The rate of release of endogenous DA from rat brain striatal minces has been measured using a rapid superfusion apparatus. The apparatus provides immediate, continuous readout of easily oxidized substances in the perfusate using an amperometric detector. Subsequent analysis of the perfusate (which contains pargyline) by liquid chromatography shows that the major substance detected is DA. DA release is induced by a 30 s exposure to 60 mM K+ and is Ca2+-dependent. Similar results are obtained with veratridine (10-4 M). The time resolution of the perfusion system permits discrimination of the decreased rate of release induced by veratridine (10-4 M) and amphetamine (10-5 M) as opposed to 60 mM K+. Repetitive stimulation of the striatal mince with 60 mM K+ results in a decreased amount and rate of DA release. Subsequent exposure of the striatal mince to exogenous DA results in a restoration of the K+-induced, Ca2+-dependent release, indicating uptake of DA is operant under these conditions.
ASJC Scopus subject areas
- Biochemistry, Genetics and Molecular Biology(all)
- Pharmacology, Toxicology and Pharmaceutics(all)