Placental protein 14 in endometrium during menstrual cycle and effect of early luteal phase mifepristone administration on its expression in implantation stage endometrium in the rhesus monkey

Placental protein 14 (PP14) is a glycoprotein which is secreted by secretory phase endometrium and decidua in women. Despite the suggestion that PP14 is involved in the process of endometrial maturation for blastocyst implantation, our understanding in this regard is poor. In the present study, the concentrations and distribution patterns of immunodetectable PP14 in the endometrium during proliferative and secretory phases of normal ovulatory menstrual cycles, as well as in implantation stage endometrium in naturally mated ovulatory cycles with or without early luteal phase mifepristone treatment, were investigated using the rhesus monkey as a primate model. Immunopositive PP14 was observed mainly in epithelial cells of glands and it was detected in one major immunopositive band at Mr 28 kDa in tissue homogenate and spent medium. The area of immunopositive precipitation of PP14 in glands was minimal in follicular phase endometrium, and was higher (P < 0.01) in early, mid- and late luteal phase endometrium compared with that in pre- and periovulatory phases of the cycle, but there was no change in its area profile in the glandular compartment throughout the luteal phase. Immunopositivity for PP14 in luminal contents of gland displayed an increasing profile from early to late secretory phases. Thus, the concentrations and the distribution of immunodetectable PP14 in luteal phase endometrium of the rhesus monkey showed marked similarity with those of human endometrium during the natural menstrual cycle. Although there was no marked change in the band characterstics for the protein in implantation stage endometrium following early luteal phase mifepristone treatment, it was markedly decreased (P < 0.01) in tissue homogenate and in vitro spent medium along with a lesser (P < 0.02) degree of immunoprecipitation in the glands in implantation stage samples of mifepristone treatment group compared with that in control group samples. Thus, the contragestional effect of early luteal phase mifepristone treatment appears to be associated with a decrease in the concentration of immunodetectable PP14 in implantation stage endometrial glands and its secretion in the rhesus monkey. It remains to be seen whether this decline is caused from direct antiprogesterone action on endometrial glands during progesterone dominance, or secondarily from associated retarded development of endometrium.     

Isolation of rat chromosome-specific paint probes by bivariate flow sorting followed by degenerate oligonucleotide primed-PCR

Angiogenesis is an essential component of endometrial regeneration after menses in preparation for implantation. Vascular endothelial growth factor (VEGF) is a secreted angiogenic peptide with mitogenic activity specific for endothelial and trophoblast cells. VEGF-immunoreactivity was detected in glandular epithelium throughout the menstrual cycle by immunohistochemistry, but, showed cyclic variation in the stroma and the blood vessels. During the early proliferative phase, strong staining was seen in the glandular epithelial cells while staining in the stroma was confined to a subpopulation of stromal cells and endometrial blood vessels appeared negative. In contrast, very intense staining of the endometrial stromal cells was seen in the mid proliferative endometrium possibly due to increased synthesis of VEGF by oestrogen. In the late proliferative endometrium, staining was seen in the endothelial cells and the perivascular stromal cells around the endometrial blood vessels. The greatest degree of immunostaining of stromal cells was observed in the mid to late proliferative endometrium. Throughout the secretory phase no staining was seen around the endometrial blood vessels and staining of endometrial stromal cells was confined to early secretory endometrium. In the late secretory endometrium only the glands were positive to VEGF antibody. The observed increase in the immunostaining of stroma suggests increased production of VEGF from early to mid and late proliferative endometrium which parallels the increase in the oestradiol levels in the proliferative phase of the menstrual cycle. It is proposed that VEGF may serve as a paracrine mediator of the effects of ovarian steroids on endometrial vascular development.     

