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Background/aims: It was the aim of this study to test the hypothesis that hypertension and/or inhibition of nitric oxide (NO) synthases alters uterine vascular remodeling during pregnancy., Methods: Using a model of hypertension (NO synthase inhibition with L-NAME) in nonpregnant and pregnant rats, comparisons were made with age-matched controls, as well as with animals receiving hydralazine along with L-NAME to maintain normotension in the presence of NO synthase inhibition. Circumferential and axial remodeling of large (main uterine, MUA) and small (premyometrial radial) arteries were quantified and compared., Results: L-NAME treatment prevented expansive circumferential remodeling of the MUA; cotreatment with hydralazine was without effect. Circumferential remodeling of smaller premyometrial radial arteries was also significantly attenuated in hypertensive pregnant animals, while premyometrial radial arteries from rats receiving hydralazine with L-NAME were of intermediate diameter. Neither hypertension nor NO synthase inhibition had any effect on the substantial (200-300%) axial growth of MUA or premyometrial radial arteries., Conclusion: NO plays a major role in facilitating pregnancy-induced expansive remodeling in the uterine circulation, particularly in larger arteries. Some beneficial effects of hydralazine on expansive circumferential remodeling were noted in smaller radial vessels, and these may be linked to its prevention of systemic hypertension and/or to local effects on the arterial wall. Neither NO synthase inhibition nor hypertension had any effect on arterial longitudinal growth.

Objective: This study was undertaken to study vascular reactivity of small myometrial arteries in women with idiopathic menorrhagia., Study Design: Small myometrial arteries were isolated from 6 patients with idiopathic menorrhagia and 4 controls. The contractile responses to thromboxane mimetic (U46619) and endothelin-1 were assessed before and after incubation with N(w)-nitro-L arginine methyl ester alone or in combination with indomethacin (Indo). Endothelium-dependent dilation to bradykinin and basal tension were compared before and after incubation with N(w)-nitro-L arginine methyl ester alone, or with N(w)-nitro-L arginine methyl ester in combination with indomethacin., Results: Constriction to endothelin-1 was enhanced in idiopathic menorrhagia arteries (P < .05). Idiopathic menorrhagia arteries demonstrated enhanced basal tension after incubation with N(w)-nitro-L arginine methyl ester, which was further exaggerated by indomethacin. NOS inhibition had no effect on basal tension in controls, but basal tension was enhanced after inhibition of cyclooxygenase-derived products (P < .05). Bradykinin-mediated dilation was significantly increased in idiopathic menorrhagia (P < .05)., Conclusion: The presence of functional alterations in small myometrial arteries could contribute to idiopathic menorrhagia.

Objective: The aim of this study was to assess myometrial vascularization with 3-dimensional (3D) power Doppler angiography (PDA) in women with different grades of primary dysmenorrhea at the moment of maximum menstrual pain in an effort to improve the pathophysiologic knowledge of one of the most common gynecologic conditions., Methods: This was a cross-sectional study involving 70 voluntary women that studied or worked at the Clinica Universitaria de Navarra between January 2006 and January 2008. All women underwent transvaginal sonographic 3D PDA on the day of maximum pain after the onset of menstruation or during the first 24 to 48 hours of the new cycle if no pain was present. Three groups were defined according to a visual analog scale: no pain to mild dysmenorrhea, moderate dysmenorrhea, and severe dysmenorrhea. Vascularity assessment was done on the basis of 3D vascularity indices: the vascularization index (VI), flow index (FI), and vascularization-flow index (VFI)., Results: The mean VI and VFI for the inner 5 mm of the myometrium and the total myometrium were significantly higher in the women with severe dysmenorrhea than in those with no pain to mild dysmenorrhea (P < .05). The VI, FI, and VFI in the women with moderate dysmenorrhea did not differ significantly from those in the women with severe dysmenorrhea., Conclusions: This study evaluated the use of 3D PDA for assessing uterine and specifically myometrial vascularization. Our data indicate that women with severe dysmenorrhea have increased myometrial vascularization during the early menstrual phase compared with women without pain.

Agonist-induced tone oscillations (rhythmic contractions and relaxations) occur in vascular beds to allow acute regulation of volume flow and thus the delivery of oxygen and nutrients to the tissue. Mechanisms responsible for the control of human placental vasomotor tone and blood flow are poorly characterized. This study aimed to characterise thromboxane-induced tone oscillations in human placental and myometrial arteries. Chorionic plate and myometrial arteries obtained from biopsies at term were mounted for isometric tension measurement. Tone oscillations were observed in chorionic arteries only when exposed to sub-maximal (<1 microM) concentrations of U46619. Slow (mean+/-SEM) frequency (2.6+/-0.5 per hour), large amplitude (39+/-7% of peak contraction) tone oscillations were elicited by 0.03 microM U46619 (n=18). In the presence of the nitric oxide synthase (NOS) inhibitor l-NNA (100 microM) the amplitude was significantly reduced (40+/-13% to 18+/-8%, P<0.05, n=6), frequency was unaltered and the bradykinin-dependent vasodilator response was reduced (68+/-13% to 40+/-19%, P<0.05, n=6). Myometrial arteries exposed to 1 microM U46619 developed tone oscillations within 10 min, which increased in amplitude over 30min occurring at relatively constant frequency. The mean amplitude of oscillations at 30 min (31+/-7%, n=16) was similar to that in chorionic arteries but the occurrence more frequent (42.8+/-9.7 per hour, P<0.001). Inhibition of NOS did not alter tone oscillations in myometrial arteries. Tone oscillations in chorionic arteries from pre-eclamptic and growth restricted (FGR) pregnancies were reduced in amplitude whereas those in myometrial arteries had increased frequency. Inhibition of NOS further reduced oscillation amplitude in chorionic arteries from FGR pregnancies. The alterations may contribute to the vasculopathology of these conditions, or, may represent compensatory mechanisms to maintain a matching of materno-placental blood flow.

Total laparoscopic hysterectomy has been shown to be an equally effective and safe technique when compared with conventional abdominal surgery for endometrial carcinoma. The procedure, as performed at our institution, involves the use of a uterine balloon manipulator (RUMI manipulator and Koh Colpotomizer system) for optimal surgical control. The fallopian tubes are cauterized to prevent transtubal spread of the tumor. The balloon manipulator thus creates a positive closed pressure system within the uterine cavity. After observing extensive displacement of tumor into small and large blood vessels in 1 case of grade 1, stage 1b endometrial carcinoma, we reviewed slides from 37 hysterectomy specimens (7 for endometrial carcinoma or atypical hyperplasia and 30 for benign conditions) performed laparoscopically between August 2004 and March 2006 at Emory University and Crawford Long Hospitals. We reviewed all slides for the presence or absence of endometrial tumor/tissue in vascular spaces. Patients with endometrial carcinoma/atypical complex hyperplasia included 6 FIGO grade I endometrioid carcinomas (3 stages 1A; 3 stages 1B) and 1 patient with atypical complex hyperplasia. Tumor within blood vessels was noted in 5 of 7 (71%) cases. In 3 cases, including the case of atypical complex hyperplasia, the number of vessels containing tumor were too numerous to count small and large caliber blood vessels. In the remainder, 1 case had 2 small vessels involved and in the other 7 small vessels showed tumor within vascular lumina. Benign endometrial glands and stromal tissue were noted within vascular spaces in 4 of 30 (13%) hysterectomy specimens removed for benign conditions. We describe a hitherto unreported artifact of vascular pseudo invasion in hysterectomy specimens obtained using the technique of total laparoscopic abdominal hysterectomy. We postulate that the creation of a closed pressure system generated as part of the operative technique is likely responsible for this phenomenon. Pathologists need to be aware of this artifact to avoid misinterpretation of vascular invasion in these cases with its associated therapeutic and prognostic implications.

