Results of the Italian Interlaboratory Quality Control Program for Estradiol Receptor Assay

This article presents results of the first Italian quality control program for determining the estradiol receptor on lypophilized guinea pig and calf uteri. Despite considerable variability in quantitative terms, the results concur in ability to define samples as positive or negative for receptor content. One of the parameters that most strongly influences accuracy of determination of receptor concentration is protein assay. The evaluation of several lyophilized preparations at scalar concentrations permitted identification, by linear regression, for each laboratory of the systematic and non-systematic variables. More comparable results will be forthcoming when a standardized methodology program has been fully adopted.

Estradiol, Progesterone and Testosterone Receptors for Pig Endometrium and Myometrium at Various Stages of the Estrous Cycle

The concentration of unoccupied, occupied and total receptors for estradiol (E2R), unoccupied receptors for testosterone (TR) and progesterone (PsR) in the endometrium (E) and myometrium (M) of cycling gilts or sows after the second or the third farrow were measured. On day O (estrus) the concentration of E2R, TR and PsR reached the maximum for total uterus (M + E). On day 0, there were no differences between concentration of PsR, TR and occupied, unoccupied and total E2R for E and M. In other stages of estrous cycle, the concentration of receptors in E and M were considerably different both in cycling gilts or sows after second or third farrow. On day 13 (luteal phase), high levels of E2R were found but only for E, while there were the lowest level of occupied, unoccupied and total E2R for M. In sows, after the second or third farrow the concentration of E2R in E as well as in M at all stages of the estrous cycle was about three times higher than in cycling young gilts. The concentration of TR in E as well as in M was lowest on day 13, increased on day 17 and reached the highest level at estrous. The concentration of PsR in M was the lowest at luteal phase (day 13), increased on day 17 and reached the highest level at estrus. Significant negative correlation between the concentration of PsR and progesterone in the blood plasma was calculated for M, but not for E.

Expression of insulin-like growth factor-I and insulin-like growth factor-binding protein-1 in the rat uterus during decidualization

Decidualization of the uterus involves proliferation and differentiation of uterine cells. The effects of decidualization on uterine expression of insulin-like growth factor-I (IGF-I) and IGF-binding protein-1 (IGFBP-1) have been examined in the hypophysectomized-ovariectomized (hypox-ovx) rat and the pituitary-intact (ovx) rat. Decidualization was induced by uterine stimulation of animals treated with a combination of 17 beta-estradiol and progesterone. The patterns of change in uterine IGF-I mRNA and IGFBP-1 mRNA abundance were similar to hypox-ovx rats, hypox-ovx rats replaced with GH and T4, and ovx rats. The changes in IGF-I mRNA abundance were temporally related to 17 beta-estradiol injections. IGFBP-1 mRNA was undetectable early in the decidualization process and reached maximal levels on day 6. Mechanical separation of the deciduoma tissue from the underlying myometrium revealed that the deciduoma tissue was depleted in IGF-I mRNA, while the majority of the IGFBP-1 was located in the deciduoma tissue. The in situ hybridization technique was used to localize IGF-I and IGFBP-1 mRNA in the decidualized uterus. The majority of the IGF-I expression was localized to the outer stroma and smooth muscle cell layer, whereas IGFBP-1 mRNA was detected in uterine epithelial cells and stromal glands. These experiments demonstrated that uterine IGF-I and IGFBP-1 expression during the process of decidualization are pituitary independent. Furthermore, our observations support the hypothesis that the expression of IGFBP-1, a protein capable of inhibiting the mitogenic activity of IGF-I, in deciduoma tissue may inhibit paracrine IGF-1 actin and allow for the differentiation of stromal tissue.

Development and characterization of monoclonal antibodies to a specific domain of human estrogen receptor

We have synthesized three peptides with amino acid sequences identical to those spanning amino acids 201-215, 231-245, and 247-261 of the human estrogen receptor (hER). These peptides were conjugated to keyhole limpet hemocyanin and used as immunogens to develop monoclonal antibodies (MoAbs) to hER. Antibody responses were only elicited by the peptide with amino acid sequence 247-261. Splenocytes from immunized mice were used for hybridoma production. Of the seven MoAbs that recognized the native (functional) form of the ER, four (MoAbs 16, 33, 114, and 213) recognized the ER with high affinity, as demonstrated by the increased sedimentation coefficient of the antibody-complexed ER in sucrose density gradients. Antibodies 318, 35, and 36 bound to ER with low affinity since they immunoprecipitated ER, but the ER-antibody complex appeared to dissociate on sucrose density gradients. The high-affinity MoAbs appear to be site-specific since the peptide competed effectively for binding of the receptor by the antibody. The fact that they reacted with ER from human breast cancer and calf, rat, and mouse uterine tissues suggests that this epitope of the receptor is conserved in these species. Although the DNA-binding region appears to be conserved among the various steroid receptors, these MoAbs did not recognize the native forms of progesterone, androgen, or glucocorticoid receptors. These MoAbs bound to the KCl-activated 4S ER and heat-transformed 5S ER, suggesting that the antibody-binding site is accessible in the monomeric and dimeric forms of ER. The antibodies did not recognize the untransformed 8S ER in the presence of molybdate and without KCl, suggesting that the antibody-binding site in the oligomeric form of ER is inaccessible. The fact that the antibodies did bind to the unoccupied 4S ER was demonstrated by the data obtained with sucrose density gradient analysis followed by postlabeling of ER with [3H]estradiol. The antibodies bound to ERs with high affinity (KD = 0.4 to 1.8 nM). At a fixed concentration of antibody, ERs ranging from 20 to 1,000 fmol were detectable. These MoAbs did not inhibit nuclear or DNA binding of ER in vitro. This can be attributed to the dissociation of the antibodies from ER when the latter interacts with its acceptor site. These results demonstrate the development of site-specific MoAbs to the native form of the hER using synthetic peptides as immunogens.

Calcitonin gene-related peptide in the rat uterus: presence in nerves and effects on uterine contraction

The influence of calcitonin gene-related peptide (CGRP) on rat uterine activity was examined in concert with the anatomical distribution of CGRP-like immunoreactivity in the uterus. CGRP-like immunoreactivity was localized in nerve fibers; these peptide-containing nerves were abundant throughout the mesometrium of the uterine horn and appeared to innervate mesometrial smooth muscle and vascular smooth muscle. In the uterine wall, CGRP-like immunoreactive fibers were prevalent in the myometrium, endometrium and the endocervix. Fibers in the endometrium and endocervix appeared to form a plexus subjacent to the epithelium and some fibers penetrated the epithelium as an intraepithelial plexus. The action of CGRP (10(-9) to 10(-6) M) on acetylcholine (10(-6) or 10(-5) M)-stimulated uterine activity was examined in vitro. Exogenously applied CGRP induced a dose-dependent relaxation of acetylcholine-stimulated uterine contractions. CGRP had no effect on basal uterine tension. The localization of CGRP-like immunoreactivity in nerves and the relaxing effect of CGRP suggests a role for CGRP-containing nerve fibers in the regulation of uterine activity.

Isolation of untransformed bovine estrogen receptor without molybdate stabilization

A low concentration estrogen-derivatized affinity resin has been used in a rapid, single step purification of the untransformed estrogen receptor from calf uterine cytosols prepared without sodium molybdata. The procedure isolates the Mr 65,000 estrogen receptor in association with the bovine heat shock protein hsp90. Small amounts of proteolyzed receptor ranging in size from Mr 50,000 to 60,000 are also present in the purified extracts. Results from affinity chromatography of receptor cytosols either untreated or presaturated with estradiol suggest that two proteins of Mr 22,000 and 38,000 are co-purified with the untransformed receptor complex and may represent additional nonhormone-binding components of the native receptor form. Some indication of the stability of protein-protein interactions within the oligomeric complex has been derived from differential salt elution studies with heparin-sepharose and affinity gel-immobilized untransformed receptor. On size exclusion high performance liquid chromatography the untransformed complex eluted with a Stokes radius of 75 +/- 2 A (n = 18), but was shown to be sensitive to extended ultracentrifugal analysis dissociating to the receptor homodimer, sedimentation coefficient 5.3 +/- 0.3 s (n = 5). Preliminary data on urea- and heat-induced transformation of the isolated receptor to the DNA-binding state is presented.

