Uterine contractility: vaginal administration of the beta-adrenergic agonist, terbutaline. Evidence of direct vagina-to-uterus transport

Spontaneous uterine contractility during the menstrual cycle is required for menstruation, gamete transport, and, most likely, embryo nidation. Abnormal uterine contractility has been linked to dysmenorrhea, a condition associated with painful uterine cramping. Based on previous studies with progesterone, we have postulated the existence of a portal system that is responsible for some degree of direct vagina-to-uterus transport of administered compounds (i.e., the "first uterine pass effect"). It is possible that treatment with uterorelaxing substances, particularly beta-adrenergic agonists, may alleviate the uterine discomfort that accompanies dysmenorrhea. However, side effects encountered with oral administration of beta-agonists limit their utility. Alternatively, vaginal delivery of beta-agonists could solve this dilemma by enhancing their efficacy and reducing side effects. Therefore, in the current study we used hysterectomy specimens and an in vitro uterine perfusion system to test the vagina-to-uterus transport of [3H]terbutaline, a well-known beta-agonist. With the use of autoradiographic and scintillation counting techniques, our results clearly show progressive diffusion of labeled terbutaline from the rim of vaginal tissue through the uterus during the first 12 hours of perfusion. This indicates that uterine targeting of terbutaline can be accomplished through vaginal administration, suggesting a new therapeutic modality in women's health care.

Uterine contractility during the menstrual cycle

The non-pregnant uterus shows different patterns of contractility during the menstrual cycle. A renewed interest in uterine contractility has resulted from reports of non-invasive ultrasound (US) based studies. To clarify the changes in uterine contractility occurring throughout the menstrual cycle, we prospectively studied uterine contractions (UC) at six representative stages with US and intrauterine pressure (IUP) based approaches in 30 cycling volunteers. Results showed UC frequency could be measured by either US or IUP. UC amplitude and resting pressure tone could only be assessed by IUP. Conversely, direction of UC displacement could only be assessed by US. UC frequency increased at mid-cycle and decreased throughout the luteal phase suggesting oestradiol and progesterone exert positive and negative actions on uterine contractility, respectively. UC amplitude increased throughout the menstrual cycle to maximum values in the late luteal phase. Retrograde UC were most frequent at mid-cycle and convergent ('opposing') UC predominated during the luteal phase. While the former pattern ensures sperm transport, the latter may facilitate embryo implantation. In conclusion, UC changes throughout the menstrual cycle assessed by US and IUP emphasize the hormonal dependence of uterine contractility. Although UC patterns favouring sperm transport appear regulated by oestradiol, uterine quiescence and the dominance of convergent UC prevailing at the time of implantation are linked to progesterone. These data will serve to identify and treat possible dyskinetic changes in uterine contractility, particularly in women suffering from infertility, endometriosis, and dysmenorrhea.

The role of leiomyomas in infertility

STUDY OBJECTIVE

To assess the role of leiomyomas and their surgical removal on pregnancy rates.

DESIGN

(Canadian Task Force classification II-1). Setting. Academic center.

PATIENTS

Two hundred twelve women who were investigated for infertility.

INTERVENTION

Laparoscopic myomectomy.

MEASUREMENTS AND MAIN RESULTS

Patients were divided according to case control criteria as those who underwent laparoscopic removal of myomas (106) and those who did not (106); both groups were compared with 106 women with unexplained infertility without myomas. Of the 318 women, 83 (26%) became pregnant and delivered live infants. The 44 (42%) who underwent surgical removal of leiomyomas had higher delivery rates than 12 (11%) who did not undergo surgery (p <0.001) and 27 (25%) who did not have myomas (p <0.001). Patients whose myomas were not surgically treated had fewer deliveries than women who did not have myomas (12 vs 27, p <0.002). Fifteen women had spontaneous abortions before week 12: 3 (3%) who had surgery, 10 (9%) who did not have surgery, and 2 (2%) who did not have myomas.

CONCLUSION

Laparoscopic myomectomy improved pregnancy rates over nonsurgical management of myomas.

