caa a22 4500 469119136 CHVBK 20180323133133.0 cr unu---uuuuu 170328e19921001xx s 000 0 eng 10.1007/BF02245506 doi (NATIONALLICENCE)springer-10.1007/BF02245506 Clonidine but not nifedipine prevents the release of noradrenaline during naloxone-precipitated opiate withdrawal: an in vivo microdialysis study in the rat [Elektronische Daten] [Peter Silverstone, Christopher Done, Trevor Sharp] In this study we have examined whether the α2-adrenoceptor agonist clonidine and the calcium channel antagonist nifedipine firstly inhibit the naloxone-precipitated withdrawal syndrome in morphine-dependent rats and secondly reduce central noradrenaline release during withdrawal. We demonstrate that both clonidine (0.1 mg/kg) and nifedipine (10 mg/kg) attenuate the naloxone-precipitated withdrwal syndrome. Using in vivo microdialysis, we demonstrate that following naloxone the release of noradrenaline, as measured by perfusates from hippocampus, increases 300% in morphine-dependent rats. However, whilst pretreatment with clonidine inhibited this increased noradrenaline release, nifedipine did not. These findings suggest that whilst the action of clonidine in attenuating the morphine withdrawal syndrome may be mediated by decreasing central noradrenline release, this is not the mechanism by which nifedipine acts. Springer-Verlag, 1992 Opiate-withdrawal nationallicence Noradrenaline nationallicence Microdialysis nationallicence Clonidine nationallicence Nifedipine nationallicence Silverstone Peter Radcliffe Infirmary, MRC Unit and University Department of Clinical Pharmacology, Woodstock Road, OX2 6HE, Oxford, UK aut Done Christopher Radcliffe Infirmary, MRC Unit and University Department of Clinical Pharmacology, Woodstock Road, OX2 6HE, Oxford, UK aut Sharp Trevor Radcliffe Infirmary, MRC Unit and University Department of Clinical Pharmacology, Woodstock Road, OX2 6HE, Oxford, UK aut Psychopharmacology Springer-Verlag 109/1-2(1992-10-01), 235-238 0033-3158 109:1-2<235 1992 109 213 https://doi.org/10.1007/BF02245506 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/BF02245506 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Silverstone Peter Radcliffe Infirmary, MRC Unit and University Department of Clinical Pharmacology, Woodstock Road, OX2 6HE, Oxford, UK aut NATIONALLICENCE 700 1- Done Christopher Radcliffe Infirmary, MRC Unit and University Department of Clinical Pharmacology, Woodstock Road, OX2 6HE, Oxford, UK aut NATIONALLICENCE 700 1- Sharp Trevor Radcliffe Infirmary, MRC Unit and University Department of Clinical Pharmacology, Woodstock Road, OX2 6HE, Oxford, UK aut NATIONALLICENCE 773 0- Psychopharmacology Springer-Verlag 109/1-2(1992-10-01), 235-238 0033-3158 109:1-2<235 1992 109 213 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer