Antispasmodic effects of Pycnocycla spinosa seed and aerial part extracts on rat ileum and uterus smooth muscle contractions

Hydroalcoholic extract of Pycnocycla spinosa has a relaxant effect on ileum and inhibits castor oil induced diarrhoea in mice. However, effects of P. spinosa seed extracts on ileum and uterus hasn't been investigated. The aim of this study was to investigate effect of P. spinosa seed and extracts of the aerial part on rat ileum and uterus smooth muscle contraction. A 70% ethanol extract of seed and aerial parts of P. spinosa was prepared by a percolation method. Uterine horns or ileum were dissected from non-pregnant female Wistar rats [200-230g] and cut into longitudinal strips and mounted for isotonic recording under Ig tension in Tyrode's solution. Effects of the extracts were examined on tonic contractions induced by KC1 [80mM] on both tissues and on phasic spasm induced by oxytocin [0.002iu/ml] on the uterus. The aerial part extract inhibited rat ileum contractions induced by 80mM KC1 [IC[50] = 42 +/- 3.4 micro g/ml] in a concentration dependent manner and it also inhibited rat uterus contraction induced by 80 mM KC1. However, its inhibitory effects were observed with higher concentration of the extract [IC5o = 420+90 micro g/ml] and at concentration of 1.28mg/ml of the extract in the bath the response was 19+7%. The aerial part extract [40-640 micro g/ml] also reduced the evoked phasic response of uterus by oxytocin [IC[50] = 71 +/- 17.3 micro g/ml]. The seed extract reduced the uterus response to oxytocin in a concentration-dependent manner, and inhibited tissue response completely at 160 micro g/ml [IC[50] = 27 +/- 4 micro g/ml]. From this study it was concluded that the seed extract of P. spinosa have similar inhibitory properties on rat isolated uterus and ileum contractions, while the extract of the aerial part of P. spinosa is more selective inhibitor of ileum contraction, and at higher concentrations it also inhibits uterus spasm

Influence of time at which oxytocin is administered during labor on uterine activity and perinatal death in pigs

Oxytocin is extensively used to induce or augment uterine contractions, especially to facilitate the third stage of labor in humans. Administration of oxytocin to parturient sows reduces duration of labor whereas mortality of the offspring may remain unchanged. This study aimed to evaluate whether time of administration of oxytocin during parturition may alter the uterine response and fetal outcomes. Two hundred parturient sows were randomly assigned to intramuscularly receive either saline solution (control group) or oxytocin 0.083 IU/kg immediately after the delivery of the 1st, 4th or 8th piglet (groups O-1, 0-4 and 0-8, respectively). Uterine effects and fetal outcomes were registered in all groups. The duration of labor was 20-40 min shorter (P < 0.0001) and time interval between babies was reduced by 3-5 min (P < 0.0001) in the three groups receiving oxytocin. The duration and intensity of contractions, meconium-stained piglets and intrapartum deaths decreased as time at which oxytocin administered during labor was increased. In group 0-8, we observed approximately 70 percent less meconium-stained piglets and intrapartum deaths than in the control group. In conclusion, oxytocin administered at early phases of parturition to sows may increase duration and intensity of uterine contractions as well as adverse fetal outcomes.

Effects of calcium channel blocker, mibefradil, and potassium channel opener, pinacidil, on the contractile response of mid-pregnant goat myometrium.

The present study was undertaken to investigate the in vitro influence of mibefradil, a calcium channel blocker, and pinacidil, a potassium channel opener, on pregnant goat myometrial spontaneous rhythmic contractility and contractions induced with the agonist, oxytocin. Longitudinal strips from the distal region of uterus, collected from goats at midgestation, were mounted in an organ bath for recording isometric contractions. Mibefradil (10(-8)-10(-4) M) or pinacidil (10(-10)-10(-4) M), added cumulatively to the bath at an increment of 1 log unit, caused concentration-dependent inhibition of the spontaneous rhythmic contractions of isolated uterine strips. The rhythmic contraction was, respectively, abolished at 100 and 10 microM concentrations of mibefradil and pinacidil. In a concentration-dependent manner, mibefradil (1 and 10 microM) antagonized the contractions elicited with oxytocin (10(-5)-10(-2) IU). Pretreatment of uterine strips with glibenclamide (10 microM), a selective KATP channel blocker, caused a rightward shift of the concentration-response curve of pinacidil with a concomitant decrease in its pD2 value. Pinacidil (0.3, 1 and 3 microM), in a concentration-related manner, antagonized the oxytocin (10(-5)-10(-2) IU)-induced contractile response. The inhibition of spontaneous rhythmic contractions and antagonism of oxytocin-induced contraction by mibefradil in the pregnant goat myometrium may be related to the antagonism of voltage-dependent Ca2+ channels, while by pinacidil suggests that KATP channel could be a therapeutic target for tocolysis.