Endometrial tissue in the myometrium vessels space, whit no relation to menstrual period, is a rarely reported event. It is unknown if it is part of the natural history of ectopic localization of endometrial tissue or it is related to more or less aggressive behavior of endometriosis. This paper reports two cases: a 35- and 51-year-old women. The first one made suspect a clear cells adenocarcinoma undiagnosed before hysterectomy, because there were no endometrial glands in the myometrium vessels space, but only nest of stromal cells isolated, simulating thrombus of an invasive neoplasm. Since a wrong diagnosis affects the integral treatment of patients, differential diagnosis must be established in order to increase certainty.

Maternal endothelial activation in pre-eclampsia is attributed to the release of unknown factors from a hypoperfused placenta. To further characterize these factors, we have used a serum-free placental villous explant culture model and investigated the effect of the liberated soluble factors produced on human endothelial cell cultures. Term placental villous explants from uncomplicated pregnancies were cultured for 4 days in 20, 6 or 1% O2 to mimic placental hyperoxia, normoxia and hypoxia. Medium collected from viable explants was applied to cultured human uterine microvascular endothelial cells. Medium conditioned by hypoxic explants caused a significant decrease in endothelial cell ATP levels and mitochondrial dehydrogenase activity, suggestive of a reduced metabolic rate. An additional reduction in mitochondrial membrane potential and increased endothelial cell death occurred as the oxygen concentration to which explants had been exposed decreased. Effects of the hypoxic explant medium were also seen ex vivo in a wire myography model of myometrial artery function, with increased vasoconstriction and attenuated vasodilation following exposure to hypoxic explant medium. These results suggest that hypoxia (1% O2) may stimulate the release of soluble factors from the placenta, which have an adverse effect on endothelial cell metabolism and mitochondrial integrity in vitro. These potentially pathogenic factors are now being characterized.

The objectives of this study were to determine whether placental growth factor (PlGF) exerts a vasodilatory effect on rat uterine vessels (arcuate arteries and veins) and to examine regional differences in reactivity by comparing these responses to those of comparably sized mesenteric vessels. We also sought to examine and compare its effects on human uterine and subcutaneous vessels. All vessels were studied in vitro, under pressurized (rat) or isometric wire-mounted (human) conditions, and exposed to a range of PlGF concentrations. Inhibitors of nitric oxide and prostaglandin synthesis were included in an effort to understand the causal mechanism(s). In rat uterine arteries, the effects of receptor inhibition and activation using selective ligands for VEGFR-1 (PlGF) vs. VEGFR-2 (VEGF-E) were determined, and real-time RT-PCR was performed to evaluate the effect of pregnancy on relative abundance of VEGFR-1 and VEGFR-2 message in the vascular wall. PlGF was a potent vasodilator of all vessels studied, with greatest sensitivity observed in rat uterine arteries. Pregnancy significantly augmented dilator sensitivity to PlGF, and this effect was associated with selective upregulation of VEGFR-1 message in the pregnant state. The contribution of nitric oxide was appreciable in rat and human uterine arteries, with lesser effects in rat uterine veins and mesenteric arteries, and with no observable effect in human subcutaneous vessels. Based on these results, we conclude that PlGF is a potent vasodilator of several vessel types in both humans and rats. Its potency and mechanism vary with physiological state and vessel location and are mediated solely by the VEGFR-1 receptor subtype. Gestational changes in the uterine circulation suggest that this factor may play a role in modulating uterine vascular remodeling and blood flow during the pregnant state.

Preeclampsia is characterized by intense and prolonged vasoconstriction. Rho A-mediated calcium sensitization is central to prolonged contractility of vascular smooth muscle. The aims of this study are (1) to investigate mRNA expression levels of Rho A/Rho kinases in placental tissues from normotensive and preeclamptic women and (2) to investigate the effects of 2 isoprostanes, 8-iso prostaglandin F(2)( alpha) (8-iso PGF(2 alpha) ) and 8-iso prostaglandin E(2) (8-iso PGE(2)), on small placental and myometrial vessel resistance and to determine if their effects were mediated via the Rho kinase pathway. Real-time reverse transcription polymerase chain reaction for Rho A, ROCK I, and ROCK II was performed on total RNA from normotensive and preeclamptic placentae. The effects of 8- iso PGF(2 alpha) and 8-iso PGE(2) (alone and with the specific Rho kinase inhibitor Y-27632) on placental and myometrial vessels (<400 microm) were measured and compared with control recordings. Rho A mRNA expression levels were significantly higher in placentae from preeclamptic women than in placentae from normotensive women (P < .01). There was no significant difference in expression levels of ROCK I and ROCK II between both tissue types (P > .05). Both isoprostanes exerted a significant concentration-dependent vasocontractile effect on both vessel types (P < .001). This effect was antagonized by Y-27632 in placental arteries but not in myometrial arteries. Increased Rho A mRNA expression in placentae from preeclamptic women is suggestive of a role for the Rho kinase pathway in the modulation of the placental vasculature in this condition. Isoprostanes exert their vasocontractile effect, in placental vasculature, in part via the Rho kinase pathway.

At term, amniotic fluid contents may mediate the onset of labor through the activation of amniotic fluid macrophages and their migration into the myometrium. To test this concept, the authors examine the histological changes that occur in myometrial biopsies at term prior to (n = 53) and during (n = 15) labor. Biopsies were stained with an antimacrophage antibody, anti-CD34 (endothelial cells), and anti-caspase 3 (apoptotic cells). The samples showed a variable inflammatory infiltrate of neutrophils and macrophages, with a greater infiltrate in the samples obtained during labor (P < .001, Fisher exact test). Prior to labor, there were prominent changes in the myometrial fibers that reflected shearing, shrinkage, edema, and particularly apoptosis; endothelial cells of thin-walled vessels prominent in the biopsies displayed marked nuclear biotinylation, and the vascular lumen contained fibrin and platelet thrombi, microparticles, desquamated endothelial cells, amniotic squamous cells, and mucoid material. These changes were also present in samples obtained during labor. In an additional 10 patients in labor with male fetuses, myometrial samples were examined for the presence of macrophages carrying a Y chromosome indicative of a fetal origin, but none were observed. These findings suggest that endothelial cell damage and amniotic fluid embolism are very common at term prior to clinical labor and provide a mechanism by which surfactant protein A and phospholipids present in the amniotic fluid may access myometrial cells and provoke the inflammatory response that occurs during parturition. The authors' studies give no support to the suggestion that fetal macrophages might invade the human myometrium at term.

Sphingosine-1-phosphate (S1P) is a potent bioactive lipid that has been implicated in cardiovascular disease. The objective of the present study was to determine the vasoactive effects and underlying mechanisms of S1P on adult human maternal arteries. The isometric tensions of the omental and myometrial arteries isolated from normal pregnant women at term were assessed in response to incremental doses of S1P in the presence or absence of the nitric oxide (NO) synthase inhibitor N(G)-nitro-L-arginine methyl ester (L-NAME). The putative involvement of Rho-associated kinases (ROCKs) in intact arteries and in those permeabilized with alpha-toxin, to study agonist-dependent calcium-sensitization, was assessed with the inhibitor Y27632. Real-time RT-PCR established the presence of mRNA encoding the S1P receptors (S1P(1) to (3)), previously known as endothelial differentiation gene receptors (EDG1, 3 and 5), in both artery types. S1P induced a dose-dependent increase in the isometric tension of all the arteries. Y27632 reduced constriction due to S1P in intact arteries and reduced S1P-induced sensitization of contraction to submaximal activating Ca(2+) in permeabilized arteries. L-NAME also modulated S1P vasoactive responses in a tissue-specific manner. Two subgroups of omental arteries were identified, one of which utilizes the NO pathway. In myometrial arteries, S1P evoked oscillatory constrictions, whereas pretreatment with L-NAME resulted in only tonic constrictions of unaltered peak magnitude. The prominent vasoactive actions of S1P in the maternal arteries of pregnant women are modulated by inhibitors of ROCKs and NO bioavailability. The subtle tissue-specific functional differences in the modulation of S1P actions by NO have important implications for vascular tone regulation by this bioactive circulatory metabolite during pregnancy.

