RESUMEN
The Frog Embryo Teratogenesis Assay-Xenopus (FETAX) was used to assess the teratogenic potential of two tocolytics. Embryos of the South African clawed frog, Xenopus laevis, were exposed to ritodrine or nifedipine. Exposure media were changed and monitored at 24-hour intervals. The 96-hour LC50 (Lethal concentration), the 96-hour EC50 (Malformation), and the No Observable Adverse Effect Concentrations (NOAEC) and the Lowest Observable Adverse Effect Concentration (LOAEC) for mortality, malformation and length were determined for each drug. Nifedipine was determined to be the more toxic and teratogenic than ritodrine, with a LC50 of 0.606 µg/L, an EC50 of 0.006 µg/L, and a teratogenicity Index (TI) value (LC50/EC50) of 101. On the other hand, the LC50 of ritodrine was 28.571 mg/L. In addition; the LC50, EC50 and TI values for nifedipine in the 5 mg/L ritodrine + nifedipine combination group were determined as 1.050 µg/L, 0.868 µg/L and 1.5 respectively. For ritodrine, the NOAEC and LOAEC values were determined as 2 mg/L and 4 mg/L, respectively. For the nifedipine and the ritodrine + nifedipine groups; while the LOAEC values of these groups were 0.0001 µg/L and 0.1 µg/L, respectively. NOAEC value couldn't be determined. Our results demonstrated that nifedipine administration was associated with higher levels of teratogenic and toxic effects. However, the ritodrine + nifedipine combination form reduced the toxic and teratogenic effects of nifedipine on Xenopus embryos. Further studies should be conducted in order to investigate the optimal combination concentrations of these substances for the treatment of preterm labor.
Asunto(s)
Anomalías Inducidas por Medicamentos/etiología , Bioensayo , Embrión no Mamífero/efectos de los fármacos , Nifedipino/toxicidad , Ritodrina/toxicidad , Teratogénesis , Tocolíticos/toxicidad , Pruebas de Toxicidad/métodos , Animales , Relación Dosis-Respuesta a Droga , Interacciones Farmacológicas , Embrión no Mamífero/anomalías , Dosificación Letal Mediana , Nivel sin Efectos Adversos Observados , Medición de Riesgo , Factores de Tiempo , Técnicas de Cultivo de Tejidos , Xenopus laevis/embriologíaRESUMEN
The tocolytic agent ritodrine acts on the ß2-adrenoceptor and is an effective treatment option for preterm labor. However, several adverse effects of ritodrine therapy, including liver damage, have been noted. To elucidate the underlying mechanisms of ritodrine-induced adverse effects, development of sensitive biomarkers of these adverse events is necessary. Here, we report the development and analysis of an animal model of ritodrine-induced liver damage. Female mice received daily ritodrine injections for 2 weeks; liver samples were then collected and subjected to DNA microarray analysis. Ritodrine significantly altered the expression of genes related to steroid and lipid metabolism, as well as the metabolism of ritodrine itself. Importantly, expression of the acute-phase reactant serum amyloid A (SAA) significantly increased after ritodrine injection, with values indicating the largest fold-change. This large increase in blood SAA levels serves as a more sensitive biomarker than conventional liver enzymes, such as aspartate aminotransferase and alanine aminotransferase. The increase in SAA expression is specific to ritodrine-induced liver damage, because SAA expression was not induced by other hepatotoxic drugs such as acetaminophen, valproic acid, or metformin. Our in vitro studies showed that cyclic adenosine 3',5'-monophosphate (cAMP) accumulation was not a primary cause of the ritodrine-induced SAA increase. Instead, SAA expression was enhanced by indirect phosphorylation of the signal transducer and activator of transcription-3 (STAT3) mediated by interleukin-6. Therefore, our study provides a method for sensitive and early detection of hepatic injury, and may thus help preclude serious liver damage due to ritodrine use in preterm labor.
