Stromal progesterone receptors mediate the inhibitory effects of progesterone on estrogen-induced uterine epithelial cell deoxyribonucleic acid synthesis

The role of epithelial and stromal progesterone (P) receptors (PR) in the regulation of uterine epithelial DNA synthesis by P was investigated by analyzing the four types of tissue recombinants prepared with uterine stroma (S) and epithelium (E) from wild-type (wt) and PR knockout (PRKO) mice: wt-S + wt-E, PRKO-S + PRKO-E, wt-S + PRKO-E, and PRKO-S + wt-E. 17-Beta estradiol (E2) stimulated DNA synthesis in all four types of tissue recombinants. On the other hand, P inhibited E2-induced DNA synthesis only in tissue recombinants prepared with wild-type (PR-positive) stroma (wt-S + wt-E or wt-S + PRKO-E) but not knockout (PR-negative) stroma (PRKO-S + wt-E or PRKO-S + PRKO-E). These results clearly demonstrate that the inhibitory effect of P on uterine epithelial DNA synthesis is mediated by stromal PR. Epithelial PR is neither necessary nor sufficient for P inhibition of E2-induced epithelial DNA synthesis.     

Ultrastructure of the uterine epithelium of mice treated neonatally with estrogen

In neonatally estrogenized mice, uterine epithelial cells possessed a few microvilli on the fuzzy-appearing apical surface, regardless of the presence or the absence of estrogen. The cells showed well-developed rough endoplasmic reticulum and a large number of mitochondria, suggesting that the cells were actively functioning. At 13 months of age, the uterine epithelium of neonatally estrogenized mice was sometimes stratified and squamous. Spherical basal cells like those appearing in cancerous vagina in estrogen-treated mice made their appearance. These cells may have the capacity of autonomous proliferation.     

Induction of progestin receptors by estradiol in the forebrain of estrogen receptor-alpha gene-disrupted mice

Mice, rats, and humans have two types of estrogen receptors, estrogen receptor-alpha (ERalpha) and estrogen receptor-beta (ERbeta). Estrogen receptor-alpha gene-disrupted (ERalpha-disrupted) mice bear two nonfunctional copies of the ERalpha gene. This mutation blocks the synthesis of full-length ERalpha, renders the animals infertile, and inhibits the induction of female sexual behaviors by estradiol and progesterone. It is likely that many of the processes contributing to the regulation of sexual receptivity by estradiol and progesterone are compromised in ERalpha-disrupted mice. However, given the importance of progesterone in the regulation of sexual receptivity and given the importance of progestin receptors (PRs) in mediating the responses of females to progesterone, we investigated the effects of ERalpha disruption on the induction of PRs by estradiol in the forebrain. We hypothesized that estradiol would induce PRs in wild-type mice but not in ERalpha-disrupted mice. Ovariectomized wild-type and ERalpha-disrupted mice were implanted with either estradiol-filled capsules or empty capsules for 5 d, after which their brains were processed for the immunocytochemical detection of PR. Estradiol increased the number of PR-immunoreactive cells in both wild-type and ERalpha-disrupted mice. The residual responsiveness of ERalpha-disrupted mice to estradiol could be accounted for by an ERbeta-dependent mechanism or another as yet unidentified estrogen receptor; however, because ERalpha-immunoreactivity and PCR product representing the 3' end of ERalpha mRNA were found in at least one PR-containing region of the ERalpha-disrupted mice, an ERalpha splice variant may also mediate the induction of PR-immunoreactivity in ERalpha-disrupted mice.     