Remodeling of the uterine spiral arteries during pregnancy transforms them from high to low resistance vessels that lack vasoconstrictive properties. This process is essential to meet the demand for increased blood flow imposed by the growing fetus. Loss of endothelial and smooth muscle cells (SMC) is evident in remodeled arteries but the mechanisms underlying this transformation remain unknown. This study investigated the hypothesis that fetal trophoblast invading from the placenta instigate remodeling by triggering cell death in vascular SMC. Specifically, a role for trophoblast-derived death inducing cytokine tumor necrosis factor-alpha-related apoptosis-inducing ligand (TRAIL) was investigated. Expression of the activating TRAIL receptors R1 and R2 was detected by flow cytometry on human aortic SMC and by immunohistochemistry on spiral artery SMC. Recombinant human TRAIL induced human aortic SMC apoptosis, which was inhibited by antibodies against TRAIL-R1 or -R2. Perfusion of denuded spiral artery segments with recombinant human TRAIL also induced SMC apoptosis. Trophoblasts isolated from first trimester placenta expressed membrane-associated TRAIL and induced apoptosis of human aortic SMC; apoptosis was significantly inhibited by a recombinant human TRAIL-R1:Fc construct. Trophoblast within the first trimester placental bed also expressed TRAIL. These data show that: 1) TRAIL causes SMC death; 2) trophoblast produce the apoptotic cytokine TRAIL; and 3) trophoblast induce SMC apoptosis via a TRAIL-dependent mechanism. We conclude that TRAIL produced by trophoblast causes apoptosis of SMC and thus may contribute to SMC loss during spiral artery remodeling in pregnancy.

Objective: The objective of the study was to quantify markers of myometrial ischemia, necrosis, and inflammation in women undergoing uterine artery embolization (UAE)., Study Design: Women with symptomatic fibroids were randomized to treatment with UAE (n = 14) or abdominal myomectomy (n = 11). Peripheral venous blood samples were taken before and after the procedure, at 24 hours and 6 weeks. Creatine kinase (CK) and ischemia-modified albumin (IMA) were measured as markers of necrosis and ischemia. Inflammation was assessed by measurement of C-reactive protein (CRP)., Outcome Measures: Changes in the markers following UAE and myomectomy were measured., Results: Following UAE, no change was seen in CK or IMA, but CRP was raised only at 6 weeks. At 24 hours after myomectomy, there were significant rises in all 3 markers, with a return to normal by 6 weeks., Conclusion: No significant ischemia or necrosis occurs in the myometrium following UAE, whereas the delayed rise in CRP is likely to reflect necrosis in fibroids.

The calcineurin/nuclear factor of activated T cells (NFAT) signaling pathway has been found to play a role in regulating growth and differentiation in several cell types. However, the functional significance of NFAT in the vasculature is largely unclear. Here we show that NFATc1, NFATc3, and NFATc4 are expressed in human myometrial arteries. Confocal immunofluorescence and Western blot analysis revealed that endothelin-1 efficiently increases NFATc3 nuclear accumulation in native arteries. Endothelin-1 also stimulates NFAT-dependent transcriptional activity, as shown by a luciferase reporter assay. Both the agonist-induced NFAT nuclear accumulation and transcriptional activity were prevented by the calcineurin inhibitor CsA and by the novel NFAT blocker A-285222. Chronic inhibition of NFAT significantly reduced IL-6 production in intact myometrial arteries and inhibited cell proliferation in vascular smooth muscle cells cultured from explants from the same arteries. Furthermore, by using small interfering RNA-mediated reduction of NFATc3, we show that this isoform is involved in the regulation of cell proliferation. Protein synthesis in intact arteries was investigated using autoradiography of [(35)S]methionine incorporation in serum-free culture. Inhibition of NFAT signaling did not affect overall protein synthesis or specifically the synthesis rates of major proteins associated with the contractile/cytoskeletal system. An intact contractile phenotype under these conditions was also shown by unchanged force response to depolarization or agonist stimulation. Our results demonstrate NFAT expression and activation in native human vessels and point out A-285222 as a powerful pharmacological blocker of NFAT signaling in the vasculature.

Aim: The purpose of the study was to investigate whether colour Doppler sonography is helpful in the surveillance of abnormal third stage of labour., Materials and Methods: 20 patients were enrolled in the prospective study. Inclusion criteria were third stage of labour > 15 min and/or clinical suspicion of retained placenta. By means of grey scale and colour Doppler sonography the length of distinct phases of third stage of labour and length of visualisation of blood flow between myometrium and placenta were measured. These data were compared with previously published normal values., Results: The patients were allocated into four groups: 1. Patients with prolonged third stage of labour, but normal vaginal delivery of the placenta (Group 1, 8 cases). 2. Patients with clinically suspected retained placental parts (Group 2, 4 cases). 3. Patients with manual removal of the placenta without confirmation of placenta accreta (Group 3, 4 cases). 4. Patients with manual removal of the placenta with confirmation of placenta accreta (Group 4, 4 cases). A significant longer latent phase was responsible for the prolonged third stage of labour in Group 1 (p < 0.05). Blood flow between myometrium and placenta was significantly longer visible in Group 4 than in the normal cohort (p < 0.0001)., Conclusion: Grey scale sonography can help to distinguish between uncomplicated and complicated prolonged third stage of labour. Colour Doppler sonography can detect persistent blood flow between myometrium and placenta during third stage of labour in cases of placenta accreta. In these instances, the patient may benefit from colour Doppler sonography-guided curettage.

Blockade of small-conductance Ca (2)(+)-activated K(+) channels (SK(Ca)) and intermediate conductance Ca(2)(+)-activated K(+) channels (IK(Ca)) can cause inhibition of endothelium-dependent hyperpolarizing factor (EDHF) in many vascular beds from animals, but there is a relative paucity of data in human vessels. Systemic arteries, isolated from women with healthy pregnancies, relax to the endothelial-dependent agonist bradykinin via a nonprostacyclin and non-nitric oxide pathway attributable to EDHF. Therefore, in this study, the authors investigated the effect of pharmacological blockade of SK(Ca) and IK(Ca) on EDHF-mediated relaxation of human omental and myometrial arteries preconstricted with either arginine vasopressin or U46619. Human arteries were isolated from omental and myometrial biopsies taken from healthy women undergoing planned cesarean section at term. Endothelial function was assessed using wire myography. In all vessels examined, nonspecific blockade of IK(Ca) with charybdotoxin attenuated EDHF-attributed relaxation. However, when Tram 34 was used to block IK(Ca), the attenuation of relaxation was evident only with U46619 preconstriction. In arteries from both vascular beds, and with either preconstrictor, a combination of either apamin and charybdotoxin or apamin plus Tram 34 almost ablated EDHF-attributable relaxation. These data support the notion that in human systemic arteries, activation of, primarily, SK(Ca) and IK(Ca)K(+) channel subtypes underlies EDHF-mediated relaxation. These results have important implications for future studies ascertaining the molecular mechanisms of hypertensive disorders (eg, preeclampsia, in which EDHF is thought to be aberrant).