Evidence for steroid control of a putative angiogenic factor in the porcine uterus

The formation of new capillaries, both in extraembryonic membranes and in the maternal endometrium, is an essential prerequisite for appropriate feto-maternal relationships throughout pregnancy. At present there is no indication of the nature of the uterine angiogenic stimulus. In-vitro, degradation products of hyaluronic acid, following its catalysis by hyaluronidase, have been shown to have angiogenic properties. In the current study, levels of hyaluronic acid in endometrial tissues and of hyaluronidase and hyaluronic acid in uterine flushings were measured during the oestrous cycle and early pregnancy. The concentration of both hyaluronic acid and hyaluronidase in uterine flushings followed the growth and regression of the corpus luteum, in that basal levels detected on days 0 and 6 increased to peak concentrations on days 12 and 15. By day 18, levels of both hyaluronidase and hyaluronic acid had decreased in cyclic gilts, but remained increased in pregnant pigs. Tissue concentrations of hyaluronic acid were not affected by pregnancy or by the day of the oestrous cycle. In a subsequent experiment, four groups of gilts were ovariectomized on day 4 and thereafter received daily injections of corn oil, progesterone, oestrogen or a combination of oestrogen and progesterone. Hyaluronidase was undetectable in uterine flushings collected on day 15 from corn oil- and oestrogen-treated gilts, but present in similar amounts in uterine flushings from gilts treated with progesterone and progesterone plus oestrogen. Similarly, uterine fluid concentrations of hyaluronic acid were increased in progesterone- and progesterone plus oestrogen-treated gilts, but not in corn oil- or oestrogen-treated pigs. Tissue concentrations of hyaluronic acid were unaffected by steroid treatment.(ABSTRACT TRUNCATED AT 250 WORDS)

Studies on the non-activated and activated forms of the estrogen receptor

The activation of the steroid receptor is a necessary process for the biological role of the receptor. Many factors are involved in this mechanism; in addition to time, temperature, and salt concentration, RNA and RNAase can also affect the transformation of the non-activated to the activated form of the receptor. Using as a model the estrogen receptor of fetal uterus of guinea-pig, the studies of the interaction with three different monoclonal antibodies (D547, H222 and H226) reveal structural transformation during the process of the receptor activation. These conformational transformations suggest that a change in the exposure of the functional domains of the estrogen receptor occurs during activation.

Purification and characterization of heparin-binding growth factors from porcine uterus

Heparin-binding growth factors present in pig uterine tissue were purified by approx. 50,000-fold using a combination of ammonium sulphate precipitation, ion-exchange chromatography and heparin-affinity chromatography. Purification of the uterus-derived growth factors (UDGFs) was monitored by the stimulation of [3H]thymidine incorporation into Swiss 3T3 cells and by a radioreceptor assay using 125I-labelled epidermal growth factor (EGF) as the ligand. The latter was shown to be a novel, rapid and reliable assay for heparin-binding growth factors which utilizes their trans-modulation of EGF receptor affinity. UDGFs exhibit strong affinity for immobilized heparin and two forms, named alpha UDGF and beta UDGF, were distinguished by salt gradient elution from heparin-agarose affinity columns. beta UDGF activity was eluted from heparin-agarose between 1.5 M- and 1.8 M-NaCl, and was correlated with the elution of a protein doublet of 17.2 kDa and 17.7 kDa. Immunoblotting of heparin-purified beta UDGF indicated that the beta UDGF doublet is immunologically related to the 146-amino-acid form of bovine basic fibroblast growth factor (bFGF), and that the 17.2 kDa component is an N-terminally truncated form of the 17.7 kDa component. After purification by C4 reversed-phase h.p.l.c., this doublet was biologically active and greater than 95% pure as assessed by silver-stained SDS/PAGE. Amino acid composition and sequence analysis confirmed that these beta UDGF polypeptides were microheterogeneous forms of bFGF. Fractions containing alpha UDGF activity were eluted from heparin-agarose in 1.3 M-NaCl. These fractions contained a 16.5 kDa protein which co-migrated on SDS/polyacrylamide gels with recombinant human acidic FGF (aFGF) and which which cross-reacted with an antiserum raised against aFGF. The identification of heparin-binding growth factors in porcine uterus at the time of implantation raises the possibility that they function in the reproductive tract during early pregnancy.

Human relaxin in the amnion, chorion, decidua parietalis, basal plate, and placental trophoblast by immunocytochemistry and northern analysis

Immunocytochemistry and Northern analysis were used to show that relaxin is a product of intrauterine tissues of pregnancy. In addition, tissues from a patient without ovaries had similar results on both immunocytochemistry and Northern analysis as tissues from intact patients. The parietal decidua was clearly the major source of relaxin within the uterus and the relaxin mRNA (1.2 kilobases) from this tissue was detected with a 48-mer oligonucleotide probe designed to hybridize with both H1 and H2 relaxin gene transcripts. The mRNA isolated from the placental trophoblast was slightly smaller (1.1 kilobases), and the placental basal plate which has both maternal and fetal cells contained relaxin mRNAs of both sizes. Two monoclonal antibodies (Mabs) raised to synthetic human relaxin (H2) gave different patterns of localization in the fetal membranes, decidua and placenta. One Mab (RLX8) stained the chorionic cytotrophoblast in the fetal membranes and all of the cells in the placental basal plate. The other Mab (RLX6) stained the chorionic cytotrophoblast in some instances and selectively stained the decidua-like cells of the placental syncytiotrophoblast, whereas Mab RLX8 failed to detect this relaxin. Tissues obtained after spontaneous labor and delivery contained significantly less relaxin mRNA than tissues obtained at elective cesarean section without labor, but their hormone contents, as judged by immunocytochemistry, were not different. We conclude that the relaxin gene (H2) is expressed in intrauterine tissues, but that expression and hormone synthesis are not ubiquitous. Whether the relaxin gene H1 is expressed has not been determined.

The presence of gonadotropin receptors in nonpregnant human uterus, human placenta, fetal membranes, and decidua

The possible presence of gonadotropin receptors in nonpregnant human uterus and human fetoplacental unit was investigated by light microscope immunocytochemistry using a monoclonal antibody to rat luteal hCG/LH receptors. The receptor antibody cross-reacted with human and bovine hCG/LH receptors and appears to be directed against the receptor rather than other proteins, including HLA class I antigens. Uterus and fetoplacental unit contained receptor antibody-binding sites, which indicates the presence of hCG/LH receptors. In the endometrium these receptors were present in glandular and luminal epithelial cells as well as in stromal cells. In the myometrium the receptors were detected in circular and elongated myometrial smooth muscle and vascular smooth muscle. Comparison of immunostaining intensities, which indicates the presence of different amounts of receptors, revealed that luminal and glandular epithelial cells contained more receptors than stromal cells. These cells, in turn, contained more receptors than myometrial and vascular smooth muscle. All cells in secretory phase uterine specimens contained more receptors than corresponding cells from the proliferative phase of the cycle. Midpregnancy placenta, amniotic epithelium, chorionic cytotrophoblasts, and decidual cells contained hCG/LH receptors. At term pregnancy, while receptors in fetal membranes and decidua continue to be detected, placental tissues did not show any detectable receptors unless the tissues were pretreated with neuraminidase. This indicated that term pregnancy placenta contain hCG/LH receptors masked by sialic acid residues. Comparison of immunostaining intensities suggested that syncytiotrophoblasts contained more receptors than cytotrophoblasts at midpregnancy; mesenchymal cells or blood vessels contained no detectable receptors. There were more receptors in decidua than in fetal membranes at mid- and term pregnancy. While the amniotic epithelial receptors decreased, the receptors in chorionic cytotrophoblasts and decidual cells increased from mid- to term pregnancy. In summary, hCG/LH receptors were demonstrated in the nonpregnant human uterus, human placenta, fetal membranes, and decidua. This indicates that hCG/LH may directly regulate functions of these tissues by endocrine, autocrine, or paracrine mechanisms.

