Chronic ethanol induces changes in opiate receptor function and in met-enkephalin release.
Ethanol induces supersensitivity of striatal delta-opiate receptor sites labelled by 3H-Etorphine. This effect may be ascribed to the diminished enkephalin release detected in striatal slices after chronic ethanol consumption. On the other hand, Kd values for 3H-Met-enkephalin and 3H-DHM (mu-opiate receptors) specific binding are enhanced. The different sensitivity of the two classes of opiate receptors to ethanol may be due to specific effects on enkephalinergic transmission. It has been hypothesized that the decrease of 3H-Met-enkephalin and 3H-DHM affinity for their receptors takes place because endogenous substances from ethanol metabolism (for example salsolinol) behave as mu opioid agonists. This hypothesis is confirmed by "in vitro" studies demonstrating that salsolinol displaces 3H-Met-enkephalin and 3H-DHM but not 3H-DADLE binding. On the contrary, it seems that delta-receptors become supersensitive because of the decreased endogenous peptide release.
Lucchi
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Rius
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Govoni
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Trabucchi
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D000818:Animals; D003342:Corpus Striatum / Q000187:drug effects*; D004090:Dihydromorphine / Q000378:metabolism; D004743:Enkephalin, Leucine / Q000031:analogs & derivatives / Q000378:metabolism; D016308:Enkephalin, Leucine-2-Alanine; D004744:Enkephalin, Methionine / Q000378:metabolism*; D000431:Ethanol / Q000494:pharmacology*; D005048:Etorphine / Q000378:metabolism; D007546:Isoquinolines / Q000494:pharmacology*; D008297:Male; D051381:Rats; D011919:Rats, Inbred Strains; D011957:Receptors, Opioid / Q000187:drug effects* / Q000378:metabolism
D007546:Isoquinolines; D011957:Receptors, Opioid; D000431:Ethanol; D005048:Etorphine; D004744:Enkephalin, Methionine; D004743:Enkephalin, Leucine; D016308:Enkephalin, Leucine-2-Alanine; C036617:salsolinol; D004090:Dihydromorphine