21st Day Of Pregnancy Research Articles

Cancer during pregnancy alters the activity of rat placenta and enhances the expression of cleaved PARP, cytochrome-c and caspase 3

BackgroundThe presence of cancer makes it difficult to predict the progress of pregnancy and can be deleterious to the maternal-foetal relationship. Apoptosis may affect a range of placental functions and result in the retardation of foetal growth. In this work, we investigated the placental alterations produced by tumour growth and the effects on the expression of apoptotic factors in placental tissue.MethodsAdult female Wistar rats (90 days old, n = 54) were allocated to control (C), tumour-bearing (W), or ascitic fluid-injected (A) groups and were killed on the 16th, 19th or 21st day of pregnancy. Placental tissues were analysed using biochemical and histochemical assays.ResultsThe placental protein content and glutathione-S-transferase activity were decreased in groups W and A. Histochemical analysis showed an increase in the number of cells with cleaved PARP, caspase 3 and cytochrome-c in groups W and A, indicating that the tumour growth clearly damaged placental tissue and affected the levels of apoptotic factors. These results were confirmed by western blotting.ConclusionSince trophoblastic cells are responsible for maintaining a normal placental function, the uncontrolled death of these cells in response to tumour cell growth or substances derived from ascitic fluid could have a negative impact on foetal development. Further knowledge of these events may help to preserve the foetus and placenta during development.

In vivo Dilatation of the Fetal and Postnatal Ductus Arteriosus by Inhibition of Phosphodiesterase 3 in Rats

Background: Clinically, it appears that phosphodiesterase 3 (PDE 3) inhibitors, which are used for acute cardiac failure in premature infants, dilate the ductus arteriosus (DA). Objectives: To clarify the ductus-dilating effects of PDE 3 inhibitors in near-term rat pups and their differential effects in near-term and preterm fetal rats, in in vivo studies. Methods: The in vivo ductal diameter of rat pups and fetuses was measured using a rapid whole-body freezing method, by cutting on a freezing microtome and measuring with a microscope and micrometer. Eight to twenty pups and fetuses were studied in each group. Milrinone and amrinone (specific inhibitors of PDE 3) were injected into 1-hour-old pups and the DA was studied 0.5 and 1 h later. The differential effects of these PDE 3 inhibitors on the near-term and preterm ductus were studied by injecting indomethacin (10 mg/kg) and PDE 3 inhibitors into 21D (21st day of pregnancy: term-21.5 days) and 19D dams and studying the fetal ductus 4 and 8 h later. Results: Milrinone and amrinone dilated the postnatal ductus dose-dependently. Large doses of these drugs dilated it completely, and clinically equivalent doses dilated it minimally. Milrinone and amrinone prevented constriction of the fetal ductus by indomethacin. Their ductus-dilating effects were more potent in the preterm than in the near-term fetuses, and clinically equivalent doses of these PDE 3 inhibitors dilated preterm ductus completely. Conclusion: In rats, PDE 3 inhibitors reopen the constricted postnatal DA slightly. PDE 3 inhibitors dilate the fetal DA constricted with indomethacin effectively and more sensitively in preterm than in near-term fetuses.

Reduction of all-trans-retinoic acid–induced teratogenesis in the rat by glycine administration

Prenatal rat embryo exposure to retinoids induces severe malformations in various organs; the most active and teratogenic metabolite is all-trans-retinoic acid (atRA). The mechanisms of this embryopathy are only partly known. In the present study, the influence of glycine on the teratogenicity of atRA was investigated. Embryos from 5 groups of white rats were studied: Group 1 remained untreated; Group 2 received glycine 2% in drinking water ad libitum from the first gestational day (GD 1); Group 3 was administered vehicle (corn oil); Group 4 was treated with atRA (50 mg/kg of body weight) injected (IP); and Group 5 was treated with atRA (50 mg/kg of body weight IP) plus glycine 2% in drinking water ad libitum from GD 1. atRA was administrated daily from GD 8-10. Dams were killed on the 21st day of pregnancy, and their fetuses were examined to detect external, visceral, and skeletal malformations. The results show that the atRA-administered dose is not toxic for the dams, and that although fetal death was not observed, it produced abnormalities in the fetuses. Glycine reduced atRA-induced teratogenic effects (external and skeletal defects). The results indicate that glycine effectively reduces the teratogenic effects of atRA. Thus, glycine might be useful for the prevention of vitamin A teratogenicity.

