title: Developing brain as an endocrine organ: secretion of dopamine.
abstract: This study was aimed to test our hypothesis that the developing brain operates as an endocrine organ before the establishment of the blood-brain barrier (BBB), in rats up to the first postnatal week. Dopamine (DA) was selected as a marker of the brain endocrine activity. The hypothesis was supported by the observations in rats of: (i) the physiological concentration of DA in peripheral blood of fetuses and neonates, before the BBB establishment, and its drop by prepubertal period, after the BBB development; (ii) a drop of the DA concentration in the brain for 54% and in blood for 74% on the 3rd postnatal day after the intraventricular administration of 50 μg of α-methyl-p-tyrosine, an inhibitor of DA synthesis, with no changes in the DA metabolism in peripheral DA-producing organs. Thus, the developing brain is a principal source of circulating DA which is capable of providing an endocrine regulation of peripheral organs and the brain.
authors.affiliation: Laboratory of Hormonal Regulations, Institute of Developmental Biology RAS, 26 Vavilov Str., Moscow 119334, Russia. michael.ugrumov@mail.ru
authors.forename: Michael V
authors.initials: MV
authors.lastname: Ugrumov
authors.forename: Julia Y
authors.initials: JY
authors.lastname: Saifetyarova
authors.forename: Antonina V
authors.initials: AV
authors.lastname: Lavrentieva
authors.forename: Anna Y
authors.initials: AY
authors.lastname: Sapronova
mesh_terms: D015102:3,4-Dihydroxyphenylacetic Acid / Q000097:blood / Q000378:metabolism; D000818:Animals; D001812:Blood-Brain Barrier / Q000196:embryology / Q000254:growth & development; D001921:Brain / Q000196:embryology / Q000254:growth & development* / Q000378:metabolism; D004298:Dopamine / Q000097:blood / Q000378:metabolism*; D005260:Female; D007031:Hypothalamus / Q000378:metabolism; D008297:Male; D008636:Mesencephalon / Q000378:metabolism; D009490:Neurosecretory Systems / Q000196:embryology / Q000254:growth & development*; D011247:Pregnancy; D051381:Rats; D017208:Rats, Wistar; D012249:Rhombencephalon / Q000378:metabolism; D014446:Tyrosine 3-Monooxygenase / Q000037:antagonists & inhibitors; D019805:alpha-Methyltyrosine / Q000494:pharmacology
chemical_list: D015102:3,4-Dihydroxyphenylacetic Acid; D019805:alpha-Methyltyrosine; D014446:Tyrosine 3-Monooxygenase; D004298:Dopamine