Specific binding of estradiol to rat coronary artery smooth muscle cells.
We report the expression and characteristics of the estrogen receptor in rat coronary artery-derived smooth muscle cells. Polymerase chain reaction analyses of total and poly(A) + mRNA from rat coronary artery-derived smooth muscle cells indicate the presence of estrogen receptor mRNA. Binding analyses reveal the presence of high affinity binding sites for 17 beta-estradiol, with a Kd equivalent to that observed for authentic estrogen receptors in other estrogen responsive tissues. Scatchard and Hill plot analyses of the properties of receptor-ligand binding indicate the presence of a single site, and the absence of cooperative binding. Unlabeled E2 but not testosterone, dexamethasone or progesterone compete with [3H] 17 beta-estradiol for binding sites. The affinity, specificity and non-cooperative nature of the estrogen binding sites are identical to those observed in other estrogen-responsive tissues. These cells may provide a novel model in which to study the effects of estrogens on the proliferation, differentiation and function of vascular smooth muscle cells.
Bei
M
M
Department of Physiology and Biophysics, Georgetown University Medical School, Washington DC 20007, USA.
Lavigne
M C
MC
Foegh
M L
ML
Ramwell
P W
PW
Clarke
R
R
D000818:Animals; D001665:Binding Sites; D001667:Binding, Competitive; D001943:Breast Neoplasms / Q000378:metabolism; D003331:Coronary Vessels / Q000166:cytology / Q000378:metabolism*; D003907:Dexamethasone / Q000378:metabolism; D004958:Estradiol / Q000378:metabolism*; D006801:Humans; D007700:Kinetics; D008024:Ligands; D009131:Muscle, Smooth, Vascular / Q000166:cytology / Q000378:metabolism*; D011374:Progesterone / Q000378:metabolism; D012333:RNA, Messenger / Q000032:analysis; D051381:Rats; D011960:Receptors, Estrogen / Q000235:genetics / Q000378:metabolism*; D013739:Testosterone / Q000378:metabolism; D014407:Tumor Cells, Cultured
D008024:Ligands; D012333:RNA, Messenger; D011960:Receptors, Estrogen; D013739:Testosterone; D011374:Progesterone; D004958:Estradiol; D003907:Dexamethasone