Background: The human uterine vasculature is highly structured, exhibiting circumferential and radial branching. Previously published angiograms of the arterial network describe a system of regular coils. Uterine fibroids lack this structured vasculature. In this study, we make a comparison between the vasculature in normal myometrium and in fibroids using robust stereological methods thus far lacking in the literature., Methods: Stereological and morphometric analysis of the vascular system was carried out on 15 normal and 27 small fibroid (5-40 mm) uteri taken from women suffering menorrhagia. Projected images of published angiograms were also re-examined, measuring tortuosity., Results: A decreasing gradient of vascular smooth muscle from outer to inner myometrium was found in normal uteri, with no corresponding gradient in capillary tissue fraction. An association between vascular luminal size, amplitude and frequency of vessel bending was also established. Conversely, fibroids were found to lack structured or muscularized vasculature., Conclusions: A quantitative gradient within the myometrial vascular system, which is absent in fibroids, has been demonstrated. These structural differences between diseased and healthy tissues are probably because of differing expression of angiogenic growth factors and may explain the distribution of particles seen after uterine artery embolization.

Objectives: In pre-eclampsia (PE), endothelium-dependent function of myometrial small arteries is markedly attenuated. The residual PE response is wholly NO mediated. We have previously demonstrated that PDE5 inhibition can improve endothelial function in myometrial small arteries from women with PE. We aimed to assess whether the effect of PDE5 inhibition in PE was myometrial artery specific., Study Design: Small arteries were dissected from omental biopsies obtained at Caesarean section from normal pregnant women (NP, N = 20) and women with PE (N = 11). Chorionic plate small arteries were dissected from NP (N = 13) and PE (N = 11) placentae. Vasoconstriction (arginine vasopressin or thromboxane-mimetic U46619) and endothelial-dependent relaxation were assessed by wire and pressure myography. Constriction/relaxation curves were repeated post 1h incubation with PDE5 inhibitors UK-343664 or sildenafil citrate (0, 10 or 100 nM)., Results: Omental artery constriction was increased in PE. Omental vessel constriction was unaffected by PDE5 inhibition. Sildenafil citrate improved bradykinin-induced but not acetylcholine-induced relaxation of omental small arteries from NP women. PDE5 inhibition did not alter relaxation of omental arteries from women with PE. Placental small arteries were unaffected by PDE5 inhibition., Conclusion: Use of PDE5 inhibitors does not significantly alter endothelial-dependent relaxation in omental or placental small arteries from PE women.

The ability of a blood vessel to develop tone is dependent upon morphological parameters of the smooth muscle cells (SMC), including density, relationship with the endothelium and subcellular distribution of myofilaments and intracellular organelles. Consequently, wall ultrastructure of isolated human placental chorionic plate arteries (n=12), fixed when pressurised to mimic their in vivo geometry, was examined qualitatively using electron microscopy, and compared with maternal arteries (omental, n=10, myometrial, n=6). Arteries from women with uncomplicated pregnancy were tested for contractile viability before fixing, with some vessels post-fixed in osmium-ferricyanide for sarcoplasmic reticulum (SR) identification. In contrast to maternal arteries, placental arteries had no internal elastic lamina but exhibited considerable extracellular matrix separating circularly orientated SMC. Human SMC contained tightly packed arrays of myofilaments running parallel to the plasma membrane, enveloping cellular organelles. Synthetic SMC, with few myofilaments and much rough SR, were observed in placental arteries only. SR in SMC from maternal arteries was located centrally, often encircling mitochondria, and also near the plasma membrane associated with caveolae. Positive SR staining was rarely observed in SMC of placental arteries. This study highlights ultrastructural differences between placental and maternal arteries that may underlie specialised mechanisms of regulating vascular tone in the placenta.

Trophoblast invasion of uterine decidua and myometrium, and spiral artery transformation, are essential for the development of normal pregnancy; this process is impaired in pre-eclampsia, fetal growth restriction, and pre-term labour. The hypothesis that late miscarriage is associated with reduced trophoblast invasion and spiral artery transformation was tested in a large series of placental bed biopsies containing decidua and myometrium from late, karyotyped, embryonic miscarriage (>or=13 weeks' gestation; n = 26; n = 96 spiral arteries) and gestationally matched ultrasound-dated normal pregnancies (n = 74; n = 236 spiral arteries). Cryostat sections were immunostained using an avidin-biotin peroxidase technique for cytokeratin, desmin, and von Willebrand factor to detect trophoblast, myometrium, and vascular smooth muscle and endothelium, respectively. Trophoblast invasion and individual features of spiral artery transformation were assessed and analysed using a logistic regression model. Compared with normal pregnancy, myometrial spiral arteries in late miscarriage showed reduced endovascular (4% vs. 31%, p = 0.001) and intramural trophoblast (76% vs. 88%, p = 0.05), and less extensive fibrinoid change (4% vs. 18%, p = 0.01). In contrast, endovascular trophoblast in decidual spiral arteries was increased (40% vs. 66%, p = 0.04). These findings suggest that, in common with pre-eclampsia, late sporadic miscarriage may be associated with reduced trophoblast invasion and inadequate transformation of myometrial spiral arteries.

Objective: Endothelial dysfunction is central to the pathogenesis of pre-eclampsia (PE). This study aimed to determine if maternal characteristics, such as age, parity, BMI, smoking status and obstetric history, which affect the risk of developing pre-eclampsia, influenced endothelial function in myometrial arteries taken during an uncomplicated pregnancy., Study Design: As part of ongoing studies investigating endothelial function in normal and compromised pregnancies, myometrial vessels were isolated from biopsies taken at elective Caesarean section. A cohort of 119 women was identified and information regarding past pregnancy outcomes and medical history was obtained. Wire myography was used to compare endothelial-dependent relaxation in response to bradykinin between different patient groups., Results: Maternal age, parity and a history of miscarriage did not affect endothelial-dependent relaxation of myometrial small arteries. Attenuated endothelial-dependent relaxation was seen in vessels taken from women with elevated BMI and enhanced relaxation was seen in women who had smoked during pregnancy. Vessels isolated from women with a history of past pregnancy complications did not show any significant difference in endothelial-dependent relaxation compared to women with uncomplicated histories., Conclusion: Maternal factors may influence endothelial function in the absence of pregnancy complications. Endothelial-dependent relaxation of myometrial arteries, isolated from multiparous women with an uncomplicated index pregnancy, is comparable between women with and without a history of pregnancy complications.

Accurate discrimination between FIGO stages IB and IC endometrial carcinomas has important prognostic and therapeutic implications, but depth of invasion as a percentage of myometrial thickness can be difficult to ascertain. In such cases, pathologists often presume that infiltration that reaches the arcuate vascular plexus (AVP) in the myometrium indicates >50% myoinvasion. The further assumption is sometimes made that the anterior and posterior uterine walls are of the same thickness. To our knowledge, neither supposition is based on published data. We performed a prospective study of myometrial thickness and the position of the AVP in 50 normal uteruses from patients aged 27 to 84 years. Myometrial thickness varied inversely with age (p < 0.0001); however, anterior and posterior wall myometrial thickness did not differ significantly in the cohort as a whole (p = 0.059) and in individual cases was highly correlated (p < 0.0001). The position of the AVP was variable. On average, its inner limit was situated at a depth of 47.3% of the thickness of the myometrium in both uterine walls, but the position varied between individuals and sometimes differed considerably between the anterior and posterior walls of the same uterus. The position of the AVP did not differ significantly with age. We conclude that carcinomatous infiltration well into or through the AVP usually signifies >50% myoinvasion; however, if infiltration barely extends into the AVP, the depth of invasion should be calculated with reference to the thickness of the myometrium in the opposite uterine wall.

