Immunologically distinct binding molecules for progesterone and RU38486 in the chick oviduct cytosol

[3H]Progesterone and [3H]RU38486 binding in the chick oviduct cytosol is associated with macromolecules which sediment as 8 S and 4 S moieties, respectively, in molybdate-containing 5-20% sucrose gradients. The [3H]progesterone binding could be displaced by excess progesterone, but not by RU38486. Conversely, the [3H]RU38486 binding was able to compete with RU38486 but not by excess progesterone. A preparation containing antibodies against chick oviduct progesterone receptor recognized only the [3H]progesterone-receptor complex but not the 4 S, [3H]RU38486 binding component of the chick cytosol. In the calf uterus cytosol, [3H]R5020 (a synthetic progestin) and [3H]RU38486 were associated with 8 S molecules and the peaks of radioactivity were displaceable upon preincubation with radionert steroids. In addition, the complexes were recognized by antibodies to chick oviduct progesterone receptor. Our data suggest that in the chick oviduct cytosol, RU38486 does not bind to progesterone receptor, but interacts with an immunologically distinct macromolecule.

The effects of ischemia on estrogen and progesterone receptor profiles in the rodent uterus

Ischemia is considered to invalidate the estrogen receptor (ER) and progesterone receptor (PR) values of tissues available for steroid hormonal analysis. To evaluate the temporal effect of devascularization on steroid receptors, complete uterine ischemia was induced in vivo in 64 female Buffalo rats (80-154 g). Animals were assigned to varying intervals of ischemia (0-90 min) and were maintained at a constant ambient (75 degrees F) and core-body temperature (100-102 degrees F). Following tissue preservation at -80 degrees C, multipoint titration of steroid binding capacity (SBC) was performed with [3H]estradiol 17-beta (3-0.15 nM) or [3H] R5020 (8-0.4 nM) in the presence or absence of a 200-fold excess of an unlabeled ligand. Applying nonlinear regression analysis, ischemia was observed to decrease the binding capacitance for both ER and PR profiles of rodent uterine tissues at 30 min with significant decay over the 90-min interval of devascularization (ER, P less than 0.01; PR, P less than 0.1). Significant reduction in SBC was evident after 80 min of ischemia for PR (P less than 0.05) and 90 min of tissue ischemia for ER (P less than 0.05) comparative to control (t0) valves. The detrimental effect of progressive ischemia on ER and PR values was such that it appears essential to assure rapid and reliable tissue aliquot preservation techniques when organ ischemia greater than or equal to 90 min is anticipated.

Estrogen receptor purification by affinity chromatography using an orange triazine dye

A rapid two-step procedure was devised for the purification of the estrogen receptor from the calf uterus. A 900- to 1700-fold purification of the estrogen receptor was obtained using ammonium sulfate precipitation followed by dye affinity chromatography with Reactive Orange 14 immobilized to Sepharose. The Reactive Orange 14-Sepharose was used to purify the estrogen receptor in the presence or absence of estradiol as well as to purify the progesterone receptor. The purified estrogen receptor retained its estradiol- and DNA-binding properties and sedimented into sucrose gradients as the 5 S receptor dimer. The Reactive Orange 14-Sepharose is easily prepared and offers a higher yield and purity of the estrogen receptor than that afforded by estrogen- or heparin-Sepharose chromatography.

Characterization of myosin heavy chains in cultured aorta smooth muscle cells. A comparative study

Myosin heavy chains (MHCs) from rat aorta smooth muscle cells were analyzed prior to and after these cells were placed into cell culture using sodium dodecyl sulfate-5% polyacrylamide gels, immunoblots, and two-dimensional peptide maps of tryptic digests. Rat aorta smooth muscle cells prior to culture were found to contain two MHCs (mass = 204 and 200 kDa) which cross-reacted with antibodies raised to smooth muscle myosin, but not with antibodies raised to platelet myosin. Tryptic peptide maps of these two MHCs showed no major differences when compared to each other and to maps of vas deferens and uterus smooth muscle MHCs. When rat aorta smooth muscle cells were placed into culture, the MHCs isolated from the cell extracts differed, depending on whether the cells were rapidly growing or postconfluent. Extracts from log-phase cultures contained predominantly MHCs that migrated more rapidly than smooth muscle myosin in sodium dodecyl sulfate-polyacrylamide gel electrophoresis (mass = 196 kDa) and cross-reacted with antibodies raised to platelet myosin, but not to smooth muscle myosin. Tryptic peptide maps of this MHC were very similar to those obtained with MHCs from non-muscle sources such as platelets and fibroblasts. In contrast, extracts from postconfluent rat aorta cell cultures contained three MHCs (mass = 204, 200, and 196 kDa). Using immunoblots and peptide maps, the fastest migrating MHC was found to be identical to the 196-kDa non-muscle MHC, while the two slower migrating MHCs had the same properties as aorta smooth muscle MHCs prior to culture. These results suggest that smooth muscle cells grown in primary culture contain predominantly (greater than 80%) non-muscle myosin while actively growing, but at a postconfluent stage, contain more equivalent amounts of smooth muscle and non-muscle myosins.

Subunit composition of the molybdate-stabilized "8-9 S" nontransformed estradiol receptor purified from calf uterus

The structure of the calf uterus nontransformed molybdate-stabilized estradiol receptor (ER) has been investigated using affinity labeling with tamoxifen aziridine and several monoclonal antibodies directed either against the steroid binding protein (Mr approximately 65,000) or against the heat shock protein of Mr approximately 90,000 (hsp 90). The purification was performed using affinity chromatography and a DEAE-Sephacel column. The [3H] estradiol-ER complex was obtained as a well-defined radioactive peak, the specific activity varying between 1,600 and 3,400 pmol/mg of protein. The purified ER sediments in glycerol gradients at 9.4 S +/- 0.2 (n = 5) and at 8.1 S +/- 0.2 (n = 15) in a 0.15 M KCl containing gradient ("8-9 S" ER). From a measured Stokes radius of 7.4 +/- 0.2 nm (n = 12), an Mr of approximately 300,000 has been calculated. Studies of the purified 8-9 S ER by glycerol gradient centrifugation and by "twin antibody" assay with the JS34/32 anti-ER monoclonal antibody suggest the presence of two binding subunits in the nontransformed molecular complex. Results of immunological analysis with polyclonal and several monoclonal antibodies against hsp 90 suggest the association of two molecules of this protein to the two steroid binding subunits. In high salt medium (0.4 M KCl), the purified ER sediments at 5.2 +/- 0.3 (n = 8), has a Stokes radius of 5.7 nm +/- 0.1 (n = 2) and the Mr is approximately 129,000, values expected for a homodimer consisting of two hormone-binding subunits (Mr approximately 65,000), a result confirmed by glycerol gradient centrifugation experiments, using the monoclonal antibody JS34/32. The relationship between the nontransformed 8-9 S ER and the transformed 5 S-ER forms are discussed, the simplest possibility being the release of the already formed homodimeric ER from 8-9 S ER during transformation.