An immunocytochemical method for localization of estrogen receptors in rat tissues using a dinitrophenyl (DNP)-labeled rat monoclonal primary antibody

We have developed an immunocytochemical method to demonstrate estrogen receptor in hormone-sensitive tissues of the rat using a dinitrophenyl (DNP) hapten-labeled rat antihuman estrogen receptor monoclonal antibody (MAb), H222. Mouse IgM anti-DNP was used secondarily, followed by a DNP/peroxidase conjugate, diaminobenzidine/hydrogen peroxide chromogen, and silver intensification. This method was applied to tissues from intact female rats and showed that estrogen receptor was localized in the nuclei of the stromal and glandular components of the uterine endometrium. Reduced receptor staining was observed in the luminal epithelium, with minimal myometrial staining. Anterior pituitary glands showed heterogeneous immunostaining and ovaries expressed the receptor predominantly in the interstitial cells; fallopian tubes demonstrated substantial epithelial staining. Uteri from chemically castrated rats showed reduced estrogen receptor immunostaining in both stromal and luminal cells, whereas staining was enhanced in the glandular elements. Classical estrogen-unresponsive tissues (heart, lung, and spleen) were unstained. Antibody controls involved pre-blocking antibody recognition sites on the receptor with unlabeled antibodies to estrogen receptor (H222, H226, and D547), as well as use of an inappropriate DNP-labeled antibody to metallothionein. These controls illustrated the specific nature of the DNP-H222 binding.

Uterine oxytocin receptors in an Australian marsupial, the brushtail possum, Trichosurus vulpecula

1. Oxytocin receptors in the uterus of the brushtail possum (T. vulpecula) were characterized by radioreceptor assay and compared with those of the sheep and rat uterus. 2. A single oxytocin binding site was found with an affinity (Kd) and receptor concentration (Ro) of 3.0 +/- 0.8 nmol/l and 200 +/- 60 fmol/mg protein, respectively (SEM; n = 5). The receptor was stable at -20 degrees C; divalent ions were required for optimum binding. 3. Competitive displacement curves with related peptides showed the following order of specificity: vasotocin greater than oxytocin greater than mesotocin = arginine-vasopressin = [Thr4, Gly7]-oxytocin greater than lysine-vasopressin = isotocin much greater than [d(CH2)5, D-Phe2, Ile4, Ala9-NH2]-AVP. 4. It was concluded that oxytocin receptors in the possum have similar characteristics to those of placental mammals.

Cellular distribution of alpha B-crystallin in non-lenticular tissues

alpha B-Crystallin is a subunit of alpha-crystallin, a major protein component of the vertebrate lens. Recently, its expression in various extra-lenticular tissues has been demonstrated by both Western and Northern blotting. In this study, the cellular distribution of alpha B-crystallin in rat organs was examined in detail using immunohistochemistry. Positive reactions were observed in lens, iris, heart, skeletal muscle (type 1 and type 2A fibers), striated muscle in skin and esophagus, Henle's loop and medullary collecting duct of the kidney, Schwann cells of peripheral nerves, glia of the central nervous system, and decidual cells of the placenta. A close correlation with markers of oxidative activity suggests that alpha B-crystallin is expressed in cells that have high levels of oxidative function.

Uterine estrogen receptors are increased by RU486 in late pregnant rhesus macaques but not after spontaneous labor

Progesterone withdrawal as a mechanism for parturition in primates is controversial. The progesterone antagonist RU486, given in late pregnancy to rhesus monkeys at a dose of 47 mmol/kg.day (20 mg/kg.day), causes an increase in uterine activity, but not the expected increase in amniotic fluid prostaglandins or cervical dilatation. We, therefore, studied the effect of RU486 on estrogen receptor (ER) localization and concentration in reproductive tract tissues in rhesus monkeys during late gestation and after spontaneous labor at term. Distribution of ER in pregnant uterine tissues was studied by immunocytochemical techniques and quantified by a biochemical assay, both of which employed a monoclonal antibody specific for ER. ER was not present in amnion and chorion by immunocytochemical investigation; however, a significant increase in receptor staining was seen in decidua and myometrium after RU486 treatment compared to that in both pregnant control tissues and parturient tissues. Sucrose gradient assay of nuclear (n) and cytosolic (c) ER revealed a low level of ER (expressed as fmol of estradiol bound/mg of DNA) in pregnant and parturient decidua (pregnant: nER = 7.3 +/- 2.4, cER = 17.1 +/- 6.4; parturient, nER = 7.7 +/- 3.1, cER = 16.4 +/- 8.8) and myometrium (pregnant: nER = 21.7 +/- 4.1, cER = 20.8 +/- 5.3; parturient: nER = 30.0 +/- 2.8, cER = 10.7 +/- 6.7). In contrast, tissues collected from RU486-treated animals contained high levels of ER in decidua (nER = 52.3 +/- 16.8, cER = 240.5 +/- 145.3) and myometrium (nER = 77.0 +/- 19.2; cER = 66.5 +/- 31.6). We conclude that 1) the increase in ER in decidua and myometrium after RU486 treatment is the result of a decrease in the inhibitory action of progesterone on ER and documents the progesterone receptor antagonism by RU486 during induced myometrial contractility in late pregnant rhesus monkeys; 2) the absence of ER from amnion and chorion indicates that the normally observed increase in prostaglandin production by rhesus fetal membranes during labor is not mediated by ER; and 3) the absence of a change in the concentration of ER in decidua and myometrium from pregnant control monkeys and those in spontaneous labor indicates that an increase in ER (and, by inference, a withdrawal of receptor-mediated progesterone inhibition) is not part of the normal events in preparation for parturition in primates.

Uterine adrenergic and cholinesterase-positive nerves and myometrial catecholamine concentrations during pregnancy in sheep

Uterine adrenergic and cholinesterase (AChE)-positive innervation of the sheep uterus during anestrus and at 4 stages of pregnancy were examined by histochemical methods. In addition, uterine and cervical myometrium concentrations of norepinephrine (NE) and dopamine (DA) were determined using high-performance liquid chromatography. During anestrus, adrenergic and AChE-positive nerve fibers in the uterine myometrium and endometrium were primarily associated with the vasculature. Innervation of myometrial smooth muscle was almost exclusively by adrenergic fibers. In the endometrium, fibers of both types were observed closely associated with endometrial glands, and adrenergic fibers were observed in the connective tissue beneath the luminal epithelium. Density of uterine innervation decreased by day 65 of pregnancy with an additional decrease by day 105. Myometrial NE concentrations were higher in the cervix than the uterus. Uterine NE concentrations generally were not affected by pregnancy. Although cervical NE per gram of tissue decreased during pregnancy, this effect of pregnancy was not detected when NE was expressed per microgram of DNA. Myometrial DA concentrations were higher in uterine segments than in the cervix. DA concentrations decreased during pregnancy in all tissues except the posterior uterine segment. The DA to NE ratio in the uterus was greater than that for the cervix and was not generally affected by the stage of pregnancy. These results demonstrate that cholinergic and adrenergic nerves supply the sheep uterus. Decreasing fiber density during pregnancy suggests that a majority of the innervation to the sheep uterus is supplied by 'short' nerve fibers whose activity is regulated by steroids of pregnancy. The possible role of DA as a neurotransmitter in the sheep uterus is discussed.