Background: The purpose of this study is to determine whether there is any difference for vascular endothelial growth factor expression in placentae and myometrial resistance arteries from control and pre-eclamptic patients to clarify the source of the increased total vascular endothelial growth factor in pre-eclampsia., Methods: With placentae tissue samples and small pieces of myometrium from the controls (n=10) and pre-eclampsia patients (n=7), vascular endothelial growth factor immunohistochemistry and mRNA in situ hybridization were performed. We also measured the serum vascular endothelial growth factor levels by competitive enzyme immunoassay at the same time., Results: Vascular endothelial growth factor was identified primarily in syncytiotrophoblast in placental tissue, and it was also identified in smooth muscle cells in the myometrium and perivascular smooth muscle in myometrial resistance arteries. However, there were no differences in vascular endothelial growth factor expression between the groups in the presence of elevated serum levels of total vascular endothelial growth factor in pre-eclamptic patients (median 18.2 ng/ml versus 4.9 ng/ml)., Conclusion: This study suggests that the placenta and perivascular smooth muscle are not the origin of the increased total vascular endothelial growth factor in pre-eclampsia. To clearly understand the role of vascular endothelial growth factor in pre-eclampsia, further studies are required to determine the sites of increased vascular endothelial growth factor synthesis.

Microangiography and vascular casting have previously been used to demonstrate the three-dimensional architecture of human uterine microvasculature. However, a limitation of these perfusion-dependent techniques is the difficulty in identifying surrounding tissue components. We have previously shown that it is possible to visualise microvascular networks on the cut surfaces of fresh tissue specimens by diffusive labelling of vascular endothelium with fluorescently conjugated UEA-1 lectin. Unlike perfusion methods that are limited to accessible vascular networks, diffusive fluorescence labelling (DFL) allows additional visualisation of extravascular cellular components, such as smooth muscle. Following UEA-1 DFL, smooth muscle-myosin and -actin were then visualised by immunolocalisation on the acetone-fixed tissue pieces. This allowed clear three-dimensional distinction between the vascular and muscle architecture of the myometrium and endometrium. This method can also be applied for studying the relative distribution of microvascular and muscle architecture in leiomyomas (fibroids). The techniques described in this methodological study provide a simple way of directly examining the uterine vasculature in three dimensions using conventional microscopy, while also distinguishing myometrial from endometrial parts of the network.

Background: Diffuse enlarged vessels throughout the myometrium are very rare. This case illustrates the diagnosis and clinical management of a pregnancy complicated by large vessels diffusely distributed throughout the myometrium., Case: A primigravida measured large for dates at 27 weeks gestation. Ultrasonography demonstrated tubular echolucent spaces throughout the myometrium. No flow could be detected within them by color or spectral Doppler. During cesarean delivery blood loss was 1,700 mL, but the uterus was successfully closed with 3 suture layers. A biopsy specimen showed myometrium containing large vascular spaces thought to be veins, consistent with a hemangioma., Conclusion: Enlarged vascular spaces diffusely distributed throughout the myometrium proved to be a cavernous hemangioma. Cesarean delivery in the present case produced some additional bleeding that was easily controlled, and the uterus was closed without incident.

Daily estradiol-17beta (E(2)beta) increases basal uterine blood flow (UBF) and enhances acute E(2)beta-mediated increases in UBF in ovariectomized nonpregnant ewes. The acute E(2)beta-mediated rise in UBF involves vascular smooth muscle (VSM) large-conductance Ca(2+)-activated K(+) channels (BK(Ca)). BK(Ca) consist of pore-forming alpha-subunits and regulatory beta(1)-subunits that modulate channel function and E(2)beta responsiveness. It is unclear whether E(2)beta also alters subunit expression and thus channel density and/or function, thereby contributing to the rise in basal UBF and enhanced UBF responses that follow daily E(2)beta. Therefore, we examined BK(Ca) subunit expression by using reverse transcription-PCR and immunoblot analysis of arterial VSM from reproductive and nonreproductive tissues and myometrium from ovariectomized nonpregnant ewes after daily E(2)beta (1 microg/kg iv) or vehicle without or with acute E(2)beta (1 microg/kg). Tissue distribution was determined by immunohistochemistry. Acute E(2)beta did not alter alpha- or beta(1)-subunit expression in any tissue (P > 0.1). Daily E(2)beta also did not affect alpha-subunit mRNA or protein in any tissue (P > 0.1) or mesenteric arterial VSM beta(1)-subunit. However, daily E(2)beta increased uterine and mammary arterial VSM beta(1)-subunit mRNA by 32% and 83% (P < 0.05), uterine VSM protein by 30%, and myometrial beta(1)-subunit mRNA and protein by 74% (P < or = 0.005). Immunostaining of uterine arteries, myometrium, and intramyometrial arteries paralleled immunoblot analyses for both subunits. Although BK(Ca) density is unaffected by daily and acute E(2)beta, daily E(2)beta increases beta(1)-subunit in proximal and distal uterine arterial VSM. Thus prolonged E(2)beta exposure may alter BK(Ca) function, estrogen responsiveness, and basal vascular tone and reactivity in reproductive arteries by modifying alpha:beta(1) stoichiometry.

Objective: The purpose of this study was to assess the involvement of rho kinase (ROK) in agonist-dependent contraction of omental, myometrial, and placental arteries of pregnant women at term., Study Design: Wire myography was used to assess if contractions of intact or alpha-toxin-permeabilized arteries obtained from women at elective cesarean section were influenced by the ROK inhibitor Y-27632., Results: Western blotting indicated the presence of ROKalpha in each of the 3 tissue types. In intact human omental, myometrial, or placental arteries, Y-27632 dose-dependently reduced constrictions to the thromboxane-mimetic U46619. In permeabilized vessels, U46619 induced substantial Ca(2+)-sensitization of contraction that was inhibited by Y27632. The phosphatase inhibitor calyculin A induced a Ca(2+)sensitization of contraction similar to that of U46619 in permeabilized omental arteries that was unaffected by Y-27632, suggesting that ROK may signal via myosin phosphatase in these vessels., Conclusion: These results are the first report of the involvement of ROK in the receptor-coupled constriction of intact and permeabilized arteries from pregnant women.

Objectives: To quantitatively examine differences in microvascular density between fibroid and myometrial tissue from fibroid uteri removed at hysterectomy, both before and after the menopause, and with hormone replacement therapy., Methods: Factor VIII immunostaining of formalin fixed tissues was used to identify blood vessels, and the vessels counted by an investigator blinded to tissue type or menopausal status., Results: The mean myometrial: fibroid MVD ratio was 2.38 higher in the post-menopausal group (95% CI: 0.12, 4.65, p=0.0474) than in the pre-menopausal group, with the hormone therapy (HT)-using post-menopausal group lying in between. An increase in microvascular density in the myometrium after the menopause was responsible for most of the change in ratios seen between the pre and post-menopausal pairs. There was a trend to increasing myometrial MVD with increasing number of years post-menopause., Conclusions: Myometrial microvascular density increases markedly after the menopause, while fibroid microvascular density does not alter. Thus, the difference between myometrial and fibroid vasculature becomes greater after the menopause. The implications of this for the treatment of fibroids in post-menopausal women is discussed.

