Tunable Electrocatalytic Annulations of o-Arylalkynylanilines: Green and Switchable Syntheses of Skeletally Diverse Indoles.

Tunable electrocatalytic annulation reactions of o-arylalkynylanilines have been established, leading to green and divergent syntheses of skeletally diverse indoles by adjusting the electrolytes and the solvents. The presence of ammonium halides as the electrolytes enabled the halogenation of o-arylalkynylanilines to give C3-halogenated indoles whereas naphtho[1',2':4,5]furo[3,2-b]indoles could be obtained by changing the electrolyte from ammonium halides to KI. Interestingly, by combining acetone as the solvent and both NH4I and NH4Cl as the electrolytes, the reaction worked through an intramolecular annulation and [5 + 1] cyclization cascade to form naphtho[1',2':5,6][1,3]oxazino[3,4-a]indoles.

Direct electrical stimulation softens the cervix in pregnant and nonpregnant rats.

OBJECTIVE: The objective of the study was to determine the effects of electrical stimulation (ES) on cervical ripening in pregnant and nonpregnant rats. STUDY DESIGN: Timed pregnant and nonpregnant Sprague-Dawley rats (n = 6-7/group) were used. Cervical ES for pregnant rats was performed in vivo on day 15 of gestation by inserting an electrical probe into the vagina in contact with the cervix. Parameters of ES varied from 0.1 to 0.2 mA, 10 pulses per second, 20 milliseconds pulse duration, and repeating pulses for 15, 30, 60, and 120 minutes for pregnant ES groups and similar times for sham control groups with electrode but without ES. Nonpregnant ES groups were stimulated with only 0.2 mA for 30 minutes. Cervical collagen was measured in controls and following ES at various times using light-induced fluorescence (LIF) of collagen. Photographs were taken following ES, and some rats were killed, the cervices were isolated, and cervical extensibility was estimated. RESULTS: LIF values of pregnant rats are significantly lower (P < .001) and extensibility greater (P < .05) in the ES treatment groups compared with the control groups on days 16 and 17 of pregnancy. Similarly LIF is lower (P < .05) and extensibility values greater (P < .05) in nonpregnant rats treated with ES. No adverse effects, including altered delivery time, pup weights, or damage to cervix, were produced by low current levels of ES needed to soften the cervix. CONCLUSION: The following conclusions were reached: (1) application of ES rapidly produces softening and ripening of the cervix in pregnant and nonpregnant rats; (2) ES treatment does not produce early delivery; (3) the exact mechanism for ES ripening is not yet known; and (4) ES might be used clinically to ripen the cervix when needed.

Nicotine treatment prolongs gestation and inhibits cervical ripening in pregnant rats.

OBJECTIVE: The aims of this study were to examine the effects of nicotine treatment on the length of gestation, on fetal outcome, on cervical ripening, and on uterine contractility during pregnancy in rats. STUDY DESIGN: Pregnant rats were treated with various concentrations of nicotine (0.25, 0.5, 1, 2 mg/kg/d, subcutaneously). Delivery times and fetal weights were obtained. Cervical collagen cross-links were assessed in vivo by collagen light-induced fluorescence (LIF), and cervical resistance to stretch was measured by in vitro extensibility tests. RESULTS: Delivery time is significantly (P = .002) prolonged after high-dose nicotine treatments. There are no significant changes in pup weights and placenta weights after nicotine treatments. Cervical collagen LIF and extensibility progressively decrease throughout pregnancy in control rats. Nicotine-treated rats showed significant (P < .001) cervical resistance to stretch and higher LIF compared with the control rats. Nicotine treatment in vitro had little effect on uterine contractility. CONCLUSION: Nicotine exposure during pregnancy prolongs gestation and inhibits cervical ripening, possibly by suppression of a cholinergic antiinflammatory response.

Nicotine, an α7 nAChR agonist, reduces lipopolysaccharide-induced inflammatory responses and protects fetuses in pregnant rats.

