Distribution and characterization of steroid hormone receptors in human thyroid tissue

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Abstract
The incidence and molecular characteristics of cytosolic steroid receptors for estrogen (ER), androgen (AR), progesterone (PR), and glucocorticoid (GR) were analyzed in human thyroidectomy specimens. All assays were performed by a protamine sulfate precipitation technique and analyzed by the method of Scatchard. Selected specimens were analyzed by sucrose density gradient. A receptor content over 1 fmol/mg cytosol protein was taken as positive. Estrogen was found in 23 of 45 specimens including 8 of 8 papillary cancers. Mean ER content (Rc) was 29.8 ±6.7 fmol/mg cytosol protein with a dissociation constant (Kd) of 0.23 ±0.09 × 10−10M. The Rc of ER was higher in neoplastic than non‐neoplastic thyroid tissue. Androgen was found in 19 of 41 specimens, including 6 of 8 papillary cancers. Mean Rc for AR was 10.6 ± 7.1 fmol/mg cytosol protein with a Kd of 0.17 ± 0.11 × 10−10. The incidence of ER and AR was significantly higher (pc for PR was 6.2 ± 2.9 fmol/mg cytosol protein with a Kd of 0.03 ± 0.02 × 10−10M. Glucocorticoid was found in 6 of 26 specimens. Rc for GR was 6.3 ± 2.3 fmol/mg cytosol protein with a Kd of 0.11 ± 0.05 × 10−10M. By sucrose density gradient, a 4S and 8S type of ER was identified, while AR was predominately 6S, and GR was predominately 8S. The steroid receptors identified were a single‐class, high‐affinity, and saturable similar to those found in other steroid hormone dependent tissues. These findings suggest that steroid hormones may influence the development and growth of thyroid tumors.