Expression of two α2-adrenergic receptor subtypes in human placenta: Evidence from direct binding studies

G. Falkay, L. Kovacs

Research output: Contribution to journalArticle

21 Citations (Scopus)

Abstract

Adrenergic receptors may play an important role for mediating a variety of metabolic and haemodynamic effects of catecholamines including placental blood flow. The α-adrenergic receptors of the human placenta were characterized in vitro by the use of [3H]rauwolscine and [3H]prazosin as radioligands. Saturation experiments would suggest that the α-adrenoceptors in the human placenta are α2. Comparative binding studies were performed, using recently synthesized compounds (Beecham Pharmaceuticals, UK) selective for α(2A) (BRL-44408) and α(2B) (BRL-41992) subtypes. The results indicate that human placenta contains at least two pharmacologically distinct α2-adrenoceptor subtypes with approximately 60 per cent α(2A) and 40 per cent α(2B) receptors. In contrast with the pattern of increasing β-adrenoceptor density, the concentration of α2-adrenoceptors in term placentae is significantly lower than in placentae from the first trimester.

Original languageEnglish
Pages (from-to)661-668
Number of pages8
JournalPlacenta
Volume15
Issue number6
Publication statusPublished - 1994

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Adrenergic Receptors
Placenta
Yohimbine
Prazosin
First Pregnancy Trimester
Catecholamines
Hemodynamics
Pharmaceutical Preparations

ASJC Scopus subject areas

  • Obstetrics and Gynaecology

Cite this

Expression of two α2-adrenergic receptor subtypes in human placenta : Evidence from direct binding studies. / Falkay, G.; Kovacs, L.

In: Placenta, Vol. 15, No. 6, 1994, p. 661-668.

Research output: Contribution to journalArticle

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