Asunto(s)
Enfermedad Hepática Inducida por Sustancias y Drogas/sangre , Ritodrina/toxicidad , Proteína Amiloide A Sérica/metabolismo , Tocolíticos/toxicidad , Adenilil Ciclasas/metabolismo , Alanina Transaminasa/sangre , Animales , Aspartato Aminotransferasas/sangre , Biomarcadores/sangre , Western Blotting , Línea Celular , Femenino , Técnicas para Inmunoenzimas , Hígado/química , Hígado/enzimología , Ratones , Ratones Endogámicos C57BL , Análisis por Micromatrices , Reacción en Cadena en Tiempo Real de la Polimerasa , Proteína Amiloide A Sérica/análisisRESUMEN
To evaluate neurological effects of terbutaline, rats were injected with saline, terbutaline (Sigma or American Pharmaceutical Partners (APP™)) at 0.5 mg/kg-d or 10 mg/kg-d between postnatal days (PND) 2-5 or 11-14. Brains collected 24 h after last injection were used to determine corpus-callosum thickness, Purkinje cell and neuronal number in the cerebellum. Ambulation, distance traveled, resting time and time on rotarod were analyzed. Terbutaline (both doses/grades at PND 11-14) decreased corpus-callosum thickness. Ambulation time was significantly decreased in the 10 mg/kg-d (Sigma) and 0.5 mg/kg-d of terbutaline (APP™) (PND 2-5) juvenile-rats and 10 mg/kg-d-Sigma adult-rats, 0.5 mg/kg-d APP™ (PND 11-14) adult-rats. Resting time was increased in both doses of APP™ (PND 2-5) in juvenile-rats, 10 mg/kg-d Sigma adult-rats. 10 mg/kg-d-Sigma (PND 2-5) decreased distance traveled in adult-rats. 0.5 mg/kg-d-Sigma (PND 2-5 and PND 11-14) decreased the time spent on rotarod (30 RPM) in adult-rats. Sigma terbutaline Sigma had 2× as much free base compared to APP™. In conclusion, APP™ terbutaline did not have a deleterious effect on the developing rat brain.
Asunto(s)
Agonistas de Receptores Adrenérgicos beta 2/toxicidad , Encéfalo/efectos de los fármacos , Síndromes de Neurotoxicidad/etiología , Terbutalina/toxicidad , Tocolíticos/toxicidad , Agonistas de Receptores Adrenérgicos beta 2/química , Factores de Edad , Envejecimiento , Análisis de Varianza , Animales , Animales Recién Nacidos , Conducta Animal/efectos de los fármacos , Encéfalo/crecimiento & desarrollo , Encéfalo/patología , Encéfalo/fisiopatología , Femenino , Masculino , Espectrometría de Masas , Actividad Motora/efectos de los fármacos , Síndromes de Neurotoxicidad/patología , Síndromes de Neurotoxicidad/fisiopatología , Equilibrio Postural/efectos de los fármacos , Ratas , Ratas Sprague-Dawley , Terbutalina/química , Tocolíticos/químicaAsunto(s)
Apoptosis/efectos de los fármacos , Encéfalo/efectos de los fármacos , Sulfato de Magnesio/toxicidad , Neuronas/efectos de los fármacos , Tocolíticos/toxicidad , Animales , Animales Recién Nacidos , Encéfalo/crecimiento & desarrollo , Encéfalo/patología , Células Cultivadas , Femenino , Hipocampo/efectos de los fármacos , Hipocampo/crecimiento & desarrollo , Hipocampo/patología , Ratones , Ratones Endogámicos C57BL , Neuronas/patologíaRESUMEN