Extraction of ER and PgR with molybdate

Extraction of ER and PgR with 10 mM molybdate in TEDG buffer greatly facilitated their solubilization and a much higher receptor value was observed. However, since molybdate also affects the hormone receptor binding reaction, the apparent receptor activity assayed with molybdate is different from the actual receptor activity normally assayed without molybdate. A correction factor obtained by assaying cytosol with and without adding molybdate can be used to convert the apparent value into the actual value. The mathematical evaluation involving two separate effects of molybdate on receptors is illustrated.

Identification of a very large nuclear estrogen receptor complex

A high mol wt estrogen receptor complex (mol wt: greater than 669,000) has been isolated from chromatin prepared from mouse uteri with the use of multiple protease inhibitors, exposure to DNAase I, and size exclusion HPLC (SEHPLC). This complex is stable in the presence of molybdate and 0.4 M KCl. Because receptors in the cytosol do not elute similarly to this large complex when investigated under a wide variety of conditions, it is unlikely that random receptor aggregation is responsible for the formation of this nuclear complex. Consequently, this complex may represent a collection of chromatin components that participate in the mechanisms of hormonal regulation. Since the large nuclear receptor complex can be isolated, this hypothesis can be readily subjected to extensive investigation.

Development of pig blastocysts in a uterine environment advanced by exogenous oestrogen

Routine embryo transfer techniques were used to establish recipient groups in which blastocysts were either asynchronous (blastocysts 24 h behind recipient uterus) or synchronous with their uterine environment. Oestradiol valerate (5 mg) was administered on Day 11 of the recipient's cycle to stimulate release of uterine secretion in the synchronous gilts (Group SE) and one group (AE) of asynchronous gilts. The gilts in the other asynchronous group (Group AC) were injected with vehicle (sesame oil). Embryos recovered on Day 14 by hysterectomy and flushing were evaluated for morphological development. Oestradiol treatment resulted in a failure of blastocyst development in Group AE gilts only. Recoverable oestradiol in the uterine flushings was increased in gilts in Groups AC and SE which contained elongated blastocysts. Plasmin inhibitor levels were lower in Groups AC and SE while PGF tended to be increased. Acid phosphatase activity was higher and recoverable Ca2+ was lower in Groups AE and SE. Failure of blastocyst development in Group AE is believed to have resulted from a failure to undergo trophoblastic elongation due to premature alteration of the uterine environment at a critical period of blastocyst development or from the presence of an unfavourable uterine environment for blastocyst attachment and development shortly after Day 12.

Tissue distribution of insulin-like growth factor I and II messenger ribonucleic acid in the adult rat

The insulin-like growth factors (IGFs) have both metabolic and growth-promoting activities in many cell and tissue types. Although the IGFs are present in serum, they are also thought to have important autocrine and paracrine functions. Using complementary DNA (cDNA) probes for rat IGF-I and mouse IGF-II, we have investigated the tissue distribution of messenger RNAs (mRNAs) for these growth factors in adult rats. IGF-I cDNA hybridized with three groups of transcripts, 7.0, 1.8 and 0.7-1.1 kilobases, which were detectable in all tissues examined, with liver demonstrating the highest level of expression. IGF-II cDNA also hybridized to a number of mRNAs, the most abundant of which was 4.0 kilobases. Of the tissues examined, IGF-II expression was highest in the brain, barely detectable in the liver, and undetectable under the conditions used, in lung, ovary, testes, and mammary gland. These studies support the notion of paracrine or autocrine function for IGF-I and demonstrate tissue-specific IGF-II expression in the adult rat.

Decreased concentrations and affinities of oestrogen and progesterone receptors of intrauterine tissue in human pregnancy

Cytoplasmic and nuclear receptors for oestrogen and progesterone were measured in non-pregnant myometrium and endometrium and compared to concentrations found in decidua of ectopic pregnancy (6-8 weeks gestation) and therapeutic abortions (8-16 weeks). Amnion, chorion, placenta, decidua and myometrium at full term pregnancy were also assayed for the same receptors. High affinity binding was confirmed in the non-pregnant tissue; in early pregnancy, decreases in concentrations of cytoplasmic receptors were demonstrated, these decreases becoming more marked as pregnancy progressed in the 1st trimester. Nuclear receptor concentrations were not significantly different. Significant decreases in the occurrence of positive receptors with the progression of pregnancy were also demonstrated for cytoplasmic and nuclear oestrogen and nuclear progesterone receptors. Tissue at full term pregnancy had no detectable receptors, irrespective of whether the patients were in labour or not. Increasing the range of the labelled steroids failed to demonstrate any low affinity binding sites and pre-assay removal of endogenous hormones also had no effect on receptor status. When endogenous hormones were removed, displaceable binding was demonstrated in the presence of excess unlabelled ligand. However, this binding did not conform with receptor dynamics on Scatchard analysis. Heating the cytosol prior to assay or failure to remove endogenous steroid hormones eliminated this binding. Cytosolic oestrogen and progesterone levels increased significantly in the decidua of therapeutic abortions, whilst term pregnant tissue had the highest concentration of endogenous hormones.

Purification of the receptor for platelet-derived growth factor from porcine uterus

The receptor for platelet-derived growth factor has been purified to homogeneity on a large scale from porcine uterus. The purification procedure utilizes solubilization of uterus membranes by Triton X-100, followed by sequential chromatographies on wheat germ agglutinin-Sepharose, fast protein liquid chromatography Mono-Q, and anti-phosphotyrosine-Sepharose. About 160 micrograms of homogeneous and functionally active 170-kDa receptor could be purified from 5 kg of uterus tissue. The pure receptor responded to platelet-derived growth factor stimulation by autophosphorylation, indicating that the receptor has a kinase domain as an integral part of the molecule. A rabbit antiserum was produced against the pure receptor, which specifically recognizes the intact 170-kDa receptor.

