ISSN:
1471-4159
Source:
Blackwell Publishing Journal Backfiles 1879-2005
Topics:
Medicine
Notes:
Abstract The basal catecholamine content of rabbit retina was determined by liquid chromatography with electrochemical detection (LC-EC) and 3,4-dihydroxyphenyl-ethylamine (dopamine, DA) found to be the major catecholamine. The immediate DA precursor, 3,4-dihydrophenylalanine (l-DOPA), and the metabolite, 3,4-dihydroxyphenylacetic acid (DOPAC), were also detected at about 2.8% and 17% of DA levels, respectively. When added exogenously, l-tyrosine did not increase the rate of DA synthesis over the basal level. In contrast, exogenous l-DOPA led to a 3.5-fold increase in DA, and to a 20-fold increase in DOPAC content. The monoamine oxidase inhibitors par-gyline and (-)-deprenyl differentially affected the degradation of DA, since 100 μM pargyline was apparently more effective than 100 μM (-)-deprenyl. Reserpine and (±)-amphetamine each induced a Ca2+-independent decrease of DA stores. The separate actions of reserpine and (±)-amphetamine in lowering tissue DA levels were additive, suggesting two separate pools of DA available for release from presynaptic stores. The present study demonstrates that the LC-EC technique may be used to investigate the modulation of the synthesis and release of retinal DA in vitro, without the prior uptake of radiolabelled transmitter.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1111/j.1471-4159.1986.tb00740.x
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