Kisspeptins, the products of the KiSS-1 gene acting via G protein-coupled receptor 54 (GPR54), have recently emerged as pivotal signals in the hypothalamic network triggering the preovulatory surge of gonadotropins and, hence, ovulation. Additional actions of kisspeptins at other levels of the hypothalamic-pituitary-ovarian axis have been suggested but remain to date scarcely studied. We report herein the pattern of expression of KiSS-1 and GPR54 in the human and nonhuman primate ovary and evaluate changes in ovarian KiSS-1 expression in a rat model of ovulatory dysfunction. KiSS-1 and GPR54 mRNAs were detected in human ovarian tissue and cultured granulosa-lutein cells. In good agreement, kisspeptin immunoreactivity was observed in cyclic human and marmoset ovaries, with prominent signals in the theca layer of growing follicles, corpora lutea, interstitial gland, and ovarian surface epithelium. GPR54 immunoreactivity was also found in human theca and luteal cells. Administration of indomethacin to cyclic female rats disturbed ovulation and resulted in a dramatic drop in ovarian KiSS-1, but not GPR54, cyclooxygenase-2 (COX-2), or progesterone receptor, mRNA levels at the time of ovulation; an effect mimicked by the selective COX-2 inhibitor NS398 and rescued by coadministration of PGE(2). Likewise, the stimulatory effect of human choriogonadotropin on ovarian KiSS-1 expression was partially blunted by indomethacin. In contrast, KiSS-1 mRNA levels remained unaltered in another model of ovulatory failure, i.e., the RU486-treated rat. In summary, we document for the first time the expression of KiSS-1/kisspeptin and GPR54 in the human and nonhuman primate ovary. In addition, we provide evidence for the ability of inhibitors of COX-2, known to disturb follicular rupture and ovulation, to selectively alter the expression of KiSS-1 gene in rat ovary. Altogether, our results are suggestive of a conserved role of local KiSS-1 in the direct control of ovarian functions in mammals.
Asunto(s)
Enfermedades del Ovario/fisiopatología , Ovario/fisiología , Proteínas/genética , Proteínas Supresoras de Tumor/genética , Animales , Callithrix , Inhibidores de la Ciclooxigenasa/farmacología , Dinoprostona/farmacología , Modelos Animales de Enfermedad , Femenino , Expresión Génica/efectos de los fármacos , Expresión Génica/fisiología , Humanos , Indometacina/toxicidad , Kisspeptinas , Mamíferos , Enfermedades del Ovario/inducido químicamente , Proteínas/metabolismo , ARN Mensajero/metabolismo , Ratas , Ratas Wistar , Receptores Acoplados a Proteínas G/genética , Receptores Acoplados a Proteínas G/metabolismo , Receptores de Kisspeptina-1 , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Tocolíticos/toxicidad , Proteínas Supresoras de Tumor/metabolismoRESUMEN
The oxytocin receptor antagonist barusiban, currently being developed for treatment of preterm labour, was investigated in pregnant cynomolgus monkeys with a 9-month postnatal follow-up of their offspring. The nature of barusiban, its indication, and the potential exposure of pre- and postnatal infants entailed the design of a unique protocol to investigate all aspects of maternal and offspring well-being. Barusiban was administered to the mothers from gestation day 85 until delivery with daily subcutaneous dosages up to 2.5mg/kg body weight/day. There were no test article-related effects seen in the mothers at any time during the study. The postnatal examination of offspring included routine toxicological parameters, as well as specialised investigation of the immune, cardiovascular, renal and central nervous systems, including a full behavioural assessment. A full pathology examination of offspring was performed at the end of the 9-month postnatal period. No adverse infant findings occurred.
