Dopamine denervation of the nucleus accumbens induces a selective increase in the number of delta-opioid binding sites.
Selective lesions of dopamine (DA) neurons of the nucleus accumbens were made in rats by local injections of 6-hydroxydopamine (6-OHDA). Seven days after 6-OHDA, the binding affinities and capacities at mu-, delta- and kappa-opioid binding sites were determined in the nucleus accumbens by selective labelling techniques. 6-OHDA pretreatment caused a significant increase in the number of delta-opioid binding sites (+30%) while the number of mu-, kappa- and total sites was not modified. The affinity at mu-, delta- and kappa-sites was unchanged after 6-OHDA pretreatment.
Esposito
E
E
Istituto di Ricerche Farmacologiche Mario Negri, Milan, Italy.
Cervo
L
L
Petrillo
P
P
Sbacchi
M
M
Tavani
A
A
Samanin
R
R
D000818:Animals; D001665:Binding Sites / Q000187:drug effects; D003714:Denervation; D006892:Hydroxydopamines / Q000494:pharmacology*; D008297:Male; D009714:Nucleus Accumbens / Q000187:drug effects / Q000378:metabolism*; D016627:Oxidopamine; D051381:Rats; D011957:Receptors, Opioid / Q000187:drug effects / Q000378:metabolism*; D012686:Septal Nuclei / Q000378:metabolism*
D006892:Hydroxydopamines; D011957:Receptors, Opioid; D016627:Oxidopamine