A progesterone receptor affinity chromatography reagent: 17 alpha-hexynyl nortestosterone sepharose

Several affinity chromatography reagents have been proposed for purification of progesterone receptor (PgR), and significant results have been achieved with some of these. None, however, have approached the results achieved in affinity chromatography of estrogen receptor. We have therefore synthesized a number of new 19-nortestosterone derivatives capable of chemically stable linkage with Sepharose beads, and have identified one with very high PgR affinity for further study. We first synthesized the epoxides of 17 alpha-allyl nortestosterone, by analogy with the estradiol derivatization of Greene and Jensen. The relative affinity of these epoxides for PgR from T47D human breast cancer cells, however, was only around 5% that of R5020, and affinity beads prepared from them bound very little PgR. We then reacted appropriately protected 17 alpha-ethynyl-nortestosterone with a series of diiodo alkanes, and found that 17 alpha-(6'-iodohex-1'-ynyl)nortestosterone had an affinity of 22% relative to R5020, equal to the affinity of progesterone itself. Reaction with Thiopropyl-Sepharose 6B yielded hexynyl-nortestosterone-Sepharose beads with a ligand density of about 7 micromoles/ml beads. One-hundred microliter of these beads adsorbed 71% of the PgR present in 1 ml of cytosol from T47D cells. This adsorption was inhibited by 10 microM progesterone but not cortisol, indicating the specificity of the binding. Comparisons with NADAC and Sterogel, other affinity beads used for PgR purification, show that the former takes up much less receptor, while the latter takes up and releases similar amounts of receptor but more extraneous protein, and is less stable. We therefore believe that hexynyl-nortestosterone-Sepharose, having a high density of a high affinity ligand, and having chemically and biochemically stable covalent bonds, should be a good reagent for affinity purification of PgR.

(Z)-17 beta-hydroxy-17 alpha-(2-[125I]iodovinyl)-4-estren-3-one: a new specific gamma-emitting ligand for determination of progesterone receptor

An iodine-125 labeled ligand for progesterone receptor determination was synthesized: (Z)-17 beta-hydroxy-17 alpha-(2-[125I]iodovinyl)-4-estren-3-one ([125I]SH-D 510). The ligand is stable chemically as well as under the conditions of a receptor assay. The relative binding affinity of the nonradioactive compound towards human uterine progesterone receptor was 7.0 for the Z-isomer (promegestone (R5020) 1.0) and 0.95 for the E-isomer. 4 S and 8 S receptor forms were obtained on sucrose density gradient analysis. Progesterone receptors were assayed in 103 human mammary tumour cytosols, using either [3H]promegestone or [125I]SH-D 510. The coefficient of correlation was r = 0.951.

Are estrogen receptors cytoplasmic or nuclear? Some immunocytochemical and biochemical studies

The subcellular localization of estradiol receptor (ER) has been examined using various experimental approaches. Immunocytochemical studies using the monoclonal antibody JS 34/32, raised against calf uterine cytosolic ER, yielded only equivocal results. In general, cells and tissues pretreated with estradiol showed positive immunostaining in the nuclei whereas those not exposed to the steroid did not show any staining. Nuclear translocation of ER was examined in intact MCF-7 cells using compounds which are known to influence receptor activation. When MCF-7 cells were exposed to molybdate (20 mM), nuclear translocation was completely inhibited while dithiothreitol (20 mM), dibutyryl cAMP (1 microM) and dibutyryl cGMP (1 microM) increased the translocation 2-3-fold. Phenol red, at the range of concentrations generally used in tissue culture media, also increased translocation. The physiological validity of such translocation was examined using cellular progesterone receptor (PR) synthesis as a specific parameter. When MCF-7 cells were grown in media containing phenol red for 48 h, the PR synthesis increased significantly. We further examined whether cytoskeletal proteins are involved in the translocation of ER. Colchicine, an inhibitor of microtubule assembly, inhibited translocation of ER in MCF-7 cells at 1-10 microM. PR synthesis was also inhibited by colchicine in a dose-dependent manner. It may be concluded from these and other published data that ER may not be located at all times in a single subcellular compartment but may rather exist in a dynamic equilibrium between the plasma membrane, cytoplasm and nucleus.

Characterization of molybdate-stabilized estrogen receptors by hydrophobic interaction HPLC: resolution of two 8S subunits

This report describes the separation and characterization of estrogen receptors (ER) according to their degree of hydrophobicity and surface charges. Molybdate-stabilized [3H]ER from rabbit uterine cytosol was sequentially purified by passage through a size-exclusion pre-column, an anion-exchange column, and a hydrophobic interaction column. With fresh cytosol, a major radioactive peak was eluted from the DEAE columns; a major peak and a minor, less hydrophobic, peak were eluted from the hydrophobic column. In contrast, ER from frozen cytosol showed one peak in the DEAE-column and exhibited four radioactive peaks in the hydrophobic column. By sodium dodecyl sulfate polyacrylamide gel electrophoresis analysis, [3H] tamoxifen aziridine(TA)-labelled ER showed radioactive bands at 62 and 48 kd. The subunits which were characterized by these radioactive bands were successfully separated by the hydrophobic column; the more hydrophobic subunit corresponded to the 62 kd band. The HPLC-purified [3H]TA-labelled ER subunits sediment at a 7.4-8.5S region in a low-salt sucrose gradient. These results show that differential negative surface charge and hydrophobic areas exist in the holo-receptor and its subunits, and the hydrophobic interaction HPLC column separates the two major 8S steroid binding subunits of ER.

Utility of [16 alpha-125I] iodoestradiol for autoradiography for the study of cellular and regional distribution of receptors

We demonstrate the utility of [16 alpha-125I]iodoestradiol for thaw-mount autoradiography with 2 micron and 4 micron thick sections of rat and mouse uterus, pituitary, and brain after in vivo administration. Under the conditions of the experiments, short-term autoradiography with exposure times between 3 and 14 days provides optimal cellular resolution, whereas long-term autoradiography with 1-2 months of exposure may be used to obtain topographic-regional surveys of distribution.

Concentrations of uterine luminal prostaglandins in mares with acute and persistent endometritis

Intrauterine infusion of 1 per cent oyster glycogen solution was used to induce acute endometritis in four genitally normal mares. Numbers of viable neutrophils recovered in uterine washings had increased by 1 h after infusion and remained elevated for at least 72 h. There was a significant correlation between numbers of viable neutrophils and total protein concentrations and between prostaglandin (PG)F and PGE2 concentrations in washings. There was also a significant relationship between concentrations of 15-keto-13, 14-dihydro PGF2 alpha in plasma and PGF in washings. Intrauterine concentrations of PGF were influenced by cycle stage and in turn the induced acute endometritis interfered with normal ovarian function. Mares with persistent endometritis had significantly higher concentrations of PGF and total protein and percentage of neutrophils and mononuclear cells in washings than normal mares. White blood cells from mares were capable of producing PGF and PGE2 in vitro.

Collagen concentration and mast cell in perinatal murine uterus

Edema was found in the uterine tissue on the day of parturition. The number of mast cells was increased significantly on this day, indicating that the time of appearance of the edema is identical to the time of a significant increase in the number of mast cells. These results suggest that mast cells induce the high vascular permeability that permits passage of collagenase-activating proteases to the uterine tissue from the serum.