Iron deposition at mineralization fronts and osteoid formation following chronic cadmium exposure in ovariectomized rats

Integrins are heterodimeric glycoproteins that have been found to undergo dynamic temporal and spatial changes in distribution in the endometrium during the menstrual cycle in women. Likewise the extracellular matrix (ECM) ligands for these receptors are likely to play a role in the establishment of a receptive endometrium. To develop primate models to study the role of these molecules in the cascade of molecular events leading to implantation, integrin expression and associated changes in ECM were investigated during the menstrual cycle and in early pregnancy in the baboon. Antibodies specific for the integrins (alpha(1-6) and alpha(v); beta1, beta3, and beta4) and ECM (laminin, collagen IV, fibronectin) were utilized. In addition, cytokeratin and alpha-smooth muscle actin were used as epithelial, stromal, and smooth muscle cell markers, respectively. Endometrium was obtained in duplicate or triplicate during the menstrual cycle and early pregnancy. Changes observed during the natural menstrual cycle were confirmed using ovariectomized, steroid-treated animals. Constitutively expressed integrins on the endometrial epithelium included the collagen/laminin receptors: alpha2, alpha3, alpha6, and beta4. The pattern of expression correlated well with the distribution of ECM in this tissue. Collagen IV was confined to the basement membrane of glandular epithelium and blood vessels. Laminin immunostaining was found in the basement membrane, mostly in the stroma of the basal region, in the glandular endometrium and vasculature. Fibronectin was present throughout the stroma but not in the basement membrane. The collagen receptor alpha1 beta1 and fibronectin receptor alpha4 beta1 appeared in the glandular epithelium in the luteal phase. As in the human, alpha1 and alpha4 disappeared from the glandular epithelium with the establishment of pregnancy. In contrast, the alpha4 beta3 vitronectin receptor appeared in the glandular epithelium only in pregnancy or following long-term steroid treatment with estrogen and progesterone but not during the time of uterine receptivity associated with the initial period of embryo attachment. Osteopontin, an ECM ligand for alpha(v) beta3, was coexpressed with this integrin in invading cytotrophoblasts, glandular epithelium, and decidualizing stromal cells. Decidualization in the baboon was associated with changes in integrin expression similar to those found in humans: there was an increase in alpha1, alpha3, alpha6, beta1, and alpha(v) beta3 in the decidualized stromal cells. Laminin and collagen IV expression also increased at the implantation site and throughout the endometrium. In contrast, fibronectin expression was most evident at the implantation site and corresponded to alpha5 expression on the invading cytotrophoblasts. In summary, marked similarities were found in the expression of ECM and the integrin receptors between the baboon and the human endometrium throughout the menstrual cycle and in pregnancy. Cycle-specific integrins, alpha1, and alpha4, were present on epithelial cells during the secretory phase. Delayed expression of alpha(v) beta3 in baboon endometrial glands correlated closely with the time of enhanced glandular secretory activity in this primate. The baboon appears to be an excellent model for the investigation of the role of integrins and ECM leading to successful implantation.     

Endometrial Th2 cytokine expression throughout the menstrual cycle and early pregnancy

Embryonic implantation and maintenance of pregnancy is influenced by the maternal immunological response. Type 2 T-helper (Th2) cells secrete interleukins 4, 5, 6 and 10 and are associated with suppression of cell-mediated immunity. Temporal changes in the expression of these cytokines were detectable by immunohistochemistry throughout the menstrual cycle. In pregnancy, 10-fold or greater increases in interleukin 6 and 10 secretion were detectable by enzyme-linked immunoassay compared with the non-pregnant state. The pattern of expression of Th2 cytokines suggests that progesterone may influence endometrial cytokine secretion. During pregnancy, Th2 expression paralleled that of vimentin, a stromal cell marker, suggesting that these cells may be a principal source of Th2 cytokines may be a mechanism of suppressing cell-mediated immunity in the endometrium, which may in turn enhance embryonic implantation and maintenance of pregnancy.     