OBJECTIVE: The objective of the study was to examine the effects of nicotine, an α7 nicotinic acetylcholine receptor agonist, on lipopolysaccharide (LPS)-induced inflammatory responses in rats during pregnancy. STUDY DESIGN: Pregnant Sprague Dawley rats were randomly divided into groups (n = 6 rats/group): group 1 rats each received a single intraperitoneal injection of LPS (25 µg/kg) on gestation day 16; group 2 rats were first pretreated with nicotine (1 mg/kg per day, subcutaneously) on gestation days 14 and 15 and then were treated with single injections of LPS on gestational day 16; group 3 rats were treated with the vehicle (saline) used for groups 2 and 3 (controls). Maternal blood was collected at 6 hours and 24 hours after LPS and vehicle treatments and assayed for tumor necrosis factor (TNF)-α, interleukin-6 (IL-6), and interleukin-10 (IL-10). In addition, the number of live pups and pup weights were obtained at the time of delivery. RESULTS: LPS treatment significantly (P < .001) elevates maternal blood levels of TNF-α and IL-6 but not IL-10 (P > .05). Nicotine treatment significantly reduces LPS-induced TNF-α and IL-6 concentrations (P < .001) but does not change (P > .05) IL-10 levels. The number of live pups in the LPS group are significantly lower (P < .001) than the vehicle treated controls, and nicotine treatment significantly (P < .011) reverses this change. Similarly, fetal weights are lower following LPS (P < .016) and higher (P < .024) in the group treated with nicotine plus LPS. CONCLUSION: Nicotine reduces the LPS-induced inflammatory responses and rescues the fetus in rats during pregnancy. Thus, nicotine exerts dramatic antiinflammatory effects. These observations have important implications for control of inflammatory responses during pregnancy.

Inhibition of uterine contractility with various tocolytics with and without progesterone: in vitro studies.

OBJECTIVE: Various tocolytics are used to suppress uterine contractility in patients in preterm labor. Progesterone (P4) is used in patients at high risk for preterm delivery. In this study, we evaluated the effects of various tocolytics with and without P4 to examine effects on uterine contractility. STUDY DESIGN: Uterine tissues (n = 280) from women undergoing cesarean at term were exposed in vitro to various agents (vehicle, magnesium sulfate [MgSO(4)], nifedipine, indomethacin, or pinacidil-all with and without P4). Contractility was measured before and after addition of the various agents. RESULTS: P4 alone at 10(-5) mol/L concentration has little effect to inhibit contractility (P ≥ .05). MgSO(4) (2-8 × 10(-3) mol/L) inhibits uterine contractility (P < .05) but there is no change when combined with P4 (P > .05). Nifedipine (10(-8) mol/L) and indomethacin (10(-5) mol/L) inhibit contractions alone (P < .05) and to a greater extent when combined with P4 (P < .05). P4 significantly (P < .05) reduced the effects of pinacidil (10(-6.5) mol/L). CONCLUSION: Combinations of P4 with nifedipine or indomethacin, but not MgSO(4), might be used to effectively suppress preterm labor.

Changes in PGRMC1, a potential progesterone receptor, in human myometrium during pregnancy and labour at term and preterm.

This study assesses the role of progesterone receptor membrane component 1 (PGRMC1) in actions of progesterone (P4) on human myometrium during pregnancy and labour. Myometrial tissues were obtained from non-pregnant patients during hysterectomy or pregnant women undergoing C-section at term and preterm, before and during labour. PGRMC1 expression in myometrial tissues and in a human myometrial cell line (HM9) was assessed by western blots and RT-PCR. The subcellular localization of PGRMC1 in HM9 was performed by immunofluorescence staining. Isometric contractions of myometrial tissues were obtained in response to P4 with and without addition of specific antibodies against PGRMC1. Endogenous and over-expressed PGRMC1 proteins are detected by western blots in myometrial tissues, HM9 and 293 cells, respectively. PGRMC1 is localized to the plasma membrane, cytoplasm and nuclear membranes. PGRMC1 is lower in myometrium of women at term either not in labour (P = 0.004) or in labour (P = 0.005) compared with tissues from women in preterm non-labour. PGRMC1 levels are also decreased (P = 0.02) in myometrial tissues from women during preterm labour compared with preterm non-labour. P4 rapidly inhibits contractions of myometrial tissues compared with control (P < 0.05) in vitro. Pretreatment of myometrial strips with PGRMC1 antibody, suppresses the P4-induced relaxation (P < 0.05). PGRMC1 may mediate the non-genomic action of P4 and the relaxation effect on human myometrium during pregnancy. A decrease in PGRMC1 during term or preterm labour might contribute to the 'functional withdrawal' of P4 action and shift the balance to a state of heightened uterine contractility.

A novel optical method to assess cervical changes during pregnancy and use to evaluate the effects of progestins on term and preterm labor.