Targeted drug delivery in gynaecology: the first uterine pass effect

The objective was to verify the hypothesis of a 'first uterine pass effect' or direct preferential vagina-to-uterus transport, suggested by the evidence of higher than expected uterine tissue concentrations after vaginal administration of progesterone; we used a human ex-vivo uterine perfusion model. A mixture of tritiated (3H) and unlabelled progesterone was applied to the cuff of vaginal tissue remaining attached to the cervix after hysterectomy. At the end of the perfusion period (up to 12 h), 3H and 14C radioactivity was measured in samples of uterine tissue. Tritiated water and [14C]dextran were tested to determine the extent of non-specific vagina-to-uterus transport (leaks). Finally, sections of uterine tissue exposed only to [3H]progesterone were prepared for autoradiography. By 4-5 h after application progesterone had diffused to the entire uterus and had reached a steady state; 4 h after application, progesterone concentrations reached 185 +/- 155 and 254 +/- 305 ng/100 mg of endometrial and myometrial tissue respectively. Endometrial extraction of progesterone was higher when the experiment was performed on uteri obtained during the luteal phase (280 +/- 156 ng/100 mg of endometrial tissue) than those removed during the proliferative phase of the menstrual cycle (74 +/- 28 ng/100 mg of endometrial tissue). These data demonstrate that a 'first uterine pass effect' occurs when drugs are delivered vaginally, thereby providing an explanation for the unexpectedly high uterine concentrations relative to the low serum concentration observed after vaginal administration. Hence, the vaginal route permits targeted drug delivery to the uterus, thereby maximizing the desired effects while minimizing the potential for adverse systemic effects.

Transforming growth factor-beta 1 in the human endometrium

Transforming growth factor-beta 1 (TGF-beta 1) is a polypeptide involved in a variety of important physiological and pathophysiological processes such as the implantation of the embryo into the endometrium. Many factors seem to be related to this event. TGF-beta 1 is involved in many mechanisms both in endometrial and in embryonic tissues: it induces proliferation and differentiation, it regulates proteolytic activity and it modulates the maternal immune response. This study evaluated the presence of TGF-beta 1 in the endometrium during normal menstrual cycles and in the uterine fluids during induction of ovulation in the framework of an in vitro fertilization program. Immunohistochemistry was used to identify TGF-beta 1 in the endometrium and immunodot-blot to quantitate TGF-beta 1 in the uterine cavity fluid. The study shows that TGF-beta 1 is present in the endometrial tissue and its secretion is modulated during the menstrual cycle, as demonstrated immunohistochemically; its production seems to be controlled by ovarian steroids. In conclusion, TGF-beta 1 influences the growth and differentiation of the embryo, as well as the activation of embryonic proteolytic enzymes, and it modulates the maternal-embryonic immune response. Its variability in the uterine cavity is demonstrated in this study, and the underexpression of TGF-beta 1 in the uterine cavity might be responsible for failed implantation.

Uterine Contractility in Patients with Endometriosis

Uterine contractility was evaluated in 30 women, 16 with endometriosis and 14 controls. Two catheters were introduced into the uterine cavity, one next to the fundus and the other in proximity of internal os. They were connected to a pressure transducer that transforms mechanical events into an electrical signal, and analyzed by a system dedicated to this purpose. Data were analyzed by unpaired Student's t and McNemar tests. Frequency and amplitude of oscillations and mean pressure uterine tone were evaluated. Frequency of oscillations in the fundus (mean &plusmn; SD) were significantly higher in women with endometriosis than in controls: 21.86 &plusmn; 9.75% at 10 minutes versus 10.20 &plusmn; 5.26%, respectively (p <0.04). The mean basal pressure tone was also higher than in controls: 55.54 &plusmn; 21.04 mm Hg and 25.28 &plusmn; 19.94 mm Hg, respectively (p <0.04). Abnormal uterine contractility in women with endometriosis may be associated with a possible tubal efflux of endometrial tissue and its ectopic implants.

Adhesion formation after laparoscopic myomectomy

STUDY OBJECTIVE

To determine the frequency of adhesion formation after myomectomy performed by operative laparoscopy or laparotomy.

DESIGN

Case-control study. Setting. Academic women's hospital.