A toxicidade do Hypericum perforatum administrado a ratas prenhes

Saint John's wort (Hypericum perforatum) is a medicinal plant used in the treatment of depression and other psychiatric disorders. In the present paper, the toxicity of H. perforatum administered to female rats during organogenesis (9th to 15th day of pregnancy) was evaluated. Thirty inseminated Wistar rats were randomly distributed into Control and Treated groups, which received by gavage, respectively, 0.5 ml of saline and 36 mg/Kg body weight of Jarsin dried extract diluted into 0.5 ml of saline. Maternal toxicity was evaluated by means of: water and food intake, body weight, piloerection, walking activity, diarrhea and death. Animals were killed on the 21st day of pregnancy, when kidneys, liver and ovaries were weighed. Implantation and reabsorption indices were calculated, as well as the average number of fetuses per mother. Clinical signs of maternal toxicity were not observed and none of the variables analyzed showed statistically significant differences. At the dose administered in the experimental model used, H. perforatum does not seem to be toxic to the mother.

Efeitos das drogas anti-retrovirais sobre o metabolismo glicídico e células de Langerhans de pâncreas de ratas Wistar prenhes

OBJECTIVE: to assess the action of antiretroviral drugs on glycid metabolism and on the pancreas of pregnant Wistar rats. METHODS: adult pregnant Wistar rats weighing 200-230g were used. Azidothymidine, lamivudine and nelfinavir were administered to the animals at doses 10 times higher than those administered to pregnant women. The animals were divided into seven groups of 10 animals, including a control group. The animals were sacrificed on the 21st day of pregnancy and glycemia, insulinemia, glucagonemia, free fatty acids (FFA) and hepatic glycogen were measured. Direct counts of the number of immunohistochemically labeled insulin- and glucagon-producing cells were used to determine pancreatic damage. Data were analyzed statistically by the Student's t-test comparing each treated group with the control group. RESULTS: increased serum glucagon (control group: 88.2 pg/ml; treated groups: 99.7-120.7 pg/ml) and reduced insulin (control group: 6.2 mIU/ml; treated groups: 2.1-2.7 mIU/ml) were observed in all groups treated with antiretroviral drugs after 21 days of pregnancy. There was no significant difference between the experimental groups and the control in glycemia, plasma FFA or hepatic glycogen. Also, there was no significant difference in number of insulin- and glucagon-producing cells between the treated groups and the control. CONCLUSION: treatment of noninfected rats with antiretroviral drugs during pregnancy altered maternal glycid metabolism causing insulin decrease and glucagon elevation, with normal glycemia and unchanged number of pancreatic cells.

Fetal growth in rats treated with lapachol

Lapachol is a naphthoquinone well known for its therapeutic potential. Previous studies have shown that lapachol does not interfere with embryonic development during the pre-implantation period. However, when administered during the organogenic period at the same dose level, it induces a high fetal death incidence. To evaluate the effect of lapachol during fetogenesis, 20 pregnant Wistar rats were randomly divided into two groups: vehicle (10 mL of a 50% aqueous ethanol solution/kg body weight) and treated (100 mg of lapachol/kg body weight). Lapachol was administered from the 17th to 20th day of pregnancy. The following variables were analyzed: maternal body weight from 16th to 21st day of pregnancy, food intake from 17th to 21st day of pregnancy, clinical signs of physical discomfort, ovarian weights, implantations, resorptions and mortality indices, fetal and placenta weights, external malformations, and fetal organ weights. Results indicated that lapachol was not toxic to mothers, although it was fetotoxic leading to fetal growth retardation.

Relationship between maternal concentrations of caprine pregnancy-associated glycoprotein in Alpine goats and the number of fetuses using a homologous radioimmunoassay

The relationship between maternal caprine pregnancy-associated glycoprotein (cPAG) concentrations and fetal number was investigated in 21 nulliparous and 17 multiparous goats. Using a homologous radioimmunoassay (hm-RIA) cPAG was detected in plasma of pregnant goats from the 21st day of pregnancy. Statistical differences between goats bearing single and multiple fetuses were observed after 63 days to the end of pregnancy, except on day 133. After 126 days (3rd week pre-partum) cPAG levels began to decrease slowly in both the groups. The hm-RIA was an efficient method to describe the relationship between maternal PAG concentrations and number of fetuses in goats.

Effect of SOD-Mimetic Fe-Chlorine e6-Na on the Level of Brain Lipid Peroxide of Rat Fetal Brains Exposed to Reactive Oxygen Species Leading to Intrauterine Growth Retardation

The influence of oxidative stress in rat brain and liver on intrauterine growth retardation (IUGR) in rat fetuses was examined. Twenty pregnant Wistar rats were used. On the 15th day of pregnancy, uterine artery and vein were ligated bilaterally using a modified Wigglesworth method. On the 21st day of pregnancy, the fetuses were delivered by hysterotomy. Fetal blood was collected by cardiac puncture. Fetal brain and liver were removed for the analysis of lipid peroxide. Sham surgical operations were performed in the control rats. Within the ligated group, a superoxide dismutase mimicking substance, Fe-chlorine e6-Na (FeCNa), was injected intraperitoneally once a day from day 15 of gestation to day 20. Fetal blood, brain, and liver were stored at –70°C until analysis. Control rats received an equivalent volume of saline. In growth-retarded fetuses, both superoxide released from erythrocytes and brain lipid peroxide showed significantly higher levels, but not superoxide dismutase in erythrocytes and liver lipid peroxide. These changes were alleviated by injection of superoxide dismutase-mimicking substance, FeCNa. Rat fetuses with intrauterine growth retardation suffered from a significant oxidative stress in utero. The increase in reactive oxygen species was alleviated by an injection of FeCNa.