The effect of leukemia inhibitory factor (LIF) on trophoblast differentiation: a potential role in human implantation

Leukemia inhibitory factor (LIF) is a multifunctional glycoprotein strongly associated with normal implantation in the mouse. We have recently determined that LIF is expressed in the human endometrium in a menstrual cycle dependent manner. Maximal expression is observed between days 19 and 25 of the menstrual cycle, coinciding with the time of human implantation. In this study we have utilized purified cultures of human cytotrophoblasts to examine the effects of LIF on several morphologic and biochemical markers of the trophoblastic differentiation. We purified human cytotrophoblasts from term placentae and cultured them with and without LIF (10 ng/mL). The secretion of human CG, oncofetal fibronectin, and progesterone were measured at 24, 48, 72, and 96 h. Northern blot analysis was used to assess messenger RNA (mRNA) expression of beta hCG and oncofetal fibronectin. We found that LIF markedly decreased trophoblast production of hCG protein at 72 and 96 h, as well as expression of beta hCG mRNA. LIF also significantly increased the expression of oncofetal fibronectin mRNA and secretion of the protein. LIF did not affect steroidogenic activity of cultured trophoblasts, as determined by progesterone production. These biochemical changes are characteristic of cytotrophoblast differentiation toward an anchoring extravillous phenotype. Thus, LIF appears to be an important regulator of human embryonic implantation by directly modulating trophoblast differentiation.     

Immunolocalization of inhibin and activin subunits in human endometrium across the menstrual cycle

Inhibin/activin alphaC/alphaN and betaA subunits were localized immunohistochemically in the human endometrium throughout the menstrual cycle using an affinity-purified sheep polyclonal antibody raised against the alphaC/alphaN subunit and an affinity-purified rabbit polyclonal antibody raised against the betaA subunit. The betaB subunit was below the level of detection in all human endometrial samples tested. Immunoreactive inhibin alphaC/alphaN subunit was localized in the luminal epithelium, glandular epithelium, stromal tissues and vascular endothelium with no significant variation across the normal menstrual cycle. Immunoreactive betaA subunit, common to inhibin A and activins AA and AB was localized in the luminal and glandular epithelium and in migratory cells while the endometrial stromal cells, decidua, vascular smooth muscle and endothelium were devoid of immunoreactivity. A significant variation of immunoreactive betaA subunit was observed in glandular and luminal epithelium across the normal menstrual cycle. In proliferative endometrium, only a very low level of betaA immunostaining was seen in luminal and glandular epithelium, while the luminal epithelial staining increased significantly in the early secretory phase and remained relatively constant over the rest of the menstrual cycle. A progressive increase in betaA immunoreactivity was observed also in the glandular epithelium during the secretory phase reaching a maximum in the late secretory phases, and decreasing at menstruation. Co-localization studies on serial sections suggested that the migratory cells expressing strong betaA immunoreactivity were macrophages and neutrophils but not eosinophils or mast cells. Thus, cells within the human endometrium are capable of expressing inhibin/activin molecules in vivo. The variation in the pattern of secretion of the betaA subunit across the menstrual cycle suggests that activin peptides may have a physiological role in endometrial function.     

Demonstration of the third antigenically distinct outer membrane lipoprotein (OmlA) in Actinobacillus pleuropneumoniae serotype 7

OBJECTIVE: To determine the expression of endothelial nitric oxide synthase in the endometrium during the menstrual cycle in endometriosis and adenomyosis. DESIGN: Immunohistochemical identification of endothelial nitric oxide in endometrial tissues using the monoclonal antibody. SETTING: Department of obstetrics and gynecology in a university hospital. PATIENT(S): The subjects were divided into three groups: 35 patients with endometriosis, 33 patients with adenomyosis proven histologically, and 46 fertile controls. MAIN OUTCOME MEASURE(S): Semiquantitative immunostaining (evaluation nomogram) score in endometrial cells. RESULT(S): The analyses revealed phase-dependent changes in the expression of endothelial nitric oxide synthase in the surface and glandular epithelia during the menstrual cycle in the fertile controls. The expression was weakest in the early proliferative phase, gradually increased, was most marked in the midsecretory phase, and decreased thereafter. In contrast, stromal cells did not change throughout the cycle. Contrary to expectations, the expression of endothelial nitric oxide synthase in endometriosis and adenomyosis was persistently greater than the control levels throughout the menstrual cycle. CONCLUSION(S): This study has shown that endothelial nitric oxide synthase is changed in a phase-dependent manner during the menstrual cycle. The exaggerated expression of endothelial nitric oxide synthase in the endometrium throughout the cycle suggests some pathologic role in endometriosis and adenomyosis.     

