Increase in uterine prostaglandin E2, F2 alpha, prostacyclin and stability in thromboxane A2 production during late pregnancy in streptozotocin-induced diabetic rats

This experiment was conducted to determine the effect of diabetes on uterine prostanoids production in near-term rats. The incidence of an insulin therapy was also studied. On the 21st day of pregnancy, uterine PGE2, PGF2 alpha and PGI2 levels showed a significant increase (respectively p less than 0.05, p less than 0.01 and p less than 0.05) in diabetic rats compared to controls whereas TxA2 production remained unchanged. The insulin therapy restored PGE2 levels, the most potent stimulatory factor of the myometrial fiber at control values, whereas it enhanced significantly PGI2 concentrations (p less than 0.05) and had no effect on PGF2 alpha production; TxA2 levels remaining always unchanged. It is suggested that the increase in uterine protanolds production during diabetes could induce a myometrial hypertonicity and play a role in the disturbances of the fetal development. The maintenance of PGE2 levels to control values by the insulin therapy might contribute to a normal delivery.

Differential growth factor content of uterine luminal fluids from large white and prolific Meishan pigs during the estrous cycle and early pregnancy

Uterine luminal fluids (ULF) from Large White (LW) and prolific Chinese Meishan (MS) gilts were compared with respect to their peptide growth factor content during an estrous cycle and early pregnancy. Insulin-like growth factor-I (IGF-I) was quantitated by RIA; in vitro growth promoting properties of uterine luminal fluid mitogen (ULFM) were measured by [3H]thymidine incorporation into DNA of quiescent AKR-2B fibroblastic cells in culture. Peak concentrations (pg/microgram ULF protein) of IGF-I in ULF of Large White and Meishan gilts, respectively, were: estrous cycle, 9.8 +/- 1.4 (on d 10) and 39.7 +/- 7.8 (on d 12); gestation, 13.1 +/- 3.2 (on d 8 and 10) and 11.9 +/- 2.1 (on d 12), with differences among days (except d 10, P greater than .5) being affected by breed (P less than .10). For both breeds, there was a rapid decline in IGF-I concentrations by d 14 of the cycle and of pregnancy. Uterine luminal fluid mitogen activity was greater (P less than .01) for LW than for MS gilts on d 10 to 14 of an estrous cycle and gestation and diminished in a time-dependent manner in both breeds. No correlation was observed between IGF-I concentrations and uterine weights for either breed. In contrast, a negative correlation between uterine weight and ULFM activity was detected for cyclic (MS: r = -.855, P less than .10; LW: r = -.834, P less than .05) and pregnant (MS: r = -.806, P less than .10; LW: r = -.928, P less than .05) gilts.(ABSTRACT TRUNCATED AT 250 WORDS)

Uterine and placental 5-HT profile in different gestational period of albino rats

Possible role of 5-HT in pregnancy was investigated in albino rats by biological estimation of uterine and placental 5-HT contents in different periods of gestation in normal and drug treated rats. Uterine 5-HT level increased steadily from day-1 of gestation to reach the peak on day-7; thereafter, the level continued to decline throughout the period till day-20 when 5-HT level was lowest. From day-20, a mild secondary rise started and remained persistent even after parturition. The results show that a critical level of 5-HT in early gestational period is necessary for conception. Manipulation of endogenous 5-HT do not influence duration of gestation.

Immunological analysis of the biochemical properties of the uterine estrogen receptor

Immunohistochemical and immunochemical analysis using Western blot techniques were carried out with estrogen receptor (ER) monoclonal antibody H-222 to 1) clarify the "nuclear translocation" phenomenon of ER, 2) elucidate the primary nuclear binding site of ER, and 3) to evaluate the binding force between ER and its nuclear binding site in the uterus of ovariectomized adult mice. Exclusive nuclear localization of ER was recognized in the epithelial cells, stroma cells, and smooth muscle cells. Uterine tissues prepared from animals injected with saline, 17 beta-estradiol (E2), estriol (E3), and diethylstilbestrol (DES) exhibited almost the same ER immunostaining when they were fixed prior to sectioning (prefixation method) and frozen sections were used. On the other hand, when fresh-frozen sections were fixed before or after incubation with various solutions (postfixation method) and then treated with various salt solutions, greater differences were seen in immunostaining of ER between saline-injected and hormone-treated animals. Immunostaining of ER in control animals was low after incubation with PBS (0.01 M phosphate buffer containing 0.16 M NaCl, pH 7.2), whereas uterine tissue from hormone-injected mice showed strong nuclear immunostaining after this treatment. After treatment with 0.4 M KCl or 0.5 M NaCl, immunostaining in the uterus of both hormone-injected and control animals was completely abolished. DNase treatment caused an almost complete loss of immunostaining of ER; however, RNase digestion slightly increased immunoreactivity in both E2-injected and control animals. Quantitative analysis using sodium dodecyl sulfate-polyacrylamide gel electrophoresis and Western blot techniques showed that after incubation of tissue sections for 30 min with PBS, 0.4 M KCl, or DNase, 60%, 10%, and 30% of ER were present, respectively, compared to amount of ER present in unincubated sections. These findings suggest the following for the ER in uterine tissue; nuclear occupancy is a phenomenon that occurs due to a differential affinity between occupied and unoccupied receptors in the nucleus; after hormone treatment, the receptor levels do not fluctuate in the nucleus to the extent demonstrated by binding assays; and the properties of the ER detected in the immunohistochemical analysis are identical to those observed in biochemical studies.

Chromogranin- and somatostatin-containing neuroendocrine cells in the porcine uterus. An immunocytochemical study

Endocrine cells scattered in organic mucosae were defined "Neuroendocrine" (NE) cells because they constitute a section of the Diffuse Neuroendocrine System (DNES). Such cells have never been evidentiated in the normal endometrium. By means of histochemical and immunohistochemical techniques, NE cells, some of which contain the hormone somatostatin, are described in the glandular epithelium of the uterine horn in non-pregnant, non-castrated, young and adult sows. As is known, the uterine horn is the organ of pregnancy in the pig. The localization, distribution and morphology of the uterine NE and somatostatin-containing cells are reported and the importance of their function, in the pregnant and non-pregnant porcine uterus, is discussed.

