delta-Opioid modulation of striatal dopaminergic activity in mice.
Mu- and delta-opioid subtype receptor antagonists were tested in the mouse for their effects on vertical climbing activity, an index of striatal dopaminergic activity. The selective delta-opioid antagonist ICI 154 129 (I/l) by itself enhanced vertical climbing activity in a dose-related manner, whereas the mu-opioid antagonist naloxone by itself was inactive on climbing behavior. Naloxone increased the climbing-stimulant effect of I/l. Unstimulated vertical climbing activity was reduced, and all opioid-antagonist enhancement of climbing behavior was antagonized, by the competitive dopamine antagonist haloperidol in dose-related fashion. The observed motor-enhancement effect of a selective delta-opioid receptor antagonist is the first demonstration of physiologically-significant tonic activity on a central opioid receptor. Our observations suggest that I/l may be useful clinically in striatal dopamine-deficient disease conditions such as parkinsonism.
Dua
A K
AK
Pinsky
C
C
D000818:Animals; D003342:Corpus Striatum / Q000502:physiology*; D004298:Dopamine / Q000502:physiology*; D004743:Enkephalin, Leucine / Q000031:analogs & derivatives / Q000494:pharmacology; D008297:Male; D051379:Mice; D009043:Motor Activity / Q000187:drug effects / Q000502:physiology*; D009270:Naloxone / Q000494:pharmacology; D011957:Receptors, Opioid / Q000502:physiology*; D017465:Receptors, Opioid, delta; D017450:Receptors, Opioid, mu; D009435:Synaptic Transmission
D011957:Receptors, Opioid; D017465:Receptors, Opioid, delta; D017450:Receptors, Opioid, mu; D009270:Naloxone; D004743:Enkephalin, Leucine; C036405:ICI 154129; D004298:Dopamine