C041068:tyrosyl-alanyl-N-(1,3-dimethylbutyl)glycinamide; C034318:enkephalin, Ser(2), Leu(5), Thr(6)-