Triglycerides in isolated rat uterine strips. Influences of glucose deprivation, 2-deoxy-D-glucose, estrogens and exogenous or endogenous prostaglandins E1, E2 and F2 alpha

Triglyceride (TG) levels in uterine strips isolated from natural estrous, ovariectomized or ovariectomized, estradiol-injected rats, were explored. Determinations were performed either immediately after isolation (initial or 0 time) as well as after one hour period of incubation (60 min time) in glucose containing or in glucose-free solution. The influences of indomethacin alone (5 X 10(-6) M) or of indomethacin plus prostaglandins (PGs) E2, E1 or F2 alpha (10(-7) M). delivered in vitro at the beginning of the incubation, and of 2-deoxy-D-glucose (2-DG) at 11.0 mM, were also studied. Ovariectomized animals (25 days); estrous animals or spayed 17-beta estradiol-injected animals (0.5 microgram + 1.0 microgram, 24 hours prior to sacrifice), were employed. At 60 min time in glucose-free medium, but not in glucose containing solution, triglycerides declined significantly in strips from spayed rats, the diminution being prevented by in vitro indomethacin. The presence of exogenous PGF2 alpha or of PGE1, but not that of PGE2, abolished the preventive effect of indomethacin. Initial TG levels in spayed uteri treated with estradiol were significantly smaller that in untreated controls. However, under these conditions, indomethacin alone or indomethacin plus the tested PGs, had no action, the same being evident at natural estrus. In strips from spayed rats and incubated in the absence of glucose but with the presence of 2-DG, the effects of indomethacin and of indomethacin plus exogenous PGs on tissue TG levels were similar, although more evident, than in the sole absence of extracellular glucose. Moreover, TG levels in uterine strips obtained from ovariectomized rats injected with 17-beta estradiol and incubated for 60 min in glucose-free medium plus 2-DG, were smaller than immediately after isolation (0 time), the decrement being prevented by indomethacin, not affected by PGE2 and abolished by PGE1 or by PGF2 alpha. The foregoing results suggest that the diminution of TG in uterine strips incubated in the absence of glucose could be due to a greater metabolic utilization of neutral fats, a phenomenon possibly associated to the lack of exogenous substrate. Moreover, this decrement of tissue TG appears to be linked to the influence of certain PGs and of estrogens, for in ovariectomized, but not in estrous or in spayed-estrogenized conditions, indomethacin prevented the TG decrement in glucose-free solution, whereas PGs E1 and PGF2 alpha abolished the preventive action of indomethacin.(ABSTRACT TRUNCATED AT 400 WORDS)

Molybdate and the molecular properties of the vervet monkey estrogen receptor

The Vervet monkey (Cercopithecus aethiops pygerythrus) uterine estrogen receptor was partially characterised. The effect of the molybdate oxyanion on various molecular properties of the receptor was investigated. Molybdate appeared to affect the subunit structure and apparent heterogeneity of the receptor. Anion exchange chromatography of uterine cytosols yielded two ligand binding subunits in a 1:1 ratio in the absence of sodium molybdate, while only a single labelled complex could be demonstrated in cytosols prepared in molybdate containing buffers. Chromatofocussing of the nonstabilized cytosols revealed substantial receptor heterogeneity (7 peaks) while a much simpler pattern (2 peaks) could be observed in the presence of the molybdate. Likewise, iso-electric focussing of labelled cytosols on agarose gels yielded at least 3 high affinity binding components (pI:6.8, 6.2, 5.9) in the absence and only one major band in the presence of sodium molybdate (pI 5.9).

31P NMR spectroscopy, chemical analysis, and free Mg2+ of rabbit bladder and uterine smooth muscle

31P NMR spectra of isolated rabbit bladder and uterus were obtained under steady-state arterial perfusion in vitro at rest and while stimulated. The spectra contained seven major peaks: phosphoethanolamine, sn-glycero(3)phosphocholine, inorganic phosphate (Pi), phosphocreatine, and the gamma, alpha, and beta peaks of ATP. Chemical analyses, high-pressure liquid chromatography, and NMR spectroscopy of aqueous extracts of bladders identified a number of other components that also made contributions to, but were not resolved in, the spectra of the intact tissues: UTP, GTP, UDP-Glc, NAD+, phosphocholine, and sn-glycero(3)phosphoethanolamine. Intracellular pH of unstimulated bladders and uteri, measured from the chemical shift of the Pi peak, was 7.10 +/- 0.09 S.D. and 7.01 +/- 0.12 S.D., respectively. The chemical shift of the beta-ATP peak in the smooth muscles was significantly upfield (-0.3 ppm) compared to the chemical shift observed in striated muscles (cat biceps and rat myocardium). An ADP peak was identified in stimulated and ischemic bladders. The chemical shifts of the nucleotides observed in perfused bladders were calibrated as a function of free Mg2+ concentration in solutions containing phosphocreatine, Pi, ADP, and ATP at an ionic strength of 180 mM. We derived the following estimates for the intracellular free Mg2+ concentration: uterus, 0.40 mM; unstimulated bladder, 0.46 mM; stimulated and ischemic bladder, 0.50 mM (from the ATP chemical shift) and 0.45 (from the ADP chemical shift); cat biceps, 1.5 mM; and rat myocardium, 1.4 mM.

Type VI collagen is composed of a 200 kd subunit and two 140 kd subunits

We have isolated type VI collagen, a transformation-sensitive glycoprotein of the extracellular matrix, in an intact, disulfide-bonded form. The protein contains a 200 kd subunit and two different 140 kd subunits in a stoichiometric ratio. Based on the amount of hydroxyproline and hydroxylysine, the sensitivity to bacterial collagenase and the cross-reactivity with antibodies to pepsin-extracted type VI collagen, we have identified the 200 kd subunit as the alpha 3(VI) chain and the two 140 kd subunits as the alpha 1(VI) and alpha 2(VI) chains. The alpha 3(VI) chain is synthesized by cells in culture as a precursor of 260 kd, while no precursor form of the other two chains could be detected.