Minocycline for the treatment of rheumatoid arthritis

This study examines the expression of the multi-functional cytokine, vascular permeability factor/vascular endothelial growth factor (VPF/VEGF) in the rat uterus during early proestrus, proestrus, estrus and diestrus. Groups of ovariectomized or hypophysectomized rats served as endocrine controls. Expression of VPF/VEGF mRNA was 2-fold greater in uteri during proestrus and estrus than in other phases of the estrous cycle. In situ hybridization techniques indicated that VPF/VEGF mRNA expression was confined to the luminal epithelium during proestrus, but shifted to the stromal compartment during estrus. Ovariectomized, hypophysectomized or diestrus rats exhibited scattered localization of VPF/VEGF mRNA among glandular epithelium and endometrial stromal compartments. Although VPF/VEGF mRNA was expressed throughout the estrous cycle, but in different compartments of the endometrium depending on the stage of the estrous cycle, VPF/VEGF protein expression appears to be restricted to the epithelial compartment during proestrus and estrus. Results indicate that circulating levels of gonadal steroids and LH may be associated with the differential expression of VPF/VEGF mRNA and its translation activity in the endometrium during different stages of the estrous cycle.     

The receptive endometrium is characterized by apoptosis in the glands

Apoptosis in the human endometrium up to now has been detected during the mid to late luteal phase and therefore connected to the onset of the menstrual shedding. However, there is increasing evidence that regulated apoptosis may be important during decidualization and implantation. To investigate a possible role for apoptosis in the human endometrium and its regulation, we correlated the immunolocalization of the apoptosis regulatory protein bcl-2 and the proliferation marker Ki67 to the in-situ nuclear DNA fragmentation - a key feature of apoptosis - detected by using the terminal deoxynucleotidyl transferase-mediated dUTP nick-end-labelling (TUNEL) method during the menstrual cycle. Whereas proliferation and bcl-2-expression were predominantly detected in the glandular compartment during the proliferative phase, only single apoptotic cells could be shown during this period. During the transformation of the endometrium (days 15-19) proliferation and bcl-2 expression decreased markedly and there was no sign of apoptosis. At the beginning of the implantation window (days 19-20) we could detect the first signs of apoptosis in the glandular epithelia in the basalis, which extended to the functionalis during the luteal phase. Proliferation and bcl-2 expression are limited to the stromal compartment comprising the large granular lymphocytes - during this time, and extend in parallel with apoptosis from the basal to the functional layers. Apoptosis therefore may be related to the loss of the protective effect of bcl-2 and may have significance for the establishment of an endometrium adequately prepared for successful implantation.     

Compartmentalization and cyclic variation of immunoreactivity of renin and angiotensin converting enzyme in human endometrium throughout the menstrual cycle

Renin and angiotensin converting enzymes (ACE) are responsible for the generation of angiotensin II which regulates blood pressure and fluid/electrolyte homeostasis. The cellular localization and cyclic distribution of renin and ACE in human endometrium are demonstrated in this study. Immunohistochemical studies revealed that both renin and ACE were consistently localized in the endometrial glandular epithelia throughout the menstrual cycle; however, the immunostainings respectively for ACE and renin were weak and moderate in stromal cells of proliferative endometrium and negligible in secretory endometrium. No renin immunostaining was detected around endometrial blood vessels. Although endothelial cells consistently stained for ACE, no renin immunoreactivity was detected in these cells during the menstrual cycle. Western blot analysis using ACE antibody directed against human kidney identified a single protein band with a relative molecular mass of approximately 153 kDa. The intensity of this band showed cyclic variation during the menstrual cycle with the highest ACE expression during the late secretory phase and at menses suggesting that ACE plays a role in the initiation of menstruation. The differences in the cellular distribution patterns of these two enzymes further supports our previous proposition that angiotensin II has different functions at the different stages of the menstrual cycle.     