Binding characteristics of novel nonsteroidal antiestrogens to the rat uterine estrogen receptors

Tamoxifen (TAM), the only antiestrogen currently available for the endocrine therapy of breast cancer behaves as a mixed agonist/antagonist of estrogen action, thus limiting its therapeutic potential. We report the binding characteristics of a novel series of nonsteroidal antiestrogens to the rat uterine estrogen receptor. As measured by competition studies, the affinity of EM-652, the active metabolite of the prodrug EM-800, for the estrogen receptor is 7-11 times higher than that of 17beta-estradiol (E2), ICI 182780, and hydroxy-tamoxifen (OH-TAM), the active metabolite of Tamoxifen. EM-652 is 20x more potent than ICI 164384 and Droloxifene while it is 400 times more potent than Toremifene in displacing [3H]E2 from the rat uterine estrogen receptor. On the other hand, the prodrug EM-800 and Tamoxifen have respectively 150-fold and 410-fold less affinity for the estrogen receptor than the pure antiestrogen EM-652. No significant binding of EM-652, EM-800, TAM or OH-TAM was observed to the rat uterine progesterone receptor at concentrations up to 10,000 nM except for TAM that caused a 50% displacement of labeled R5020 at 4000 nM. No significant binding of EM-652 or EM-800 was observed on the rat ventral prostate androgen receptor or the rat uterine progesterone receptor. The present data demonstrate the high affinity and specificity of the new antiestrogen, EM-652, for the rat uterine estrogen receptor. The antiestrogen EM-652 thus becomes the compound having the highest known affinity for the estrogen receptor. Due to its unique potency and its pure antiestrogenic activity already demonstrated in many systems, this antiestrogen could well offer an important advance for the endocrine therapy of breast cancer, uterine cancer, and other estrogen-sensitive diseases in women.     

Characterization of the estrogen receptors in the uterine and blood eosinophil leukocytes

Estrogen receptors are found in the rat uterine and in the eosinophil-rich human blood leukocyte 24,000 g fractions, but not in the low-eosinophil count human blood leukocyte 24,000 g fraction. The total number of binding sites per blood eosinophil leukocyte is 7,400 sites per cell, and the Kp=5.6 X 10(-10) M.     

Adrenomedullin and CGRP receptors mediate different effects in the rat adrenal cortex

Adrenomedullin (AM) exerts its effects through two distinct receptor subtypes: the AM receptor, and the CGRPI receptor. In most tissues activation of these subtypes brings about similar effects, with only the magnitude of the effect varying. In the rat adrenal cortex, however, this does not appear to be the case. Both CGRPI and AM receptors are present in the rat adrenal cortex. Incubation of zona glomerulosa cells with AM caused an increase in aldosterone secretion, but AM had no effect on angiotensin II-stimulated aldosterone secretion. The action of AM was not affected by CGRP8-37, the CGRP receptor antagonist, suggesting that its effect was mediated by the adrenomedullin receptor. CGRP on the other hand, did not significantly affect basal aldosterone although it attenuated the response to angiotensin II. These data suggest that the CGRP receptor and the AM receptor mediate different effects in the rat adrenal zona glomerulosa.     

Development of a microassay for estradiol receptors

The calculation of equilibrium binding constants for a specific receptor-hormone interaction requires the exact determination of the unbound ligand concentration and the specifically bound concentration at equilibrium. These determinations usually require corrections for the contribution of non-specific binding. We introduce several parameters allowing equilibrium concentrations to be calculated from experimental concentration values; these parameters can be measured for the particular receptor assay procedure used. These parameters are used in a microassay of estradiol-receptor complex by selective retention on DE-81 cellulose paper.     

Changes in uterine estrogen and progesterone receptors during delayed implantation and early implantation in the spotted skunk

Although the exact cause(s) of embryonic diapause in the western spotted skunk and other carnivores remains unknown, it has been hypothesized that it may be due to levels of ovarian hormone secretion that are insufficient to promote a uterine environment conducive to continuous embryonic development and implantation. Immunocytochemistry was used to determine whether changes in abundance or distribution of estrogen receptors (ER) and progesterone receptors (PR) may be associated with the cessation or renewal of embryonic development. Thirty pregnant skunks were killed during delayed implantation and periimplantation periods. ER and PR were detected in luminal and glandular epithelium, endometrial stroma, vasculature, and myometrium of the uterus during the period of delayed implantation. There was a significant reduction of both ER and PR receptors during the periimplantation period. The most pronounced change was the complete loss or reduction in staining intensity for PR and ER in the luminal epithelium during the first 2-3 days after implantation. These findings suggest that the failure of skunk blastocysts to undergo continuous development and implant without a prolonged period of diapause is not the result of an insufficient number of ER or PR in the uterus. The data also indicate that renewed embryonic development and implantation is not associated with an increase in these uterine steroid receptors.     

