METABOLISM OF [H-3] NORADRENALINE BY UMBILICAL ARTERIES AND PLACENTAL BED TISSUE OBTAINED FROM NORMOTENSIVE AND PREECLAMPTIC HUMAN PREGNANCIES

• Tipo: Artigo em Revista Científica Internacional
• Data: 1994

Autores

FERREIRADEALMEIDA, JA (Autor) Outra; Martel, F (Autor) FMUP; AZEVEDO, I (Autor) Outra; OSSWALD, W (Autor) Outra

Revista

Título: Journal of Maternal-Fetal Investigation

Vol. 4

Páginas: 81-85

ISSN: 0939-6322

Editora: Springer

Indexação

ISI Web of Knowledge - 1 Citação

Scopus - 2 Citações

Outras Informações

ID Authenticus: P-001-KBK

Abstract (EN): Objective: To ascertain if the catecholamine content of placental bed tissue as well as the capacity of umbilical arteries and placental bed tissue to take up and metabolize [H-3]noradrenaline are different under conditions of normotensive and preeclamptic pregnancy. Methods: Placental bed samples were obtained by biopsy at cesarean sections. Umbilical arteries were dissected immediately after delivery. Noradrenaline, adrenaline, dopamine, and 3,4-dihydroxyphenylglycol (DOPEG) were measured in placental bed tissue by HPLC-ED. Umbilical arteries and placental bed slices were incubated with [H-3]noradrenaline, under control conditions or in the presence of inhibitors of uptake1 or uptake2. [H-3]Noradrenaline and its metabolites were measured in tissues and incubation fluids by scintillation counting after column chromatographic separation. Results: Placental bed tissue had no detectable levels of noradrenaline, adrenaline, or dopamine. Relatively high levels of DOPEG were found in specimens from both normotensive and preeclamptic pregnancies. Placental bed tissue showed a high capacity to take up (mainly through a mechanism that was sensitive to uptake2 blockers) and metabolize [H-3]noradrenaline (through monoamine oxidase). Desipramine had no significant effect on uptake and/or metabolism of [H-3]noradrenaline. Umbilical arteries formed a much smaller amount (25%) of metabolites than placental bed tissue, and uptake blockers had no significant effect on metabolite formation, In preeclampsia the capacity to take up and/or to deaminate [H-3]noradrenaline to [H-3]DOPEG was significantly reduced in both umbilical arteries and placental bed tissue. Conclusions: Placental bed tissue seems to be devoid of adrenergic innervation in both normotension and in preeclampsia. This tissue has a high capacity to take up and deaminate [H-3]noradrenaline. The capacity to take up and/or deaminate [H-3]noradrenaline to [H-3]DOPEG is significantly reduced in preeclampsia. The presence of high levels of endogenous DOPEG in placental bed tissue from preeclamptic pregnancies is compatible with high levels of circulating catecholamines in this situation.

Idioma: Inglês

Tipo (Avaliação Docente): Científica

Nº de páginas: 5