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Changes in Levels of Dopamine and Tyramine in the Rat Caudate Nucleus Following Alterations of Impulse Flow in the Nigrostriatal Pathway
Author(s) -
Jones R. S. G.,
Juorio A. V.,
Boulton A. A.
Publication year - 1983
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.1471-4159.1983.tb11295.x
Subject(s) - substantia nigra , homovanillic acid , caudate nucleus , dopamine , tyrosine hydroxylase , tyramine , medicine , endocrinology , chemistry , stimulation , nigrostriatal pathway , tyrosine , dopaminergic , biology , biochemistry , serotonin , receptor
Following electrical stimulation of the substantia nigra for 1 h there was a substantial increase in dopamine (DA) turnover in the rat caudate nucleus evidenced by an increase in its acid metabolite homovanillic acid (HVA). Concurrently there was an increase in striatal m ‐tyramine (mTA) and a substantial decrease in p ‐tyramine (pTA). Lesioning the substantia nigra to decrease impulse flow resulted in a buildup of striatal DA and mTA, but again a decrease in pTA. Following pre‐treatment with a tyrosine hydroxylase inhibitor, the effects of stimulation of the nigra on mTA were reversed, there being a significant decrease in this amine. The decrease of pTA in response was partially prevented by tyrosine hydroxylase inhibition. The effects of stimulation or substantia nigra lesions on pTA levels were reversed, however, by tyrosine hydroxylase inhibition, a significant increase in this amine being recorded. mTA and DA levels were largely unaffected by a combination of lesion and tyrosine hydroxylase inhibition. The results provide insight into the possible biosynthetic interrelationships between DA and the tyramine isomers in the rat caudate nucleus.