OBJECTIVE: The purpose of this study was to determine whether optical methods can estimate cervix function during pregnancy and whether progestins modify this process. STUDY DESIGN: Photos of the external cervix of timed-pregnant rats were taken every other day from day 13 until postpartum day 5 after daily treatments with vehicle (controls) or progestin treatments (progesterone, subcutaneously or vaginally; 17-alpha-hydroxyprogesterone caproate [17P] and RU-486 subcutaneously, once on day 16). The surface area of the cervix was estimated from photos. RESULTS: The surface area of cervix increases throughout pregnancy and reverses after delivery in controls. In the progesterone subcutaneously or 17P subcutaneously groups, increases in surface area are lower (17P group until day 19 only; P < .05). Vaginal progesterone does not prevent surface area increases. Only the progesterone subcutaneously blocked delivery. RU-486 increases the surface area of the cervix (P < .05) during preterm delivery. CONCLUSION: An optical method is useful for quantitative assessment of the cervix and evaluation of agents that modify cervical function.

Progestin treatment for the prevention of preterm birth.

Progestin supplementation appears to be a promising approach to both preventing initiation of preterm labor and treating it once it is already established, given the role of progesterone in maintaining pregnancy, as well as support from basic and clinical research. Progesterone and 17α-hydroxyprogesterone acetate slow the process of cervical ripening, and this is the rationale for prophylactic long-term progestin supplementation mostly studied so far. However, progesterone (but not 17α-hydroxyprogesterone acetate) also inhibits myometrial activity even after the cervix has already ripened. Moreover, these effects depend greatly on the vehicle used and the route of administration. Understanding different mechanisms of action, as well as the importance of progestin formulation, vehicle and route of administration, is the key to finding the optimal progestin treatment for prevention of preterm birth.

Use of uterine electromyography to diagnose term and preterm labor.

Current methodologies to assess the process of labor, such as tocodynamometry or intrauterine pressure catheters, fetal fibronectin, cervical length measurement and digital cervical examination, have several major drawbacks. They only measure the onset of labor indirectly and do not detect cellular changes characteristic of true labor. Consequently, their predictive values for term or preterm delivery are poor. Uterine contractions are a result of the electrical activity within the myometrium. Measurement of uterine electromyography (EMG) has been shown to detect contractions as accurately as the currently used methods. In addition, changes in cell excitability and coupling required for effective contractions that lead to delivery are reflected in changes of several EMG parameters. Use of uterine EMG can help to identify patients in true labor better than any other method presently employed in the clinic.

Pharmacologic actions of progestins to inhibit cervical ripening and prevent delivery depend on their properties, the route of administration, and the vehicle.

OBJECTIVE: The purpose of this study was to evaluate cervical changes and delivery at term during pregnancy in rats after various progestin treatments. STUDY DESIGN: Pregnant rats were treated by various routes and vehicles with progesterone, 17-alpha-hydroxyprogesterone caproate (17P), R5020, and RU-486. Delivery time was determined and cervical ripening was assessed in vivo by collagen light-induced fluorescence. RESULTS: The cervix is rigid in the progesterone injection, 17P, and vaginal R5020 groups vs controls. Vaginal progesterone had no effect. RU-486 treatment softened the cervix during preterm delivery. Only subcutaneous injected progesterone, R5020 (subcutaneous and vaginal), and topical progesterone in sesame and fish oil inhibits delivery. Delivery is not changed by subcutaneous injection of 17P, vaginal progesterone, oral progesterone, and topical progesterone in Replens (Crinone; Columbia Labs, Livingston, NJ). CONCLUSION: Inhibition of cervical ripening and delivery by progestins depends on many factors that include their properties, the route of administration, and the vehicle. This study suggests reasons that the present treatments for preterm labor are not efficacious.

Evaluation of cervical maturity by cervical collagen measurement using light-induced fluorescence (LIF) during pregnancy.

