Assessment of Noradrenaline and 5-Hydroxytryptamine Uptake in Intact Rat Brain |
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Authors: | M G Wyllie M D Wood P C Moser |
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Institution: | Department of Pharmacology, Wyeth Laboratories, Taplow, Maidenhead, Berkshire, England;Department of Pharmacology, University of Bath, Bath, England |
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Abstract: | 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. |
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Keywords: | Intracerebroventricular injections Radiolabelled monoamines Tricyclic antidepressants |
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