Ultrastructural studies of prepubertal porcine uterine tube epithelium

Ultrastructural details of prepubertal porcine uterine tube (oviduct) were studied in normal, growing gilts and compared with observations reported in other species. Tissues from the ampulla region of uterine tube were taken from 6 prepubertal gilts (106 to 139 days old) to determine cytodifferentiation of ciliated and secretory cells. The epithelium consisted of 2 distinctive cells, the ciliated and the secretory cells. Cilia were observed in the uterine tube of prepubertal gilts; however, degeneration of cilia was not observed in the present study. Most prominent observations were the occurrence of fibrous granules in the apical cytoplasm of ciliated cells. These fibrous granules contained electron-dense material and were present near basal bodies. The most unusual feature was the occurrence of procentrioles around a condensation form. These data indicate that ciliated cells are sensitive to estrogen. Intimate morphologic association between fibrous granules and basal bodies indicate that fibrous granules might provide precursor material for the development of cilia and rootlets. The cytoplasm of the secretory cells contained rough endoplasmic reticulum of tubular form and numerous ribosomes. Evidence for synthesis, storage, and release of secretory granules was not apparent. It is suggested that the secretory cells are not sensitive to the low, circulating concentration of plasma estrogen. The ultrastructure of the stromal cells and lymphatic capillary was described for the 1st time. The uterine tube stromal cells were characterized by prominent nucleus and a few cytoplasmic organelles. The lymphatic capillaries were distinguished by the blood capillaries, their much wider lumen, endothelium with an attenuated cytoplasm, absence of basal lamina, and overlapping and interdigitating intercellular junctions. The fine structure of the porcine uterine tube lymphatic capillary generally resembled that of other mammalian species.     

The vagina: effects of progesterone pretreatment and neonatal treatment with estrogen or androgen on [3H] estradiol retention

The paper deals with efficiency of sodium selenite in case of acute damage of the liver in rats as well as with its effect on main functions of the liver in norm and pathology, especially on biligenesis, synthesis and secretion of bile acids, bilirubin and cholesterol. The preparation in doses of 1 and 10 Mg per 100 g of weight is established to produce a normalizing effect of intensity of biliation synthesis and secretion of bile acids, secretion of bilirubin and excretion of cholesterol in the animals with the affected liver. The preparation has a cholagogic effect as well. In the healthy rats sodium selenite increases the intensity of bile secretion, intensifies synthesis and secretion of bile acids and bilirubin. A stimulating effect of the preparation on biligenesis is maintained with the liver dystrophy induced by carbon tetrachloride and polychlorines as well. Under these conditions it is manifested to a greater extent than in the healthy animals.     

Interaction of estradiol, progesterone and corticosterone on uterine connective tissue degrading enzymes