OBJECTIVE: The study aimed to evaluate cervical ripening by measuring cervical collagen levels in non-pregnant women, women with a normal pregnancy, and postpartum women by light-induced fluorescence (LIF). METHODS: Cervical collagen content in normal pregnant women (n = 165) at various times of gestation was measured by LIF with a collascope, which is specifically designed to measure fluorescence of collagen. Cervical LIF in non-pregnant women (n = 12) and postpartum women (n = 14) was also detected. The demographic characteristics of women at various times were recorded. The Bishop score at 40 to 41 gestational weeks (n = 37) before the onset of labor was analyzed. RESULTS: Cervical LIF values progressively declined from the non-pregnant state to late gestation (R = -0.836) and reached their lowest levels during parturition and then increased at postpartum. LIF values and the Bishop score were significantly negatively correlated (R = -0.83). In patients with a Bishop score ≥6, the first stage of labor was shortened with a decrease in LIF values (R = 0.718). CONCLUSIONS: Cervical collagen levels as measured by LIF could be a useful method for evaluating cervical maturity.

Identification of term and preterm labor in rats using artificial neural networks on uterine electromyography signals.

OBJECTIVE: This study was undertaken to use artificial neural networks on uterine electromyography data to identify term and preterm labor in rats. STUDY DESIGN: Controls (group 1: n = 4) and preterm labor models (group 2: n = 4, treated with onapristone) were used. Uterine electromyography and intrauterine pressure (IUP) variables were measured by implanted telemetric devices. For each timepoint assessed, either a "labor event" or "nonlabor event" was first assigned by using visual and other means. 112 total labor and nonlabor events were observed. Artificial neural networks were then used with electromyography and intrauterine pressure parameters to attempt algorithmic, objective identification for time of labor in each group. RESULTS: For group 1, all 8 (100%) labor events and all 44 (100%) nonlabor events were correctly identified by the artificial neural networks. For group 2, 22 of 24 (92%) labor events and 31 of 36 (86%) nonlabor events were correctly determined by the artificial neural networks. CONCLUSION: Artificial neural networks can effectively predict term and preterm labor during pregnancy with the use of uterine electromyography and intrauterine pressure variables.

Progesterone, but not 17-alpha-hydroxyprogesterone caproate, inhibits human myometrial contractions.

OBJECTIVE: The aim was to determine whether progesterone (P4) or 17-alpha-hydroxyprogesterone caproate (17P) directly inhibit human uterine contractility in vitro and thereby clarify their mechanisms of action. STUDY DESIGN: Myometrial tissues were suspended in organ chambers and exposed for 2 to 20 hours to varying concentrations of P4 or 17P or solvent. Contractile activity was registered, stored, and analyzed. Dose response curves were then generated for P4 or 17P at various times. RESULTS: P4 significantly inhibited spontaneous contractility dose dependently. The inhibition was not blocked by RU486 but was reversible after washing. Surprisingly, 17P dose dependently stimulated contractility. HPLC and GC-MS methods were used to determine the detectable concentrations of progestins in the baths. CONCLUSION: P4, at concentrations equivalent to those present in the placenta and uterus, inhibit spontaneous myometrial contractility in vitro by nongenomic mechanisms.

Choline Supplementation During Pregnancy Protects Against Gestational Lipopolysaccharide-Induced Inflammatory Responses.

OBJECTIVES: To estimate the effects and mechanisms of choline, an essential nutrient and a selective α7 nicotinic acetylcholine receptor (α7nAChR) agonist, on the prevention of symptoms and the effects on the cholinergic anti-inflammatory pathways (CAP) in a lipopolysaccharide (LPS)-induced inflammatory response in a rat model. METHODS: Inflammation was induced by LPS treatment (1.0 µg LPS/kg body weight) on gestational day (GD) 14. Nonpregnant and pregnant Sprague Dawley rats were placed on a normal choline diet (1.1 g/kg) or supplemented choline diet (5.0 g/kg) from GDs 1 to 20. Systolic blood pressure (SBP), urinary albumin, and pregnancy outcomes were recorded. On GD 20, serum and placentas were assayed for cytokines. Western blots were used to determine the expression of placenta α7nAChR and components of the α7nAChR-CAP, including nuclear factor-κB (NF-κB) and protein kinase B (AKT). Immunohistochemistry was used to localize placental sites for the p65 subunit of NF-κB. RESULTS: Lipopolysaccharide significantly increased SBP and urinary albumin and decreased pregnancy outcomes, and these effects were partially reversed by higher choline treatment. Choline supplementation also significantly attenuated the LPS-induced increase in serum and placental inflammatory cytokines, decreased the expression of placental α7nAChR, lowered the activation of NF-κB signaling in placenta mononuclear cells, and inhibited placental AKT phosphorylation. CONCLUSION: This study confirms that LPS induces inflammatory conditions in pregnant rats and shows that choline supplementation protects against the inflammatory symptoms through its action on α7nAChR and CAP. These observations have important implications for the prevention and treatment of inflammatory responses associated with pregnancy.

