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Relationship Between Phenolamines and Catecholamines During Rat Brain Embryonic Development In Vivo and In Vitro
Author(s) -
David J. C.
Publication year - 1984
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.1471-4159.1984.tb12786.x
Subject(s) - tyrosine hydroxylase , octopamine (neurotransmitter) , catecholaminergic , monoamine oxidase , endocrinology , medicine , dopamine , phenylethanolamine , catecholamine , hypothalamus , monoamine neurotransmitter , biology , tyramine , catecholaminergic cell groups , phenylethanolamine n methyltransferase , in vivo , chemistry , serotonin , enzyme , biochemistry , receptor , microbiology and biotechnology
p ‐Octopamine and phenylethanolamine are present in the embryonic rat brain earlier than catecholamines. These phenolamines are localized mainly in the hypothalamus, where the level of p ‐octopamine is very high. The parallel developmental study of the activities of dopamine β‐hydroxylase, 3,4‐dihydroxyphenylalanine decarboxylase, tyrosine hydroxylase, and monoamine oxidase shows that phenolamines are present in significant amounts in the hypothalamus until tyrosine hydroxylase and monoamine oxidase become catalytically active. The culture of embryonic hypothalamus at different ages shows that no tyrosine hydroxylase and monoamine oxidase activities can be detected if the tissue is cultured before 15 days. This clearly indicates that all the enzymes related to catecholamine biosynthesis are not triggered at the same time during the development of the rat brain. These results are discussed on the basis of the physiological importance of phenolamines in mammals and of the use of the developing rat brain as a model for the study of the onset of the catecholaminergic system and the decline of the octopamine.