Unique molecular properties of a urea- and salt-stable DNA-binding estrogen receptor dimer covalently labeled with the antiestrogen [3H]desmethylnafoxidine aziridine. A comparison with the estrogen-receptor complex.

A new antiestrogen affinity ligand for the covalent labeling of estrogen receptors, [3H]desmethylnafoxidine aziridine, has been used to investigate the salt- and temperature-independent formation of DNA-binding estrogen receptor forms from untransformed (300 kilodaltons) receptor. Calf uterine estrogen receptor proteins labeled with [3H]estradiol or [3H]desmethylnafoxidine aziridine were quantitatively transformed (greater than 90%) to their DNA-binding configuration in low ionic strength buffers by brief exposure to 3 M urea at 0 C. The urea effect was hormone-dependent and partially reversible.

Temporal relation of ovulation to salivary and vaginal electrical resistance patterns: implications for natural family planning.

An independent assessment of the CUE Monitor (Zetek, Aurora, Colorado) as an ovulation predictor was made with emphasis on its potential role in "natural family planning". The device provides a digital measurement of the electrical resistance of saliva and vaginal secretions. Twenty-nine menstrual cycles from 11 regularly cycling women were monitored with basal temperatures, urinary LH, pelvic ultrasound and the CUE monitor.

Plasma gonadotropin-releasing hormone profiles after intravenous and subcutaneous bolus injection in thin and obese women.

Other studies of plasma gonadotropin-releasing hormone profiles after bolus injection have revealed earlier, sharper peaks and higher blood gonadotropin-releasing hormone levels with the intravenous (IV) than with the subcutaneous route of administration. We used both routes to administer gonadotropin-releasing hormone by bolus injection to thin and obese subjects. Plasma gonadotropin-releasing hormone profiles after IV administration were similar in both groups.

Proteins associated with untransformed estrogen receptor in vitro. Perturbation of hydrophobic interactions induces alterations in quaternary structure and exposure of the DNA-binding site.

Estrogen receptors from calf uteri have been analyzed by high-performance size-exclusion chromatography, chromatofocusing, and DNA affinity chromatography using conditions designed to evaluate the relative contribution of hydrophobic interactions between the steroid-binding subunit and other receptor-associated proteins. The single large (untransformed) species of soluble estrogen-receptor consistently (n = 9) found in calf uteri displayed a rapid change in Stokes radius from 8.0 to 3.