Uterine and Abdominal Muscle Electromyographic Activities in Control and PCEA-Treated Nulliparous Women During the Second Stage of Labor.

OBJECTIVE: Patient-controlled epidural analgesia (PCEA), used to relieve pain during delivery, delays labor but the mechanism is unknown. The aim was to investigate the effects of PCEA on uterine and abdominal muscles electromyographic (EMG) activity during the second stage of labor. METHODS: This study included 45 nulliparous pregnant women without PCEA, 42 women with standard PCEA treatment given during the first stage of labor and stopped near the end of the first stage, and 22 women with standard PCEA treatment with continued use throughout the first and second stages of labor. The EMG signals were recorded from the abdominal surface using PowerLab hardware and LabChart software (ADInstruments, New South Wales, Australia) and filtered to separate uterine and abdominal EMG. Various EMG burst parameters were obtained. RESULTS: There are no differences ( P > .05) in the age, body mass index, fetal weight, and Apgar scores between the patients from the various groups. PCEA (both stopped and continued) inhibits ( P < .05) duration, number of bursts, and root mean square of uterine EMG. PCEA also produces statistically significant ( P < .001) reductions in abdominal EMG. The decrease in EMG activity is accompanied by a significant ( P < .001) prolongation of the second stage duration (PCEA continued = 95.08 ± 8.60 minutes, PCEA stopped = 79.39 ± 6.25 minutes, no PCEA = 61.00 ± 7.23 minutes). CONCLUSION: PCEA suppresses uterine and abdominal muscle EMG during the second stage of labor but inhibition depends upon the treatment schedule. PCEA prolongs the duration of labor by inhibition of uterine and abdominal muscle and neural activity.

Computational exploration of regioselectivity and atmospheric lifetime in NO3-initiated reactions of CH3OCH3 and CH3OCH2CH3.

The NO3-initiated reactions of CH3OCH3 and CH3OCH2CH3 have been investigated by the BHandHLYP method in conjunction with the 6-311G(d,p) basis set. Thermodynamic and kinetic data are further refined using the comparatively accurate CCSD(T) method. According to the values of reaction enthalpies (ΔHr,298θ) and reaction Gibbs free energies (ΔGr,298θ) from CH3OCH2CH3 with NO3 system, we find that H-abstraction pathway from the α-CH2 group is more exothermic. It is further confirmed by the calculated CH bond dissociation energy of CH3OCH2CH3 molecule. All the rate constants, computed through means of canonical variational transition state with small-curvature tunneling correction, are fitted to the three-parameter expressions k1=1.54×10-23T3.34exp(-1035.53/T) and k2=3.55×10-26T4.31exp(-281.24/T)cm3molecule-1s-1 and branching ratios are computed over the temperature range 200-600K. The branching ratios are also discussed. The atmospheric lifetimes of CH3OCH3 and CH3OCH2CH3 determined by the NO3 radical are about 270 and 29days, respectively.

Simultaneous Recording and Analysis of Uterine and Abdominal Muscle Electromyographic Activity in Nulliparous Women During Labor.

OBJECTIVE: To record and characterize electromyography (EMG) from the uterus and abdominal muscles during the nonlabor to first and second stages of labor and to define relationships to contractions. METHODS: Nulliparous patients without any treatments were used (n = 12 nonlabor stage, 48 during first stage and 33 during second stage). Electromyography of both uterine and abdominal muscles was simultaneously recorded from electrodes placed on patients' abdominal surface using filters to separate uterine and abdominal EMG. Contractions of muscles were also recorded using tocodynamometry. Electromyography was characterized by analysis of various parameters. RESULTS: During the first stage of labor, when abdominal EMG is absent, uterine EMG bursts temporally correspond to contractions. In the second stage, uterine EMG bursts usually occur at same frequency as groups of abdominal bursts and precede abdominal bursts, whereas abdominal EMG bursts correspond to contractions and are accompanied by feelings of "urge to push." Uterine EMG increases progressively from nonlabor to second stage of labor. CONCLUSIONS: (1) Uterine EMG activity can be separated from abdominal EMG events by filtering. (2) Uterine EMG gradually evolves from the antepartum stage to the first and second stages of labor. (3) Uterine and abdominal EMG reflect electrical activity of the muscles during labor and are valuable to assess uterine and abdominal muscle events that control labor. (4) During the first stage of labor uterine, EMG is responsible for contractions, and during the second stage, both uterine and abdominal muscle participate in labor.

