title: Effect of adenosine analogues on the expression of opiate withdrawal in rats.
abstract: The aim of this study was to test whether convergent dependence occurs in vivo. The adenosine A1 receptor agonist N6-[(R)-1-methyl-2-phenylethyl]adenosine (R-PIA), the A2 agonist 2-(phenylamino)adenosine (CV-1808), the nonselective A1, A2 agonist (adenosine-5'-ethylcarboxamide (NECA), and the alpha 2-adrenoceptor agonist clonidine were screened (each at 30, 100, and 300 micrograms/kg, SC) for their ability to alter naloxine-precipitated withdrawal signs in morphine-dependent rats. The results indicate that there is convergent dependence involving opioid and adenosine A1 receptors on those effects expressed by withdrawal diarrhoea, paw-shakes, teeth-chattering, body-shakes, and jumping. Further, dependence expressed by body-shakes involves convergence involving A1 receptors, as well as alpha 2-adrenoceptors; while A1 receptors are involved in dependence expressed by jumping, stimulation of alpha 2-adrenoceptors augments this sign. Adenosine analogues may be of clinical value for detoxification of opiate addicts.
authors.affiliation: Unit of Addictive Drug Research, School of Pharmacology, Victorian College of Pharmacy, Parkville, Australia.
authors.forename: T
authors.initials: T
authors.lastname: Dionyssopoulos
authors.forename: W
authors.initials: W
authors.lastname: Hope
authors.forename: I M
authors.initials: IM
authors.lastname: Coupar
mesh_terms: D000241:Adenosine / Q000031:analogs & derivatives* / Q000494:pharmacology*; D000818:Animals; D001522:Behavior, Animal / Q000187:drug effects; D003000:Clonidine / Q000494:pharmacology; D003967:Diarrhea / Q000517:prevention & control; D005260:Female; D008297:Male; D009021:Morphine Dependence / Q000523:psychology; D009043:Motor Activity / Q000187:drug effects; D009270:Naloxone / Q000494:pharmacology; D051381:Rats; D011919:Rats, Inbred Strains; D013375:Substance Withdrawal Syndrome / Q000517:prevention & control* / Q000523:psychology
chemical_list: D009270:Naloxone; D000241:Adenosine; D003000:Clonidine