Histomorphometric study of cardiomyocytes of the left ventricle of pregnant albino rats

In the present study we evaluated, by light microscopy, and throughout morphometry, whether hypertrophy of cardiac striated muscular fibers of left ventricular occur in albino rat, during pregnancy. After maiting, 12 nuliparous rats were divided into four groups with three animals for each group. The female rats corresponding to each group were killed at 1st, 7th, 14th and 21st days of pregnancy. Observation, on light microscopy (H.E) had at one view, did not display any alterations during pregnancy. However, the morphometry revealed that nuclei of cardiomyocytes are augmented in volume at 14th day of pregnancy and statistically significant data show the hypertrophy. The obtained data show the existence of a dinamic and reversible process of ventricular remodelling in consequence of adaptation physiological alterations of the cardiovascular normal pregnancy.

Study of the evolution of the placenta and fetal pancreas in the pathophysiology of growth retardation intrauterine due to restricted maternal diet.

Intrauterine growth retard (IUGR) continues to be a significant perinatology problem at the end of this century. The nature of the etiologic agent, the time when the attack occurred during pregnancy and its duration affect the type of IUGR. To study the evolution of fetal pancreas and placenta between the 18th and 21st day of pregnancy in rats submitted to maternal protein-calorie restriction. Randomized controlled trial on laboratory animal. Forty-one normoglycemic pregnant Wistar rats. Rats were divided into six experimental groups according to their access to food and date of cesarean section (18th or 21st day): control with free access to food; diet restricted to 25% introduced on 1st day of pregnancy; and diet restricted to 25% after the 3rd day of pregnancy. Newborn weight, placenta weight, histopathological study (morphological histochemistry). Maternal protein-calorie malnutrition caused intrauterine growth retard (IUGR) after the 18th day of pregnancy. Dietary restriction did not interfere with the morphology of the fetal pancreas and the immunohistochemical study of the placenta showed that glycogen stores were decreased between the 18th and 21st day in the control group and in a diet restricted to 25% from the first day of pregnancy. Dietary restriction after the 3rd day of pregnancy led to low placental glycogen concentrations on the 18th day and disappearance on the 21st day. The pathophysiology of IUGR due to maternal protein-calorie restriction in rats is related to lower placental weight and low placental glycogen stores.

Estudo Longitudinal, Bioquímico e Histoquímico, de Placentas de Ratas Diabéticas: Relação com a Macrossomia e o Retardo de Crescimento Intra-uterino

Objetivo: o estudo longitudinal, entre o 18o e o 21o dias de prenhez, das alteracoes bioquimicas e histoquimicas das placentas de ratas diabeticas, cujos fetos tiveram macrossomia e retardo de crescimento intra-uterino (CIUR). Material e Metodo: usando modelo experimental em ratas, foram estudados 3 grupos: controle, diabete moderado e grave. A prenhez foi resolvida por cesarea no 18o ou no 21o dia. Compararam-se as glicemias materna e fetal; a incidencia de recem-nascidos (RN) de peso pequeno (PIP), adequado (AIP) e grande (GIP) para tempo de prenhez; peso, indice e conteudo de DNA, RNA e proteinas placentarios e quantidade de glicogenio na superficie de trocas materno-fetais. Resultados: no diabete moderado houve maior proporcao de RN-GIP com placentas ricas em DNA e diminuicao progressiva de glicogenio em suas membranas no final da prenhez. No diabete grave houve predominio de RN-GIP e as placentas exibiram menor conteudo de DNA, sintese aumentada de RNA e tendencia a maior producao proteica, com manutencao dos depositos de glicogenio. Conclusoes: concluiu-se que, entre o 18o e o 21o dias, os desvios do crescimento fetal no diabete materno, moderado e grave relacionam-se a alteracoes placentarias distintas. No moderado ha apenas hiperplasia celular, com desaparecimento do glicogenio no final da prenhez. No grave, a superficie de trocas materno-fetais e mais espessada e, alem de hiperplasia, ha hipertrofia das celulas, com manutencao dos estoques placentarios de glicogenio.