Nicotine inhibits LPS-induced cytokine production and leukocyte infiltration in rat placenta.

INTRODUCTION: Previous work conducted by our group has shown that nicotine reduces lipopolysaccharide (LPS)-induced systemic inflammatory responses and protects fetuses in pregnant Sprague-Dawley (SD) rats. In the present study, we aim to evaluate the influence of nicotine on rat placenta, including cytokine release, leukocyte infiltration, and α7 nicotinic acetylcholine receptor (α7-nAChR) expression. METHODS: Placental tissues of SD rats on gestation day 14 (GD14) were obtained and cultured in the presence or absence of LPS and/or nicotine. Culture media after 24 h were analyzed for cytokines release using Luminex. Other pregnant SD rats were first pretreated with nicotine on GD14 and GD15, followed by LPS injection on GD16. Placentas were collected on GD18 for H&E staining to evaluate leukocyte density and for real-time PCR and western blotting to identify the α7-nAChR expression in different groups. RESULTS: Nicotine suppresses LPS-stimulated placental proinflammatory cytokines (IL-1, IL-2, IL-6, TNF-α, IFN-γ) production except IL-17 in vitro, and reduces leucocytes infiltration in the placental chorionic plate caused by LPS in vivo. Moreover, LPS increases the α7-nAChR protein expression in placentas while pretreatment of nicotine inhibits it. DISCUSSION: These data show that nicotine suppresses LPS-induced placental inflammation by inhibition of cytokine release and infiltration of leukocytes into the placenta, and regulates the increased expression of α7-nAChR in placenta after LPS treatment. Nicotine and other nicotinic agonists may be an alternative therapeutic strategy for placental inflammation.

Changes in ectocervical surface area in women throughout pregnancy compared to non-pregnant and postpartum states.

OBJECTIVE: The objective of this study is to estimate changes in the surface area of the ectocervix (CA) in women during pregnancy and compare this to postpartum and non-pregnant states. METHODS: CA was evaluated in 210 normal nulliparous women divided into groups from early to late gestation, 40 postpartum women, and 25 non-pregnant women. CA in cm(2) was estimated from analysis of images taken with an endoscope of the cervical face and an mm scale. An mm scale was also used to determine fornix length and fornix area computed. RESULTS: The face, fornix, and total areas of the CA of non-pregnant and postpartum groups are significantly smaller (p < 0.001) than these areas in groups during pregnancy. Generally, the CA of the face, fornix, and total area are also less in early pregnancy compared with late gestation (p < 0.01 to <0.001). Total CA correlates with gestational age (r = 0.196, p < 0.004). CONCLUSIONS: (1) During pregnancy, CA slowly and progressively increases to >75% area compared with CA of non-pregnant patients and then reverts back to low CA postpartum. (2) Increases in CA during pregnancy occur in both the face and fornix areas. (3) Increases in CA reflect enlargement in cervical volume and remodeling during pregnancy.

Electrical inhibition of preterm birth: inhibition of uterine contractility in the rabbit and pup births in the rat.

OBJECTIVE: The purpose of this study was to inhibit uterine contractility during parturition with an electrical current, which is called electrical inhibition, in the rabbit and the rat. STUDY DESIGN: We studied the electrical inhibition of in vitro spontaneously contracting preterm or term gestational rat myometrium tissue and in vivo spontaneously contracting uterus either directly in the rabbit and rat or transvaginally in the rat. Values for myometrial tension, intrauterine pressure, pup birth intervals, and electromyographic activity before and after electrical inhibition were compared. RESULTS: Electrical inhibition decreased rat in vitro myometrial tension by 50%, decreased in vivo rabbit intrauterine pressure by 48%, decreased in vivo rat intrauterine pressure by 80%, and increased birth intervals (latency) by factors of 50 (direct electrical inhibition) and 20 (transvaginal electrical inhibition). All electromyographic activity parameters were reduced significantly. CONCLUSION: Electrical inhibition of the uterus is possible. Electrical inhibition is rapid and localized; the duration can be prolonged, and the reversibility is spontaneous. Electrical inhibition may be a new method of tocolysis in the human.