Changes in gonadotrophin response to gonadotrophin releasing hormone in normal women following bilateral ovariectomy

OBJECTIVE: Pituitary responsiveness to GnRH varies throughout the normal menstrual cycle. We have investigated whether there are differences in the ovarian mechanisms which regulate gonadotrophin secretion between the follicular and the luteal phase of the cycle. DESIGN: Normally ovulating women were studied during the first week following hysterectomy plus bilateral ovariectomy performed either in the mid- to late follicular phase (follicle size 16 mm) or in the early to midluteal phase (5 days post LH peak). The response of LH to a single dose of 10 micrograms GnRH was investigated 2 hours before the operation and every 12 hours after the operation until postoperative day 4 and every 24 hours until day 8. PATIENTS: Fourteen normally cycling premenopausal women with normal FSH (< 10 IU/l). Seven women were ovariectomized in the follicular and 7 in the luteal phase. MEASUREMENTS: Pituitary response to GnRH was calculated as the net increase in FSH (delta FSH) and LH (delta LH) at 30 minutes above the basal value. RESULTS: Basal levels of FSH and LH before the operation were significantly lower in the luteal than the follicular phase (P < 0.05), while those of oestradiol (E2) were similar. Also, similar were delta LH and delta FSH values. Serum progesterone and immunoreactive inhibin (Ir-inhibin) concentrations before the operation were higher in the luteal than the follicular phase (P < 0.05). Following the operation, serum E2, progesterone and Ir-inhibin values declined dramatically, while basal FSH and LH as well as delta FSH values showed a gradual and significant increase. The percentage increase in FSH and LH values (mean +/- SEM) on day 8 after the operation was similar in the follicular (453 +/- 99% and 118 +/- 35% respectively) and the luteal phase (480 +/- 71% and 192 +/- 45% respectively). In contrast to delta FSH, delta LH values after a temporal increase 12 hours from the operation, remained stable in the follicular phase and declined significantly in the luteal phase up to day 4. CONCLUSIONS: Basal gonadotrophin secretion during the normal menstrual cycle is predominantly under a negative ovarian effect. It is suggested that in contrast to FSH, the secretion of LH in response to GnRH is controlled by different ovarian mechanisms during the two phases of the menstrual cycle.     

Computerized assessment of endometrial echogenicity: clues to the endometrial effects of premature progesterone elevation

OBJECTIVE: To determine whether premature progesterone elevation affects the timing of hyperechogenic transformation of the endometrium during the early luteal phase of controlled ovarian hyperstimulation (COH) cycles. DESIGN: Prospective analysis. SETTING: Assisted Reproduction Unit, H?pital Antoine Béclère, Clamart, France. PATIENT(S): Fifty-nine women undergoing 59 IVF-ET cycles. INTERVENTION(S): Patients underwent COH with a GnRH agonist and hMG. Endometrial echogenicity was assessed on the days of hCG administration, oocyte retrieval, and ET. Results are expressed as the extent of submyometrial hyperechogenic area in relation to the total endometrial surface as determined by a computer-assisted analysis system. Patients were sorted according to whether their plasma progesterone level exceeded 0.9 ng/mL (n = 26) or not (n = 33) on the day of hCG administration. MAIN OUTCOME MEASURE(S): Endometrial echogenicity. RESULT(S): On the day of hCG administration, the degree of endometrial echogenicity was similar in both groups (41% vs. 40%), but after hCG administration, it increased significantly faster in the high progesterone group than in the low progesterone group (70% vs. 63% at oocyte retrieval and 90% vs. 79% at ET, respectively). CONCLUSION(S): End-follicular phase elevation in plasma progesterone (>0.9 ng/mL on the day of hCG administration) was associated with a faster increase in endometrial echogenicity during the early luteal phase of COH cycles. This observation is consistent with the hypothesis that premature progesterone elevation hastens the secretory transformation of the endometrium.     

