Naslov
Acute effects of noradrenaline and serotonin (5-HT)uptake inhibitors (desipramine and fluoxetine)on the 5-HT synthesis rate in the rat brain regions : an autoradiographic study

Autori
Pivac, Nela ; Muck-Šeler, Dorotea ; Diksic, Mirko

Vrsta, podvrsta i kategorija rada
Sažeci sa skupova, sažetak, znanstveni

Izvornik
XXIInd Collegium Internationale Neuro-psychopharmacologicum : abstracts ; u: The International Journal of Neuropsychopharmacology 3 (2000) (S1) / Mendlewicz, J. ; Souery, D. - Brisel : Cambridge University Press, 2000, 188-188

Skup
Collegium Internationale Neuro-psychopharmacologicum (22 ; 2000)

Mjesto i datum
Bruxelles, Belgija, 09.07.2000. - 13.07.2000

Vrsta sudjelovanja
Poster

Vrsta recenzije
Međunarodna recenzija

Ključne riječi
serotonin synthesis rate; rat brain regions; desipramine; fluoxetine; autoradiography

Sažetak
Various studies have implicated the involvement of noradrenaline and/or serotonin (5-HT) in the pathogenesis and treatment of depression. Since noradrenaline uptake inhibitor (desipramine) and 5-HT uptake inhibitor (fluoxetine) are antidepressants, the aim of the present study was to compare the acute effects of both drugs on the rate of 5-HT synthesis in the rat brain by an original autoradiographic method (Diksic et al 1990), using a-14C-methyl-L-tryptophan (specific activity 55 mCi/mmol) as a tracer (30 mCi). The administration of desipramine (10 mg/kg , i.p., 2 h before i.v. infusion of the tracer) or fluoxetine (10 mg/kg, i.p. 2 h before tracer) did not affect significantly plasma tryptophan concentration in male rats. Desipramine and fluoxetine decreased the rate of 5-HT synthesis in the regions that contain serotonergic cell bodies (i.e. dorsal raphe, median raphe, magnus raphe). These decreases, calculated as percent (%) of the synthesis rate in the control group, were 23, 19 and 28% after desipramine and 17, 18 and 23 % after fluoxetine administration, respectively. Desipramine and fluoxetine increased the rate of 5-HT synthesis in the majority of areas containing serotonergic terminals. The administration of desipramine elevated the rate of 5-HT synthesis in sensory-motor (65%), frontal (21%), auditory (21%), parietal (45%) cortex, caudate (39%), mediate geniculate body (42%), in superior colliculus (26%), and in globus pallidus (31%). The administration of fluoxetine increased the rate of 5-HT synthesis in sensory-motor (32%), visual (35%), auditory (28%) cortex, in caudate (42%), in mediate geniculate body (29%), and in superior colliculus (57%). In some brain regions of the serotonergic terminals and in pineal body desipramine and fluoxetine showed the opposite effects on the 5-HT synthesis rate. The administration of desipramine decreased the rate of 5-HT synthesis in ventral tegmental area (17%), in superior olive (31%), and in pineal body (75%). The administration of fluoxetine increased the 5-HT synthesis rate in ventral tegmental area (23%), in substantia nigra (27%), in inferior colliculus (53%), and in pineal body (41%). These data suggest that the effects of desipramine (noradrenaline uptake inhibitor) and fluoxetine (5-HT uptake inhibitor) on the 5-HT synthesis rate in the rat brain, are regionally dependent. Supported by the MRC of Canada (MT-13368), US Public Service (RO1-NS29629) and Croatian Ministry of Science. Diksic M, Nagahiro S, Sourkes TL, Yamamoto YL. A new method to measure brain serotonin synthesis in vivo. I. Theory and basic data for a biological model. J Cereb. Blood Flow Metab. 10: 1-12, 1990.

Izvorni jezik
Engleski

Znanstvena područja
Temeljne medicinske znanosti

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