The involvement of endovascular trophoblast in fibrinoid deposition, replacement of the endothelium and vascular smooth muscle breakdown is studied in spiral arteries of the mesometrial triangle from day 15 to day 21 of rat pregnancy, by examining arterial cross sections after staining for cytokeratin, PAS, CD31 and alpha-actin. From day 15 to day 18 of pregnancy, fibrinoid deposition underneath the endovascular trophoblast increases gradually, whereas the amount of endovascular trophoblast in invaded arteries remains constant. CD31 staining is significantly reduced in sub-ET (= underlying the endovascular trophoblast) as compared to extra-ET (= outside the endovascular trophoblast) and no-ET (= non-invaded arterial sections) at each time-point of pregnancy examined (P < 0.005 and P < 0.0005 at each day of pregnancy), whereas alpha-actin staining is reduced both in sub-ET and in extra-ET as compared to no-ET. During pregnancy, CD31 staining in sub-ET initially declines, but increases significantly on day 21 (P < 0.001 versus d20) suggesting re-endothelialization of the vascular wall. In conclusion, changes in spiral arteries of pregnant rats reveal striking similarities with physiological changes seen in human pregnancy, thus emphasizing the usefulness of this species as an experimental model for studying normal and complicated pregnancies in humans.

Extravillous trophoblasts (EVTs) invade and remodel uterine spiral arteries. Regulatory factors may include inherent vessel susceptibility, local oxygen levels and tumour necrosis factor alpha (TNFalpha). We have used an in vitro model to investigate interstitial and endovascular invasion of myometrial spiral arteries from pregnant and non-pregnant uteri and also omental arteries. To model endovascular invasion, fluorescent-labelled EVTs were perfused into the lumen of these dissected vessels. For interstitial invasion, labelled EVTs were layered on top. Cultures were either maintained in 17% or 3% oxygen, or cultured with TNFalpha. The invasion of arteries from pregnant women occurred via both routes at 17% oxygen, with endovascular invasion more efficient than interstitial. In omental arteries and spiral arteries from non-pregnant women, endovascular invasion was limited. Endovascular and interstitial invasion were lower in all arteries at 3% oxygen. Typically, endovascular events were clustered, with an associated disruption in the adjacent endothelium and smooth muscle. A role for TNFalpha in limiting invasion was also supported. In conclusion, priming of uterine arteries may be necessary prior to EVT invasion. Oxygen is a sensitive regulator within this physiological model and increased invasion at higher pO2 may explain the homing of EVT to maternal arteries rather than veins. Adequate vascular transformation may therefore rely on a balance between vascular receptivity, oxygen partial pressure, and exposure to inflammatory mediators., (Copyright 2005 Pathological Society of Great Britain and Ireland)

In the present study, human myometrial microvascular endothelial cells (HMMEC) were cocultured with human vascular smooth muscle cells (VSMC) labeled with fluorescent dyes to examine their morphological interaction using confocal laser fluorescent microscopy. HMMEC and VSMC labeled with fluorescent green and red dyes, respectively, attached to opposite sides of polyethyleneterephthalate membranes and remained viable for up to 96 h. In defined medium, 5%+/-3% of the VSMC cytoplasmic processes and 71%+/-17% of the HMMEC processes extended completely across the 13 microm thickness of the transmembrane. However, 41%+/-21% of the VSMC projections and 10%+/-3% of the HMMEC processes that traversed the membrane made contact with the opposing cell type. In cocultures incubated with angiopoietin-1 (Ang-1), although the number of VSMC or HMMEC projections was not significantly increased, the number of VSMC extending across the membrane and making contact with HMMEC was increased (P<0.05) to 88%+/-2%. The results of the current study demonstrate that coculture of fluorescent-labeled HMMEC and VSMC on a semipermeable transmembrane coupled with confocal laser fluorescent microscopy provides an in vitro experimental model to study morphological association of microvascular endothelial cells with mural cells. We propose that this system will greatly facilitate study of remodeling of the microvasculature in various organ systems.

Objective: Report a case of a difficult myomectomy after a failed uterine artery embolization (UAE)., Design: Case report., Setting: A university medical center., Patient(s): A 30-year-old woman with pelvic pain and menorrhagia secondary to an enlarging 18- to 20-week-size fibroid uterus., Intervention(s): Abdominal myomectomy., Main Outcome Measure(s): Complicated myomectomy after UAE., Result(s): A patient underwent a difficult myomectomy after failed UAE. The myomectomy was only partially completed due to the difficult dissection of the myomas., Conclusion(s): Myomectomy after UAE may be unusually difficult due to the degenerative changes that occur within the leiomyomas.

Objective: To investigate the structural basis of abnormal Doppler waveforms in the utero-placental circulations in cases of chronic fetal hypoxia., Study Design: Morphometric analysis was performed on placental samples from 58 pregnancies with abnormal Doppler waveforms in the uterine, placental and umbilical circulations at 32-34 weeks, and 10 pregnancies with normal waveforms., Results: The volume of placental villi reduced from 350.5 cm3 in controls to 286.4 cm3 (P<0.05) in the severest cases. The volume of the fetal capillaries reduced from 59.7 cm3 to 20.5 cm3 (P<0.05). These reductions were associated with increased placental infarction. The myometrial segments of the spiral arteries were severely constricted, demonstrating failure of physiological conversion secondary to deficient trophoblast invasion., Conclusion: The placental vascular bed is greatly reduced in cases of chronic fetal hypoxia. We propose impaired placental perfusion causes oxidative stress and regression of the fetal vasculature, leading to fetal growth retardation and distress.

Background: Fetal growth restriction (FGR) affects up to 8% of all pregnancies and has massive short-term (increased fetal morbidity and mortality) and long-term (increased incidence of cardiovascular disease in adulthood) health implications. Doppler waveform analysis of pregnancies complicated by FGR suggests compromised uteroplacental circulation and placental hypoperfusion. Our aim was to determine whether myometrial small artery function was aberrant in FGR and to assess whether sildenafil citrate could improve vasodilatation in FGR pregnancies., Methods: Small arteries dissected from myometrial biopsies obtained at cesarean section from normal pregnant women (n = 27) or women whose pregnancies were complicated by FGR (n = 12) were mounted on wire myographs. Vessels were constricted (with arginine vasopressin or U46619) and relaxed (with bradykinin) before and after incubation with a phosphodiesterase-5 inhibitor, sildenafil citrate., Results: We demonstrated increased myometrial small artery vasoconstriction and decreased endothelium-dependent vasodilatation in vessels from women whose pregnancies were complicated by FGR. Sildenafil citrate significantly reduced vasoconstriction and significantly improved relaxation of FGR small arteries., Conclusions: We conclude that sildenafil citrate improves endothelial function of myometrial vessels from women whose pregnancies are complicated by intrauterine growth restriction. Sildenafil citrate may offer a potential therapeutic strategy to improve uteroplacental blood flow in FGR pregnancies.

In order to facilitate characterization of the circulating factor(s) in pre-eclampsia, the present study aimed to determine whether plasma from women with pre-eclampsia, which induces attenuated endothelial-dependent relaxation in human myometrial arteries, is also capable of inducing altered endothelial function in mouse vessels. Human vessels were isolated from myometrial biopsies taken from women with uncomplicated pregnancies (n = 6). Mesenteric and uterine arteries were isolated from male, female, non-pregnant and pregnant C57B mice (n = 24). Vessels were studied using a wire myograph and incubated with plasma (2%) from women with pre-eclampsia (n = 12) or controls (n = 12). Incubation of myometrial vessels from normal pregnant women with plasma from women with pre-eclampsia reduced endothelial-dependent relaxation. This effect was not reproduced in male or female mouse mesenteric or uterine vessels incubated with plasma from women with pre-eclampsia. In conclusion, there are species-specific differences in the actions of the circulating factor(s) on endothelial-dependent relaxation of human and mouse small arteries.