A novel 17 kD heparin-binding growth factor (HBGF-8) in bovine uterus: purification and N-terminal amino acid sequence

We have purified to near homogeneity a novel 17 kD growth factor from bovine uterus which we designated heparin-binding growth factor-8 (HBGF-8). The growth factor binds tightly to cation exchange resins and to Heparin-Sepharose and is stable to acetone precipitation and labile in acid. Based upon total activity in acetone extracts of bovine uterus stimulating 3H-thymidine incorporation into DNA of serum-starved NIH 313 cells, a 6940 fold purification was achieved with an overall yield of HBGF-8 activity of 0.4%, using extraction of acetone powders and chromatographic separations at neutral pH. Approximately 18 micrograms protein was obtained from 1.2 kg wet weight of tissue. HBGF-8 was clearly separated from 17.5 kD bovine uterus basic fibroblast growth factor (bFGF) by purification and its N-terminal amino acid sequence analyzed. A polypeptide with a unique 25 N-terminal amino acid sequence was found. HBGF-8 was as active as acidic fibroblast growth factor (aFGF) and slightly less active than bFGF in the mouse NIH 3T3 fibroblast mitogenic assay system with an intrinsic specific activity of 5000 dpm/ng under standard assay conditions.

Comparative study of placental protein 19, human chorionic gonadotrophin and pregnancy-specific beta 1-glycoprotein as immunohistochemical markers for extravillous trophoblast in pregnancy and trophoblastic disease

PP19, a new placental tissue protein, has alpha 1-beta 1 electrophoretic mobility, a molecular weight of 36,500 and 3.9% carbohydrate. To study immunocytochemical PP19 localization in extravillous trophoblast, we obtained formalin-fixed specimens from extravillous tubal pregnancy at gestational weeks (GW) 7-9 (12 blocks); four early intrauterine pregnancies at GW 7-13 (12 blocks); four late pregnancies at GW 28-38 complicated with intramural uterine myoma, placenta increta and abruptio placenta (8 blocks); four invasive complete moles (9 blocks); and seven primary and metastatic gestational choriocarcinomas (12 blocks). Immunohistochemical staining was done for PP19, pregnancy-specific beta 1-glycoprotein (SP1) and human chorionic gonadotrophin (hCG) using the indirect-labeled antibody method [purified PP19 (Lot no. 225/242) and antibody against PP19 (Lot no. 632ZA) prepared by H. Bohn, antibodies against hCG (Behringwerke, Marburg, FRG) and SP1 (Dakopatts, Copenhagen, Denmark)]. In both early and late intrauterine pregnancies, the extravillous syncytiotrophoblastic cell (XST) showed positive staining for hCG and SP1 in the cytoplasm, as well as for PP19, which stained more intensively in the nucleus than in the cytoplasm. The three proteins were not seen in the evtravillous cytotrophoblastic cell (XCT) in the trophoblastic cell column and shell. The interstitial cytotrophoblast-like cell (ICT), which infiltrated into the decidua and myometrium, and their blood vessels, was immunoreactively positive for PP19 but negative for hCG and SP1 with the exception of SP1-positive ICT in the myometrium in late pregnancy. XST and ICT in the endosalpinx of tubal pregnancy stained for all three proteins.(ABSTRACT TRUNCATED AT 250 WORDS)

A putative growth factor in extract from uterine cancers

Extracts from uterine cervical and corpus cancers, but not from benign tumor or intact tissues tested, were found to contain a growth-promoting activity which induced the proliferation of human endometrial fibroblasts. Exposure of cultured fibroblasts to the cancer extracts increased the rate of [3H]thymidine incorporation in a dose-dependent manner. The activity was heat-labil, and not inacticated by removal lipid-soluble fraction, suggesting that the activity is associated with a protein. However, the cancer extract failed to stimulate phosphoinositide turnover. The substance(s) present in the uterine cancer extracts may activate endometrial fibroblasts proliferation through the transmembrane signaling mechanisms other than phosphoinositide turnover. The bindings of previously identified growth factors including somatomedine C, thrombin, insulin, fibroblast growth factor were not inhibited by the extracts. This is the first report to provide direct evidence that malignant uterine tumor may produce and secrete a putative growth factor-like peptide.

Hormonal correlates of sexual behavior and ovulation in male-induced and postpartum estrus in female prairie voles

The purpose of the present study was a description of hormonal profiles in female prairie voles (Microtus ochrogaster) in estrus that was induced by male exposure versus postpartum estrus. Hormonal profiles are reported in sexually naive females and in sexually experienced females, as a function of varying amounts of coital stimulation and as a function of time since male exposure. Ovarian estradiol levels, uterine weights and uterine protein levels increased in virgin females after exposure to a male, were highest in females that showed lordosis, declined slowly when estrous females were isolated from males and decreased sharply following mating. Ovarian progesterone levels increased more rapidly following mating in females in male-induced estrus than in females in postpartum estrus. Serum progesterone levels did not increase significantly within 24 hr following mating, but were elevated by 72 hr after mating. These findings are discussed as they relate to the hormonal control of female sexual behavior.

Lipomatous neometaplasia of the uterus. Report of 11 cases with discussion of histogenesis and pathogenesis

Eleven cases of uterine lipomatous neometaplasia were studied. The patients ranged in age from 41 to 74 years (mean, 56.6 years). There were eight lipoleiomyomas and 3 angiolipoleiomyomas. In eight tumors the lipomatous component consisted only of mature lipocytes. In three tumors, pericapillary differentiating lipocytes also occurred. No correlation between the proportion of the lipomatous and leiomyomatous components and the size of tumor was observed. There was also no correlation between the amount and distribution of the lipomatous component and the hyalinized fibrous stroma. The levels of cytosolic estrogen and progesterone receptors, studied in one case, were lower in the lipoleiomyoma than in the myometrium. Leiomyomas and adenomyosis were the most frequent accompanying lesions. The study supports a notion that uterine lipomatous neometaplasia originates from pericapillary pluripotential mesenchymal cells. Present findings suggest that lipomatous differentiation of immature neoplastic cells can occur in a preexisting leiomyoma, as well as simultaneously with leiomyomatous differentiation.

Multidimensional chromatographic separation of estrogen receptors

Analyses of estrogen and progesterone receptors in biopsies of breast carcinoma play a vital role in the selection of patients likely to respond to hormone manipulation. Sucrose density gradient centrifugation has been the reference method in the determination of estrogen receptors in human breast carcinoma cytosols. To reduce assay time and circumvent prolonged manipulation of labile receptor preparations, high performance liquid chromatography techniques in the size-exclusion and ion-exchange modes were compared as potential alternate methods for the rapid separation of receptor isoforms. Multidimensional analyses were performed by reapplying estrogen receptor isoforms obtained from high performance size-exclusion and ion-exchange chromatography to sucrose density gradients and vice versa. This confirmed that the estrogen-binding components identified by high performance liquid chromatography appear to correspond to estrogen receptor species from sucrose density gradients.