Healthy women and patients with endometriosis show high concentrations of inhibin A, inhibin B, and activin A in peritoneal fluid throughout the menstrual cycle

Inhibin A, inhibin B, and activin A are growth factors which play local autocrine/paracrine roles in reproductive tissues. Since peritoneal fluid hormone content may reflect in part ovarian and endometrial secretory activities, the present study aimed to evaluate: (i) whether inhibin alpha-, activin betaA- and betaB-subunits, and activin receptor type II and type IIB mRNA are expressed in peritoneal tissues; (ii) expression and secretion of inhibin A and B, and activin A in cultured endometriotic cells; and (iii) concentrations of inhibin A and B, and activin A in serum and in peritoneal fluid in healthy women and in patients with endometriosis throughout the menstrual cycle. A group of women (n = 72) was recruited at laparoscopy for infertility investigation and divided into two groups: (i) control healthy women (n = 35), (ii) women with endometriosis (n = 37). Both groups were subdivided according to the follicular and luteal phase of the menstrual cycle. At the time of laparoscopy, specimens of peritoneal tissues were collected from three healthy women, while endometriotic tissue samples were collected and cultured from three women with endometriosis. Peritoneal tissues and cultured endometriotic cells expressed inhibin alpha-, activin betaA-, and betaB-subunits, and activin receptors mRNAs; in addition, inhibin-related proteins were measurable in culture medium. In healthy women, inhibin A and B, and activin A concentrations in peritoneal fluid were significantly higher than in serum (P < 0.001), at both phases of the menstrual cycle. Peritoneal inhibin A and B, and activin A concentrations were not significantly different between healthy women and patients with endometriosis, either when evaluated according to the degree of the disease and/or to the phase of the menstrual cycle. In conclusion, the findings that high concentrations are present in peritoneal fluid and that menstrual cycle-related changes occur suggest that reproductive organs may contribute to inhibin-related proteins in peritoneal fluid.     

Cyclic changes in genital organs and vaginal cytology in cynomolgus monkeys (Macaca fascicularis)

Vaginal cytology was evaluated weekly over 12 months in 20 adult female Cynomolgus monkeys (Macaca fascicularis). After sacrifice of the animals the histology of the ovaries, uterus and vagina were studied in different phases of the menstrual cycle. The cytological examination of the vaginal smears showed that the superficial cells increased in number towards the middle of the cycle and the number of intermediate cells declined gradually. Parabasal cells were observed mainly at the beginning of the cycle; they disappeared towards the middle of the menstrual cycle. During the early follicular phase, the cells were moderately separated from each other, and during the second half of the proliferative or follicular phase, the superficial cells appeared clumped together. Leucocytes were usually absent except for at the beginning of the cycle and in the last few days of the late secretory or luteal phase. The maturation index of the vaginal smears can be considered as a tool for distinguishing the different phases of the menstrual cycle. The microscopic examination of the genital organs showed that during the proliferative or follicular phase of the cycle, which corresponds to the development of the ovarian follicles, the uterus showed growth of endometrial glands, stroma and endothelial cell proliferation with capillary sprouts. Shortly after ovulation and parallel to the formation of the corpora lutea, the endometrium enters the secretory or luteal phase, which is characterized by coiling of endometrial glands, glandular secretion and the differentiation of the spiral artery. The most striking changes in the vagina, is the marked basal cell proliferation and thickening of the stratum granulosum during the follicular phase of the menstrual cycle. The histological changes observed in the vagina demonstrated a good correlation with the observation on cytological examination of the smears. The present study demonstrated that the process of angiogenesis in the uterus during the different phases of the menstrual cycle is a multiple phenomenon involving proliferation, maturation and differentiation.     

Ovarian steroid regulation of vascular endothelial growth factor in the human endometrium: implications for angiogenesis during the menstrual cycle and in the pathogenesis of endometriosis

