title: Treatment with delta opioid peptide enhances in vitro and in vivo survival of rat dopaminergic neurons.
abstract: A major problem in neural transplantation therapy is poor survival of grafted cells, which may be due to low cell viability prior to transplantation or scarce trophic factors available to the cells following transplantation. Recently, the delta enkephalin analogue [D-Ala(2),D-Leu(5)]-enkephalin (DADLE) has been demonstrated to protect against, as well as to reverse methamphetamine-induced loss of dopamine transporters. Here, we show that pretreatment with DADLE (0.0025, 0.005, 0.01 g/ml) dose-dependently enhanced cell viability of cultured primary rat fetal mesencephalic cells. In addition, DADLE administration in adult rats (4 mg/kg every 2 h, 4 injections, i.p.) prior to 6-hydroxydopamine lesions of the medial forebrain bundle, significantly reduced the severity of loss of tyrosine hydroxylase-immunoreactive neurons in the substantia nigra 1 month post-lesion. This is the first report suggesting that DADLE can be used as a supplement factor for improving the cell viability of fetal mesencephalic cells and as a protective agent against neurotoxicity in a Parkinson's disease model.
authors.affiliation: Intramural Research Program, National Institute on Drug Abuse, National Institutes of Health, Baltimore, MD 21224, USA.
authors.forename: C V
authors.initials: CV
authors.lastname: Borlongan
authors.forename: T P
authors.initials: TP
authors.lastname: Su
authors.forename: Y
authors.initials: Y
authors.lastname: Wang
mesh_terms: D018663:Adrenergic Agents / Q000494:pharmacology; D000367:Age Factors; D000818:Animals; D016380:Brain Tissue Transplantation / Q000379:methods; D016923:Cell Death / Q000187:drug effects / Q000502:physiology; D002470:Cell Survival / Q000187:drug effects* / Q000502:physiology*; D002478:Cells, Cultured; D004298:Dopamine / Q000378:metabolism*; D016308:Enkephalin, Leucine-2-Alanine / Q000494:pharmacology*; D005333:Fetus / Q000166:cytology* / Q000187:drug effects*; D008297:Male; D009410:Nerve Degeneration / Q000139:chemically induced; D009474:Neurons / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism*; D018696:Neuroprotective Agents / Q000494:pharmacology; D016627:Oxidopamine / Q000494:pharmacology; D010300:Parkinson Disease / Q000188:drug therapy / Q000503:physiopathology; D051381:Rats; D017207:Rats, Sprague-Dawley; D013378:Substantia Nigra / Q000166:cytology / Q000187:drug effects / Q000378:metabolism; D013997:Time Factors
chemical_list: D018663:Adrenergic Agents; D018696:Neuroprotective Agents; D016308:Enkephalin, Leucine-2-Alanine; D016627:Oxidopamine; D004298:Dopamine