Increases in calbindin D 28K mRNA in the uterus of the domestic fowl induced by sexual maturity and shell formation

Uterine concentrations of calbindin D 28K mRNA were measured in immature pullets and laying hens by dot-blot hybridization using a [32P]cRNA probe prepared from the calbindin cDNA. In immature pullets, estrogen increased the calbindin mRNA level and the plasma concentration of 1,25-dihydroxyvitamin D3 [1,25-(OH)2D3]. When testosterone was administered with estrogen there was a further increase in calbindin and its mRNA and an increase in the free 1,25-(OH)2D3 index calculated as the ratio of the molar concentrations of total 1,25-(OH)2D3 and vitamin D-binding protein (DBP). In laying hens the uterine concentration of calbindin mRNA was low 4 hr after ovulation, but increased most markedly 12 and 18 hr later, when shell calcification took place. Calbindin concentration remained unchanged during the different stages of egg formation but was much higher in laying hens than in pullets treated with sex steroids. Suppression of shell formation by premature expulsion of the egg decreased the concentrations of calbindin mRNA and uterine calbindin and the free 1,25-(OH)2D3 index in the plasma. A concomitant increase in calbindin and its mRNA was observed at resumption of shell formation in hens previously laying shell-less eggs. Withdrawal of food for 44 hr decreased the uterine concentration of calbindin and its mRNA without a change in the free 1,25-(OH)2D3 index in the blood. It is concluded that the synthesis of uterine calbindin is stimulated primarily at sexual maturity and at calcification of the first shell by transcriptional processes. The daily increase in calbindin mRNA associated with shell formation and the absence of a concomitant change in calbindin concentration suggest that post-transcriptional processes exist and that stimuli other than the sex steroid or the 1,25-(OH)2D3 are involved in regulation of calbindin synthesis in the uterus.

Arachidonic acid in uterine phospholipid during early pregnancy and following hormone treatment

Evidence that prostaglandins are involved in intercellular communication during blastocyst implantation suggested that development and loss of uterine sensitivity to deciduogenic stimuli during early pregnancy might depend upon changes in uterine capacity to mobilize arachidonic acid from phospholipid. We measured levels of arachidonic acid in lipid fractions on Day 6 of pregnancy in uterine segments containing implantation sites, in uterine segments between implantation sites, and in luminal epithelial cells after a deciduogenic stimulus. Arachidonic acid in uterine phospholipid was depleted at implantation sites. With an intrauterine deciduogenic stimulus of hormonally primed ovariectomized rat uteri, the arachidonic acid content of the luminal epithelium decreased. When the fatty acid composition of the luminal epithelium was examined during pseudopregnancy and after progestin-estrogen treatment, however, no changes in arachidonic acid composition and content were observed. These data suggest that during blastocyst implantation, luminal epithelial cells at implantation sites mobilize arachidonic acid from phospholipid for prostaglandin synthesis, but that uterine sensitivity and the capacity to synthesize prostaglandins in response to the blastocyst does not depend upon changes in arachidonic acid levels in uterine phospholipid.

IUDs are contraceptives, not abortifacients: a comment on research and belief

No studies show that IUDs destroy developing embryos at rates higher than those found in women who are not using contraceptives. Studies of early pregnancy factors have not shown statistically significant differences in transient levels of hCG between IUD and control groups, a sign of early abortion. The small, careful study by Segal et al. (1985) found no transient rise of hCG in the IUD group. The highly sensitive assay in a larger sample of IUD users, by Wilcox et al. (1985), suggests that an upper limit of only 3 or 4 percent of ovulatory matings with an IUD in situ might show transient rises of hCG. The electron microscopy of Hurst et al. (1980) demonstrated the existence of leukocyte-ridden degenerating embryos in rhesus monkeys fitted with IUDs, but found the same percentage of degenerating embryos in the control group. In this respect, IUDs do no more than nature. The work of Hurst et al. also demonstrates the comparative rarity of fertilized ova in rhesus monkeys fitted with IUDs. Croxatto (1974) and Alvarez et al. (1988) showed that this was also true for humans. A variety of studies demonstrate that IUD use diminishes both the number of sperm reaching the oviduct and their capacity to fertilize ova. Depending on the type of IUD and the drug dose, sperm are hindered from penetrating cervical mucus, are phagocytized by leukocytes, are incapacitated, with head-tail separation in the presence of copper, and suffer other cytotoxic effects in the IUD-altered uterine fluid. In the oviducts of copper-IUD users, ova are found significantly less frequently than in controls.(ABSTRACT TRUNCATED AT 250 WORDS)

Rapid purification of the estrogen receptor by sequence-specific DNA affinity chromatography

Rapid purification of calf uterine estrogen receptor (ER) to near homogeneity has been accomplished by use of sequence-specific DNA affinity resin. Very high selectivity for the estrogen receptor is achieved through the use of DNA-Sepharose containing eight tandem copies of a consensus estrogen response element (ERE) DNA sequence. The highly purified ER prepared by this new scheme may be labeled economically with ligands of high specific activity. This purification scheme selects for intact receptors retaining function in both estrogen-binding and DNA-binding domains. Purified receptor has an electrophoretic mobility consistent with a molecular weight of 68,000, sediments as a 5S species on sucrose gradients, and reacts with antibody specific to the human estrogen receptor.

Changes in the connective tissue of corpus and cervix uteri during ripening and labour in term pregnancy

The composition of the connective tissue of human cervix and corpus uteri was studied in tissue specimens from seven nonpregnant women and 14 pregnant women, delivered at term by section, to examine spontaneous cervical ripening and labour-induced changes in both the uterine and the cervical connective tissue. The main finding in both the cervix and the corpus was a large (40-60%) decrease of the collagen concentration. The collagen extractability, obtained by pepsin digestion, was increased twofold, suggesting a change of the organization of the collagen fibrils. This reorganization process could also be demonstrated by a large increase of the collagenolytic activity demonstrated with an artificial DNP-peptide substrate. The concentrations of sulphated glycosaminoglycans was lower in pregnant women than in non-pregnant women. The results show that both the cervix and the corpus uteri contain substantial amounts of connective tissue components (collagen, sulphated glycosaminoglycans and hyaluronic acid) and that during ripening, reconstruction of the connective tissue components occurs in both sites. This indicates that the cervical state reflects that of the myometrium.

Reactivity of epidermal growth factor receptor monoclonal antibodies with human uterine tissues

Two monoclonal antibodies (29.1 and 528), which were raised against the epidermal growth factor receptor, were used to evaluate expression of epidermal growth factor receptor in frozen uterine tissue with immunohistochemical techniques. Monoclonal antibody 29.1 stained only vascular endothelium and glandular epithelium in patients who were blood type A. This staining pattern is consistent with the previously reported blood type A specificity of this antibody. Monoclonal antibody 528, which recognizes a peptide determinant is thought to be specific for the epidermal growth factor receptor, stained both endometrial glands and endometrial stromal cells heavily. Faint staining was also seen in myometrium in most cases. This marked difference in expression of epidermal growth factor receptor between endometrium and myometrium contrasts with results of prior biochemical studies in which tissue homogenates were used. No variation in intensity of staining was seen between proliferative and secretory endometrium with the use of either antibody.

Coexistence of cytoplasmic and nuclear estrogen receptors. A histochemical study on human mammary cancer and rabbit uterus

Consecutive serial cryostat-frozen sections of 157 human mammary carcinomas and the uteri of six immature New Zealand white rabbits were stained histochemically for cytoplasmic estrogen receptor (ER) and nuclear ER by a fluorescent estrogen compound (Fluorocep Estrogen, Zeus Technologies, Inc., Raritan, NJ) and by a monoclonal antibody immunoperoxidase technique (ER-ICA, Abbott Laboratories, North Chicago, IL), respectively. The percentage of the ER-positive cells in the cancer cell population under observation was estimated and recorded. The results of the cytoplasmic ER assay were compared with those of the nuclear ER assay in each tumor; all cancers with less than 10% ER-positive cancer cells were grouped together as ER-negative tumors, the cancers with 30% or more ER-positive cancer cells as ER-positive tumors, and those with 10% to 29% ER-positive cancer cells as borderline positive. According to this manner of classification, 94% to 97% of the ER-positive mammary carcinomas diagnosed by one histochemical assay would have been identified as such by the other with no more than 10% difference in the ER-positive cell counts. The majority of ER-positive breast cancer cells and practically all of the luminal lining cells of the immature rabbit endometrium had coexistent cytoplasmic and nuclear ER. In the mammary cancers containing less than 30% ER-positive cancer cells, there was a greater (up to 20%) discrepancy in positive cell counts between the cytoplasmic ER assay and the nuclear ER assay. This discrepancy may be due to sampling errors of small clones of ER-positive cancer cells in two adjacent sections, difference in antigenic determinants between the cytoplasmic and the nuclear ER, and the binding sites in the nuclear ER being preoccupied by estrogen. The findings of this study appear to support the hypothesis that there are ER in the cytoplasm and the nucleus of the mammary carcinoma cells and the epithelial cells of the endometrium.