PATIENTS

Thirty-two premenopausal women scheduled for myomectomy by one of two techniques.

INTERVENTIONS

Surgical removal of myomata.

MEASUREMENTS AND MAIN RESULTS

Of the 32 women, 16 underwent laparotomy and 16 laparoscopy. Second-look laparoscopy was performed in 28 patients, at which time adhesions were lysed. Compared with laparotomy, laparoscopy resulted in adhesions in significantly fewer patients, and in significantly lower scores when adhesions were detected.

CONCLUSION

Laparoscopic removal of uterine myomata is associated with fewer adhesions than removal by laparotomy.

The efficacy of drugs in the management of endometriosis

STUDY OBJECTIVE

To establish the crude effects of danazol and gonadotropin-releasing hormone (GnRH) analogs in the management of endometriosis.

DESIGN

Prospective case-control study.

SETTING

Unit of the Pathophysiology of Reproduction outpatient department.

PATIENTS

Two groups of 110 women each with endometriosis (American Fertility Society score 1-3) who received danazol and GnRH analogs, and a control group who did not receive any drugs.

INTERVENTIONS

Women in the treatment groups received danazol 200 mg every 8 hours for 6 months, or a different GnRH agonist at standard dosages for 6 months. Laparoscopy was performed twice, at the time of diagnosis and just before the end of treatment (or no therapy for controls). Surgical treatment of the implants was performed at the second laparoscopy.

MEASUREMENTS AND MAIN RESULTS

Samples of both eutopic and ectopic endometrium were collected during both laparoscopies. Both danazol and GnRH agonists were useful in reducing the AFS scores to inactive endometriotic implants, and there were no significant differences between the effects (p <0.001). Fibrosis was found after 6 months of observation in the implants in one control woman (0.9%), in 20 patients (18.2%) treated with danazol (p <0.001 vs controls), and in 4 patients (3.6%) treated with GnRH agonists (NS vs controls). A correlation between a clinical diagnosis of AFS score zero and histologic features of fibrosis in the ectopic specimens after therapies was observed in 28% of women, with poor agreement (k = 0.07).

CONCLUSIONS

Fibrosis, which represent the absence of endometrial cells within the specimens of endometriotic lesions or eutopic endometrium, did not appear in eutopic endometria but it was found in some endometriotic implants. Danazol and GnRH agonists reduced the clinical AFS scores of endometriosis, but their histologic effects in completely and permanently eliminating endometriotic implants were unacceptable.

Financial impact in the Italian Health Service of laparoscopic versus laparotomic surgery for the treatment of ovarian cysts

To assess the cost of two procedures for the removal of ovarian cysts, 200 pre-menopausal women were recruited for the surgical removal of ovarian cysts by laparoscopy (n = 100) and laparotomy (n = 100) according to case-control criteria. Patients operated by laparoscopy (mean age +/- SD 32.22 +/- 9.98 years) and laparotomy (mean age +/- SD 29.57 +/- 6.62 years) for ovarian cysts (mean diameters +/- SD 4.98 +/- 3.62 and 4.83 +/- 2.78 cm) had a post-surgical hospital stay of 3.12 +/- 0.41 and 7.25 +/- 1.08 days (P < 0.001) respectively. The total rate of complications occurring in patients operated by laparoscopy was 9 versus 53% (P < 0.001) of those operated by laparotomy; body temperature > 38 degrees C was recorded in 52/100 of patients operated by laparotomy versus 6/100 of those operated by laparoscopy. The mean cost for each pure surgical treatment performed by laparoscopy was US $498.17 versus US $642.47 when it was performed by laparotomy (P < 0.001). The laparoscopic surgical approach is more expensive in the first 36 operations, thereafter becoming cheaper. The mean of the entire overall expenditure was US $1142.08 and US $2138.72 for laparoscopy and laparotomy (P < 0.001) respectively. The entire expenditure for laparoscopy is higher than laparotomy only until eight operations. In conclusion, laparoscopy versus laparotomy has resulted in a saving of US $14,429.3 for 100 operations while the saving on entire costs was US $99,664.8.