Identification of lung major GTP-binding protein as Gi2 and its distribution in various rat tissues determined by immunoassay

Antisera were raised in rabbits against the 40-kDa alpha subunit of bovine lung GTP-binding protein, which were identified as the alpha subunit of Gi2 (Gi2 alpha) by the analysis of the partial amino acid sequence. Antibodies were purified with a Gi2 alpha-coupled Sepharose column and then were passed through a Gi1 alpha-coupled Sepharose column to remove antibodies reactive also with 41-kDa alpha. Purified antibodies reacted with Gi2 alpha, but not with Gi1 alpha, Gi3 alpha, or Go alpha in an immunoblot assay. A sensitive enzyme immunoassay method for the quantification of Gi2 alpha was developed by using these purified antibodies. The assay system consisted of polystyrene balls with immobilized antibody F(ab')2 fragments and the same antibody Fab' fragments labeled with beta-D-galactosidase from Escherichia coli. The minimal detection limit of the assay was 1 fmol, or 40 pg. Samples from various tissues were solubilized with 2% sodium cholate and 1 M NaCl, and the concentrations of Gi2 alpha were determined. Gi2 alpha was detected in all the tissues examined in the rat. The highest concentration was found in platelets and leukocytes when the data were expressed as picomoles per milligram of protein. The spleen, lung, and cerebral cortex contained relatively high levels of Gi2 alpha. In the bovine brain, Gi2 alpha was distributed almost uniformly among the various regions. The concentrations of Gi2 alpha were constant in the rat brain throughout ontogenic development, in contrast with those of Go alpha which were markedly increased with age.

Ontogeny and implication of pregnancy-associated agglutinin of the rat uterus

The mannose/fructose-binding agglutinin from Day 1-7 post coitum (p.c.) rat uteri was purified on Concanavalin A. The specific haemagglutination activity peaked on Days 4 and 5 p.c. and a 1.4-fold increase in the yield was accompanied by a 10-12-fold increase in specific agglutination titre. The mannose-binding affinity of the protein also increased, but the highest fructose-binding affinity was found on Day 1 p.c., which may indicate a role of the protein in fructose concentration for utilization by the spermatozoa. Rats that were pseudopregnant, superovulated and pseudopregnant, and had one uterine horn ligated showed that, although a basal level of the protein was induced by the hormonal milieu, actual stimulation of the protein synthesis occurred in the presence of the fertilized ova.

Immunofluorescent localization, by use of anti-idiotypic antibody, of monoclonal anti-progesterone antibody in the mouse uterus before implantation

Mouse monoclonal anti-progesterone IgG1 antibody designated DB3 has an anti-fertility effect when injected into female mice shortly after mating. In BALB/c mice, pregnancy is blocked, probably as a result of progesterone withdrawal with inhibition of implantation. Rabbit polyclonal anti-idiotype raised against DB3 has been used in an indirect immunofluorescence method on frozen tissue sections to demonstrate the presence of DB3 on the surface of uterine luminal and glandular epithelia before implantation. DB3 was only detectable 30-60 h after a single parenteral injection (9 nmol antibody per mouse i.p. or i.v. at 32 h post coitum). Immunolocalization was both pregnancy-dependent and anti-progesterone antibody-specific, as it was not seen in pseudopregnant mice or mice treated with P3 (mouse myeloma IgG1 protein, using polyclonal anti-P3 anti-idiotype as a probe) or saline. The immunofluorescent reaction was completely blocked by addition of DB3 idiotype in vitro. The results indicate that anti-progesterone antibody binds to an antigen associated with luminal and glandular epithelia which may locally inhibit the uterine uptake of progesterone and disrupt the process of implantation.

Changes in cytosolic and nuclear progesterone receptors during pregnancy in rat placenta

These studies examine changes in placental growth and the abundance of progesterone receptors (Rp) in whole placentas between Days 9 and 22 of pregnancy. In addition, some placentas were dissected into decidual basalis, junctional zone, and labyrinth zone before assay of Rp. High affinity binding of 3H-progesterone to Rp was detected at all stages of pregnancy in whole placentas and in decidua basalis and the junctional zone of the placenta. Cytosolic and nuclear receptors exhibited similar affinity for progesterone in both tissues (Kd = 3.1 +/- 0.3 and 4.4 +/- 0.7 nM, respectively). Receptor binding in whole placentas increased from Day 9 to Day 12 (p less than 0.05), declined markedly at Day 16 (p less than 0.05), and returned to former levels on Days 19 and 22 (p less than 0.05). Decidua basalis contained 84% of total Rp on Day 14, which declined to 67% on Day 17 (p less than 0.05). The junctional zone contained 16% of total Rp on Day 14 and 33% on Day 17. After Day 17, junctional zone was the only source of Rp. The decline in Rp on Day 16 followed regression of decidua basalis; recovery of Rp thereafter was due to growth of the junctional zone. The labyrinth zone did not express significant amounts of Rp at any stage despite a 4-fold increase in growth in late pregnancy. Although the biologic role of the Rp in maintenance of pregnancy is poorly understood, these studies suggest that the maternal decidua basalis and fetal junctional zone are targets of progesterone action.

Changes in electrical activity of myometrium during intrauterine distribution of rat blastocysts and after prazosin administration

In the early pregnant rat, electrical activity of the myometrium consisted of regular bursts of spike potential, which appeared well propagated on Day 2 of pregnancy. During Day 3, there was a gradual disappearance of propagated activity. Concomitantly, there was a 7-fold increase (P less than 0.001) of uterine progesterone concentrations. At this stage, mean duration of bursts was 15.2 +/- 0.9 sec and intervals of complete quiescence between bursts were 84.2 +/- 7.0 sec. At 10:00 h on Day 4, there were peaks in the uterine concentrations of oestradiol and progesterone, +36% and +654%, respectively, compared with values on Day 2 (P less than 0.05). Between 10:00 and 20:00 h on Day 4, EMG activity exhibited a rapid and transient rise: bursts were of longer duration at the utero-tubal end of the horn (+60%, P less than 0.05) with an increased amplitude of spike potentials (+67% and +90% respectively at the tubal and cervical ends of the uterus, P less than 0.05). The administration of prazosin depressed EMG activity reversibly in a dose-dependent manner with maximal inhibition at about 2-3 h later. It is concluded that the changes observed during EMG recordings are relevant to the intrauterine distribution of blastocysts and related to changes in the steroidal environment and/or to catecholamine effects via alpha 1-adrenoceptors.

Gestational changes in calbindin-D9k in rat uterus, yolk sac, and placenta: implications for maternal-fetal calcium transport and uterine muscle function

Calbindin-D9k was quantified and its cellular location was defined in uterus, yolk sac, and placenta. In late gestation (days 17 to term) coordinated induction of calbindin-D9k was seen in uterine epithelial lining cells and juxtaposed yolk sac visceral epithelium as well as the intraplacental yolk sac epithelium. The induction of calbindin-D9k in these cells coincided with the time of exponential fetal bone growth and maximal fetal accumulation of calcium, suggesting a role of the protein in these epithelial layers in maternal-fetal calcium transport. Dynamic changes also occurred in the calbindin-D9k contents of the two layers of uterine smooth muscle (outer longitudinal and inner circular) during mid- and late gestation. During early pregnancy (days 0-4), calbindin-D9k was present in the two smooth muscle layers. By midgestation (day 10), calbindin-D9k had decreased by a factor of 10 in these tissue layers. During late gestation calbindin-D9k rebounded in the inner circular smooth muscle layer. These uterine changes of early and midgestation were reproduced by the endocrine changes of pseudopregnancy. Progesterone appeared to be a good candidate for controlling the midgestational decrease of uterine muscle calbindin-D9k, as it blunted estrogen's induction of the protein in the muscle layers and stroma in a dose-dependent manner. Changes in myometrial calbindin-D9k may reflect variations in muscular calcium storage, thereby representing alterations in potential for contraction.

