Characterization of beta-adrenergic receptors in human myometrium and placenta.

The binding characteristics of the beta-adrenergic ligand [3H]-dihydroalprenolol (DHA) were determined in particulate membranes of early and term human placenta and myometrium. Human placenta is rich in beta adrenergic receptors and the binding capacity increases with increasing gestation. There was no difference in receptor density in human myometrium comparing the first trimester and term. Binding of DHA to human myometrial beta-adrenergic receptors provides a tool for the analysis of beta-adrenergic agents as potentially useful tocolytic agents.