title: Peptidic delta opioid receptor agonists produce antidepressant-like effects in the forced swim test and regulate BDNF mRNA expression in rats.
abstract: Systemically active, nonpeptidic delta opioid receptor agonists have been shown to produce antidepressant and anxiolytic effects in animal models in rodents. In addition, delta agonists have been shown to increase expression of brain-derived neurotrophic factor (BDNF) mRNA, an effect of some antidepressants, which may be important for the clinical efficacy of antidepressant drugs. The present study examined whether a variety of peptidic delta agonists, DPDPE, JOM-13, a systemically active derivative of DPDPE, deltorphin II, and H-Dmt-Tic-NH-CH2-Bid could produce convulsions and antidepressant-like effects in the forced swim test. In addition, some of these compounds were examined for their influence on BDNF mRNA expression. All four agonists dose-dependently decreased immobility in the forced swim test, indicating an antidepressant-like effect. Only JOM-13 produced convulsions at doses required for antidepressant-like effects. In addition, DPDPE increased BDNF mRNA expression, as measured by in situ hybridization, in the frontal cortex. The antidepressant-like effect of the agonists in the forced swim test and the increase in BDNF mRNA expression produced by DPDPE were blocked by the delta antagonist naltrindole. Therefore, activation of the delta receptor by centrally administered peptidic agonists and intravenously administered JOM-13 produces behavioral antidepressant-like effects without producing convulsions, and some peptidic agonists can increase BDNF mRNA expression, however, not as consistently as the systemically active nonpeptidic agonists.
authors.affiliation: Neuroscience Program, University of Michigan, Ann Arbor, MI 48109, USA. mtorregr@umich.edu
authors.forename: Mary M
authors.initials: MM
authors.lastname: Torregrossa
authors.forename: Emily M
authors.initials: EM
authors.lastname: Jutkiewicz
authors.forename: Henry I
authors.initials: HI
authors.lastname: Mosberg
authors.forename: Gianfranco
authors.initials: G
authors.lastname: Balboni
authors.forename: Stanley J
authors.initials: SJ
authors.lastname: Watson
authors.forename: James H
authors.initials: JH
authors.lastname: Woods
mesh_terms: D000218:Adamantane / Q000008:administration & dosage / Q000031:analogs & derivatives; D000818:Animals; D000928:Antidepressive Agents / Q000008:administration & dosage*; D001345:Autoradiography / Q000379:methods; D001522:Behavior, Animal / Q000187:drug effects; D019208:Brain-Derived Neurotrophic Factor / Q000235:genetics / Q000378:metabolism*; D003863:Depression / Q000188:drug therapy*; D004151:Dipeptides / Q000008:administration & dosage; D004195:Disease Models, Animal; D004305:Dose-Response Relationship, Drug; D004333:Drug Administration Routes; D004347:Drug Interactions; D020881:Enkephalin, D-Penicillamine (2,5)- / Q000008:administration & dosage; D004745:Enkephalins / Q000008:administration & dosage; D005786:Gene Expression Regulation / Q000187:drug effects*; D046353:Immobility Response, Tonic / Q000187:drug effects; D017403:In Situ Hybridization / Q000379:methods; D008297:Male; D009842:Oligopeptides / Q000008:administration & dosage; D012333:RNA, Messenger / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley; D017465:Receptors, Opioid, delta / Q000819:agonists* / Q000037:antagonists & inhibitors; D013550:Swimming; D044005:Tetrahydroisoquinolines / Q000008:administration & dosage
chemical_list: C434929:2',6'-dimethyltyrosyl-1,2,3,4-tetrahydroisoquinoline-3-carbonylamino-1-adamantane; D000928:Antidepressive Agents; D019208:Brain-Derived Neurotrophic Factor; D004151:Dipeptides; D004745:Enkephalins; D009842:Oligopeptides; D012333:RNA, Messenger; D017465:Receptors, Opioid, delta; D044005:Tetrahydroisoquinolines; C070386:H-tyrosyl-cyclo(cysteinyl-phenylalanyl-penicillaminyl)-OH; C060209:deltorphin II, Ala(2)-; D020881:Enkephalin, D-Penicillamine (2,5)-; D000218:Adamantane