title: Dopamine binding to the alpha receptor in pregnant rabbit myometrium.
abstract: This study evaluated in vitro binding of dopamine ligands to myometrial alpha adrenoceptors. With cell membranes from pregnant rabbits, receptor radioligand binding studies utilizing [3H] dihydroergocryptine +/- dopamine demonstrated receptor affinity (KD) = 0.75 +/- 0.10 nM (+/- SEM) and density (Bmax) = 533.2 +/- 45.2 fM/mg protein. Similar studies utilizing phentolamine or apomorphine gave essentially identical results. Competition binding studies demonstrated steriospecific butaclamol binding, along with significant binding of haloperidol, spiperone, apomorphine, and bromoergocryptine. These observations provide a mechanism for the observed uterotonic effects of dopamine.
mesh_terms: D000818:Animals; D001058:Apomorphine / Q000378:metabolism; D001667:Binding, Competitive; D002462:Cell Membrane / Q000378:metabolism; D004088:Dihydroergotoxine / Q000378:metabolism; D004298:Dopamine / Q000378:metabolism*; D005260:Female; D009215:Myometrium / Q000378:metabolism*; D010646:Phentolamine / Q000378:metabolism; D011247:Pregnancy; D011270:Pregnancy, Animal / Q000378:metabolism*; D011817:Rabbits; D011942:Receptors, Adrenergic, alpha / Q000378:metabolism*
chemical_list: D011942:Receptors, Adrenergic, alpha; D004088:Dihydroergotoxine; D001058:Apomorphine; D004298:Dopamine; D010646:Phentolamine