Regulación de la proliferación celular uterina por estrógenos y factores de crecimiento / Regulation of uterine cellular proliferation by estrogen and growth-factors

En el presente trabajo se analiza el papel de los estrógenos y los factores de crecimiento como inductores de la proliferación celular uterina. Las evidencias indican que la división celular estimulada por el estradiol está asociada con la inducción de una variedad de factores de crecimiento por pate de las tres principales poblaciones celulares del útero (epitelio, estroma y miometrio). Se piensa que tales factores funcionan de manera autrocrina y/o paracrina en la amplificación de la señal proliferativa de los estrógenos. Los factores de crecimiento que mejor se han estudiado en la respuesta uterina a estradiol son el factor de crecimiento epidermal (EGF) y el insulinoide tipo I (IGF-I). La proliferación celular uterina es un proceso complejo que involucra la interacción de varios factores de crecimiento, la acción de las hormonas esteroides ováricas y la intercomunicación entre sus distintas células

Efecto de la dinoprostona sobre la maduración cervical en enfermedad hipertensiva aguda del embarazo / Dinoprostone effect on cervical maturation in pregnant with hypertension

Objetivo. Determinar el fecto de la dinoprostona sobre la maduración cervical y la tensión arterial en una grupo de gestantes con enfermedad hipertensiva aguda del embarazo. Material y método. Se estudiaron 28 mujeres con diagnóstico de EHAE que fueron tratadas con una dosis de dinoprostona (0.5 mg intracervical). Resultados. El 67 por ciento de las mujeres mostraron aumento en el valor de Bishop (19 casos). El 50 por ciento de las mujeres tuvo indicación de cesárea por falta de progreso de trabajo de parto. La media de la tensión arterial disminuyó después de la aplicación del medicamento. Conclusión. Se obtuvo una disminución de la frecuencia de resolución por cesárea en mujeres con EHAE con relación al esperado (100 por ciento), sin incremento de riesgo para la mujer

Effects of ovarian hormone tratment on Ca2+-induced contractions and Ca2+-antagonism in the depolarized rat myometrium

The effects of estrogen (E), progesterone (P) and estrogen plus progesterone (E+P) treatment on Cainduced contraction in the KCL-depolarized uterine muscle, and the influences on the Ca2+ antagonism induced by reserpine and verapamil "in vivo" were studied. Uterine muscles from rats in estrus were taken as controls. Uteri from spayed untreated rats showed the same sensivity to Ca2+ as those from estrus rats, but castration decreased maximal contractile tension to Ca2+ and Ca2+ thereshold. P tratment failed to modified the effects of castration on the responses to Ca2+. E or E+P treatments decreased the sensitivity to Ca2+ but only E+P increased slope values and maximal contractile tension. E and E+P increased the potency of verapamil Ca2+ antagonism but none the treatments modified reserpine direct inhibitory effects. The results obtained suggest that alterations on uterine contractility by hormone treatment are the result of complex interactions between both genomic effects on the contractile process as well as nongenomic direct actions of the hormones on Ca2+ membrane permeability.

Inhibitory effect of spironolactone on the contractions of the rabbit uterine horn and the human myometrial strip.

The spontaneous contractions of the rabbit uterine horns and the human myometrial strips were stimulated by oxytocin and buserelin acetate in isolated preparations. Spironolactone application to these models produced inhibitory effects on the contractions. It is concluded that spironolactone has inhibitory effect on the rabbit uterine horn and the human myometrial strip contractions.