Kinins contribute to the contractile effects of rat glandular kallikrein on the isolated rat uterus

Glandular kallikrein is known to promote contractions of the isolated, estrogenized rat uterus, perhaps independently of kinin formation. The recent availability of kinin receptor antagonists led us to study whether they might affect the oxytocic activity of kallikrein. DArg0-Hyp3-Thi5,8-DPhe7-bradykinin (8.5 x 10(-7) M) displaced the dose-response curves to both bradykinin (from 1.0 x 10(-9) to 4.0 x 10(-6) M) and kallikrein (from 4.7 x 10(-11) to 8.0 x 10(-9) M) approximately one order of magnitude to the right. This inhibition could not be due to a nonspecific effect on the uterine muscle, as the contractile response to oxytocin was not altered. In addition, carboxypeptidase B (a potent kininase) and kinin antibodies reduced the contractile response to kallikrein by 70 and 60%, respectively. Removal of the intervening agent restored the normal response. The effect of kallikrein depended on its enzymatic activity, inasmuch as kallikrein inactivated with D-Phe-Arg-Arg-CH2Cl was not oxytocic. Prolonged or multiple exposures to kallikrein completely abolished uterine response, whereas the effect of bradykinin was unaltered. Uterine horns rendered insensitive to kallikrein by prolonged exposure still contracted in response to trypsin. Kininogen was present in the uterine tissue in a concentration of 1.5 +/- 0.3 ng of bradykinin equivalents per mg wet wt. No more than 15.9 +/- 1.2% of this total was due to plasma contamination. Only 21.5 +/- 2.9% of total kininogen could be cleaved by kallikrein. We conclude that part of the oxytocic activity of kallikrein is related to generation of kinins from a kallikrein-sensitive kininogen present in the isolated rat uterus.(ABSTRACT TRUNCATED AT 250 WORDS)

Characterization and estrogen regulation of growth factor activity from uterus

Acid-stable uterine-derived growth factor activity, extracted from uteri of several species (rat, rabbit and bovine), stimulates DNA synthesis as measured by [3H]thymidine incorporation into hamster uterine carcinosarcoma (UCS) cells. A time course of [3H]thymidine incorporation demonstrates maximum incorporation at 24 h. These extracts also stimulate [3H]thymidine incorporation in a variety of other cell types from 17 beta-estradiol (E2) target tissues and non-target tissues. Uterine extracts from E2-treated ovariectomized rats show a 3-fold increase in growth factor activity above control values. Activity is elevated within 18-24 h after estradiol injection and remains elevated wtih subsequent injections. Growth factor activity is acid-stable, heat-labile, reduced by trypsin but not reduced by treatment with dextran-coated charcoal. Gel filtration shows molecular weight (Mr) heterogeneity with activity eluting at Mr of 10,000-30,000. Since uterine extracts can restore in vitro the estrogen-regulated properties of uterine growth observed previously in vivo, it is possible that the substances found in these extracts may be mediators of E2 actions.

Steroid hormone receptors in the uterus and ovary of immature rats treated with gonadotropins

We administered either saline (group A) or 10 IU of pregnant mare serum gonadotropin (PMS; groups B and C) to female immature rats. Fifty-three hours later, the rats were injected with saline (groups A and B) or 30 IU of human chorionic gonadotropin (hCG; group C). The rats were decapitated 17 h after the last treatment, and the serum levels of progesterone (P4) and estradiol (E2) were measured by specific radioimmunoassays (RIA). The receptor levels of progesterone (PR) and estrogen (ER) in the uterus and ovaries were measured and the dissociation constant (Kd) of PR was obtained. The highest serum level of P4 was found in group C and that of E2 in group B. Cytosol levels of PR and ER in the uterus and ovary of the group B were the highest. It was indicated that the PMS treated-group (B), which had developing follicles in the ovary and the high serum level of E2, showed the highest concentration of ER and PR in both the ovary and the uterus. In the PMS and hCG-treated group (C), the uterine and ovarian steroid receptors decreased probably because of the luteinization and the high serum level of P4. The Kd uterine PR value was less than that of ovarian PR.

Characterization of electrolytes and protein content in isthmic and uterine flushings from hens laying shell-less versus hard-shell eggs

In Experiment 1, hens laying hard-shell (HS) eggs were sacrificed at each of eight stages of egg formation including oviposition (0 h) and 1, 4, 8, 12, 16, 20, and 24 h after oviposition. In Experiment 2, hens laying either shell-less (SL) or HS eggs were sacrificed at four stages of egg formation (oviposition, 4, 8, and 20 h after oviposition). The isthmus and uterus were flushed with 6 and 10 mL of cold .85% NaCl, respectively, and electrolyte contents were determined. Total flushing contents of calcium, potassium, and magnesium were higher (P less than or equal to .01) in uterine than in isthmic flushings (Experiment 1). In every case, an interaction (P less than or equal to .01) between time of collection and organ (isthmus and uterus) was found, indicating that patterns of change in flushing content of each electrolyte differed in the two organs over time in birds laying HS eggs. In Experiment 2, total recoverable calcium, magnesium, potassium, and total protein were higher in uterine than isthmic flushings (P less than .01). Interactions between time of collection (0, 4, 8, and 20 h) and treatment group (SL or HS) were observed for all electrolytes measured in uterine flushings. Results suggest that calcium, required for shell calcification, does not appear in the isthmic or uterine lumen or both at an appropriate time in SL hens. Thus, production of SL eggs may be related to mechanisms regulating patterns of change or ratios of electrolytes (calcium, magnesium, potassium) or both in the isthmus or uterus of the laying hen.