Dysfunctional uterine bleeding (DUB)

Cyclic or irregular uterine bleeding is common in perimenarchal and perimenopausal women with or without endometrial hyperplasia. The disturbance often requires surgical treatment because of its negative effects on both blood loss and abnormal endometrial growth including the development of endometrial cancer. The endometrium is often overstimulated during the perimenopausal period when estrogen/progesterone production is unbalanced. A therapeutical approach with gonadotropin-releasing hormone agonist (GnRHa) was proposed in a depot formulation (Zoladex) that induces a sustained and reversible ovarian suppression. To avoid the risk of osteoporosis and to obtain adequate endometrial proliferation and differentiation during ovarian suppression, transdermal 17-beta-estradiol and oral progestin were administered. Results of 20 cases versus 20 controls showed a reduction of metrorrhagia, a normalization of hemoglobin plasma concentration, and an adequate proliferation and secretory differentiation of the endometrium of patients with abnormal endometrial growth. Abnormal uterine bleeding is mainly due to uterine fibrosis and an inadequate estrogen and/or progesterone production or to a disordered estrogen transport from blood into the endometrium. In premenopausal women, endometrial hyperplasia may be part of a continuum that is ultimately manifested in the histological and biological pattern of endometrial carcinoma. The regression of endometrial hyperplasia obtained by using the therapeutic regimen mentioned above represents a preventive measure for endometrial cancer. Finally the normalization of blood loss offers a good medical alternative to surgery for patients with DUB.

Dating the endometrial biopsy by flow cytometry

OBJECTIVE

To determine endometrial changes throughout the menstrual cycle.

DESIGN

Flow cytometric analysis of endometrial cells versus chronological dating.

SETTING

Women volunteers with a normal menstrual cycle participated in this study that was done in an academic research environment.

PATIENTS

Two hundred thirty regular menstruating women with adequate luteal phase underwent endometrial biopsy at different days of their menstrual cycle; 138 biopsies were analyzed both histologically and by flow cytometry.

MAIN OUTCOME MEASURE

Percentage of biopsies correctly classified in terms of chronological dating.

RESULTS

Flow cytometry correctly classified the chronological day of biopsies in 59% of cases, the proliferative versus secretory days in 91% of cases, and the early, mid, and late secretory phases of the menstrual cycle were correctly predicted in 86% of cases.

CONCLUSION

Flow cytometry is a good method to determine growth and differentiation of the endometrium during the menstrual cycle. Detection of phases of the whole endometrial cell population offer information on the biological adequacy of endometrial response to the biochemical environment.

Immunologically mediated abortion (IMA)

Roughly 20% of all clinical pregnancies evolve into "spontaneous abortions". The causes of spontaneous abortion have been determined in under 60% of the total and comprise genetic, infectious, hormonal and immunological factors. In some cases the immune tolerance mechanism may be impaired and the foetus immunologically rejected (IMA, immunologically mediated abortion). The immunological mechanism implicated depends on the time in which pregnancy loss takes place. During preimplantation and up to the end of implantation (13th day) the cell-mediated immune mechanism (potential alloimmune etiologies) is responsible for early abortion. This mechanism involves immunocompetent decidual cells (eGL, endometrial granulated lymphocytes) already present during pre-decidualization (late luteal phase) and their production of soluble factors or cytokines. Once the implantation process is over, after blastocyst penetration of the stroma and the decidual reaction of uterine tissue, IMA could be caused by cell-mediated and humoral mechanism (anti-paternal cytotoxic antibodies or autoantibody etiology), by the production of paternal anti major histocompatibility complex antibodies, or even by an autoimmune disorder leading to the production of autoantibodies (antiphospholipid antibodies, antinuclear antibodies or polyclonal B cell activation). The diagnostic work-up adopted to select IMA patients is crucial and includes primary (karyotype of both partners, toxo-test, hysterosalpingography, endometrial biopsy, thyroid function tests, serum hprolactin, luteal phase dating) and secondary (full hemochromocytometric test, search for LE cells, lupus anticoagulant, anticardiolipin, antinuclear antibodies, Rheumatoid factor, blood complement VDRL) investigations. Therapeutical approaches vary. If autoimmune disorders are demonstrated therapies with different combinations of corticosteroids, aspirin and heparin or intravenous immunoglobulin are administered. Otherwise, therapy with paternal or donor peripheral blood mononuclear cells should be instituted.