Composition of the fetal and maternal guinea pig throughout gestation

The guinea pig is a small animal species in which the conceptus constitutes a large proportion of maternal weight at term, thereby imposing a major metabolic demand on the mother during pregnancy. In addition the neonatal fat concentration is similar to the human making the guinea pig an interesting model for comparative physiologic study. The purpose of our study was to describe the fetal and maternal physical/chemical growth characteristics of the Hartley albino guinea pig throughout the latter half of gestation. Forty-eight pregnant adult and 122 fetal guinea pigs were sacrificed at intervals throughout gestation and the carcasses analyzed for a variety of growth parameters. The fetal growth rate during the last 8 days of gestation (5.8 g/day) was 9.7 times faster than from 30 to 40 days of gestation (0.6 g/day). The fetal mass comprised 55.4% of the maternal weight gain at term. Fetal energy increased from 403 cal/g at 30 days to 1950 cal/g at term and was paralleled by an increase in fetal fat concentration from 0.3 to 9.8% (wet weight). Nitrogen concentration increased from 0.9% wet weight at 30 days to 2.6% at term. An increasing carbon concentration and carbon:nitrogen ratio was also evident. Fetal water concentration declined from 91.6 to 67.8% during latter gestation. On a wet weight basis, the concentration of fetal sodium remained stable throughout the latter half of pregnancy; potassium, magnesium, iron, calcium, and phosphorus concentrations increased. In contrast to the changes in fetal composition, maternal energy, fat, protein, water, sodium, potassium, calcium, phosphorus, magnesium, and iron concentrations remained relatively constant throughout pregnancy.(ABSTRACT TRUNCATED AT 250 WORDS)

Pharmacokinetics of mitomycin-C in plasma and tumor tissue of cervical cancer patients and in selected tissues of female rats

Mitomycin-C (MMC) is an alkylating agent which has shown significant activity in gynecologic cancers, both in vivo and in vitro. We determined the delivery of MMC to target tissue by comparing plasma and tumor tissue concentrations of MMC as measured by high-performance liquid chromatography (HPLC) in five patients with cervical cancer. In a companion study, we measured MMC concentrations in plasma and selected tumors of female rats given an equivalent dose. In patients, the mean terminal half-life and total body clearance rates of MMC were 40 min and 275 ml/min/m2, respectively. The mean cervical tumor to plasma concentration of MMC was 1.26 +/- 0.34 (mean +/- SE, n = 4). In female rats, the terminal half-life and total body clearance rates of MMC were 28.4 min and 270 ml/min/m2, respectively. Tissue concentrations of MMC in rats were lower than plasma concentrations measured at corresponding times. The highest concentrations were found in lung and uterus (including cervix) with lower concentrations in ovary and liver. The mean half-life for elimination of MMC from tissues of rats was 20.3 +/- 2.8 min (mean +/- SE, n = 6). Based on similar pharmacokinetic parameters in rats and patients, the rat appears to be a suitable model for the disposition of MMC in human patients. The near equivalent drug concentrations found in tumor and plasma of patients suggests that the in vitro tests conducted at concentrations based on plasma level may be relevant to cervical tumor tissue, as well.

Quantification of an estrogen-dependent cat uterine protein (CUPED) in uterine flushings of estrogen- and progesterone-treated ovariectomized cats by radioimmunoassay

We previously reported the purification of an estrogen-dependent cat uterine protein (CUPED) and the preparation of a specific anti-CUPED serum in rabbits. Here, we describe a specific radioimmunoassay for CUPED using the purified CUPED and anti-CUPED serum that was utilized to quantify CUPED in daily uterine flushings obtained from steroid-treated ovariectomized cats. The radioimmunoassay was sufficiently sensitive to measure 0.1-100 ng CUPED. CUPED levels were low in untreated ovariectomized cats, increased within one day after the onset of treatment with estradiol, and remained elevated as long as estradiol was unopposed by progesterone. The levels of CUPED decreased when progesterone was added to the treatment regimen either 7, 14, or 28 days after the initiation of estradiol treatment. The data indicate that the presence of CUPED in the uterine flushings is dependent on the presence of estradiol and the absence of progesterone, that CUPED appears in the uterine lumen within one day after the onset of treatment with estradiol, and that the levels of CUPED are sharply reduced within one day of administration of progesterone and become nondetectable after three days.

Further characterization of the beta-glycoprotein of the rabbit uterus

beta-Glycoprotein was isolated from preimplantation uterine secretions of the rabbit by gel- and ion-exchange chromatography. Two fractions, called DF1 and DF2, were analyzed by isoelectric focusing (IEF) and sodium-dodecyl-sulfate polyacrylamide gel electrophoresis (SDS-PAGE) in combination with Western blotting and immunoelectrophoresis. DF1 displayed 21 bands with isoelectric points of pH 5.2-7.6, and DF2 15 bands of pH 4.2-5.7. SDS-PAGE yielded up to 14 bands with major components at molecular weights of 63,000 and 135,000 respectively. Two-dimensional gel electrophoresis of DF2 in combination with Western blotting revealed five groups of proteins of equal molecular weights but with different isoelectric points, indicating immunological identities. Glycosidase activities in uterine secretions before and after implantation were studied and compared with those of the blastocyst fluids. alpha-L-Fucosidase co-eluted with DF1, and beta-N-acetylglycosaminidase was distributed in DF1 and DF2. Both enzymes were localized on isoelectric focusing gels, and N-acetylglucosaminidase was also demonstrated in an immunoprecipitate of DF1.

Uteroglobin messenger ribonucleic acid: localization in rabbit uterus and lung by in situ hybridization

The messenger RNA (mRNA) coding for uteroglobin has been localized in the rabbit uterus and lung by in situ hybridization. Tissue sections fixed in ethanol-acetic acid were hybridized to the cloned complementary DNA probe labeled with tritium. The hybridization sites were detected by radioautography. Control experiments using [3H]pBR322 DNA demonstrated the specificity of the observed labeling. In the lung, uteroglobin mRNA, present in small concentrations, could be clearly visualized only after background was decreased by incubation of sections with S1 nuclease. In pregnant rabbit uterine horns, uteroglobin mRNA, visualized by silver grains, was found in the endometrial epithelium. The concentration was greater in the cells of glandular epithelium than in the cells of surface epithelium. Specific and intense labeling was spread through the cytoplasm. Practically all epithelial cells contained uteroglobin mRNA. Hybridization was very weak in the uterine epithelial cells of the nonpregnant rabbit. In the lung, a high degree of labeling occurred on the ciliated and bronchiolar cells of the epithelium of bronchi and bronchioles whereas the goblet cells remained unlabeled. Certain cells lining alveolar ducts and alveoli in the pulmonary parenchyma also showed a slight labeling. No differences in the labeling were observed in the lung of either pregnant or non-pregnant animals. There are several differences in the intensity and distribution of labeling between our hybridization experiments and previous studies involving immunocytochemical detection of uteroglobin protein. The latter technique thus probably not only reflects the pattern of synthesis of the protein but also depends on uteroglobin retention in the cells. Moreover, no evidence was found to bear out the hypothesis that some endometrial cells which contain uteroglobin do not synthesize this protein but take it up from endometrial fluid.

