Dependence liability of enkephalin in the myenteric plexus of the guinea pig.
The endogenous ligands of opiate receptors, methionine-eukephalin and leucine-enkephalin, were tested for their ability to maintain or to reinduce dependence in myenteric plexus-longitudinal muscle strips taken from tolerant/dependent guinea pigs. Both peptides fully substituted for the function morphine exerts in this preparation. It is concluded that the enkephalins posses a high degree of dependence liability.
D000818:Animals; D004361:Drug Tolerance; D006168:Guinea Pigs; D006801:Humans; D007082:Ileum / Q000187:drug effects; D009020:Morphine / Q000494:pharmacology*; D009021:Morphine Dependence; D009130:Muscle, Smooth / Q000187:drug effects; D009197:Myenteric Plexus / Q000187:drug effects*; D009419:Nerve Tissue Proteins / Q000494:pharmacology; D010455:Peptides / Q000494:pharmacology*; D011957:Receptors, Opioid / Q000187:drug effects*
D009419:Nerve Tissue Proteins; D010455:Peptides; D011957:Receptors, Opioid; D009020:Morphine