Electromechanical activities of human uteri during extra-corporeal perfusion with ovarian steroids

A new experimental system was designed to study human uterine activities based on the extra-corporeal perfusion of isolated human uteri. Electromechanical activities in the uterine wall were recorded using bipolar silver-silver electrodes, endoluminal pressure catheters and a dedicated acquisition, storage and analytical system. The electrical signals recorded were isolated spikes and rhythmic activities; the last being primarily associated with organized mechanical events. Perfusion media containing 17 beta-oestradiol alone or with progesterone were used for those uteri obtained during proliferative (n = 5) or secretory (n = 5) phases of the menstrual cycle, respectively. Progesterone caused a reduction of frequency (P < 0.001) and duration (P < 0.001) of the rhythmic electrical activity, and decreased the endoluminal pressure at both detection sites (P < 0.01). 17 beta-Oestradiol increased both frequency (P < 0.001) and duration (P < 0.001) of the rhythmic electrical activity as well as the endoluminal pressure at two different detection sites (3 and 5 cm from the fundus) (P < 0.05). Significant differences between the fundus and cervix sites in the uterine wall were detected. In conclusion, uterine perfusion would be useful to examine the effects of uterotonic and tocolytic drugs before administration to humans, at no risk to the patients. Oestrogens increase and progesterone decreases both electrical and mechanical uterine activities.

Basement membrane in human endometrium: possible role of proteolytic enzymes in developing hyperplasia and carcinoma

Basement membranes (BM) are elements of the extracellular matrix that are essential for growth and differentiation of tissues. Several collagenolytic enzymes of tumor cells are involved in degradation of the extracellular matrix; growth and inhibitor factors [e.g. Epidermal Growth Factor (EGF), Transforming Growth Factors alpha and beta (TGF-alpha, beta)] seem to be involved in the extracellular matrix formation and degradation. To establish a possible association between the presence of collagenase (C), urokinase-type plasminogen activator (uPA) and the neoplastic growth of the endometrium, 44 endometrial specimens (14 proliferative, 11 secretive, 7 adenomatous hyperplasia, 12 adenocarcinoma) were studied using immunohistochemistry with antisera for C, uPA, EGF receptors and TGF-alpha. Immunostaining for collagenase revealed a positive reaction in moderately differentiated adeno-carcinoma without staining the normal and hyperplastic endometrium. A progressive increase in uPA immunostaining was observed in proliferative and neoplastic endometrium. TGF-alpha and its receptor (EGFr) were stained in proliferative and more clearly in hyperplastic and carcinomatous endometrium. In conclusion, BM play an important role in proliferation and differentiation of human endometrium; their degradation influences estrogen transportation from blood to the stroma. Endometrial BM degradation is associated with the presence of collagenolytic enzymes and growth factors.

Factors regulating interaction between trophoblast and human endometrium

Implantation is a crucial step in human reproduction. Disturbances of this process are responsible for pregnancy failure after both in vivo and in vitro fertilization. The endometrium provides the implanting embryo with a unique substratum where the embryo communicates with biochemical signals, attaches itself, penetrates and grows without blood circulation. The highly proliferative phase of the cytotrophoblast, during early human embryogenesis, may be due to endogenous production of growth factors that may establish autocrine/short range paracrine stimulator loops which explain the tumor-like properties of these tissues. Endometrial BM penetration and stroma invasion may be due to the proteolytic capability of the human embryo. It is suggested that collagenase and the urokinase-like plasminogen activator are responsible for this activity. To clarify the molecular mechanisms involved in human embryo implantation several models are suggested: culture of blastocysts, culture of endometrial cells, and endometrial explant co-culture. Human blastocysts cultured with whole perfused human uteri make it possible to recognize some aspects of the entire implantation process and give us the possibility of improving the benefits provided by new technologies in reproductive medicine and reducing embryonic loss at an early stage.