title: [D-Pen2,5]enkephalin and glutamate regulate the expression of delta-opioid receptors in rat cortical astrocytes.
abstract: Recent work from our and other laboratories have shown that glial cells in culture express opioid receptors. In the present study we have analyzed the regulation of delta-opioid receptor mRNA and the regulation of delta-opioid receptor activated astroglial Ca2+ responses in primary cultures from the rat cerebral cortex. Astroglial cultures were incubated with glutamate (Glu) or [D-Pen2,5]enkephalin (DPDPE) for 48 h, and delta-opioid receptor mRNA levels were analyzed using a solution hybridization RNase protection assay. Our results suggest that incubation in Glu or DPDPE upregulates the abundance of delta-opioid receptor mRNA in a dose dependent way. Glu incubated cells showed a maximum upregulation at the highest agonist concentration used (10[-5] M), whereas DPDPE was most effective at low concentrations (l0[-9] M). Furthermore, corresponding Ca2+ imaging experiments showed that incubation in Glu or DPDPE upregulated the responding frequency of delta-opioid receptor activated glial calcium fluxes from a control value of 5% to 14% and 17% responding cells, respectively.
authors.affiliation: Institute of Neurobiology, Department of Neurology, Goteborg University, Sweden.
authors.forename: T
authors.initials: T
authors.lastname: Thorlin
authors.forename: P S
authors.initials: PS
authors.lastname: Eriksson
authors.forename: E
authors.initials: E
authors.lastname: Hansson
authors.forename: L
authors.initials: L
authors.lastname: Ronnback
mesh_terms: D000814:Aniline Compounds / Q000032:analysis; D000818:Animals; D000831:Animals, Newborn; D001253:Astrocytes / Q000187:drug effects / Q000378:metabolism*; D002118:Calcium / Q000378:metabolism; D002478:Cells, Cultured; D002540:Cerebral Cortex / Q000187:drug effects / Q000378:metabolism*; D004305:Dose-Response Relationship, Drug; D020881:Enkephalin, D-Penicillamine (2,5)-; D004745:Enkephalins / Q000494:pharmacology*; D005456:Fluorescent Dyes / Q000032:analysis; D005786:Gene Expression Regulation; D018698:Glutamic Acid / Q000494:pharmacology*; D011188:Potassium / Q000494:pharmacology; D012333:RNA, Messenger / Q000032:analysis; D051381:Rats; D017207:Rats, Sprague-Dawley; D017465:Receptors, Opioid, delta / Q000819:agonists / Q000378:metabolism*; D014966:Xanthenes / Q000032:analysis
chemical_list: D000814:Aniline Compounds; D004745:Enkephalins; D005456:Fluorescent Dyes; D012333:RNA, Messenger; D017465:Receptors, Opioid, delta; D014966:Xanthenes; C059715:Fluo-3; D018698:Glutamic Acid; D020881:Enkephalin, D-Penicillamine (2,5)-; D011188:Potassium; D002118:Calcium