Progesterone versus dehydrogesterone as replacement therapy in women with premature ovarian failure

Dehydrogesterone (DH) induces normal endometrial secretory patterns in infertile as well as post-menopausal women, and has been successfully employed in the treatment of luteal-phase defects. The purpose of this study was to compare DH and progesterone (P) as progestins in steroid replacement cycles in eight women with premature ovarian failure (POF). Patients were treated during two subsequent cycles. Oestradiol valerate was used as the oestrogen. Four women received P as progestin in the first treatment cycle, while the remaining four patients began with DH. Histological dating and total protein content of uterine fluids (PCUF) were used as markers of P action on the endometrium. Samples were obtained on days 18-19 (early luteal phase, ELP) and day 26 of each cycle. Five regularly cycling women served as control for the normal range of PCUF. Histological dating of the endometrium showed ELP out-of-phase glands in 37.5% of cases treated with DH in comparison to none in the P group. Moreover, a characteristic ELP stromal haemorrhagic suffusion and increased oedema were present at the surface of the endometrium in all cases treated with DH. There was no histological difference between treatments on day 26 of the cycle. A significant (P less than 0.05) decrease in PCUF was observed in DH-treated endometria in comparison to P-treated endometria and controls. All three cases dated as out-of-phase endometria in the ELP had a PCUF less than or equal to 0.5 mg/ml. There was no difference between groups in PCUF on day 26. In conclusion, the morphological and biochemical data suggest that the endometrium supplemented with DH in women with POF fails to present optimal conditions for implantation of human embryos in the ELP. It is recommended that oral DH should not replace i.m. P as the progestin in steroid replacement cycles.

Changes in the connective tissue of corpus and cervix uteri during ripening and labour in term pregnancy

The composition of the connective tissue of human cervix and corpus uteri was studied in tissue specimens from seven nonpregnant women and 14 pregnant women, delivered at term by section, to examine spontaneous cervical ripening and labour-induced changes in both the uterine and the cervical connective tissue. The main finding in both the cervix and the corpus was a large (40-60%) decrease of the collagen concentration. The collagen extractability, obtained by pepsin digestion, was increased twofold, suggesting a change of the organization of the collagen fibrils. This reorganization process could also be demonstrated by a large increase of the collagenolytic activity demonstrated with an artificial DNP-peptide substrate. The concentrations of sulphated glycosaminoglycans was lower in pregnant women than in non-pregnant women. The results show that both the cervix and the corpus uteri contain substantial amounts of connective tissue components (collagen, sulphated glycosaminoglycans and hyaluronic acid) and that during ripening, reconstruction of the connective tissue components occurs in both sites. This indicates that the cervical state reflects that of the myometrium.

Species differences in estrogen receptors and in the response to 2,3,7,8-tetrachlorodibenzo-p-dioxin exposure

The acute toxicity of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) exhibits marked interspecies variability, with the guinea-pig, rat and hamster representing the species most sensitive, intermediate and most resistant to acute toxicity. Prepubertal guinea-pigs, rats and hamsters were treated with a single intraperitoneal injection of TCDD in olive oil at doses of 4, 50 and 1500 micrograms/kg, respectively. These exposures were chosen to produce acute toxicity and all 3 species exhibited a decrease in the rate of body weight gain during the 7 days following TCDD exposure when compared with control (olive oil-treated) animals. On the 7th day after exposure, the density and affinity of 17 beta-estradiol receptors were determined in the uterus and liver of TCDD-treated and control animals. The treatment with TCDD did not alter the affinity of the receptors in these 3 species. The density of hepatic 17 beta-estradiol receptors was decreased 65% in the guinea pig and 92% in the rat following exposure to TCDD. In contrast, TCDD-treated hamsters exhibited no change in the density of hepatic 17 beta-estradiol receptors. The uterine 17 beta-estradiol receptors were increased in density by TCDD treatment in the hamster and in the rat when expressed per mg protein. Uterine wet weights in the guinea-pig and rat were also significantly decreased by TCDD treatment but were not changed in the hamster. When the Bmax for uterine 17 beta-estradiol receptors was expressed as pmol/g tissue wet weight. TCDD exposure was found to produce an 11% decrease in density in the rat, while producing a 44% increase in the hamster. In control animals, the density of uterine 17 beta-estradiol receptors correlated inversely with the lethal dose of TCDD in these 3 species (i.e., the guinea-pig has the lowest LD50 and highest density of uterine 17 beta-estradiol receptors). The different responses to TCDD in the 3 species suggest that the changes in 17 beta-estradiol receptors may be related to species-specific toxic responses associated with TCDD exposure.

Concentration and turnover of estradiol in the rat uterus in vivo

The concentrations and turnover of estradiol isolated from cytosolic and nuclear fractions of uteri from ovariectomized rats given estradiol, either in single injections or in continuous infusion, were analyzed by gas chromatography-mass spectrometry. The analytical method was validated for different organs and lower limits of analysis were established. After infusion of 20 ng x h-1 for 18-22 h, mean estradiol levels were 2.0-2.4 fmol x mg-1 uterine wet weight in the nuclear fraction, and 1.2-1.5 fmol x mg-1 in the cytosolic fraction. The concentrations were about five times higher after a single injection of one microgram estradiol but the distribution between nuclear and cytosolic fractions was almost the same. The concentrations of estradiol in nuclei from liver and spleen were 50-200 times lower than those in uterus. Taken together with previous knowledge, the results indicate that the distributions of estradiol and its receptor are not the same and that hormone response cannot be predicted from the concentration of receptors alone. The exchange of estradiol molecules in the uterus was followed after a change of the infusion from unlabelled to [11,12,12-2H3]-labelled estradiol, or vice versa. The uterine uptake of estradiol was calculated to be about 0.7 fmol x h-1 x mg-1 uterine wet weight. The half-life time was calculated to be at least 4 h for estradiol molecules isolated from the nuclear fraction and 3 h (significantly shorter) for those isolated from the cytosolic fraction. The results indicate an uptake of 40-90% of all estradiol passing through the uterus in proestrus with only about 10% of available receptors becoming occupied. When the infusion was changed from estradiol to ethynylestradiol, estradiol disappeared from the uterus at the same rate as in the experiments above. Ethynylestradiol was taken up at a rate of about 0.3-0.4 fmol x h-1 x mg-1 tissue. The percentage of total steroid found in the nuclear fraction was higher for ethynylestradiol, about 70%, than for estradiol, about 60%, indicative of a more stable association of receptor to nuclear binding sites when ethynylestradiol is the ligand.

Differential tissue expression of three 35-kDa annexin calcium-dependent phospholipid-binding proteins

We have purified three 35-kDa calcium- and phospholipid-binding proteins from rat liver. These three calcimedins bind to phosphatidylserine in a calcium-dependent manner and have been termed 35 alpha, 35 beta, and 35 gamma based on their relative charge as determined by isoelectric focusing. Purification of the three 35-kDa calcimedins is achieved by phenyl-Sepharose, ion exchange, and gel filtration chromatography. Antibody was produced against the annexin consensus peptide, Lys-Ala-Met-Lys-Gly-Leu-Gly-Thr-Asp-Glu, which was derived from the sequence of several Ca2+/phospholipid-binding proteins including calpactin, lipocortin, endonexin II, 67-kDa calelectrin, lymphocyte 68-kDa protein, and protein II. Recognition of each 35-kDa calcimedin by anticonsensus sequence antibody places them in this protein family. Antibodies against each 35-kDa calcimedin were raised and purified by antigen-affinity chromatography. Each antibody is monospecific for the respective 35-kDa calcimedin. Immunological cross-reactivity defines 35 alpha, 35 beta, and 35 gamma as lipocortins III, IV, and V, respectively. Surveys by immunoblot analysis using these monospecific antibodies demonstrate a markedly different tissue expression pattern for each 35-kDa calcimedin. Furthermore, the levels of 35 alpha, 35 beta, and 35 gamma are differentially regulated in maturing rat ovary and uterus. Each calcimedin has been localized by indirect immunofluorescence within specific cell types. These results support the concept that mediation of the intracellular calcium signal can occur via multiple pathways through several related yet independent mediator proteins.