The human endometrium undergoes a complex process of vascular and glandular proliferation, differentiation, and regeneration with each menstrual cycle in preparation for implantation. Vascular endothelial growth factor (VEGF) is an endothelial cell-specific angiogenic protein that appears to play an important role in both physiological and pathological neovascularization. To investigate whether VEGF may regulate human endometrial angiogenesis, we examined VEGF messenger ribonucleic acid (mRNA) and protein throughout the menstrual cycle and studied the regulation of VEGF by reproductive steroids in isolated human endometrial cells. By ribonuclease protection analysis, VEGF mRNA increased relative to early proliferative phase expression by 1.6-,2.0-, and 3.6-fold in midproliferative, late proliferative, and secretory endometrium, respectively. In histological sections, VEGF mRNA and protein were localized focally in glandular epithelial cells and more diffusely in surrounding stroma, with greatest VEGF expression in secretory endometrium. Consistent with these in vivo results, the treatment of isolated human endometrial cells with estradiol (E2), medroxyprogesterone acetate (MPA), or E2 plus MPA significantly increased VEGF mRNA expression over the control value by 3.1-, 2.8-, and 4.7-fold, respectively. The VEGF response to E2 was rapid, with steady state levels of VEGF mRNA reaching 85% maximum 1 h after the addition of steroid. E2 also caused a 46% increase in secreted VEGF protein, and the combination of E2 and MPA caused an 18% increase. VEGF expression in endometriosis, an angiogenesis-dependent, estrogen-sensitive disease was similar to that seen in eutopic endometrium. Peritoneal fluid concentrations of VEGF were significantly higher in women with moderate to severe endometriosis than in women with minimal to mild endometriosis or no disease. VEGF, therefore, may be important in both physiological and pathological angiogenesis of human endometrium, as it is an estrogen-responsive angiogenic factor that varies throughout the menstrual cycle and is elevated in women with endometriosis.     

Prostaglandin F and progesterone secretion by porcine endometrium and corpus luteum in vitro

Slices of porcine endometrium and corpus luteum tissue obtained from mature sows throughout the luteal phase of the oestrous cycle were incubated in culture medium which was analysed at regular intervals over a period of 8 hours for prostaglandin F and progesterone. Prostaglandin F secretion was greatest by endometrium obtained during the mid III to late I luteal stage of the cycle and the increased levels secreted by this tissue were paralleled by high levels of secretion from corpus luteum tissue. The addition of indomethacin (10 mug/ml) to the culture medium completely abolished prostaglandin F secretion by both endometrium and luteal tissue indicating that the high levels of the prostaglandin were due to synthesis. Progesterone secretion by the corpus luteum was maximal from early luteal tissue and had declined to considerably lower levels by late stage tissue when prostaglandin secretion was greatest. The possible physiological significance of luteal prostaglandin F secretion is discussed.     

Immunohistochemical localization of extracellular matrix proteins in luteal phase endometrium of fertile and infertile patients

The lack of expression of certain components involved in cell adhesion and migration is believed to contribute to endometrial dysfunction and implantation failure. The purpose of this study was to investigate whether luteal phase endometrium in women with unexplained infertility differs, with respect to specific extracellular matrix (ECM) proteins, from endometrium of normal fertile women. A panel of monoclonal antibodies to collagen type IV, fibronectin and laminin was used to characterize the localization of ECM components in the different endometrial compartments. Precisely timed endometrial biopsies obtained at 4, 7, 10 and 13 days following the luteinizing hormone surge were obtained from 22 normal fertile women (group 1) and 24 women suffering from unexplained infertility (group 2). Paraffin-embedded sections were labelled using the streptavidin-biotin alkaline phosphatase technique. In group 1, collagen type IV, fibronectin and laminin were absent from the luminal epithelium but present in stromal cells and the basement membrane of glands and blood vessels. In group 2, these components were absent from all endometrial regions using equivalent titres of antibody to those used in group 1. This suggests that the endometrium of women with unexplained infertility demonstrates defects in the distribution of certain ECM glycoproteins. A possible consequence of this defect may be implantation failure.     

Detection of human chorionic gonadotropin in blood of regularly bleeding women using copper intrauterine contraceptive devices

Highly sensitive and specific radioreceptorassay and radioimmunoassay of human chorionic gonadtropin (hCG) have been used in the detection of hCG in random serum samples during the luteal phase of the menstrual cycles of 200 women and in daily serum samples obtained a few days prior to expected ovulation through the luteal phase in 3 women with regular bleeding patterns and using a copper intrauterine device (IUD). Twelve to nineteen per cent of IUD users showed hCG in serum during the luteal phase, indicating that the presence of the IUD, while permitting fertilization, probably causes interference through degeneration of the blastocyst and consequent lack of implantation.