Antidepressants and endogenous opioid peptide systems.
The influence of antidepressants on the brain and pituitary content of immunoreactive beta-endorphin (ir-beta E) and dynorphin (ir-DYN) was studied in rats. Chronic administration of the first and second generation antidepressants imipramine, citalopram and rolipram, and of the antidepressant neuroleptics levomepromazine and chlorprothixene elevated the level of ir-beta E in the hypothalamus. Imipramine and levomepromazine also increased the level of ir-DYN in this tissue. Imipramine administered chronically potentiated stress-induced as well as morphine analgesia. The results obtained suggest that chronic antidepressants enhance the brain opioid system activity and increase the sensitivity of opiate receptors.
D000818:Animals; D000928:Antidepressive Agents / Q000494:pharmacology*; D001923:Brain Chemistry / Q000187:drug effects*; D002749:Chlorprothixene / Q000494:pharmacology; D015283:Citalopram; D004723:Endorphins / Q000032:analysis*; D007099:Imipramine / Q000494:pharmacology; D008297:Male; D008728:Methotrimeprazine / Q000494:pharmacology; D010903:Pituitary Gland, Anterior / Q000032:analysis*; D011437:Propylamines / Q000494:pharmacology; D011760:Pyrrolidinones / Q000494:pharmacology; D051381:Rats; D011919:Rats, Inbred Strains; D020889:Rolipram
D000928:Antidepressive Agents; D004723:Endorphins; D011437:Propylamines; D011760:Pyrrolidinones; D015283:Citalopram; D008728:Methotrimeprazine; D002749:Chlorprothixene; D020889:Rolipram; D007099:Imipramine