Asunto(s)
Conducta Animal , Sistema Inmunológico , Oligopéptidos/toxicidad , Efectos Tardíos de la Exposición Prenatal , Receptores de Oxitocina/antagonistas & inhibidores , Tocolíticos/toxicidad , Pruebas de Toxicidad/métodos , Animales , Animales Recién Nacidos , Conducta Animal/efectos de los fármacos , Sistema Cardiovascular/efectos de los fármacos , Relación Dosis-Respuesta a Droga , Desarrollo Embrionario/efectos de los fármacos , Femenino , Edad Gestacional , Sistema Inmunológico/efectos de los fármacos , Inyecciones Subcutáneas , Riñón/efectos de los fármacos , Macaca fascicularis , Oligopéptidos/administración & dosificación , Oligopéptidos/farmacocinética , Parto/efectos de los fármacos , Embarazo , Medición de Riesgo/métodos , Factores de Tiempo , Tocolíticos/administración & dosificación , Tocolíticos/farmacocinéticaRESUMEN
Developmental exposure to unrelated neurotoxicants can nevertheless produce similar neurobehavioral outcomes. We examined the effects of developmental exposure to terbutaline, a tocolytic beta2-adrenoceptor agonist used to arrest preterm labor, and chlorpyrifos (CPF), a widely used organophosphate pesticide, on serotonin (5HT) systems. Treatments were chosen to parallel periods typical of human developmental exposures, terbutaline (10 mg/kg) on postnatal days (PN) 2-5 and CPF (5 mg/kg) on PN11-14, with assessments conducted on PN45, comparing each agent alone as well as sequential administration of both. Although neither treatment affected growth or viability, each elicited similar alterations in factors that are critical to the function of the 5HT synapse: 5HT1A receptors, 5HT2 receptors, and the presynaptic 5HT transporter (5HTT). Either agent elicited global increases in 5HT receptors and the 5HTT in brain regions possessing 5HT cell bodies (midbrain, brainstem) as well as in the hippocampus, which contains 5HT projections. For both terbutaline and CPF, males were affected more than females, although there were some regional disparities in the sex selectivity between the two agents. Both altered 5HT receptor-mediated cell signaling, suppressing stimulatory effects on adenylyl cyclase and enhancing inhibitory effects. When animals were exposed sequentially to both agents, the outcomes were no more than additive and, for many effects, less than additive, suggesting convergence of the two agents on a common set of developmental mechanisms. Our results indicate that 5HT systems represent a target for otherwise unrelated neuroteratogens.
Asunto(s)
Cloropirifos/toxicidad , Insecticidas/toxicidad , Efectos Tardíos de la Exposición Prenatal , Receptores de Serotonina 5-HT1/efectos de los fármacos , Receptores de Serotonina 5-HT2/efectos de los fármacos , Terbutalina/toxicidad , Tocolíticos/toxicidad , Inhibidores de Adenilato Ciclasa , Adenilil Ciclasas/metabolismo , Animales , Animales Recién Nacidos , Encéfalo/efectos de los fármacos , Encéfalo/metabolismo , Cloropirifos/administración & dosificación , Femenino , Insecticidas/administración & dosificación , Masculino , Glicoproteínas de Membrana/metabolismo , Proteínas de Transporte de Membrana/metabolismo , Proteínas del Tejido Nervioso/metabolismo , Embarazo , Ratas , Ratas Sprague-Dawley , Receptores de Serotonina 5-HT1/metabolismo , Receptores de Serotonina 5-HT2/metabolismo , Serotonina , Proteínas de Transporte de Serotonina en la Membrana Plasmática , Factores Sexuales , Teratógenos/toxicidad , Terbutalina/administración & dosificación , Tocolíticos/administración & dosificaciónRESUMEN
Exposure to apparently unrelated neurotoxicants can nevertheless converge on common neurodevelopmental events. We examined the long-term effects of developmental exposure of rats to terbutaline, a beta-adrenoceptor agonist used to arrest preterm labor, and the organophosphorus insecticide chlorpyrifos (CPF) separately and together. Treatments mimicked the appropriate neurodevelopmental stages for human exposures: terbutaline on postnatal days (PN) 2-5 and CPF on PN11-14, with assessments conducted on PN45. Although neither treatment affected growth or viability, each elicited alterations in CNS cell signaling mediated by adenylyl cyclase (AC), a transduction pathway shared by numerous neuronal and hormonal signals. Terbutaline altered signaling in the brainstem and cerebellum, with gender differences particularly notable in the cerebellum (enhanced AC in males, suppressed in females). By itself, CPF exposure elicited deficits in AC signaling in the midbrain, brainstem, and striatum. However, sequential exposure to terbutaline followed by CPF produced larger alterations and involved a wider spectrum of brain regions than were obtained with either agent alone. In the cerebral cortex, adverse effects of the combined treatment intensified between PN45 and PN60, suggesting that exposures alter the long-term program for development of synaptic communication, leading to alterations in AC signaling that emerge even after adolescence. These findings indicate that terbutaline, like CPF, is a developmental neurotoxicant, and reinforce the idea that its use in preterm labor may create a subpopulation that is sensitized to long-term CNS effects of organophosphorus insecticides.