Regulation of rat uterine steroid receptors by nomegestrol acetate, a new 19-nor-progesterone derivative

The regulatory effects of nomegestrol acetate (NOM-Ac: 17 alpha-acetoxy-6 alpha-methyl-19-nor-pregna-4,6-diene-3,20-dione), a new 19-nor-progesterone derivative, active p.o. progestin, were studied on rat uterine estrogen (ER) and progestogen receptor (PgR) levels. The actions of estradiol (E2), progesterone (P) and various progestins were investigated. The effects of E2 were reproduced with 5 micrograms/animal: a 2-fold increase in activated ER level in the nucleus at 30 min, 2-fold stimulation of cytosolic ER replenishment at 48 hr and a 4-fold induction of PgR synthesis at 48 hr. The negative regulatory effects of P were also reproduced at doses ranging from 0.25 to 2 mg/animal: inhibition of basal and E2-stimulated cytosolic ER replenishment and inhibition of E2-induced PgR synthesis. NOM-Ac reproduced these negative regulatory effects. The 50% effective doses in reducing estrogen receptor levels and the corresponding potencies relative to P showed NOM-Ac to be 2.4-fold more active than P and to present, when compared to the other progestins, the highest antiestrogenic capacity. Furthermore, in contrast with norethisterone acetate, a 19-nor-testosterone derivative, it was completely devoid of estrogenic potency.

Three-month treatment with a long-acting gonadotropin-releasing hormone agonist of patients with benign prostatic hyperplasia: effects on tissue androgen concentration, 5 alpha-reductase activity and androgen receptor content

The intraprostatic concentrations of testosterone (T) and dihydrotestosterone (DHT) have been measured in only a few men. We measured, in prostatic tissue obtained at surgery from seven men with benign prostatic hyperplasia, the effects of 3-month treatment with a long-acting GnRH agonist on 1) the intraprostatic concentrations of T, DHT, and 5 alpha-androstan-3 alpha, 17 beta-diol (3 alpha-diol); 2) prostatic 5 alpha-reductase activity; and 3) the prostatic content of androgen receptors (AR). Plasma T, DHT, and 3 alpha-diol levels also were measured. Prostatic tissue samples obtained at surgery from a group of untreated men with benign prostatic hyperplasia also were studied. The mean DHT and 3 alpha-diol concentrations in the prostatic tissue of the treated men were about 10% of those in untreated men (n = 19; P less than 0.01 for DHT and P less than 0.05 for 3 alpha-diol), and the mean intraprostatic T concentration in the treated men was about 25% of that in the control group (0.10 greater than P greater than 0.05). The mean in vitro formation of DHT by the prostatic tissue of the treated men was about 50% lower (P less than 0.05) than that by prostatic tissue of the untreated men (n = 9). The mean cytosolic AR content in the prostatic tissue of the treated men was significantly higher (P less than 0.05), whereas the mean nuclear content of both salt-extractable and salt-resistant AR was significantly lower (P less than 0.05) than that in the prostatic tissue of the untreated men (n = 8). The mean plasma T levels in treated men decreased from 4.77 +/- 1.79 (SD) ng/mL (16.5 +/- 6.2 nmol/L) to 0.27 +/- 0.42 ng/mL (0.9 +/- 1.5 nmol/L) after 1 month of therapy and remained in the castrate range thereafter. We conclude that pharmacological castration resulting from 3-month treatment with a long-acting GnRH agonist decreases the intraprostatic T concentration to about one fourth and those of DHT and 3 alpha-diol to about one tenth of the levels in untreated men. Thus, GnRH agonist treatment may not completely abolish intraprostatic androgen concentrations in metastatic prostatic cancer patients. The decrease in prostatic 5 alpha-reductase activity as well as the decrease in nuclear receptors are probably secondary to the decrease in plasma T concentrations.

Immunohistochemical localization of calcitonin gene-related peptide and bombesin/gastrin-releasing peptide in nerve fibers of the rat, guinea pig and pig female genital organs

The localization and distribution of calcitonin gene-related peptide (CGRP) and bombesin/gastrin-releasing peptide (GRP) immunoreactivity were studied in the rat, guinea pig and pig female genital organs with indirect immunohistochemical technique. In the rat, guinea pig and pig, CGRP and GRP immunoreactivities were localized in nerve fibers of the uterus, ovary and oviduct. Generally, CGRP-immunoreactive nerve fibers were intensely stained, while GRP-immunoreactive nerve fibers exhibited moderate immunoreactivity. The number of GRP-immunoreactive nerve fibers in these organs was lower in comparison with that of CGRP-immunoreactive nerve fibers. The pattern of distribution of these nerve fibers was very similar in different genital organs of all species studied. In the uterus of rat, guinea pig and pig, CGRP- and GRP-immunoreactive nerve fibers and nerve bundles were observed in the muscular membrane and around blood vessels. Some delicate CGRP- and GRP-immunoreactive nerve fibers were also present in the submucous layer of the uterus. In the oviduct, CGRP- and GRP-immunoreactive nerve fibers were seen in the muscular membrane, around blood vessels and in the submucous layer. In the ovary, CGRP- and GRP-immunoreactive nerve fibers were distributed in medullary stroma, in close contact with blood vessels and between follicles of different stages of development.

Estrogen and progesterone receptors in leiomyomas and normal uterine tissues during reproductive life

Estrogen and progesterone receptors (ER, PR) were measured in leiomyomas and normal uterine tissues. Estrogen receptors concentration was higher in endometrium than in leiomyomas, lowest in normal myometrium. In the case of progesterone receptors, the concentrations in endometrium and leiomyomas were similar whereas that of myometrium was lower. ER and PR concentration were similar in leiomyomas of the uterine fundus, body and isthmus and steroid receptor content in the inner parts of large myomas was the same as in the outer parts. ER and PR concentrations in tumor-bearing myometrium were not different from those in myometrium of a control group.

Effect of aging on populations of estrogen receptor-containing cells in the rat uterus

Estrogen receptor-containing cells were identified in uteri of mature and senescent rats by means of quantitative autoradiography. Cell numbers and density were assessed in the various uterine layers. It was determined that despite decreases in receptor concentrations in endometrium, endometrial stroma, myometrium, and epithelium, no significant cell loss occurred in any region. Receptor content per cell clearly decreased with age in the endometrial stroma, while only in the myometrium was there any suggestion of cell loss in the absence of receptor loss from individual cells. Thus, age-related reductions in uterine estradiol receptor levels may be due to different mechanisms in different tissue regions.

Unmasking of surface negativity on day 6 pregnant rat uterine epithelial cells by trypsin and pronase

Cationic Ferritin and Ruthenium Red were used to label rat uterine luminal epithelial cells at estrus and 6th d of pregnancy. Labelling was heavy at estrus and light on 6th d. Trypsin and pronase reduced labelling at estrus and restored labelling at 6th d suggesting that negatively charged carbohydrates may become masked at the time of implantation.

