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Plasma concentrations of protein hormones (LH, FSH, prolactin) and steroid hormones (estradiol, progesterone, testosterone, cortisol) have been assayed during the follicular and luteal phase of the cycle in patients with benign cysts and endometrioid cysts of the ovaries. Endometrial estradiol and progesterone receptors were also examined in these patients in the midluteal phase. These studies described steroid and gonadotropic hormone secretion of both the luteal and follicular phase in the two populations, as well as steroid receptors of the secretory endometrium. The most serious abnormalities were found in the endometrium of the patients with endometrioid ovarian cysts. These disorders suggest their relationship with infertility in the patients with benign ovarian neoplasms.

Patients with ovarian endometriosis have been examined during the follicular and luteal phase of the ovulatory and the second phase of the anovulatory cycles. Estradiol and progesterone blood concentrations measured on operation days and during the respective ovulatory phases were in a normal range. Ovulation and endometrial hyperplasia reduced basal progesterone concentrations. Comparison of findings on steroid receptor systems in the endometrium and endometrioid ovarian cysts indicated that they were identical. The findings were different in ovulation and endometrial hyperplasia. These patterns provided criteria for endometrial response to female sex hormones by assaying endometrial intracellular steroid receptor systems in normally ovulating patients with ovarian endometriosis.

Specificity of interaction between estrogen-receptor systems of guinea pig uterus and oviducts and six estrogens was studied. The obtained datas suggest existence of tissue specificity in estrogen-receptor interaction in uterus and oviducts. Modifications of the steroid molecule led to decrease in extent of estrogen affinity. Introduction of an ethyl group into 17 alpha-position resulted in the effect, by the rate of estrogen-receptor binding equal to reduction of 17 beta-hydroxyl. Low but distinct affinity of 17 alpha-estradiol, its structure and stability, enabled to select this substance as a preparation with anticipated anti-estrogenic activity.

Quantity of estrogen- and progesterone-specific binding sites was measured in endometrial tissues of 10 females treated with danazol during 3 month in a dose of 400 mg per day after surgical treatment for endometriosis. It was demonstrated that the amount of estrogen receptors in endometrium of the patients was the same as in endometrial tissue of healthy females but the quantity of nuclear progesterone receptors was markedly increased.

Equilibrium binding of labeled estron, estradiol, estriol and DES was studied in uterine cytosol of immature Wistar rats. The dissociation kinetics of the ligand complexes with specific high affinity sites suggested the homogeneity of estrogen receptors in rat uterine cytosol. The feasibility of intracellular regulation of estrogen action in target cells both at the receptor and post-receptor levels is discussed.

The authors described a simple and economic modification of the competitive protein binding method of cortisol determination in human blood plasma satisfying the current requirements presented to the saturation analysis. Blood plasma of women given combined contraceptive the preparation was used as a binding system. Analysis of experimental results using a programmed computer was carried out on the basis of standard curve linearization. Preeision sensitivity and specificity of this modified method are assessed. This modification was approved in measuring the cortisol level in the blood plasma of various groups of patients. Comparison with routine competitive binding methods and their analysis is presented.

The presence of a specific receptor system (E2-R) wthith low capacity and high stability of the E2-R complex formation was shown in the guinea pig adenohypophysis and anterior hypothalamus cytozols under the vivo and in vitro conditions. Some parameters of the physico-chemical properties of the E2-R system in these tissues differed. The adenohypophysis and the anterior hypothalamus receptor complexes formed at different temperatures were not identical.

In order to elucidate whether specific estrogen-binding sites were heterogeneous, these sites were studied in uterine cytosols of guinea pig and green monkey Cercopithecus griseus. Concentrations of the estrogen-binding sites for labelled estrogens (estrone, estradiol, estriol and diethylstilbestrol) were estimated in the cytosols by means of the exchange method and Scatchard plot analysis. High linear correlation was shown between the Scatchard plots and the curves of estrogen-binding site complexes dissociation plotted in semilogarithmic coordinates (r-0.98 and 0.99, respectively; p less than 0.05). The linearity of the curves was confirmed by means of F-criterion. The data obtained suggest that only one type of specific estrogen-binding sites occurs in the cytosols at 30 degrees and at concentration of estrogens which did not exceed 50 nM. These estrogen-binding sites exhibited the same limited binding capacity for all the estrogens studied.

Kinetic and thermodynamic parameters of the estradiol receptor (E2-R) interact in the guinea pig oviduct cytozol were studied. Specificity of the receptor system was characterized by measurment of the affinity of 14 compounds to the system. It was shown that the guinea pig oviduct R-system had a high affinity to E2 and a limited capacity. Free energy change value (52 KJ/mol) indicated stability of the complex formed. Activity of the steroid-receptor (S-R) complex formation is determined by the presence of the intact hydroxils in positions 3 (phenolic) and 17-beta of the steroid molecule; dependence of the S-R interaction rate on the different steroid molecule modifications at a number of positions supports this point. Besides, the immediate enviroment of hydroxils in positions 3 and 17 beta also influences the S-R interaction rate. Some properties of the nonsteroid diethylstilbestrol estrogen attract attention.

Physico-chemical parameters (the rate constants of association and dissociation, half life of the estradiol-receptor complex, equilibrium constant, alteration of free energy of the bond) of estradiol-receptor interaction were studied in cytosole in human Fallopian tubes. Amounts of the cytoplasmic binding sites per cell were estimated. Specific interaction of the tube cytosole receptor system with 13 substances was examined. Steroid-receptor reaction has mainly been determined by presence of hydroxyl groups in the 3-d phenol and 17beta-positions. Nearest surroundings at the hydroxyls was also important for manifestation of the affinity of the steroids to the system studied.

The interaction of promegestone (R-5020), progesterone (P) and its derivatives having and additional carbocyclic D' (pregna-D'-pentrans) with progestin-binding cytosol system of the uterus was studied in different species (rabbits, rats, guinea-pigs and men). A comparative analysis of the competitive binding data for the mentioned compounds has shown interspecies differences in ligand specificity. Two types of binding sites for 3H-D'-pentran (in contrast to R-5020 and P) have been detected in rabbit uterus cytosol, both in intact and estrogenized animals. However, in rabbits, estrogenization altered the values of the apparent equilibrium constants and binding capacities. At the same time, the interaction of pentran with progestin-binding sites in guinea-pig and human uterus cytosol is nonspecific. It is suggested that the features of the interaction of 3H-D'-pentran with its binding sites in rabbit uterus cytosol may be determined by an increase in hydrophobic bond.

A comparative study of binding of labelled estrone, estradiol, ethinylestradiol and estriol was conducted in uterine cytosol of postmenopausal women.

The specificity of estrogen-receptor (ER) interaction was studied in cytosols of the adenohypophysis and anterior hypothalamus of guinea-pigs. The fundamental condition of active ER binding was shown to be the integrity of 17 beta- and C3-positions of the estradiol molecule excepting compounds with the combination of 17 beta-OH and 17 alpha-ethinyl groups. Significant differences were demonstrated in the affinity of the test compounds to ER systems of hypophyseal and hypothalamic cytosols.