title: Correlation between beta- and alpha-adrenergic receptor concentrations in human placenta.
abstract: alpha 2- and beta-adrenergic receptors in human placental membranes have been investigated using the radioligands [3H]-RX 821002 and [3H]-dihydroalprenolol, respectively. The specific binding of the alpha 2-adrenoceptor antagonist RX 821002 confirms the presence of an alpha 2-adrenoceptor in the human placenta, which has been characterized previously with [3H]-rauwolscine. The major finding presented here is a correlation between the alpha 2- and beta-adrenergic receptor concentrations (r = 0.765) in the human placenta at term. It is suggested that the alpha 2/beta adrenoceptor balance may play an important role in regulation of the vascular bed of the placenta. Determination of the alpha 2/beta ratio may help towards an understanding of the contractility of the placental vascular muscles.
authors.affiliation: Department of Obstetrics and Gynecology, A. Szent-Györgyi Medical University, Szeged, Hungary.
authors.forename: G
authors.initials: G
authors.lastname: Falkay
authors.forename: K
authors.initials: K
authors.lastname: Melis
authors.forename: L
authors.initials: L
authors.lastname: Kovács
mesh_terms: D004082:Dihydroalprenolol / Q000378:metabolism; D004146:Dioxanes / Q000378:metabolism; D005260:Female; D006801:Humans; D019329:Idazoxan / Q000031:analogs & derivatives; D010920:Placenta / Q000737:chemistry*; D011247:Pregnancy; D018341:Receptors, Adrenergic, alpha-2 / Q000032:analysis*; D011943:Receptors, Adrenergic, beta / Q000032:analysis*
chemical_list: D004146:Dioxanes; D018341:Receptors, Adrenergic, alpha-2; D011943:Receptors, Adrenergic, beta; D004082:Dihydroalprenolol; C058525:2-methoxyidazoxan; D019329:Idazoxan