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Updated: Oct 1, 2026

Assessment of Dopaminergic Homeostasis in Mice by Use of High-performance Liquid Chromatography Analysis and Synaptosomal Dopamine Uptake
Published on: September 21, 2017
Reversible and irreversible components of [(3)H]-N-propylnorapomorphine interaction with rat striatal membranes
Martin Lepiku1, Jaak Järv, Kjell Fuxe
1Institute of Organic and Bioorganic Chemistry, University of Tartu, Jakobi Str. 2, EE-51014, Tartu, Estonia.
Abstract:
The kinetics of L-(-)-[N-propyl-(3)H(N)]-norapomorphine ([(3)H]NPA) interactions with rat striatal membranes were studied. The analysis revealed that in addition to specific dopaminergic binding a substantial part of the radioligand was bound irreversibly to heterogeneous populations of non-specific binding sites of these membranes. The specific binding of [(3)H]NPA with dopamine receptors, determined from the differences of kinetic curves of total and non-specific binding, was fast, reversible, and revealed high affinity. The irreversible component was heterogeneous and seems to be related to oxidative degradation of the radioligand, as the rate of this process was substantially reduced by antioxidants like ascorbic acid and dithiothreitol.
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