The impact of ovarian hormones and corticosterone acetate on uterine connective tissue degrading enzymes were studied in mature albino rats. Ovariectomy resulted in a significant increase in the activities of alpha- and beta-galactosidases and glucosidases in the uterus. Administration of estradiol to ovariectomized rats brought back the activities of alpha-galactosidase and alpha-glucosidase to normalcy. While beta-galactosidase and beta-glucosidase were significantly decreased. Administration of progesterone to ovariectomized rats resulted in the increase of alpha- and beta-galactosidases and glucosidases. Administration of corticosterone to ovariectomized rats produced a further increase in alpha- and beta-galactosidases and glucosidases in the uterus. Adrenalectomy in ovary intact rats produced a decrease in alpha-galactosidase however, beta-glucosidase was significantly increased. Administration of corticosterone to ovary intact rats significantly increased the activities of alpha- and beta-galactosidases, while alpha- and beta-glucosidases were found to be decreased. Ovariectomy resulted in a significant increase in the activities of cathepsin-D and cathepsin-E. Administration of estradiol to ovariectomized rats brought back the activity of cathepsin-D to normalcy, whereas cathepsin-E was significantly increased. Administration of progesterone as well as estradiol to ovariectomized rats significantly increased the levels of cathepsin-E, however, cathepsin-D was brought back to normalcy. Administration of corticosterone to ovariectomized rats as well as ovariectomy + adrenalectomy significantly increased the activity of cathepsin-D and cathepsin-E. Adrenalectomy significantly decreased the activity of cathepsin-D, while administration of corticosterone increased the cathepsin-D and cathepsin-E in the uterus. Therefore, these results suggest that estradiol is a potent ovarian steroid protecting the extra cellular matrix components. The effect of progesterone appears to modulate and act hand in hand with estradiol. Corticosterone appears to have an opposite effect to that of estradiol.     

Immunohistochemical study of estrogen receptor and estradiol on papillary thyroid carcinoma in young patients

The Winnipeg Rh Laboratory has reviewed its experiences with maternal CW alloimmunization. From September 24, 1956, to March 31, 1992, 12 women with significant CW alloimmunization underwent 18 pregnancies. In 3 (4 pregnancies) the antibody, despite its strength, was 'naturally occurring' (i.e. there was no known exposure to CW-positive red cells). The remaining 9 women (14 pregnancies) had CW-positive husbands. Two had CW-negative babies and a third infant, probably CW negative, was stillborn and macerated at 43 weeks gestation. Eleven babies were CW positive and had hemolytic disease of the newborn (HDN), with antiglobulin-positive red cells. Five did not require treatment; 2 needed phototherapy only, and 4 (born between 1956 and 1963) required exchange transfusions. No anti-CW screening was carried out until 1977; thereafter it was sporadic, 11 of 51 screening red cells being CW positive in the 39-month period ending March 31st, 1992. From November 1, 1977, to March 31, 1992, 24 women (30 pregnancies, 31 conceptuses) with insignificant anti-CW alloantibodies were identified. Extrapolating these figures to the entire period from September 24, 1956, to March 31, 1992, we estimate that at least 430 women (at least 573 pregnancies) were CW alloimmunized, most of the antibodies being 'naturally occurring'. Only 2% of the conceptuses were CW positive and affected; none were severely affected. Anti-CW is relatively common, occurring in about 1 pregnant Manitoban woman in 1,100. On very rare occasions (11 times in Manitoba in 36 years and 5 months) anti-CW HDN occurs which, although not severe, may end in kernicterus with brain damage or neonatal death unless it is detected promptly and treated appropriately.     

Melatonin receptors mediate contraction of a rat cerebral artery

Melatonin receptors are expressed in the cerebral arteries of the rat which form the circle of Willis. We report here that melatonin induces contraction of in vitro preparations of pressurized rat posterior communicating artery, in a concentration-dependent manner. This action of melatonin is inhibited by S-20928, a specific melatonin receptor antagonist. Our results demonstrate that the contractile action of melatonin is mediated by its receptors in the cerebral artery, and suggest a role for melatonin in the regulation of cerebral circulation.     

Stromal sarcoma of the uterine body in an 18-year old girl

The authors describe diagnostic difficulties connected with proper estimation of stromal sarcoma biological activities, which developed in uterus corpus in 18 years old girl previously treated with hormones, because of irregular painful menses. Macroscopic and microscopic investigations of postoperative specimen allowed to set final diagnosis: stromal sarcoma with intermediate grade of malignancy, which showed an aggressive growth in the surrounding tissue and demonstrated moderate, focal polymorphism and different amounts of the mitoses in different areas.     