1. Pre-eclampsia is a serious pregnancy disorder associated with widespread activation of the maternal vascular endothelium. Recent evidence implicates a role for oxidative stress in the aetiology of this condition. 2. Reactive oxygen species, particularly superoxide anions, invokes endothelial cell activation through many pathways. Oxidant-induced cell injury triggers the activation of nuclear enzyme poly(ADP-ribose) polymerase (PARP) leading to endothelial dysfunction in various pathophysiological conditions (reperfusion, shock, diabetes). 3. We have studied whether the loss of endothelial function in pre-eclampsia is dependent on PARP activity. Endothelium-dependent responses of myometrial arteries were tested following exposure to either plasma from women with pre-eclampsia or normal pregnant women in the presence and absence of a novel potent inhibitor of PARP, PJ34. Additional effects of plasma and PJ34 inhibition were identified in microvascular endothelial cell cultures. 4. In myometrial arteries, PARP inhibition blocked the attenuation of endothelium-dependent responses following exposure to plasma from women with pre-eclampsia. In endothelial cell cultures, plasma from pre-eclamptics induced measurable oxidative stress and a concomitant increase in PARP activity and reduction in cellular ATP. Again, these biochemical changes were reversed by PJ34. 5. These results suggest that PARP activity plays a pathogenic role in the development of endothelial dysfunction in pre-eclampsia and promotes PARP inhibition as a potential therapy in this condition.

Objective: Preeclampsia is a common and serious complication of pregnancy, characterized by maternal hypertension and proteinuria, placental insufficiency, and fetal growth restriction. The purpose of this study was to investigate whether intracellular Ca 2+ ([Ca 2+ ] i ) and contractile responses of vascular smooth muscle to vasoactive agents are altered in preeclampsia compared with normal pregnancy and the nonpregnant state., Study Design: Subcutaneous and myometrial resistance arteries from women who had preeclampsia, normal pregnancy, and nonpregnant women were obtained at the time of cesarean section or hysterectomy. Arteries were mounted on an isometric myograph and loaded with the Ca 2+ indicator, fura-2AM, to permit simultaneous measurement of force and [Ca 2+ ] i . Reponses to endothelium-dependent relaxants (acetylcholine and substance P) and vasoconstrictors (depolarizing potassium solution, phenylephrine, and angiotensin II) were examined., Results: The fall in [Ca 2+ ] i and relaxation in response to acetylcholine was significantly inhibited in both myometrial and subcutaneous arteries from preeclamptic women compared with arteries from nonpregnant or normal pregnant women. However, responses to substance P did not differ between the 3 groups. There were no significant differences in [Ca 2+ ] i or force responses to high potassium, phenylephrine, or angiotensin II in myometrial and subcutaneous resistance vessels in women with preeclampsia compared with normal pregnant women. However, force, but not [Ca 2+ ] i responses to angiotensin II, in subcutaneous vessels from normal pregnant and preeclamptic women were reduced compared with subcutaneous arteries from nonpregnant women, indicating that pregnancy is associated with a reduction in Ca 2+ sensitization in this tissue. A similar effect was not seen in myometrial arteries., Conclusion: Endothelial function is altered in preeclampsia, with loss of effect of acetylcholine, but not substance P. Vasoconstrictor reactivity is not increased in preeclampsia compared with uncomplicated normal pregnancy, and this is unlikely to be an explanation for the increased peripheral vascular resistance seen in preeclampsia.

The pathophysiology of preeclampsia involves the release of a circulating factor(s) from a hypoperfused placenta that activates the maternal endothelium. This study investigated the effect on in vitro endothelial function of plasma taken from women in whom preeclampsia subsequently developed. Women at increased risk for an adverse pregnancy outcome were identified using Doppler waveform analysis. Plasma samples (22 and 26 weeks) were incubated with myometrial vessels taken from women with uncomplicated pregnancies. Wire myography was used to study the effect of plasma on the endothelium-dependent vessel behavior. Incubation of vessels from normal pregnant women with plasma from women in whom preeclampsia subsequently developed (n=19) significantly reduced endothelium-dependent relaxation, compared with vessels incubated with plasma from normal pregnant women (n=48). This effect was demonstrable for plasma taken at 22 weeks (residual constriction 47.1+/-6.6% versus 32.0+/-4.4%, P=0.004 at 1-hour incubation; and 59.1+/-8.4% versus 42.3+/-5.9%, P=0.001 at 18-hour incubation) and 26 weeks (59.2+/-5.2% versus 29.1+/-5.6%, P<0.001 at 1 hour; and 63.3+/-7.6% versus 31.9 +/-7.2%, P<0.0001 at 18 hours). Endothelial-dependent relaxation was unaltered after incubation with plasma taken from women in whom normotensive intrauterine growth restriction subsequently developed (n=19). This study supports the hypothesis that plasma, from women in whom preeclampsia develops, collected weeks before diagnosis is capable of altering endothelial function.

Objective: This study was undertaken to test for structural differences between myometrial radial arteries isolated from women having normal pregnancies and pregnancies complicated by preeclampsia and intrauterine growth restriction., Study Design: Pressure myography was used to study myometrial radial arteries obtained at cesarean section. With the use of a transilluminating system, lumen diameter, wall thickness, wall/lumen ratio, distensibility and stress-strain relationship were studied through a range of pressures. Arteries were then fixed in glutaraldehyde, embedded in resin, cross-sectioned, and studied in greater detail by light and electron microscopy., Results: Pressure myography showed that arteries from women with preeclampsia had a reduced lumen diameter, thicker wall, and greater wall/lumen ratio compared with vessels isolated from women with normal pregnancy. Light microscopy indicated an identical media content remodeled around a smaller lumen. Electron microscopy indicated enlarged extracellular spaces in the media but no change in myocyte profile size or number. There was no clear evidence of structural changes in myometrial radial arteries isolated from women with intrauterine growth restriction compared with normal pregnancy. No differences in vessel distensibility or stress-strain relationships were detected in complicated pregnancies., Conclusion: The changes observed in myometrial radial arteries isolated from women with preeclampsia are due to inward eutrophic remodeling. Alterations in these vessels may contribute to increased uterine vascular resistance in preeclampsia.

Objective: Parathyroid hormone-related protein (PTHrP) has been reported to relax different vessels. We investigated the influence of both endothelium and gestation on the relaxation of uterine arteries (UA), which supply blood to myometrium and placenta., Methods: Small uterine and mesenteric arteries (MA) with (E+) and without endothelium (E-) from day 20 pregnant (P) and nonpregnant (NP) rats were mounted in a myograph, precontracted with phenylephrine (PE) in a physiologic salt solution. Relaxations to PTHrP, acetylcholine, and forskolin were performed and expressed as a percentage of the PE-induced contraction. Blockade of nitric oxide (NO) and endothelium-derived hyperpolarizing factor (EDHF) was also studied with Nomega-nitro-L-arginine methyl ester (L-NAME) and with charybdotoxin + apamin, respectively., Results: Gestation significantly increases maximal vasodilating effect of acetylcholine in UA (68% vs 52%, P < .05) and sensitivity to acetylcholine in small mesenteric vessels (P < .05). PTHrP relaxes uterine (maximal relaxation P: 32%, NP: 46%), as well as small MA (P: 68%, NP: 89%), but the maximal relaxation is significantly greater in NP than in P rats (P: 32%, NP: 46%, P < .01) in both vascular beds. In addition, in the UA of P rats, PTHrP only produces relaxation if functional endothelium is present; nevertheless in the absence of endothelium, forskolin still elicits relaxation (65%, P < .01). L-NAME significantly impairs relaxation of E+ UA (P < .05), and so does the association of charybdotoxin + apamin (P < .05). Thus, NO and EDHF contribute largely to this vasorelaxant effect., Conclusion: PTHrP induces a relaxation on UA that is strongly endothelium-dependent during gestation, in contrast to what happens simultaneously in MA.