Localization and purification of SBU-4--a pregnancy specific protein of the ovine uterus

In order to elucidate the function of molecules of the ovine maternal-fetal interface a monoclonal antibody was produced to intact interplacentomal trophoblast membranes. Extensive immunohistological studies revealed that the monoclonal antibody recognizes a protein designated SBU-4 which originates in the intercaruncular regions of the gravid sheep uterus at about the time of implantation and increases in concentration throughout gestation. The data suggest that SBU-4 is produced by endometrial epithelial cells and that adjacent uninucleate cells of the trophoblast acquire the antigen by endocytosis. Initial biochemical analysis of the purified SBU-4 molecule prepared by monoclonal antibody immunoaffinity chromatography indicates that SBU-4 is high molecular weight glycoprotein complex comprising several sub-units.

Decreased myometrial beta-adrenoceptors in women receiving beta 2-adrenergic tocolytic therapy: correlation with lymphocyte beta-adrenoceptors

We have determined simultaneously the density of beta-adrenoceptors in human myometria (by (-)-[125I]iodopindolol binding) derived from 36 women undergoing cesarean section and in the corresponding circulating lymphocytes (by (-)-[125I]iodocyanopindolol binding). In myometrial membranes about 80% to 85% of the beta-adrenoceptors were of the beta 2-subtype. The density of myometrial and lymphocyte beta-adrenoceptors in women treated with the beta 2-adrenoceptor agonist hexoprenaline to prevent preterm labor was about 65% to 70% lower than that in nontreated women. Concomitantly, in hexoprenaline-treated women the 10 mumol/L isoproterenol-evoked increase in lymphocyte cyclic adenosine monophosphate content (as index for lymphocyte beta-adrenoceptor responsiveness) was diminished to a similar extent. Combining all data resulted in a significant positive correlation between myometrial and lymphocyte beta-adrenoceptor densities (r = 0.7303; n = 36; p less than 0.001). It is possible that determination of beta-adrenoceptor function in circulating lymphocytes may be a useful model to monitor myometrial beta-adrenoceptor changes during tocolytic therapy.

Influence of progesterone on the sodium and potassium concentrations of rat uterine fluid investigated by microdialysis

Currently used techniques to measure the chemical composition of the rat uterine fluid are accompanied by interference with the physiology of the uterus, and the sampling procedure creates a methodological problem as the amount of uterine fluid is small. The aim of the present study was to investigate the utility of a new in vivo technique, microdialysis. A microdialysis probe, which functions as an 'artificial blood vessel' was implanted into the uterine lumen and perfused with a Ringer solution. This perfusion technique makes it possible to study ions and other components in the uterine fluid without withdrawal of any liquid. Compared to previous techniques it offers the advantage of continuous monitoring of the chemical composition of the uterine fluid over time. The sodium and potassium concentrations in the uterine fluid of 10 rats were monitored during oestrous. After 1-2 h of baseline perfusion an intramuscular injection of progesterone was given. The mean sodium concentration was 124.9 +/- 2.4 mEq/l before and increased in all 10 rats to 133.9 +/- 2.3 mEq/l (p less than 0.001) after injection. The mean potassium concentration was 22.3 +/- 2.4 mEq/l before and decreased to 17.9 +/- 2.1 mEq/l (p less than 0.001) after injection. This study proves the validity and applicability of microdialysis to the monitoring of chemicals in uterine fluid and especially to follow dynamic changes.

Compositional analysis of the three main gangliosides from adult human myometrium by a rapid capillary gas chromatographic method

A new capillary GC method is described for the compositional analysis of the three main gangliosides isolated from adult human myometrium. The sample was subjected to methanolysis, acetylation and trimethylsilylation which allows all the constituents to be analyzed simultaneously. The predominant ganglioside was found to be GD3, with GM3 and GT1b the next most abundant.

Ammonium sulfate fractionation and assay of hormone receptors

Ammonium sulfate (AS) precipitation by consecutive steps at 10% to 50% saturation has been utilized for fractionation of cytoplasmic estrogen receptor (ER) and progesterone receptor (PgR). The highest percentage of both receptor activities are confined mainly in two fractions at AS saturation from 20% to 30% and 30% to 40%. The total percentages of activity of the cytoplasmic ER and PgR salted out at 50% saturation are 77% and 53%, respectively. Precipitation of hormone-receptor complexes at 50% saturation for assay of ER and PgR can be achieved, but needs improvement for efficient salting out of the receptors. ER and PgR salted out in the AS pellet are much more stable for storage than in the cytosol.

Species crossreactivity of human progesterone receptor monoclonal antibodies: Western blot analysis

The crossreactivity of monoclonal antibodies (hPRa 1, 2, 3 and 6) generated against human progesterone receptor was examined in six mammalian and an avian species using the techniques of sodium-dodecylsulfate polyacrylamide gel electrophoresis and Western blot analysis. Immunoreactive bands were detected on protein blots of receptor-containing preparations from human endometrial carcinoma grown in nude mice, human T47D breast cancer cells, rabbit, cow and mouse uteri, and chick oviduct. No receptor-associated, immunoreactive bands were detected in rat, guinea pig or hamster uteri. The number and molecular weights of the receptor subunits detected varied between species, and only human progesterone receptor displayed electrophoretic microheterogeneity in its high molecular weight subunit. These data demonstrate that the human progesterone receptor antibodies recognize epitopes not common to all species.

Structural characterization of the 9-10S estradiol receptor from calf uterus

An affinity chromatography-based method has been developed for estrogen receptor isolation which requires the inclusion of sodium molybdate in purification buffers for maintaining the large 9-10S form of the receptor. The protein products obtained from affinity chromatography of calf uterine receptor extracts or from extracts presaturated with estradiol have been analyzed by gel electrophoresis under denaturing conditions. Major estrogen sensitive proteins were peptides with Mr approximately 90,000, 65,000 and 50,000. Two additional proteins (60,000 and 53,000) of lower abundance and with demonstrated estrogen sensitivity were also observed. Affinity labeling with [3H]tamoxifen aziridine identified the Mr 65,000 protein as the estrogen receptor and suggested that the Mr 60,000, 53,000 and 50,000 peptide components were derived proteolytically from this parent unit. The 90,000 mol. wt component was readily dissociated from heparin-sepharose immobilized estrogen receptor by elution with low salt buffers without molybdate. Peptide mapping experiments indicated that the 90,000 mol. wt component was not related to the Mr 65,000 and 50,000 estrogen receptors, but confirmed the smaller binding unit to be a proteolytic fragment of the 65,000 mol. wt receptor. The results suggest that the 90K protein associates non-covalently with the Mr 65,000 estrogen binding unit as a nonhormone binding component of the 9-10S receptor.

