[3H]-flunitrazepam binding after morphine treatment and under abstinence syndrome.
Chronic morphine treatment produced increases in [3H]-flunitrazepam binding in some hippocampal areas of the rat brain. The differences in binding were statistically significant in some cases. Both morphine-dependent and morphine-deprived (abstinence syndrome) animals showed an identical response in binding, which confirms a real, although small, increase in benzodiazepine binding sites in the hippocampus after morphine treatment, that is not affected by a naloxone-induced abstinence syndrome under the conditions studied. These findings support the hypothesis of a morphine-induced up-regulation of benzodiazepine binding sites in the hippocampus. A possible different response in benzodiazepine binding sites 1 and 2 could explain the different findings reported in the literature. Our data suggest that the detected increase in benzodiazepine binding would be mainly due to type 2 binding sites, since the hippocampus has a higher density of this type of benzodiazepine binding sites.
Soria
C
C
Department of Biochemistry and Molecular Biology, University of León, Spain.
Fernandez-Lopez
A
A
Gomez
T
T
Calvo
P
P
D000818:Animals; D001345:Autoradiography; D001921:Brain / Q000187:drug effects / Q000378:metabolism*; D005445:Flunitrazepam / Q000378:metabolism*; D006624:Hippocampus / Q000187:drug effects / Q000378:metabolism*; D008297:Male; D009020:Morphine / Q000494:pharmacology*; D009928:Organ Specificity; D011712:Pyramidal Tracts / Q000187:drug effects / Q000378:metabolism; D051381:Rats; D011919:Rats, Inbred Strains; D011963:Receptors, GABA-A / Q000187:drug effects / Q000378:metabolism*; D012016:Reference Values; D013375:Substance Withdrawal Syndrome / Q000378:metabolism*; D014316:Tritium
D011963:Receptors, GABA-A; D014316:Tritium; D005445:Flunitrazepam; D009020:Morphine