Oestrogen binding sites in fresh human aortic tissue.

Biopsies of aortic tissue were obtained from patients undergoing heart surgery, and were tested for oestrogen binding sites. Tests were carried out using a 7 + 1-point dextran-coated charcoal method, and receptors were quantified both in the cytoplasmic and in the nuclear fractions using Scatchard plot analyses. Tests yielded positive results in 8 cases out of 13 (cytosol fraction) and in 10 cases out of 13 (nuclear fraction). Receptors showed high affinity for oestrogens, the Kd values ranging from 10(-11) M to 10(-10) M. These findings therefore suggest the occurrence of oestrogen receptors in human blood-vessels.