Repeated heroin administration increases extracellular opioid peptide-like immunoreactivity in the globus pallidus/ventral pallidum of freely moving rats.
Microdialysis was used to investigate the effects of heroin administration on extracellular opioid peptide levels in the globus pallidus/ventral pallidum of freely moving rats. Two injections of heroin (0.6 mg/ kg i.p.) were given 3 h apart. The first injection had no significant effect on opioid peptide levels, but the second injection produced a transient yet significant increase (+268%) in opioid peptide-like immunoreactivity in pallidal dialysates, peaking 1 h after injection. This effect was blocked by administration of naloxone (3 mg/kg i.p.) prior to the second injection. The implications of these data are discussed with regards to the role of the endogenous opioid peptide system in opiate reward.
Olive
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MF
Interdepartmental Neuroscience PhD Program, University of California at Los Angeles, 90024, USA.
Maidment
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NT
D000704:Analysis of Variance; D000818:Animals; D005917:Globus Pallidus / Q000187:drug effects* / Q000378:metabolism; D003932:Heroin / Q000008:administration & dosage / Q000378:metabolism / Q000494:pharmacology*; D008297:Male; D017551:Microdialysis; D009020:Morphine / Q000378:metabolism; D018847:Opioid Peptides / Q000378:metabolism*; D051381:Rats; D017207:Rats, Sprague-Dawley
D018847:Opioid Peptides; D003932:Heroin; D009020:Morphine