Separation of two molecular forms of human estrogen receptor by hydrophobic interaction chromatography. Gradient optimization and tissue comparison

High-performance hydrophobic interaction chromatography (HPHIC) was used to separate and characterize two molecular forms of estrogen receptor with a SynChropak propyl hydrophobic column (300 A pore size). The linear gradient utilized earlier with a polyether-bonded column (2 to 0 M) ammonium sulfate in 40 min, gave poor resolution with the propyl column. However, resolution was maximized with either an initial ammonium sulfate concentration of 1 M (40-min gradient) or with a two-phase gradient (2 to 0.5 M in 10 min, 0.5 to 0 M in 30 min). This indicated that the propyl column was more hydrophobic than the polyether column. Estrogen receptor separated into two isoforms, either in the presence [MI, retention time (tR) = 13-14 min; MII, tR = 20-21 min] or absence (I, tR = 21-23 min; II, tR = 31-33 min) of the estrogen receptor stabilizing reagent, sodium molybdate. Similar isoforms were observed in cytosols from human breast tumors, uterus, and MCF-7 breast cancer cells. Unlike others, MCF-7 estrogen receptor did not show MI. Since MCF-7 cells contain 90,000 dalton heat shock proteins (HSP-90), HSP-90 is probably not directly involved in MI formation. Sodium molybdate selectively interacted with isoform II and converted it to MI. All isoforms appeared to be high-molecular-weight proteins (greater than 60 A) when subsequently analyzed by high-performance size-exclusion chromatography. Interestingly, when estrogen receptor was immobilized on the stationary phase, no change was detected in either hydrophobicity or steroid-binding capacity. After 16-18 h, immobilized receptor was eluted with a slightly longer tR. During incubation on the column, component MI was converted into I and/or II. HPHIC appears to be a rapid, yet gentle procedure for isolating large receptor complexes in significant quantities with high recoveries. This allows one to discern the complicated structure-function relationships of estrogen receptor and associated non-receptor proteins and provides information about the on-column behavior of complex proteins.

Uterine insulin-like growth factor-I receptors: regulation by estrogen and variation throughout the estrous cycle

This study was undertaken to identify uterine insulin-like growth factor-I (IGF-I) receptors and examine the regulation of these receptors throughout the estrous cycle and after 17 beta-estradiol (E2) administration to immature rats. We have demonstrated type I IGF receptors in crude uterine membranes by binding and cross-linking experiments. The characteristics of the uterine IGF-I receptor are similar to those reported for other tissues, with a high affinity component (Kd = 0.12 nM; binding capacity = 0.028 pmol/mg protein) and a low affinity component (Kd = 0.98 nM; binding capacity = 0.041 pmol/mg protein). Autoradiographic visualization of [125I]IGF-I binding to uterine sections localized the IGF-I receptors to the smooth muscle cells of the myometrial layer of the uterus, with a higher density of IGF-I receptors in the outer longitudinal layer than in the inner circular layer. In immature rats administration of E2 significantly increased total [125I]IGF-I binding per uterus as early as 6 h after E2 injection. Although [125I]IGF-I binding was significantly increased per mg DNA, because of a more marked increase in membrane protein after E2, [125I]IGF-I binding, when expressed per mg membrane protein, decreased. This change in [125I]IGF-I binding resulted from a change in receptor number with no change in receptor affinity. In mature cycling rats, the proestrous uteri showed the lowest level of [125I]IGF-I binding per mg membrane protein, although because of the greater yield of protein from proestrous uteri, the total [125I]IGF-I-binding capacity of these uteri were greater than that of uteri from other stages of the estrous cycle. The lowest [125I]IGF-I binding was seen in the diestrous uteri. These studies demonstrate the presence of authentic type I IGF-I receptors in the rat uterus localized predominantly to the myometrial smooth muscle cells. In addition, E2 appears to regulate the uterine IGF-I receptor in the immature rat, and the cyclical changes in the mature rat are consistent with a role of E2 in regulation of this receptor in vivo.

Characterization of oxytocin receptors in rat adenohypophysis using a radioiodinated receptor antagonist peptide

Oxytocin may function as a hypothalamic releasing hormone for prolactin and ACTH secretion in the rat. In the present study we have investigated the properties of putative oxytocin receptors in the rat adenohypophysis by radioligand-binding assay. A novel oxytocin receptor antagonist [1-(beta-mercapto-beta,beta-cyclopentamethylene propionic acid),2-(ortho-methyl)-Tyr2-Thr4-Orn8-Tyr9-NH2]-vasotocin (OTA) was radioiodinated by the iodogen method to a specific activity of 0.6 nCi/fmol. The radioiodinated derivative 125I-labelled OTA (125I-OTA) was reacted with membrane suspensions prepared from the uterus or adenohypophysis of female rats which were (a) ovariectomized for 7 days, (b) ovariectomized and treated with 5 micrograms oestradiol-17 beta 48 h before death or (c) implanted with a piece of silicone elastomer tubing containing 50 mg diethylstilboestrol (DES) 5 days before death. In uterine as well as the pituitary membrane suspensions, the radioligand was bound reversibly and with high affinity (dissociation constants 0.2 +/- 0.1 and 0.1 +/- 0.01 nmol/l respectively; mean +/- S.E.M., n = 3) to a single class of sites with limited binding capacity, which varied with the type of pretreatment. Oestradiol-17 beta increased the binding capacity fivefold in the uterus in ovariectomized rats, but only very low specific radioligand binding was found in pituitary preparations from the same animals. Treatment with DES markedly increased the number of receptors in both the uterus and the adenohypophysis. Studies with several agonist and antagonist analogues revealed no difference in the ligand specificity of the uterine and adenohypophysial sites binding 125I-OTA, indicating that they are the same species of receptor.(ABSTRACT TRUNCATED AT 250 WORDS)

Immunofluorescent analysis of estrogen induction of progesterone receptor in the rhesus uterus

Estrogen (E) has been shown to induce an increase in progesterone (P) receptor (PR) concentration in uterine tissue of both rodents and primates. Because of the presence of different cell types within the uterus, we were interested in determining whether estrogen-induced PR were cell type specific in the nonhuman primate uterus (rhesus monkey). Immunofluorescent analyses of E receptor (ER) and PR were performed on fresh frozen cryostat sections (6 microns) of uterine tissue from ovariectomized (3 months) and estradiol (E2)-treated (peak level of E2 during an artificial menstrual cycle) rhesus monkeys. Antibodies to ER and PR were obtained from Abbott Laboratories (H222) and Transbio (MPR1). The avidin-biotin complex technique was used with streptavidin-conjugated Texas red for fluorescent detection. Ovariectomized monkeys showed positive fluorescence for ER in luminal and glandular epithelia, stromal cells, and smooth muscle cells of the myometrium. In contrast, positive fluorescence for PR was observed primarily in glandular epithelia, with little or no fluorescent detection in luminal epithelium, stromal cells, or myometrial smooth muscle cells. After E2 treatment strong positive fluorescence for PR was observed in luminal and glandular epithelia, stromal cells, and myometrial smooth muscle cells. Strong positive fluorescence for ER was also observed in the same cell types. Fluorescent detection of ER and PR was restricted to the nuclei of these cell types. These studies show that ER are present constitutively in all cell types of the E-withdrawn (ovariectomized) nonhuman primate uterus, whereas PR are primarily restricted to glandular epithelia. E2 treatment, which simulated the follicular phase and E2 surge, resulted in the appearance of immunofluorescent PR in luminal epithelia, stromal cells, and myometrial smooth muscle cells. These studies serve to define the cellular pattern of E2-induced PR in the primate uterus.