Objective: This study compared myoendometrial versus placental radial uterine arteries from late-pregnant rats to evaluate differences in passive mechanical properties and arterial wall hyperplasia., Study Design: Myoendometrial and placental radial uterine arteries were dissected from late-pregnant (day 17-19) Sprague-Dawley rats (n = 21) for determination of the lumen diameter and passive distensibility. Arterial wall hyperplasia was evaluated by bromodeoxyuridine incorporation and histologic determination of mitotic indices of endothelial, smooth muscle, and adventitial cells. Nonpregnant radial uterine and mesenteric arteries were used as control cells., Results: Both placental and myoendometrial uterine arteries were significantly larger than nonpregnant uterine arteries by 40% and 28%, respectively (P < .05). The lumen diameter of placental arteries was significantly (16%) larger than adjacent myoendometrial arteries (P < .05). In addition to the larger luminal diameter, placental arteries were significantly more distensible than myoendometrial arteries at all pressures that were studied, which demonstrates differential remodeling. Comparison of mitotic indices revealed that placental arteries had significantly increased cell division rates of both endothelial and smooth muscle significantly compared to myoendometrial arteries. Both types of arteries from pregnant animals had increased cell division rates compared with vessels from nonpregnant animals. The mitotic index of endothelial and smooth muscle cells for placental and myoendometrial arteries from late-pregnant and nonpregnant animals was 15.08% +/- 2.05% and 6.57% +/- 1.37%, 8.73% +/- 1.23%, and 3.04% +/- 0.48% (P < .05 vs placental), and 0.29% +/- 0.29% and 0.23% +/- 0.23% (P < .05 vs placental endothelial), respectively. Adventitial cell division was 10- to 15-fold higher in late-pregnant versus nonpregnant animals., Conclusion: These data demonstrate differential growth and remodeling of uterine arteries that supply the placenta versus the myoendometrium, which likely is facilitated by enhanced arterial wall hyperplasia in placental arteries.

Pre-eclampsia is characterised by a maternal syndrome of hypertension and proteinuria, that is frequently associated with reduced fetal growth. The characteristic histopathological observation in the placental bed is narrowing and atherosis of the distal branches of the uterine arteries at, and around, the deciduo-myometrial interface. In the maternal kidneys there is swelling of the glomerular capillaries and mesangium with some inclusions in the basement membrane ("glomeruloendotheliosis") and evidence of vasoconstriction in many other organs. Untreated maternal hypertension leads to convulsions (eclampsia) which may result in maternal and fetal death. The nerve plexus at the endometrial(decidual)--myometrial interface was first reported in 1959 though has received little attention in the intervening years. It appears to play an important role in maintaining the separation of two tissues with intrinsic proliferative potential (endometrium and myometrium). The present hypothesis proposes that damage to the nerve plexus at the endometrial-myometrial interface causes impaired control of a third proliferative tissue (invading trophoblast) resulting in the characteristic histological changes. Growth factors produced by nerves and blood vessels may contribute to the process of normal placentation e.g. nerve growth factor, vascular endothelial growth factor, etc. and these processes may be compromised in areas of denervation. Neural connections between the uterine and renal innervations (L1, 2) result in renal vasoconstriction and widespread systemic maternal vasoconstriction in an attempt to provide increased blood flow for the uteroplacental circulation (maternal hypertension, small-for-gestational age fetus). Loss of these neural connections through the same process of partial uterine denervation may cause reduced fetal growth without the maternal circulatory changes of pre-eclampsia (maternal normotension, small-for-gestational age, fetus). Variations in maternal circulatory compliance alter the "phenotype" of the condition such that prior maternal hypertension may cause pre-eclampsia through intrarenal mechanisms without significant fetal growth restriction. Increases in circulatory compliance in multiparity prevent the typical features of the condition, or, if they are expressed then they present in a different sequence with haematological and hepatic consequences presenting before the renal manifestations (HELLP syndrome, haemolysis, elevated liver enzymes, low platelets).

Objective: The relative role of the two estrogen receptors, ERalpha and ERbeta, in mediating angiogenic responses in adult human endothelium is unknown. The aim of this study was to determine whether novel ERalpha-selective agonists, propyl pyrazole triol (PPT) and the tetrahydrochrysene (R,R-THC), up-regulate the expression of vascular endothelial growth factor receptor-2 (VEGFR-2), and promote VEGF-stimulated endothelial cell proliferation in primary cultures of adult female microvascular endothelial cells co-expressing endogenous ERalpha and ERbeta., Methods: Confluent primary cultures of microvascular endothelial cells isolated from human myometrium were incubated with 17beta-estradiol (1 and 10 nM), PPT (10 nM to 3 microM), or R,R-THC (10 nM to 3 microM) for 18 hours and VEGFR-2 expression measured by biotin-VEGF165 binding and flow cytometry. Endothelial cell proliferation was assessed in microvascular endothelial cells after incubation with 17beta-estradiol (10 nM), PPT (100 nM), and R,R-THC (100 nM) for 6 days using a tetrazolium-based bioassay., Results: Both PPT and R,R-THC increased VEGFR-2 expression on myometrial microvascular endothelial cells in a dose-dependent manner, reaching a maximum at 1 microM. Approximately 40% of myometrial microvascular endothelial cell isolates only express ERbeta and do not express ERalpha, and in these neither PPT, R,R-THC, nor 17beta-estradiol increased VEGF binding. PPT- or R,R-THC-stimulated increase in VEGF binding was significantly different between ERalpha+ and ERalpha- microvascular endothelial cell samples (P < .001 and P < .05, respectively). PPT, R,R-THC, and 17beta-estradiol significantly augmented VEGF-stimulated microvascular endothelial cell proliferation in ERalpha+ (P < .05), but not in ERalpha- samples., Conclusions: This angiogenic effect of 17beta-estradiol on adult female microvascular endothelial cells is mediated by ERalpha, rather than ERbeta.

By comparison of dopplerometry results of right uterine artery and umbilical cords of a fetus with the histologic and morpho-stereometric data studies of the placenta, and also placental bed and myometrium in an operational material at Cesarian sections, a morphological basis of disturbances of communications in a functional system "mother-placenta-fetus" in hypotonic and hypertonic dysfunction of the uterus is revealed. The morphological picture of chronic placental insufficiency of the fetoplacentary form in the presence of pathological chorion immaturity is revealed in the development of weakness of activity. The uteroplacentary form of chronic placentaly insufficiency, incomplete gestation reorganization MPA and reduction morphometric parameters of a vascular channel miometrium documented formed discoordination of uterine muscles at child birth.

Objective: In preeclampsia, endothelium-dependent function is markedly aberrant. Myometrial resistance arteries from women with preeclampsia show a minimal, wholly nitric oxide-mediated, bradykinin-induced relaxation. Our aim was to test that phosphodiesterase 5 (PDE5) inhibition could improve endothelium-dependent function in preeclampsia. Study design Small arteries dissected from myometrial biopsies obtained at cesarean section from normal pregnant women (N=22) or women with preeclampsia (N=24) were mounted on wire or pressure myographs. Vessels were constricted (arginine vasopressin or U46619) and relaxed (bradykinin) before and after incubation with a PDE5 inhibitor, UK-343664., Results: Endothelium-dependent vasodilatation was decreased in vessels from women with preeclampsia. 100 nmol/L UK-343664 did not affect normal pregnant but significantly improved relaxation of the vessels from women with preeclampsia., Conclusion: A PDE5 inhibitor enhances endothelial function of myometrial vessels from women with preeclampsia, such that the behavior of these arteries approximates to those from normal women. These agents offer a potential therapeutic strategy for the management of preeclampsia.