Quality control of estrogen and progesterone receptor assays

The intra-laboratory QC materials for estrogen and progesterone receptor assays were prepared using different methods. The most convenient and economical method was found to be the use of lyophilized rat uterine cytosol. The level of receptors remained stable for 12 months when stored at -70 degrees C with the inclusion of 10 mM phenylmethyl sulfonyl-fluoride in the cytosol extraction buffer. For inter-laboratory comparison, we received QC materials from Dr E D Ryan (McMaster University, Canada) monthly and our results fell within +/- 1SD of the mean value of 15 centres from North America and Europe participating in this program.

Further characterization of a steroid receptor-active protease from the mature rabbit epididymis

The nucleomyofibrillar fraction of mature rabbit epididymides contains a salt-extractable and leupeptin-sensitive protease that alters the sedimentation coefficient of cytosolic steroid receptors. We refer to this modification as receptor conversion. The substrate used in these studies was cytosolic estrogen receptor obtained from frozen rabbit uteri. The unactivated form of the receptor exists as an oligomer under hypotonic (0.01 M KCl) conditions (S20,w congruent to 9.6, Stokes radius (Rs) congruent to 7.4 nm, Mr congruent to 320,000) and dissociates under hypertonic (0.4 M KCl) conditions to yield the steroid-binding monomer (S20,w congruent to 4.7, Rs congruent to 5.1 nm, Mr congruent to 104,000). According to analysis under hypotonic conditions, the epididymal protease disrupts the oligomeric architecture of the receptor and reduces the size of the steroid-binding monomer (S20,w congruent to 3.2, Rs congruent to 3.0 nm, Mr congruent to 42,000). The epididymal protease had no detectable effect on the structure of the proteins used as standards for the ultracentrifugal or gel filtration analyses. Although inhibited by leupeptin, the epididymal enzyme is not a typical thiol protease since it was unaffected by thiol-blocking agents (iodoacetamide and N-ethylmaleimide), and was partially inhibited by thiol-reducing agents (monothioglycerol and dithiothreitol). Calcium and magnesium ions alone, or in combination with ATP, had no effect on the activity of the protease. However, both cations selectively suppressed recovery of the oligomeric receptor form. These results, in conjunction with those from previous studies, serve to distinguish the epididymal protease from receptor-active proteases described in extracts of other animal tissues. Molybdate, at a concentration of 50 mM, blocked receptor conversion. The ability of the receptor to be stabilized by molybdate was lost following conversion. Finally, the epididymal protease appears to remove a portion of the estrogen receptor that is necessary for nucleotide-binding.

Regulation of colony-stimulating factor 1 during pregnancy

Pregnancy results in an elevation in serum and tissue concentrations of the mononuclear phagocytic growth factor, CSF-1 (colony-stimulating factor 1). These increases are associated with an increase in the number of monocytes in the circulation, and with increases in the number of splenic macrophage precursors. In contrast to the approximately 2-fold elevation of the CSF-1 concentrations in serum and most tissues, pregnancy results in a 1,000-fold increase in the concentration of uterine CSF-1. The roughly fivefold elevation in uterine CSF-1 concentration observed at day 5 of pregnancy could be mimicked by administration of chorionic gonadotrophin in intact but not ovariectomized mice. These dramatic changes in uterine CSF-1 concentrations may indicate a role for CSF-1 in the regulation of nonmononuclear phagocytic cell types.

Temporal effects of progesterone domination on estrogen and oxytocin receptors in hamster uterus

The purpose of this study was to determine whether progesterone (P)-induced down regulation of estrogen receptors (Re) and oxytocin receptors (ROT) changes with the time of P exposure. Ovariectomized hamsters were given s.c. Silastic implants of estradiol (E2) and P for 4, 8 and 16 days. Cytosol and nuclear Re were measured at low temperature with the pyridoxal phosphate exchange assay, and ROT was assayed in the membrane fraction by [3H] oxytocin binding. Nuclear Re and ROT were down regulated throughout the 16-day P exposure period, but cytosol Re (and total Re) increased progressively from 4 to 16 days indicating that the down regulation of cytosol Re escapes P control with time. This conclusion was supported by P withdrawal studies in which P implants were removed for 6 or 12 h. P withdrawal resulted in equivalent recovery responses of nuclear Re and ROT after 4, 8 and 16 days of P exposure. Although cytosol Re recovery to P withdrawal occurred at 4 and 8 days, no response was obtained after 16 days of P exposure. Uterine weight increased during steroid treatment, and morphometric analysis of the P-dominated uterus revealed significant increases in the cross sectional area of the endometrium and myometrium with time of P exposure. Cytological examination of the uterus showed prominent secretory changes in the epithelial compartment on day 16 with accumulation of secretion in the uterine lumen. These results demonstrate that P can chronically down regulate nuclear Re and ROT. However, the control of cytosol Re varies with the time of P exposure, and cytosol Re levels become refractory to P domination by 16 days. The present observations indicate that the escape of cytosol Re from P control may be associated with the proliferation of one of more uterine cell populations such as glandular and luminal epithelial cells.

Comparison of immunocytochemical estrogen receptor assay, estrogen receptor enzyme immunoassay, and radioligand-labeled estrogen receptor assay in human breast cancer and uterine tissue

Determination of estrogen receptor content in 82 breast cancer specimens with immunocytochemical estrogen receptor assay (ER-EIA) (Abbott) was compared with our routinely used binding assay using 125I-estradiol as radioligand with Scatchard plot analysis of the binding data. Although the estrogen receptor content measured with the ER-EIA was approximately 2-fold higher compared with the binding assay, the immunochemical method proved to be a useful alternative for estrogen receptor determination. Furthermore, it is possible to detect estrogen receptors in FPLC Superose 12 (size exclusion column) eluates or in the fractions obtained after sucrose density centrifugation using the ER-EIA. Forty breast cancer samples were analyzed utilizing the immunocytochemical technique (ER-ICA) for visualization of the estrogen receptor content in frozen tumor tissues in relationship to the quantitative results obtained with the ER-EIA assay. Specific staining for estrogen receptor was confined only to the cell nucleus, was distributed irregularly among the tumor cells, and was variable in intensity. The staining intensity and the percentage of positively stained cells increased with increasing level of cytosolic estrogen receptor. In 27 of 40 cases the immunocytochemical results correlated well with the ER-EIA assay. Nine cases were ER-ICA negative with positive ER-EIA, and four were ER-ICA positive with negative ER-EIA.

Endogenous opioid peptides in uterine fluid

The present study demonstrates the presence of the endogenous opioid peptides beta-endorphin (beta-EP) and methionine-enkephalin (MET-ENK), in the uterine fluid of fertile women and normally cycling and superovulated cows. The two peptides are undetectable in the uterine fluid of untreated postmenopausal women, whereas they are present following estrogen-progesterone treatment. Immunoreactive (IR) MET-ENK concentrations were higher in the secretory than in the proliferative phase of the menstrual cycle. IR beta-EP and IR MET-ENK are present also in the follicular, oviductal, and uterine fluid of cows, and in the uterine fluid, concentrations of IR MET-ENK are higher in the superovulated than in the control animals. Because opioids play important roles on endocrine and immune functions, the present data support the potential physiologic role of endometrial secretions.

