Brain opioid receptor binding of [3H]CTOP and [3H]naltrindole in alcohol-preferring AA and alcohol-avoiding ANA rats.
We compared mu- and delta-opioid receptor distributions between the brains of alcohol-preferring Alko, Alcohol (AA) and alcohol-avoiding Alko, Non-Alcohol (ANA) rat lines, using autoradiography on brain sections with mu- and delta-opioid receptor antagonist ligands [3H]CTOP and [3H]naltrindole, respectively. The labeling patterns of the ligands were consistent with the known opioid receptor distributions in both rat lines and no major genetic differences were found between the lines. However, the binding density of mu- and delta-opioid receptors differed slightly in several brain areas: in the AA brain sections, limbic areas, such as hippocampus and amygdala, showed decreased mu- and delta-opioid receptor binding, whereas the striatal patches were larger and the substantia nigra showed higher binding density of the mu-receptors compared to the ANA sections. The small differences observed between the rat lines could be due to adaptations to altered endogenous opioid peptide levels or neural circuits, and associated with the differences in alcohol drinking or other behaviors.
Soini
S L
SL
Department of Pharmacology and Clinical Pharmacology, University of Turku, Finland.
Ovaska
T
T
Honkanen
A
A
Hyytiä
P
P
Korpi
E R
ER
D000428:Alcohol Drinking / Q000235:genetics*; D000679:Amygdala / Q000378:metabolism; D000818:Animals; D001345:Autoradiography; D001921:Brain / Q000378:metabolism*; D003342:Corpus Striatum / Q000378:metabolism; D005518:Food Preferences; D006624:Hippocampus / Q000378:metabolism; D008297:Male; D009271:Naltrexone / Q000031:analogs & derivatives* / Q000378:metabolism; D009292:Narcotic Antagonists / Q000378:metabolism; D051381:Rats; D011922:Rats, Mutant Strains; D011957:Receptors, Opioid / Q000378:metabolism*; D017465:Receptors, Opioid, delta / Q000378:metabolism; D017450:Receptors, Opioid, mu / Q000378:metabolism; D013004:Somatostatin / Q000031:analogs & derivatives* / Q000378:metabolism; D013378:Substantia Nigra / Q000378:metabolism; D014316:Tritium
D009292:Narcotic Antagonists; D011957:Receptors, Opioid; D017465:Receptors, Opioid, delta; D017450:Receptors, Opioid, mu; D014316:Tritium; C049352:phenylalanyl-cyclo(cysteinyltyrosyl-tryptophyl-ornithyl-threonyl-penicillamine)threoninamide; D013004:Somatostatin; D009271:Naltrexone; C055382:naltrindole