Study on estrogen and progesterone receptors in endometriosis and adenomyosis

Estrogen and progesterone receptors (ER and PR) in 18 cases of ovarian endometriosis and 13 cases of adenomyosis were determined with dextran coated charcoal (DCC) method. The levels of ER and PR in those specimens were lower than those of normal endometrium. Among the 18 cases of ovarian endometriosis, 6 (33.4%) were negative for PR, which accounted for the unsatisfactory results of progesterone treatment for some endometriosis. In the 13 cases of adenomyosis there were 10 (76.9%) showing positive PR. It is suggested that the hormone therapy may be useful to treat those young patients with adenomyosis instead of surgery. The correlation of the ER and PR levels, the treatment and prognosis in endometriosis and adenomyosis are worth further studying.     

Effects of estradiol on in vitro nucleoside incorporation and methylation of rat uterine ribonucleic acid

The in vitro nucleoside incorporation and methylation of uterine RNA was examined by incubating immature rat uteri with either 3H-uridine, 3H-uridine-3H-cytidine, and/or 14C-methyl-methionine. Radioactivity was determined in extracted RNA which was fractionated by gel electrophoresis or by differential solubility in zine acetate or lithium chloride. Estradiol (E2)-treated uteri respond by showing a maximum in vitro incorporation of nucleosides into total RNA and high M.W. RNA within one hr of in vivo treatment. Nucleoside incorporation into low M.W. RNA increased gradually throughout the first 3 hrs of a 4-hr hormone treatment period. E2 in vivo also caused increased in vitro methylation of total, high, and low M.W. uterine RNA fractions. Methylation of all fractions increased through the first 3 hrs of hormone treatment, but greater methylation of low M.W. RNA was apparent. The data indicate that in vivo E2 treatment stimulates an initial transitory stage of in vitro nucleoside incorporation into uterine RNA followed by a more prolonged interval of RNA methylation.     

Endothelin-A receptors mediate vasoconstriction of capillaries in the spiral ligament

The purpose of this study was to determine whether endothelin-1 (ET-1), endothelin-2 (ET-2) or endothelin-3 (ET-3) alter the vascular diameter of capillaries in the spiral ligament. Changes in vascular tone were measured in capillaries from the isolated spiral ligament in vitro. Capillaries were occluded on one end and opened on the other end. Red blood cells trapped in the capillaries served as markers for a luminal volume defined by the red cell itself, the capillary wall and the occluder. Movement of the red cell toward the open end was taken as evidence for vasoconstriction and movement of the red cell toward the occluder was taken as evidence for vasodilation. The inner diameter of the capillaries was 7.0 microm and decreased maximally by a factor of 0.8 in response to ET-1 and ET-2 (both 10(-8) M). Vasoconstriction induced by ET-1 and ET-2 was concentration-dependent in the range between 10(-12) and 10(-8) M whereas ET-3 (10(-8) M) had no effect. The EC50s for ET-1 and ET-2 were 1.2 x 10(-10) M and 1.4 x 10(-9) M, respectively. Thus, the potency order was ET-1 > ET-2 > ET-3. Vasoconstriction induced by ET-1 and ET-2 was completely inhibited by the competitive antagonist 10(-6) M BQ-123 (cyclic D-Asp-L-Pro-D-Val-L-Leu-D-Trp). Vasoconstriction induced by ET-1 or ET-2 continued for more than 1 min after removal of agonist from the perfusate. Rapid vasodilation of capillaries preconstricted by ET-1 was observed in response to 10(-3) M sodium nitroprusside. Sodium nitroprusside, however, had no significant effect on the vascular diameter of resting capillaries. These results demonstrate that capillaries in the spiral ligament can constrict and the endothelin-mediated vasoconstriction occurs via ET(A) receptors.