Gamma-aminobutyric acid in the genital tract of the rat during the oestrous cycle

The highest values of gamma-aminobutyric acid (GABA) in the genital tract of the rat at different stages of the oestrous cycle were found in the oviduct (3.5-7 micrograms/mg protein) and the lowest in the ovary (50-100 ng/mg protein). The values for uterus and vagina ranged between 80 and 150 ng/mg protein. GABA (10-30 ng/microliter) was also found in fluid in the ovarian bursa. At 11:00 h, on the day of oestrus, GABA content increased in the ovaries but values in the oviducts were maximal at 11:00 h on the day of pro-oestrus. Variations in GABA content of the vagina were also found. Uterine cervix or uterine horn showed no changes during the oestrous cycle. The GABA content was not uniform throughout the oviduct: the highest values were found in the portion next to the ovary. At 10 days after removal of the right oviduct, GABA values in the ovary and ovarian bursa fluid decreased on the operated side. At 1 month after surgery, the values in ovary were normal but the values in ovarian bursa fluid were still low, suggesting that the source of ovarian GABA was not the oviduct. The variations observed in the present paper suggest an involvement of GABA in reproductive physiology.

The regional distribution of NPY-, PHM-, and VIP-containing nerves in the human female genital tract

The regional distributions of neuropeptide Y (NPY), peptide histidine-methionine (PHM), and vasoactive intestinal polypeptide (VIP) immunoreactivities in the human female genital tract have been estimated by specific radioimmunoassays, and their molecular forms determined by chromatography. The localisation and distribution of these three peptides was carried out by immunocytochemistry. The vagina and cervix contain high concentrations of NPY- and VIP-immunoreactive nerves, mainly localised around the vascular and nonvascular smooth muscle. VIP-containing nerves were, in addition, seen beneath the cervical and, in particular, the vaginal epithelium. A comparatively high level of immunoreactive NPY is found in the fallopian tube, mainly around the circular muscle coat. There is evidence that VIP is a neurotransmitter in the female genital tract, and these results suggest a similar role for NPY and PHM.

Efficacy of extraction and incubation of ER and PgR with different solvent systems from rabbit uterus

Methods for improving the estrogen receptor (ER) and progestin receptor (PgR) assay were studied. Using DCC procedure as the basis, the extraction and incubation of ER and PgR is more efficiently achieved by phosphate buffer as compared with water, tris and veronal buffers. The multiple extractions of hormone receptors by any solvent system used is more complete than a single operation of homogenization and centrifugation. The utilization of combined extraction first with water and then phosphate buffer, followed by incubation of the cytosol in phosphate buffer with hormone is also an efficient procedure for the assay of both ER and PgR.

16 Alpha-[125I]iodo-11 beta-methoxy-17 beta-estradiol: a radiochemical probe for estrogen-sensitive tissues

We have synthesized an analog of 16 alpha-iodoestradiol, 11 beta-methoxy-16 alpha-iodo-estra-1,3,5-(10)triene-3,17 beta-diol (16 alpha-iodo-11 beta-methoxyestradiol), as a potential radiopharmaceutical for the in vivo imaging of estrogen-sensitive tissues. This steroid was synthesized labeled with 125I by halogen exchange of the stable intermediate 11 beta-methoxy-16 beta-bromo-17 beta-estradiol with Na125I. The halogen exchange reaction produces the radioiodinated steroid with a 65-80% yield in 3 h. This rapid synthesis and purification of the 125I-labeled estrogen permits a similar synthesis with 123I, a radioisotope with excellent properties for imaging. The 11-methoxy analog is a highly potent estrogen that binds to the estrogen receptor with an affinity equal to that of estradiol. In vivo, 11 beta-methoxy-16 alpha-[125I]iodoestradiol concentrates in an estrogen receptor-dependent manner in the uterus, producing remarkably sustained and much higher uterus to blood ratios than 16 alpha-[125I]iodoestradiol. Thus, this radiosteroid shows great promise, both as a research probe of the estrogen receptor and as a clinical tool for the imaging of estrogen-responsive tumors.

Identification of uterine nuclear type II estrogen binding sites in estrogen treated rats

Uterine nuclear fractions from estrogen-treated rats contain both the estrogen receptor and a lower affinity estrogen binding site (type II site). In Scatchard plots of estrogen binding, two types of curves are seen. The hook-shaped form is composed of a linear component (the estrogen receptor) and a convex component (the type II site) while the curvilinear form is resolvable into two linear binding species (the estrogen receptor and a secondary site). To clarify the relationship between the two forms, we examined the curvilinear form from immature rats injected for 4 days with estradiol (E2) for type II site properties. Like the hook-shaped type II, this form could be detected in a nuclear exchange assay at both 37 and 4 degrees C, but at neither temperature in the presence of reducing agent. Additionally, the steroid specificity of the curvilinear form was identical to the hook-shaped form. The hook-shaped form was found in both immature and ovariectomized adult rats implanted for 6 days with an E2-releasing Silastic capsule to provide pharmacological E2 levels. When uteri from implanted animals displaying the hook-shaped form were mixed in various ratios with uteri lacking type II sites, the curvilinear form was produced. Animals given an E2 implant for 3 days, followed by a 3 day hormone-free period showed a curvilinear form. In vivo E2 dose-response experiments showed the curvilinear form at low E2 doses and the hook-shaped form at the high dose and in implanted animals. We conclude that curvilinear Scatchard plots result from the presence of authentic type II at lower concentrations than those giving rise to the hook-shaped form.

Cytosol and nuclear levels of thymic progesterone receptors in pregnant, pseudopregnant and steroid-treated rats

Cytosol and nuclear levels of progesterone receptors in rat thymus and uterus were compared in mature Sprague-Dawley rats under a variety of physiological (non-oestrus, oestrus, pregnancy) and experimental circumstances (pseudopregnancy, oestrogen administration, oestrogen plus progesterone administration). Cytosols and nuclear extracts were charcoal treated to remove endogenous steroids, and incubated overnight at 4 degrees C with the synthetic progestin [3H]R5020 +/- greater than 100-fold R5020, in the presence of greater than 200-fold RU26988 (a highly specific synthetic glucocorticoid) to exclude tracer from glucocorticoid receptors. In the various states examined, levels of progesterone receptors in the uterus were an order of magnitude higher (350-1300 fmol/mg protein) than in the thymus (40-140 fmol/mg protein). In contrast, considerable parallelism between uterus and thymus was seen in terms of the effects of the various manipulations upon tissue levels of progesterone receptors, and of their distribution between cytosol and nuclear compartments.

