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EFFECT OF DIVALENT CATIONS ON THE AMPHETAMINE‐INDUCED STIMULATION OF [ 3 H]CATECHOL SYNTHESIS IN THE STRIATUM 1
Author(s) -
Uretsky Norman J.,
Kamal Linda,
Snodgrass S. Robert
Publication year - 1979
Publication title -
journal of neurochemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.75
H-Index - 229
eISSN - 1471-4159
pISSN - 0022-3042
DOI - 10.1111/j.1471-4159.1979.tb04580.x
Subject(s) - chemistry , divalent , catechol , amphetamine , calcium , stimulation , barium , magnesium , inorganic chemistry , biochemistry , dopamine , endocrinology , organic chemistry , medicine
— The effects of divalent cations on the stimulation of [ 3 H]catechol formation in striatal slices induced by d ‐amphetamine was studied in order to determine the role of calcium in this action of amphetamine. In the absence of any divalent cations in the medium, amphetamine did not significantly stimulate [ 3 H]catechol synthesis in striatal slices, but it produced a marked stimulation of synthesis when calcium (1.25 m m ) was added to the medium. In the presence of calcium (1.25 m m ), high concentrations of magnesium (15m m ), other divalent cations (2.5 m m ) such as barium, strontium, manganese and cobalt, as well as verapamil, inhibited the amphetamine‐induced stimulation. When the slices were incubated in medium containing no divalent cations, the addition to the medium of either strontium, cobalt, zinc, or magnesium (2.5 m m ) could not support the amphetamine‐induced stimulation of [ 3 H]catechol synthesis, while the addition of barium resulted in a significant stimulation of synthesis. In contrast, the stimulation produced by amphetamine in the presence of manganese was comparable to that observed when calcium had been added to the medium. Since amphetamine did not alter the specific activity of [ 3 H]tyrosine in the tissue in the presence of any of the divalent cations tested, the amphetamine‐induced stimulation of [ 3 H]catechol synthesis was probably due to an increase in tyrosine hydroxylase activity. Calcium and manganese were also able to support the stimulation of [ 3 H]catechol synthesis in striatal slices induced by high potassium concentration. However, compared to the effects with amphetamine, manganese was much less effective than calcium in supporting the stimulation induced by high potassium concentration. These results show that specific divalent cations can support the stimulation of catechol synthesis induced by amphetamine in striatal slices, and suggest that the entry of these specific ions into cells, presumably dopamine neurons, is involved in this action.