[Assay of activated form of progesterone receptor with ATP-sepharose column chromatography]

Biological actions of progesterone are correlated with the ability of the progesterone receptor(PR) to bind to nuclear acceptor sites. Measurement of not only the presence of PR in a tissue but also the amount of that receptor which is able to bind to nuclear acceptor sites is important in predicting tissue response to progesterone. Activation of PR is required for effective binding to chromatin. Since the dextrancoated charcoal assay does not distinguish between an activated and a non-activated receptor, a rapid, relatively simple assay is needed which can account for an activated form of PR. Therefore, ATP-Sepharose column chromatography was tested to identify an activated form of PR. PR in crude uterine cytosol from estrogen-primed immature rabbits was labeled with 3H-progesterone at 0 degree C. The labeled PR was then incubated at 4 degrees C with uterine chromatin from ovariectomized mature rabbits. The freshly prepared PR had little capacity to bind to the chromatin. After activation manipulation at low temperature, low ionic strength and neutral pH, this PR was able to bind to chromatin approximately fourfold more than that activated by heating at 25 degrees C. The affinity of the activated and the non-activated PR for ATP was evaluated on ATP-Sepharose column chromatography. The activated PR was selectively adsorbed onto columns of ATP-Sepharose, and the binding ability of the activated PR to ATP paralleled that of the rabbit uterine chromatin. These results suggest that ATP-Sepharose column chromatography could be useful to identify an activated PR as a substitute for chromatin binding assay.

Hippocampus: a target for estrogen action in mammalian brain

An analysis of the distribution of estrogen receptor (ER) via immunoenzymatic assay in the brain of ovariectomized rats reveals the presence of large amounts of ER-like immunoreactive material in the cytosol of the hippocampus: a brain area described to contain little estrogen-binding activity. The protein detected in the hippocampus by the specific antibody is indistinguishable from the rat ER in its response to hormonal treatments and in its electrophoretic mobility. The presence of elevated amounts of ER in such an important part of the limbic system creates new possibilities for interpreting the role played by this sex hormone in the central nervous system of rat.

Mesonephric duct hyperplasia of the uterus. Report of two cases and three other cases of mesonephric duct remnant with findings of mucin histochemistry and lectin binding immunohistochemistry

Two cases of mesonephric duct hyperplasia of the uterus, together with three cases of uterine mesonephric duct remnant, are reported. The latter cases were identified by serial transverse sectioning of 42 surgically resected uteri, yielding a frequency of approximately 7%. Histochemical studies showed no mucin in the cytoplasm of cells lining the mesonephric duct remnant, as well as mesonephric duct hyperplasia. In contrast, the endocervical epithelium had abundant neutral mucin, sialomucin and sulfomucin. Immunohistochemical studies on lectin binding showed positive binding of PNA and SBA lectins only to the lining cells of mesonephric duct hyperplasia.

Identification of the major sources of error in estrogen receptor measurements for individual laboratories using both tissue and cytosol samples

The major sources of error between laboratories performing estrogen receptor measurements in tissue samples were identified for 17 participating laboratories in a trial conducted by the Australasian Quality Assurance programme. Both tissue and cytosol samples were provided, and the In-House assays were compared with the ER-EIA kit (Abbott Laboratories, U.S.A.) as a reference assay. For both the In-House and Abbott assays, tissue samples resulted in a between laboratory CV of about 55% and a within laboratory CV of about 30%. In contrast to tissue samples, the between laboratory CV for cytosol samples was reduced to 41% for the In-House assays and to 33% for the Abbott assay, whereas the within laboratory CV was reduced to 10% for both types of assay. The different methods of tissue homogenization by themselves were not found to be sources of error, and protein extraction efficiency from tissue was strongly correlated with protein measurement (P less than 0.0005). The major sources of error due to protein measurement, cytosol preparation, In-House and Abbott assays were evaluated for individual laboratories. The results indicated absence of any major sources of error for four laboratories, while one, two and three or more sources were indicated for seven, three and three laboratories respectively. The conclusion that about half the participants need to improve their ER assays was confirmed by three independent reviews. Furthermore, the trial demonstrated that tissue samples are essential as quality assurance material for a realistic assessment of ER assays in biopsy specimens.

Sources of improvement in between laboratory variation in estrogen and progestin receptor measurement using tissue samples during the Australian Quality Assurance Programme

Tissue and cytosol samples were compared as quality control material for assessment of between and within laboratory error in measurement of estrogen and progestin receptors (ER and PR) in a series of four trials for a total of 17 participating laboratories during the Australasian Quality Assurance Programme. For tissue samples, a substantial reduction in between laboratory CVs for both ER and PR from about 90 to 50% was achieved during the programme. In contrast, for cytosol samples a substantially lower between laboratory CV of about 30% was obtained. Tissue sample heterogeneity could be excluded as a major source of variation between laboratories. The likely source of the observed improvement in CV for tissue samples during the trials was due to a reduction of the initial under-estimation of receptor concentration in tissue samples by some of the participants. Although cytosol preparation from tissue samples was shown to be one major source of error, other sources of error such as the receptor assay itself and the associated protein measurements were identified. It is concluded that fragmented tissue samples are essential for a realistic assessment of between laboratory error in receptor measurements in biopsy material such as obtained from clinical breast cancer samples.

Progesterone in uterine and arterial tissue and in jugular and uterine venous plasma of sheep

Concentrations of progesterone in uterine and arterial tissue and in uterine and jugular venous plasma were determined. Blood was collected on Days 4 and 9 postestrus from the jugular vein and the first and last venous branches draining each uterine cornu; uterine tissue and arteries were subsequently collected. Progesterone was greater (p less than 0.05) in the cranial third than in the middle or caudal thirds of the uterine horn adjacent to the corpus luteum (CL)-bearing ovary or in any third of the contralateral horn. Progesterone in uterine arterial segments adjacent to the CL-bearing ovary was higher (p less than 0.05) than in contralateral segments. Progesterone was higher (p less than 0.05) in blood from the first venous branch of the cranial third of the uterine cornu adjacent to the ovary with the CL, than in the last branch of the caudal third, or contralateral horn, or in jugular blood. When oviductal veins were resected on Day 9 postestrus, progesterone in the first vein draining the cranial third of the uterine cornu adjacent to the CL-containing ovary was not different (p greater than 0.05) 48 h after resection than in the same vessel in the opposite horn or in jugular blood. We concluded that progesterone and other ovarian products may be delivered to the uterus locally.

Met5-enkephalin- and Met5-enkephalin-Arg6-Gly7-Leu8-immunoreactive nerve fibers in the pig female reproductive system

The localization of Met5-enkephalin (ME) immunoreactivity in the female genital organs of the rat, guinea pig and pig was studied by indirect immunofluorescence method. In the rat and guinea pig, no ME immunoreactivity was observed in the uterus, fallopian tube or ovary. In the pig uterus and fallopian tube ME-immunoreactive nerve fibers were observed in muscular and submucose layers as well as around the blood vessels. In the pig ovary, ME immunoreactivity was localized in nerve fibers in medullary and cortical parts of the organ. Met5-enkephalin-Arg6-Gly7-Leu8 (MEAGL) immunoreactivity was also studied in the pig uterus, where its distribution was similar to that of ME. The present results suggest that the pig genital organs receive innervation by nerve fibers containing proenkephalin A-derived peptides, which may have a role in modulation of neurotransmission in these organs.