title: Adenosine kinase inhibitors attenuate opiate withdrawal via adenosine receptor activation.
abstract: Previous studies have demonstrated a role for adenosine in mediating opiate effects. This study examines the effects of indirect activation of adenosine receptors, via treatment with adenosine kinase inhibitors, on the expression of opiate withdrawal in mice. Mice receive chronic morphine treatment via implantation of subcutaneous morphine pellets (75 mg) for 72 h. Mice then receive parenteral treatment with adenosine kinase inhibitors, either 5'-amino-5'-deoxyadenosine (2, 5, 20, 40 mg/kg, intraperitoneal or i.p.) or iodotubericidin (1, 2, 5 mg/kg, i.p.), followed by naloxone injection and opiate withdrawal signs are measured over 20 min. Both adenosine kinase inhibitors significantly reduce the following opiate withdrawal signs in a dose-dependent manner compared to vehicle: withdrawal jumps, teeth chattering, forepaw tremors, and forepaw treads. Additionally, 5'-amino-5'-deoxyadenosine significantly reduces withdrawal-induced diarrhea and weight loss. Effects of 5'-amino-5'-deoxyadenosine (40 mg/kg) on opiate withdrawal signs appear to be mediated via adenosine receptor activation as they are reversed by pretreatment by adenosine receptor antagonist caffeine (20 mg, i.p.) but not by selective phosphodiesterase inhibitor Ro 20-1724 (10 mg/kg, i.p.). Adenosine receptor activation via adenosine kinase inhibitor treatment attenuates opiate withdrawal and these agents may be generally useful in the treatment of drug withdrawal syndromes.
authors.affiliation: Department of Psychiatry and Human Behavior, Veterans Affairs Medical Center and Brown University School of Medicine, Providence, RI 02908, USA. Gary_Kaplan@brown.edu
authors.forename: G B
authors.initials: GB
authors.lastname: Kaplan
authors.forename: T S
authors.initials: TS
authors.lastname: Coyle
mesh_terms: D012368:4-(3-Butoxy-4-methoxybenzyl)-2-imidazolidinone / Q000494:pharmacology; D000248:Adenosine Kinase / Q000037:antagonists & inhibitors*; D000818:Animals; D001835:Body Weight / Q000187:drug effects; D002110:Caffeine / Q000494:pharmacology; D003839:Deoxyadenosines / Q000494:pharmacology; D004305:Dose-Response Relationship, Drug; D004791:Enzyme Inhibitors / Q000494:pharmacology; D008297:Male; D051379:Mice; D009020:Morphine / Q000494:pharmacology*; D018047:Receptors, Purinergic P1 / Q000378:metabolism*; D013375:Substance Withdrawal Syndrome / Q000517:prevention & control*
chemical_list: D003839:Deoxyadenosines; D004791:Enzyme Inhibitors; D018047:Receptors, Purinergic P1; C057928:5'-amino-5'-deoxyadenosine; D012368:4-(3-Butoxy-4-methoxybenzyl)-2-imidazolidinone; D002110:Caffeine; D009020:Morphine; D000248:Adenosine Kinase