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Dextro‐phenylalanine inhibits potassium‐evoked 3 H‐noradrenaline release from hypothalamus but not of 3 H‐dopamine from rat caudate nucleus
Author(s) -
Julio Pardal Fernández
Publication year - 1980
Publication title -
journal of neuroscience research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.72
H-Index - 160
eISSN - 1097-4547
pISSN - 0360-4012
DOI - 10.1002/jnr.490050207
Subject(s) - dopamine , medicine , endocrinology , chemistry , phenylalanine , hypothalamus , catecholamine , receptor , caudate nucleus , amino acid , biochemistry , biology
Action of dextro‐phenylalanine (d‐Phe) on catecholamine release elicited by K + 20 mM has been studied in isolated slices of rat central nervous system (CNS). d‐Phe (3 × 10 −3 M) produced inhibition of the fractional release of 3 H‐noradrenaline but not of 3 H‐dopamine. The mentioned effect is Ca 2+ dependent and was antagonized when this ion was incremented to 2.6 mM in the medium or in the presence of ionophore A‐23187 (4 × 10 −5 M). Neither acetylsalicylic acid nor indomethacin (prostaglandin biosynthesis inhibitors) interferes with the effect of d‐Phe, showing that by itself it would not reach through the prostaglandin pathway. d‐Phe modified neither the noradrenaline neuronal uptake nor its metabolism at the CNS. The findings suggest that d‐Phe acts through a Ca 2+ ‐dependent mechanism, possibly by specific receptors and in parallel with feedback circuits that involve alpha‐adrenoceptors, muscarinic receptors, or prostaglandins.