title: Supraspinal delta opioid receptor mRNA levels are not altered in [D-Ala2]deltorphin II tolerant mice.
abstract: Delta opioid receptor (DOR) mRNA levels were studied in mice rendered tolerant to [D-Ala2]deltorphin II by 4 days of repeated intracerebroventricular administration (10 micrograms, [tid]). ED50 determinations on day 5 revealed a 10-fold loss in [D-Ala2]deltorphin II potency with the tail-flick test. Utilization of a microdissection technique followed by quantitative solution hybridization of RNA extracts from mouse brain revealed mean levels of DOR mRNA ranging from 3.9 pg/micrograms RNA in the caudate-putamen to 0.4 pg/micrograms RNA in the cerebellum. DOR mRNA levels were not different when RNA extracts from tolerant and non-tolerant mice were compared. These data suggest that altered DOR mRNA levels are not one of the adaptive changes that occur with delta opioid ([D-Ala2]deltorphin II) tolerance.
authors.affiliation: Department of Pharmacology, Cornell University Medical College, New York, New York 10021.
authors.forename: B
authors.initials: B
authors.lastname: Kest
authors.forename: S
authors.initials: S
authors.lastname: Jenab
authors.forename: M
authors.initials: M
authors.lastname: Brodsky
authors.forename: K
authors.initials: K
authors.lastname: Elliott
authors.forename: C E
authors.initials: CE
authors.lastname: Inturrisi
mesh_terms: D000818:Animals; D018076:DNA, Complementary / Q000096:biosynthesis; D004305:Dose-Response Relationship, Drug; D004361:Drug Tolerance; D020881:Enkephalin, D-Penicillamine (2,5)-; D004745:Enkephalins / Q000008:administration & dosage / Q000494:pharmacology*; D017403:In Situ Hybridization; D007276:Injections, Intraventricular; D008297:Male; D051379:Mice; D010147:Pain Measurement / Q000187:drug effects; D015347:RNA Probes; D012333:RNA, Messenger / Q000096:biosynthesis*; D017465:Receptors, Opioid, delta / Q000819:agonists* / Q000096:biosynthesis* / Q000187:drug effects; D013116:Spinal Cord / Q000187:drug effects / Q000378:metabolism*
chemical_list: D018076:DNA, Complementary; D004745:Enkephalins; D015347:RNA Probes; D012333:RNA, Messenger; D017465:Receptors, Opioid, delta; D020881:Enkephalin, D-Penicillamine (2,5)-