Efecto de fármacos tocolíticos sobre la actividad contractil evocada por prostaglandinas en el utero gestante / Tocolytic drugs effect in contractil activity evoked by prostaglandines in the pregnant uterus

Se estudió el efecto in vitro de ritodrine (28,7 ng/ml), fenoterol (30,0 ng/ml), verapamil (43 ng/ml), nifedipino (34,6 ng/ml) y sulfato de magnesio (6 meq/lt) sobre la actividad contráctil espontánea y evocada por prostaglandina PGF 2* en cuernos uterinos de ratones con 15 días de gestación. El rango de concentraciones usadas fue cercana a los niveles plasmáticos efectivos alcanzados para cada tocolítico respectivamente. A las dosis señaladas, la actividad contráctil espontánea fue completamente abolida por los tocolíticos investigados. En cambio, las contracciones evocadas por PGF 2* fueron inhibidas solamente por ritodrine, fenoterol y nifedipino. Se discuten posibles mecanismos involucrados en estas interacciones

Efeito da Alsophila plagiopteris, Mart sobre a musculatura lisa de ratas com ou sem hormonizaçäo prévia (útero isolado) e sobre a pressäo intra uterina de ratas wistar virgens em estro / Effect of Alsophila plagiopteris, Mart on the smooth muscle of female rats with or without praevia hormonization (isolated uterus) and the intrauterina pressure of virgin female wistar rats in estrus

O presente estudo tem por finalidade verificar alteraçöes nas contraçöes uterinas e na pressäo intra-uterina de ratas Wistar mediante a açäo de extrato aquoso do rizoma da Alsophila plagiopteris, Mart na vigência ou näo de hormonizaçäo prévia. Foram utilizados 46 ratas Wistar virgens em estro onde utilizou-se duas técnicas distintas, ou seja, preparaçäo de útero isolado e pressäo intra-uterina "in situ". Observou-se diminuiçäo significativa na frequência e amplitude dos movimentos uterinos, e até mesmo ausência dos mesmos. Observou-se também diminuiçäo significativa na pressäo intra-uterina (PIU), em animais com ou sem hormonizaçäo prévia. Concluimos que o extrto aquoso de alsophila plagiopteris, Mart produz relaxamento da musculatura lisa uterina bem como uma diminuiçäo da PIU normal. Sugerimos que o extrato aquoso do rizoma de Alsophi la plagiopteris Mart induz um relaxamento da musculatura lisa por um efeito direto, talvéz musculotrópico

Effect of PAF-acether on the reactivity of the isolated rat myometrium

In non-pregnant rat isolated uterine strips PAF-acether (1-1000 nM) produced contractile effects on 74% of the preparations tested which were concentration-dependent in 44% of the cases (EC50 = 28 nM). All the preparations tested exhibited contractile responses to either acetylcholine or potassium. PAF-acether was less potent on myometrial strips from pregnant animals (EC50 = 0.3 micronM) and was only effective on 24% of the preparations tested. A second contractile concentration-response curve was reproducible in only 14% of the preparations from non-pregnant rats (EC50 = 13 nM), whereas all strips from pregnant animals were completely refractory to a second challenge with PAF-acether. These results indicate that PAF-acether induces contraction of the isolated rat myometrium within the Ssame range of concentration at which it is active in other tissues

Gossypol affects the responsiveness of isolated rat myometrium and vas deferens

The effects of gossypol on responsiveness of both rat myometrium and vas deferens were analyzed. In myometrial strips, gossypol (1-30 micronM) produced rightward displacemtns of the cumulative concentration-response curves to acetylcholine, bradykinin and oxytocin, accompanied by reductions in maximal responses. Gossypol (30 micronM) also completely abolished the contractions induced by field stimulation of the rat vas deferens. The IC50 values for gossypol against agonist-uinduced myometrial contractions and field-stimulated vas deferens contractions were similar, ranging between 13 and 18 micronM. These results provide additional evidence that gossypol exerts a direct and irreversible inhibition of the contractility of both male and female reproductive organs