Transformation (4S to 5S) of the nuclear estrogen receptor is reversible but not accompanied by a change in the affinity for DNA

The nuclear estrogen receptor from calf uterus was used to investigate the possible relationship between receptor transformation (4S to 5S) and receptor activation (DNA binding). Receptors extracted from nuclei after exposure of uterine tissue tc [3H]estradiol sedimented at 5.2S, the characteristic value of the transformed receptor. After storage at -20 degrees C the receptor sedimented at 4.0S, indicating conversion of the 5S form into the non-transformed 4S form. Upon reincubation at 28 degrees C the 4S form transformed into the 5S form following second-order kinetics. The rate constant obtained was 4.3 x 10(7) M-1 min-1, a value identical to that reported for the cytosol receptor. These data show that receptor transformation is reversible. Molybdate (10-50 mM) was not able to prevent receptor transformation in the nuclear extract, but was inhibitory in cytosol. This suggests that molybdate does not prevent receptor transformation, but rather inhibits disaggregation of the 8S oligomer into the 4S monomer. In DNA-binding assays (DNA-cellulose or nuclei) the non-transformed (4S) and transformed (5S) states of the nuclear estrogen receptors displayed identical affinities for DNA. The present data show that 4S to 5S transformation of nuclear receptors follows a readily reversible process, but this process is not an essential step for the exposure of the receptors' DNA-binding site. Although the physiological function of the 5S form remains unclear it may be important for the recognition of specific gene regulatory sites.

Immunohistochemical demonstration of estrogen receptors (ER) in formalin-fixed, paraffin-embedded human breast cancer tissue by use of a monoclonal antibody to ER

We describe an immunohistochemical method using a monoclonal antibody to localize estrogen receptors (ER) in formalin-fixed, paraffin-embedded tissue. The avidin-biotin-peroxidase complex method was used, preceded by trypsin treatment to expose antigenic sites. In 111 breast cancer specimens studied simultaneously by a dextran-coated charcoal (DCC) assay and the paraffin section method, agreement on receptor status was found in 101 (91%) specimens. Quantitative staining features showed a high degree of correlation with the results of the steroid binding assay (r = 0.81). Studies on the influence of fixation on ER localization done in rabbit uteri showed that fixatives mainly composed of coagulating reagents (Carnoy's, Zenker's, Bouin's, Lilly's AAF, Helly's, ethanol) precluded ER staining, whereas cross-linking fixatives (formaldehyde, glutaraldehyde) preserved antigenic sites, although the immunoreactivity of the receptor was somewhat decreased. Studies on the effect of enzyme preincubation showed this to increase antigenic expression of ER in formaldehyde-fixed breast tumors and in formaldehyde-, glutaraldehyde-, and Zamboni-fixed rabbit uteri.

[Localization of histamine in uterine structures]

By means of luminescent-histochemical method of Cross, Even, Rost histamine is revealed in all uterine structures. Visual and fluorometric data demonstrate uneven distribution of histamine in the organ's structures. A high content of histamine is specific for macrophages and mast cells, less high--in tegmental epithelium and endometrial glands. A low level of histamine have endometrial stroma, smooth myocytes, cells of the serous membrane and vessels. Basing on the literature data, concerning various sensitivity of the uterine tissues to estrogens and regarding effect of the estrogens upon histamine metabolism in the uterine and regarding interconnection of the histamine receptors in the uterus and the estrogens, a suggestion is made that various contents of histamine in the uterine structures depend on various amount of the histamine receptors in them and on different abilities of the uterine tissues to inactivate histamine. The ability of macrophages to accept free forms of bioamines, as it is described in the literature, evidently can be spread to the uterine macrophages, where a high content of histamine is revealed.

PGE measurement in mouse embryos and uterine/embryo tissue

Embryonic tissue of rodents and other species has been reported to produce prostaglandins (PG) of the E series during gestation. We attempted to establish the presence of PGE in C57BL/6J mouse embryos and peri-embryonic tissue as an initial step in examining the role of maternal ethanol treatment on PG production. Gestation day 10 embryos were found not to produce or degrade PGE. However, a tissue complex which included embryonic tissue, peri-embryonic membranes, placenta and uterus was capable of producing PGE from both endogenous and exogenous arachidonic acid. Furthermore, in vivo and in vitro aspirin was able to suppress PGE production from this tissue. It is concluded that gestation day 10 C57BL/6J mouse embryonic tissue, unlike that of rat, is not capable of measurable PGE production. However, uterine and peri-embryonic tissues, needed to support pregnancy, are capable of significant PGE production.

Autoradiographic localization of beta-adrenoreceptors in rat uterus

The inhibitory effects of catecholamines on uterine smooth muscle are known to be mediated through beta-adrenergic receptors. To investigate further the distribution of these receptors in the rat uterus, we utilized in vitro autoradiography using [125I]-cyanopindolol [CYP], a specific beta-receptor ligand that has equal activity for both beta 1- and beta 2-receptor subtypes. The specificity of the labeling and the characterization of receptor subtypes in different cell types were achieved by displacement of radioligand with increasing concentrations of zinterol, a beta-adrenergic agonist with preferential affinity for the beta 2-adrenoreceptor subtype, and practolol, a beta-adrenergic antagonist that binds preferentially to the beta 1-subtype. Quantitative estimation of ligand binding was performed by densitometry. It was shown that the vast majority of beta-adrenoreceptors were of the beta 2-subtype and were found in high concentration not only in the myometrium but also in the endometrial and serosal epithelia. Specific labeling was also observed in glandular elements. These results suggest that beta-adrenoreceptors might be involved in different functions in the uterus.

Biochemical and immunological similarity of soluble angiotensin II-binding proteins in different organs

Binding of angiotensin II has been detected in soluble extracts of rabbit liver, adrenal gland, aorta, brain, kidney and uterus. In each case, binding required p-chloromercuriphenylsulfonic acid and bound angiotensin II was released by treatment with dithiothreitol. These properties resemble those of the 75 kDa binding protein purified from liver. Immobilized guinea pig antiserum developed against the isolated hepatic protein removed binding activities from the different extracts in an immune-specific, quantitatively comparable manner. In addition, the activities were removed by a mouse monoclonal antibody which specifically recognized a protein of 75 kDa in the various preparations. An immunologically homologous angiotensin II-binding protein with similar characteristics was also identified in the soluble fraction of rat liver.

[Effect of estrogens on the lipid composition of the plasma membranes of the uterine cells in ovariectomized rats]

The effects of estradiol, estrone and estriol on lipid composition of plasma membranes of the ovariectomized rat uterus cells were studied. It was found that estrogens (10 micrograms/100 g weight) and estrone (25 micrograms/100 g) fail to produce statistically significant changes in lipid contents in plasma membranes. Estradiol and estriol (25 micrograms/100 g) were shown to increase phospholipid content in plasma membranes calculated for protein.