Asunto(s)
Adenilil Ciclasas/metabolismo , Animales Recién Nacidos/metabolismo , Encéfalo/efectos de los fármacos , Cloropirifos/toxicidad , Insecticidas/toxicidad , Efectos Tardíos de la Exposición Prenatal , Terbutalina/toxicidad , Tocolíticos/toxicidad , Agonistas Adrenérgicos beta/farmacología , Animales , Encéfalo/enzimología , Encéfalo/metabolismo , Cloropirifos/administración & dosificación , Femenino , Insecticidas/administración & dosificación , Isoproterenol/farmacología , Masculino , Embarazo , Ratas , Ratas Sprague-Dawley , Receptores Adrenérgicos beta/metabolismo , Factores Sexuales , Transducción de Señal/efectos de los fármacos , Teratógenos/toxicidad , Terbutalina/administración & dosificación , Tocolíticos/administración & dosificaciónRESUMEN
OBJECTIVES: Even though magnesium sulfate is commonly prescribed for women with preeclampsia as prophylaxis against seizure and for women with preterm labor as a tocolytic agent there is limited information about its effects on the fetus. It is of particular concern that women with preeclampsia or in premature labor are at high risk for abruptio placentae with consequent compromise of fetal oxygenation. Magnesium sulfate is a vasodilator and thus may exert cardiovascular effects on the fetus. The goal of this study was to evaluate the effects of magnesium sulfate on fetal organ blood flow, especially regional cerebral blood flow, during the stressful condition of maternal hemorrhage. STUDY DESIGN: Studies were performed with 11 long-term instrumented pregnant ewes and their fetuses at 121 to 128 days' gestation (term, 147 days' gestation). Animals were randomly allocated to either the experimental (n = 5) or the control (n = 6) group. After a 60-minute baseline period, experimental fetuses received intravenous magnesium sulfate diluted in 0.9% sodium chloride (0.3 g loading dose, then 0.3 g/h at a rate of 3 mL/h) and control fetuses were infused with an equivalent volume of intravenous 0.9% sodium chloride. After 60 minutes of this infusion-only period, the infusions were continued and ewes were intermittently bled 4 times at a rate of 5 mL/kg for 10 minutes with 5 minutes between hemorrhages. The total blood lost at the end of the hemorrhage-plus-infusion hour was 20 mL/kg. The infusions were continued and the sheep were observed for 1 hour after this period (posthemorrhage period). At the end of baseline, infusion-only, and hemorrhage-plus-infusion periods, fetal and maternal blood pressures and blood gas values were measured and fetal organ blood flows were determined through a fluorescent microsphere technique. Repeated-measures analysis of variance and Wilcoxon tests were used to determine the significance of changes in hemodynamic, blood gas, and organ blood flow parameters between different time points within each group. Comparisons between groups were made with rank sum tests (Mann-Whitney tests). RESULTS: There were no significant differences between groups or within groups for baseline and infusion-only measurements in any measured hemodynamic or hematologic factor. Mean maternal blood pressure decreased significantly (P <.05) after hemorrhage, with similar median decrements in both control and experimental groups of 41 mm Hg (interquartile range, 24-57 mm Hg) and 41 mm Hg (interquartile range, 12-43 mm Hg), respectively. There were no significant differences between groups in fetal blood gas values or hemodynamic parameters. Fetal arterial PO(2) decreased significantly after hemorrhage plus infusion, with similar mean (+/-SEM) decreases in control and experimental groups of 5.9 +/- 1.4 mm Hg and 4.5 +/- 1.5 mm Hg, respectively. Fetal pH also decreased significantly in both groups. After hemorrhage plus infusion there were significant increases in fetal regional cerebral and myocardial blood flows in both groups. Adrenal blood flow increased significantly from baseline (214%, 183%-294%) in the control group after hemorrhage plus infusion but not in the experimental group. No other difference in organ blood flow between control and experimental groups was observed. Significant regional variations in cerebral blood flow were not observed in either group at any time. CONCLUSIONS: In these initially healthy, late-gestation fetal lambs magnesium sulfate exposure did not impair cardiac output redistribution, nor did it cause fetal death in response to maternal hemorrhage.
