Enkephalinergic modulation of non-cholinergic transmission in mammalian prevertebral ganglia.
The non-cholinergic excitatory potential elicited in neurons of the isolated inferior mesenteric ganglia was depressed by bath application of Met- or Leu-enkephalin and enhanced by naloxone or naltrexone. The membrane depolarization induced by exogenously applied putative transmitter substance P was not appreciably affected by either enkephalin (Enk) or opiate antagonists. Our results indicate that the non-cholinergic excitatory transmission which may be mediated by substance P in prevertebral ganglia is modulated presynaptically by endogenously released Enk in a manner that may resemble the interaction between these two peptides in the spinal cord.
D000818:Animals; D004743:Enkephalin, Leucine / Q000494:pharmacology; D004744:Enkephalin, Methionine / Q000494:pharmacology; D004745:Enkephalins / Q000502:physiology*; D005728:Ganglia, Sympathetic / Q000187:drug effects / Q000502:physiology*; D006168:Guinea Pigs; D008297:Male; D009270:Naloxone / Q000494:pharmacology; D018377:Neurotransmitter Agents; D013373:Substance P / Q000494:pharmacology; D009435:Synaptic Transmission / Q000187:drug effects
D004745:Enkephalins; D018377:Neurotransmitter Agents; D013373:Substance P; D009270:Naloxone; D004744:Enkephalin, Methionine; D004743:Enkephalin, Leucine