Tissue levels of prostaglandins and what do they mean? Studies on the guinea-pig uterus

The ratios of the concentrations of PGF2 alpha, PGE2 and 6-keto-PGF1 alpha in guinea-pig uterine horns, which were removed and placed in ethanol in 1.5 to 2 min, were 0.3:1.0:0.6 on day 7 and 13.8:1.0:0.8 on day 15 of the oestrous cycle. Adding indomethacin (10 micrograms/ml) to the ethanol had no significant effect on the tissue levels observed. These ratios were similar to the ratios of the outputs of PGF2 alpha, PGE2 and 6-keto-PGF1 alpha from the guinea-pig uterus (0.6:1.0:0.9 on day 7 and 7.6:1.0:1.5 on day 15), but were different (particularly on day 7, but only for 6-keto-PGF1 alpha on day 15) to the ratios of the amounts of the three PGs synthesized by homogenates of the guinea-pig uterus (7.2:1.0:2.4 on day 7 and 11.7:1.0:3.3 on day 15). Consequently, the measurement of tissue levels of PGs in the guinea-pig uterus reflects PG synthesis by intact tissue and changes in this synthesis, rather than PG synthesis by homogenates (broken cell preparations). Therefore, it appears meaningful to measure levels of PGs in the guinea-pig uterus since they reflect uterine PG output. Separation of the endometrium from the myometrium, which involved handling and mild trauma, stimulated uterine PG levels, but the ratio of the levels of PGF2 alpha, PGE2 and 6-keto-PGF1 alpha in the endometrium was still similar to that found in the non-separated uterus.

Detection of IL-1 alpha and IL-1 beta gene expression by in situ hybridization. Tissue localization of IL-1 mRNA in the normal C57BL/6 mouse

IL-1 is a cytokine with a wide variety of effects on cells involved in inflammatory and immune responses, hemopoiesis, and bone formation. Many cell types have been shown to produce IL-1 in vitro; however, very little is known about the source and role of IL-1 in vivo. By using in situ hybridization, we examined the tissue distribution of cells containing IL-1 mRNA in normal C57BL/6 mice. The results show that many organs contain IL-1 mRNA-positive cells, but the highest frequency was found in lymphoid organs. The distribution and localization of these cells suggest that many of the IL-1 mRNA-producing cells are tissue macrophages. Organs exposed to environmental Ag and microbial products (lymph nodes, liver, intestine, lung, and uterus) had high frequencies of IL-1 mRNA-producing cells, suggesting that IL-1 is produced in local inflammatory or immune responses in vivo. The production of IL-1 mRNA in the thymus and in the bone marrow suggests that IL-1 is available to play physiologic roles in T cell differentiation and in hemopoiesis.

Identification of a uterine elastase in the pregnant rat uterus

During development of the pregnant rat uterus there is a several fold increase in elastin content. Using Verhoeff's elastic fiber stain, we have shown that a significant proportion of these elastin fibers are in the extracellular matrix of the myometrium. They do not appear as an organized structure but rather in a variety of partially extended, random configurations. An elastase was identified in both the pregnant and the postpartum uterus. Partial characterization of the enzyme indicated that it is a serine protease with a molecular weight around 24,500 and a pH optimum of 8.5. In addition to the enzyme, relatively high levels on an elastase inhibitor were found in the uterine extracts. The inhibitor did not inhibit trypsin, indicating that it was not alpha-1-antiprotease. The data suggest that the elastase and inhibitor are uterine tissue derived and perhaps important in the normal remodeling process of uterine connective tissue.

Autoradiographic visualization of the GABA-A receptor agonist, 3H-muscimol in the rat uterus

In the present study the distribution of specific binding sites for the GABA-A receptor agonist, 3H-muscimol, was studied in the rat uterus using an autoradiographic technique. Specific binding sites were present in both myometrium and endometrium suggesting a dual role for GABA in this organ.

Hormonal control of the expression of antibody-defined lactosaminoglycans in the mouse uterus

The uterus undergoes a number of hormone-induced changes during estrus and early pregnancy. Changes in the uterine glycoprotein population have been investigated by using the monoclonal antibodies SSEA-1, IIC 3, A5, and C6. These antibodies detect specific terminal or side-chain modifications of lactosaminoglycan molecules. In ovariectomized female mice treated with estrogen, SSEA-1 was the only antigen expressed at the uterine epithelium. Progestational stimuli for 2 days induced SSEA-1 expression in the uterine glands and the sialylated form of A5 at the uterine epithelium. Three days of progesterone treatment induced IIC3 expression within the uterine glands. An additional day of progesterone treatment resulted in a uterine epithelial expression of IIC3. The expression of these antigens in the progestational phase were confirmed in naturally mated females. In these preparations, expression of the sialylated form of C6 was also observed, beginning on Day 2.0 of gestation. These observations suggest subtle modification of lactosaminoglycan chains during the hormonally induced preparative and receptive phases of the mouse uterus.

Acyl type platelet-activating factor in normal rat uterus determined by gas chromatography mass spectrometry

1-Fatty acyl-2-acetyl-sn-glycero-3-phosphocholine (1-fatty acyl-2-acetyl GPC, acyl type platelet-activating factor (PAF) was found in normal rat uterus without addition of any exogenous stimuli and identified as 1-palmitoyl, 1-oleoyl and 1-stearoyl species by gas chromatography/mass spectrometry coupled with selected ion monitoring (SIM). The main species was the 1-palmitoyl species. The ions used for SIM were chosen on the basis of the acetyl and fatty acyl moieties and molecular weight. The amount of 1-fatty acyl-2-acetyl GPC was significantly more than that of PAF (1-fatty alkyl-2-acetyl GPC, AGEPC), and the ratio of 1-palmitoyl-2-acetyl GPC to 1-0-hexadecyl-2-acetyl GPC was about 4.5:1 in normal rat uterus.

Identification of transferrin receptor in cervical and endometrial tissues

The location of transferrin receptor (Tf.R) which is abundantly contained in proliferating cells and positional relationships of cells containing much Tf.R was observed on cervical and endometrial tissue sections by immunohistochemistry. In normal squamous epithelium, the parabasal cell layer was positive and the basal, intermediate, and superficial cell layers negative. This shows that the cells of the parabasal cell layer are proliferating most actively among those layers. Squamous carcinoma contained many positive cancer cells. But negative as well as positive cells were present, indicating that cancer cells proliferate under various conditions. Cancer cells infiltrating the stroma were made clear by Tf.R staining, and it became easier to identify them when only a few were present. Endometrial glandular cells in the basal layer stained only on the basal side of a cell regardless of the menstrual cycle, whereas in the functional layer glandular lumen side also stained positive in the secretory phase. Based on the present data, an immunohistochemical study of Tf.R seems useful to confirm the localization of proliferating cells and cancer cells and determine the conditions for cancer cell proliferation on the tissue sections.

