Assessment of noradrenaline and 5-hydroxytryptamine uptake in intact rat brain.
A method for the measurement of 3H-monoamine [noradrenaline (NA) and 5-hydroxytryptamine (5-HT)] uptake into intact brain following intracerebroventricular injection is described. Most of the accumulated monoamine was associated with nerve terminals (synaptosomes). Radioactivity in the synaptosomal fraction was retained by 0.45-micron filters and was osmotically sensitive, features indicative of accumulation within particles rather than binding to membranes. [3H]5-HT associated with synaptosomes was reduced in animals pretreated with the neurotoxin 5,7-dihydroxytryptamine, in parallel with a reduction in endogenous 5-HT levels. Oral administration of tricyclic antidepressants including clomipramine, desipramine, and imipramine inhibited the synaptosomal accumulation of 3H-monoamines. Overall, the features of the accumulation of 3H-monoamines, after intracerebroventricular administration, displayed many of the characteristics expected of a physiological monoamine reuptake system.
D015116:5,7-Dihydroxytryptamine / Q000494:pharmacology; D000818:Animals; D001921:Brain / Q000378:metabolism*; D001923:Brain Chemistry / Q000187:drug effects; D007099:Imipramine / Q000494:pharmacology; D007276:Injections, Intraventricular; D008297:Male; D009638:Norepinephrine / Q000032:analysis / Q000378:metabolism*; D051381:Rats; D011919:Rats, Inbred Strains; D012701:Serotonin / Q000032:analysis / Q000378:metabolism*; D013347:Subcellular Fractions / Q000032:analysis
D015116:5,7-Dihydroxytryptamine; D012701:Serotonin; D007099:Imipramine; D009638:Norepinephrine