Asunto(s)
Anticonvulsivantes/toxicidad , Feto/efectos de los fármacos , Sulfato de Magnesio/toxicidad , Complicaciones Cardiovasculares del Embarazo/fisiopatología , Tocolíticos/toxicidad , Hemorragia Uterina/fisiopatología , Animales , Anticonvulsivantes/administración & dosificación , Encéfalo/irrigación sanguínea , Encéfalo/embriología , Femenino , Sangre Fetal/química , Feto/irrigación sanguínea , Infusiones Intravenosas , Sulfato de Magnesio/administración & dosificación , Embarazo , Distribución Aleatoria , Flujo Sanguíneo Regional/efectos de los fármacos , Ovinos , Tocolíticos/administración & dosificaciónRESUMEN
Magnesium sulfate is commonly used in high-risk pregnancies, even though its actions in the fetus during maternal/fetal stress are not completely understood. The present study tested the hypothesis that magnesium sulfate alters the fetal cerebral blood flow response to hypoxemia produced during maternal hemorrhage. It was conducted in instrumented near-term fetal lambs at 123 days of gestation. Experimental treatment involved four periods of maternal hemorrhage over a 60-min period during fetal infusion of 0.25 g (n = 5) or 0.30 g (n = 6) magnesium sulfate, or normal saline (n = 11). The level of fetal cerx500l blood flow was determined using radiolabeled microspheres. For all three treatment groups, maternal hemorrhage produced fetal hypoxemia and some fetal demise. During fetal infusion of saline, 1 of 11 (9%) of the fetuses died; with the 0.25-g magnesium sulfate regimen, 1 of 5 (20%) died; and with the 0.30-g magnesium sulfate regimen, 3 of 6 (50%) of the fetuses died. Magnesium sulfate caused an increase in the proportion of fetal death produced by maternal hemorrhage (P < 0.05). Among surviving fetuses, hemorrhage-induced hypoxemia increased fetal cerebral blood flow during saline infusion. In contrast, infusion of magnesium sulfate had an inhibitory effect on this compensatory increase in fetal cerebral blood flow (P = 0.003). These data indicate that, in the sheep, magnesium sulfate increases fetal mortality and inhibits the compensatory increase in fetal cerebral blood flow during maternal hemorrhage-induced fetal hypoxemia.
Asunto(s)
Circulación Cerebrovascular/efectos de los fármacos , Muerte Fetal/inducido químicamente , Feto/efectos de los fármacos , Hemorragia , Sulfato de Magnesio/toxicidad , Complicaciones Cardiovasculares del Embarazo , Tocolíticos/toxicidad , Animales , Femenino , Enfermedades Fetales/fisiopatología , Feto/fisiología , Hemorragia/fisiopatología , Hipoxia/fisiopatología , Embarazo , Complicaciones Cardiovasculares del Embarazo/fisiopatología , OvinosRESUMEN
Clinical and experimental studies have revealed that salbupart, a beta-mimetic agent, administered in a dose of 0.14 mg/kg (the maximal therapeutic dose) markedly inhibited the spontaneous and oxytocin-induced uterine contractility, caused no embryotoxic or teratogenic effects, and did not influence fetal growth and development. The efficacy of salbupart tocolytic therapy was estimated as 75%. Blood plasma cAMP levels normalized in the pregnant women over the course of therapy. Clinical and experimental results recommend salbupart for pregnancy protecting therapy in cases with threatened spontaneous abortions.