[Studies of implantation traces in rats. III. Histological examination]

We carried out a histological examination of the implantation traces in delivered rats. The implantation traces could be identified more than 500 days after delivery on the mesometrial side as black and brown spots. The implantation traces were recognizable as a cicatrix remaining in the parametrium, mesometrial triangle, which was formed by repair of injury caused by placental desquamation. In this area, metrial gland cells which were laid down through pregnancy were recognized for about two months after delivery. The implantation traces consisted of cicatrix tissue associated with collagen production and hemosiderin. It was possible to distinguish old and new traces by the size of the siderophile cells and by the degree of hemosiderin present. It was also possible to discriminate new traces as yellowish-brown areas, covered with a yellowish-white mass of degenerated metrial gland, in cleared uteri stained with 2% NaOH solution. Siderophile cells on the implantation traces were derived from giant cells which persisted around the peripheral region of the placental desquamation site, and these giant cells were considered to be identifiable with metrial gland cells. It was considered that formation of the cicatrix is essentially the same in abortion, stillbirth and normal delivery. However, it was found that the implantation traces had different histological appearances depending on the degree of injury to the endometrium and myometrium and time of placental desquamation. The iron content of the implantation traces corresponded quantitatively with the hemosiderin observed in the histological investigations. The iron content decreased rapidly up to 21 days after delivery, decreasing gradually thereafter. The iron in the implantation traces could, however, be analyzed quantitatively by atomic absorption spectroscopy until day 365 after delivery.

Characterization of the phosphorylatable myosin light chain in rat uterus

The 20 kDa myosin light chain of 32P-labeled rat uterus exhibited four spots on two-dimensional gel electrophoretograms; the corresponding autoradiograms revealed that three spots were radioactive. Completely dephosphorylated light chain exhibited three spots on electrophoretograms. Serine and threonine residues of the light chain were found to be phosphorylated in the uterus at a ratio of 6 to 1. During contraction, the amount of each phosphoamino acid increased proportionally to the increase in the total phosphate content of the light chain.

Cytoplasmic progesterone receptors in uterine tissue of the snapping turtle (Chelydra serpentina)

A high affinity progesterone-binding component was detected in the cytosol of the uterus of the snapping turtle, Chelydra serpentina. Density gradient centrifugation indicated that binding of [3H]progesterone and [3H]promegestone (R5020) was to a fraction with a heavier sedimentation coefficient than bovine serum albumin (BSA) appearing as a broader peak in the 6-7 S region; it was not affected by excess cortisol. Another binding peak, lighter than BSA and appearing with [3H]R5020 and [3H]progesterone near the 4 S region, was affected by excess cortisol. Excess progesterone decreased both the heavier and lighter peaks. Analysis of steroid specificity revealed that, of the natural steroids, progesterone had the highest affinity for the uterine cytosol. This was followed by deoxycorticosterone, 5 alpha-pregnanedione, testosterone, oestradiol-17 beta, corticosterone, 5 alpha-dihydrotestosterone and cortisol. Non-linear regression analysis of saturation data indicated the presence of two classes of high affinity binding sites: progesterone-binding sites (R-sites) with equilibrium association constants (Ka) of 2.9 +/- 0.28 litres/nmol (mean +/- 95% confidence limit) for [3H]R5020 and 0.34 +/- 0.20 litres/nmol for [3H]progesterone, and corticosteroid-binding globulin-like sites (G-sites) with Ka of 4.5 +/- 1.6 litres/nmol for progesterone. The concentration of R-sites was between 0.66 +/- 0.10 and 2.6 +/- 0.55 pmol/mg protein while that of G-sites was between 0.73 +/- 0.05 and 5.0 +/- 0.27 pmol/mg protein. DEAE-cellulose filtration assay also confirmed the presence of R-sites and G-sites in the cytosol. R-sites were detectable without oestrogen priming during the preovulatory and vitellogenic phases (low progesterone, high oestrogen concentrations) when the ovarian follicles are mature (18-22 mm diameter).(ABSTRACT TRUNCATED AT 250 WORDS)

[Bradykinin receptor and the mechanism of the onset of labor]

Bradykinin (BK) receptor of uterus and chorionic membrane were studied by radioreceptor assay to clarify the role of BK as theta an agent contracting uterine muscle. Basic examination revealed that incubation at 0 degrees C for 45 minutes with [3H] BK in buffer containing 5mM Mg++ was the most suitable condition for receptor-BK binding. BK receptor assay of several kinds of tissue such as pregnant rat uterus, human chorionic membrane, and placenta was done and the following results were obtained. Specific BK receptor existed in human chorionic membrane and in rat uterus. Ultracentrifugation revealed that it was on the plasma membrane (145 f mole./mg protein: The highest binding in the pellet at 10,000 g centrifugation followed by 600 g centrifugation). Association constant (Ka) and maximal binding capacity (MBC) showed the lowest level at 15 days gestation in rat uterus. These seemed to effectively maintain pregnancy by inhibiting uterine contraction. Both Ka and MBC were increased in the uterus of intrapartum rat compared with that of prepartum, but the former was about 45%, and the latter was almost the same as, that of non pregnant rat.

Estrogen receptor localization in the female genital tract

The authors have used monoclonal estrophilin antibodies and the peroxidase antiperoxidase technique to characterize the distribution of estrogen receptor in the human vagina, uterus, and fallopian tubes. Exclusively nuclear localization of estrogen receptor was observed in epithelial cells, stromal cells of the lamina propria, and smooth muscle cells with both immunohistologic studies and immunoelectron-microscopy studies. The endometrium in various regions of the uterus (uterine isthmus, corpus, and fundus) was stained for estrogen receptor, with similar staining intensities in each of the respective cell types. There was no systematic regional variation in the staining intensity or distribution of cells with stained nuclei. The functionalis of the endometrium showed distinctive variation in the intensity of the staining for estrogen receptor with the menstrual cycle. The staining intensity of both endometrial epithelium and stroma was greatly reduced in the functionalis during the secretory phase. The vaginal epithelium did show some variation with the menstrual cycle, but it was much less than that observed in the functionalis of the endometrium. The basal cells of the vaginal stratified squamous epithelium, strongly stained during the proliferative phase, were less strongly stained during the secretory phase. No variation in the staining intensity for estrogen receptor was observed in different regions of the fallopian tube (isthmus, ampulla, and infundibulum), and the staining intensity varied only minimally with the menstrual cycle. The serosa of the female reproductive tract, connective tissues in the muscularis and in the vicinity of blood vessels, as well as neutrophils, eosinophils, mast cells, and lymphoid cells in the female genital tract were not stained for estrogen receptor.