Anti-idiotypic antibody used for the localization of parenterally administered monoclonal anti-progesterone antibody in mice

Affinity-purified rabbit and sheep anti-idiotypic antisera raised against mouse monoclonal anti-progesterone IgG1 antibody (DB3) or mouse myeloma IgG1 protein P3 (MOPC 21) showed high binding specificities to the respective idiotypes used for immunization as determined by RIA or ELISA. They have been used in an indirect immunofluorescent method to demonstrate the localization of parenterally administered idiotypes in pregnant or pseudopregnant BALB/c mouse frozen tissue preparations, at known stages post coitum after a single intraperitoneal or intravenous injection of DB3 or P3. DB3 was visualized on the surface of uterine luminal and glandular epithelia of pregnant mice 36 h after treatment; the localization was DB3-specific as it was not seen in mice treated with P3 (using sheep anti-P3 anti-idiotype as a probe) or saline. The fluorescent staining reaction in oviduct was weak and only appeared on the surface of the oviducal serosa (peritoneal side). Both DB3 and P3 were also localized in liver (granules of Kupffer cells), kidney (glomerular basement membrane), spleen (on the membrane surface of mononuclear cells in the white pulp), and peritoneal exudate cells (on the membrane surface). Staining could be completely blocked by the addition of the free idiotypes against which the anti-idiotypes were made but not by the unrelated idiotype. Anti-idiotypic labelling in vivo is more specific and selective than anti-whole immunoglobulin labelling.

Ovine trophoblast protein-1 and bovine trophoblast protein-1 are present as specific components of uterine flushings of pregnant ewes and cows

A rabbit antiserum raised against ovine trophoblast protein-1 (oTP-1) was used to stain Western blots of the protein components from the uterine flushings of pregnant ewes (n = 61), non-bred cyclic ewes (n = 22), bred-but-nonpregnant ewes (n = 36), pregnant cows (n = 34), and bred-but-nonpregnant cows (n = 15). Nonpregnant animals were defined as ones from which no embryo was recovered. Uterine flushings of pregnant ewes contained oTP-1 between Days 14 and 24 of pregnancy, but not at Day 12. All of the cyclic ewes and 34 of 36 bred ewes, judged as nonpregnant, tested negatively for the presence of oTP-1. With one exception, oTP-1 was not detected in the nongravid uterine horns of pregnant ewes in which the conceptus had been confined to one uterine horn. Bovine trophoblast protein-1 (bTP-1), which cross-reacts immunologically with oTP-1, was also detectable specifically in the uterine flushings of pregnant cows when anti-oTP-1 antiserum was used. The urine (n = 14) and certival mucus (n = 20) samples of all the pregnant ewes tested were free of any detectable oTP-1. Thus, a useful pregnancy test for ewes based on oTP-1 release into these fluids seems unlikely. Results of this study show that oTP-1 and bTP-1 are pregnancy-specific proteins that are secreted into the uterine lumen where they possibly exert a local response.

Distribution of progesterone to the uterus and associated vasculature of cattle

Multiparous dairy cows were sampled to study the concentrations of progesterone in tissue of the uterus and associated vasculature and to determine whether progesterone was delivered to the uterus locally. In study 1, progesterone was greater (p less than or equal to 0.05) in the first venous branch draining the cranial portion of the uterine cornu adjacent to the vary with a corpus luteum than in jugular blood or in the same vein draining the opposite uterine cornu on day 11 postestrus. Concentrations of progesterone were also greater (p less than or equal to 0.05) in the cranial than in the caudal half of the uterine cornu adjacent to the luteal-bearing ovary or in the cranial and caudal halves of the opposite uterine cornu. Concentrations of progesterone were also greater (p less than or equal to 0.05) in the uterine or ovarian arterial tissue adjacent to the ovary with the corpus luteum than in those same vessels on the contralateral side. In a second study, progesterone at 0 h on day 11 postestrus was greater (p less than or equal to 0.05) in the first venous branch draining the cranial portion of the uterine horn adjacent to the luteal-bearing ovary than in jugular blood, the same vein in the contralateral uterine cornu or in the same uterine vein 48 h after ligation and resection of the oviductal vein adjacent to the ovary with the corpus luteum. It is concluded that progesterone is delivered locally to the uterus and associated vasculature and the route of local delivery appears to be via the oviductal vein.

Partial characterization of a uteroglobin-like protein in the human uterus and its temporal relationship to prostaglandin levels in this organ

During the past decade several corticosteroid-dependent, low mol wt proteins with phospholipase-A2 (PLA2) inhibitory activity have been described. This family of proteins is collectively known as lipocortins. Blastokinin or uteroglobin (utg), a progesterone-induced protein, first discovered in the pregnant rabbit uterus, is also a potent PLA2 inhibitor, but genetically distinct from lipocortins. Although utg has been found in rabbits, its presence in humans has not been well established. Here, we present biochemical, immunological, and immunohistological evidence for the detection of a utg-like protein in the human uterus. Since inhibition of PLA2 may modulate tissue eicosanoid levels and since rabbit utg has been reported to be a potent PLA2 inhibitor, we also studied the temporal relationship between utg and tissue prostaglandin E2 and F2 alpha levels in estrogen- and progesterone-dominated endometrial tissue. We found an inverse temporal relationship between utg-like protein and eicosanoid levels in this organ. Since some eicosanoids (e.g. prostaglandins, leukotrienes, etc.) are known to be involved in smooth muscle contractility and inflammatory processes, our findings may help to understand the pathogenesis of some human disorders in which abnormal eicosanoid production occurs.

Immunohistochemical analysis of human uterine estrogen and progesterone receptors throughout the menstrual cycle

Estrogen receptors (ER) and progesterone receptors (PgR) were studied immunohistochemically using specific antireceptor monoclonal antibodies in uterine tissue samples from 33 women in various stages of the menstrual cycle. Immunohistochemical localization was quantified as to intensity of staining and tissue distribution in glandular epithelium, stroma, and myometrium, and the results were compared with those of standard ligand binding assays. In all samples ER and PgR localized within the nuclei of target cells. The maximal concentrations of ER and PgR occurred in the mid- to late proliferative phase of the menstrual cycle. ER content declined throughout the secretory phase. In contrast, PgR content underwent unexpectedly complex and dyssynchronous fluctuations during the secretory phase of the menstrual cycle. Specifically, the glandular epithelium had diminished PgR content, while the stroma and myometrium maintained a significant PgR content. PgR and perhaps ER are not concordant in different cell types within the uterus. Segregation of function through alteration of receptor content may be an important mechanism in steroid-dependent growth and differentiation of target tissues.