IN VIVO ESTIMATION OF CHANGES IN BODY COMPOSITION OF RABBIT DOES DURING PREGNANCY USING THE TOBEC METHOD

In the present experiment the TOBEC method was used to follow the changes in body composition of rabbit does during their first pregnancy. To determine the water, fat and protein content of the body in living animals regression equations were created using the E-value (measured by TOBEC) and the live weight as independent variables. The accuracy of these equations was medium in the case of water and fat (r=0.63 and 0.56), and low in the case of protein (r=0.16). The estimated fat content of pregnant does increased up to the 21st day of pregnancy and decreased thereafter. In the control does an increase of fat was observed throughout the experimental period. The estimated fat content differed significantly (p<0.001) between pregnant and control does at the end of the experiment.

Influence of stress of a maternal organism on the turnover of catecholamines in the brain of early postnatal rats

Effects of prenatal stress (daily 1-h-long immobilization of pregnant females at the 15th–21st days of pregnancy) on the formation of sex-related dimorphism of the turnover of noradrenaline (NA) and dopamine (DA) in the preoptic area (POA) of the brain and mediobasal hypothalamus (MBH) were studied in 10-day-old rats. Sex-related differences of the turnover of a functional NA pool in the POA and DA pool in the MBH were demonstrated in intact control rats: a higher rate of the monoamine turnover was observed in males. Prenatal stress abolished these sex-related differences and, at the same time, induced such differences in the DA turnover in the POA. It is supposed that prenatal stress-evoked early modifications of sex-related dimorphism of the catecholamine turnover in the brain can result in the development of remote disturbances in the neuroendocrine control of reproduction and adaptation.

Embryotoxicity and teratogenicity of trichlorphon on wistar rats

Abstract The effects of trichlorphon on the fertility and embryotoxicity/teratogenicity of male and female rats treated during spermatogenesis and ovogenesis with water solutions of technical grade trichlorphon (10, 95, or 165 mg/kg/day) were studied. All animals were fed a commercial diet and water ad libitum, and sacrificed at the 21st day of pregnancy. Half the fetuses were examined macroscopically [1] and the remaining fetuses prepared for skeletal examination [2, 3]. High embryotoxic effects were found at doses of 165 mg/kg, but not at 95 or 10 mg/kg. The fertility index (F.I.) at 95 and 165 mg/kg was 25% lower than the F.I. for the control animals which were treated with water only. For animals dosed at 10 mg/kg, the F.I. was 10% lower than the control animals. The embryotoxic and fetus toxic effects of trichlorphon increased with dose.

Effects of kinin blockade on the blood pressure of salt-loaded pregnant rats.

We evaluated whether chronic inhibition of bradykinin B2 receptors by the long-acting antagonist D-Arg, [Hyp3, Thi5,D-Tic7,Oic8]-bradykinin (Hoe 140) affects blood pressure of salt-loaded pregnant rats. Pairs of rats fed a high sodium diet (0.84 mmol sodium per gram chow) were mated at 14 weeks of age. Infusion of vehicle or Hoe 140 (300 nmol/d per kilogram body weight) was performed throughout each dam's pregnancy by use of an Alzet osmotic pump implanted in the abdominal cavity. In both groups, no significant change in systolic pressure (tail-cuff plethysmography) or renal blood flow (Doppler flow-meter) was observed from that in the unmated state to that at midterm pregnancy. In the control group, systolic pressure decreased at the 21st day of pregnancy (from 126 +/- 2 to 97 +/- 2 mm Hg, P < .01), and renal blood flow increased (from 6.1 +/- 0.1 to 7.5 +/- 0.2 kHz, P < .01). These changes were nullified by the administration of Hoe 140 (systolic pressure changing from 124 +/- 2 to 118 +/- 4 mm Hg, P = NS; renal blood flow changing from 6.3 +/- 0.2 to 6.2 +/- 0.1 kHz, P = NS). In the group given Hoe 140, placental weight was greater (0.50 +/- 0.01 versus 0.43 +/- 0.01 g in controls, P < .01) and the fetal/placental weight ratio was reduced (4.53 +/- 0.09 versus 5.31 +/- 0.17 in controls, P < .01).(ABSTRACT TRUNCATED AT 250 WORDS)

Changes in experimental anxiety during pregnancy and lactation

The animals' reactivity and the levels of experimental anxiety during pregnancy and lactation in female rats were studied using the burying behavior test. The three main parameters analyzed in this test were: the cumulative burying behavior, the burying behavior latency, and the number of shocks necessary for displaying the behavior. The burying behavior was studied at the 7th, 14th, and 21st days of pregnancy and lactation. An additional group tested 12 h after parturition was also included. Simultaneously, in all animals, the ambulatory behavior was evaluated. All results were compared with those obtained in a control group of ovariectomized females. At the end of pregnancy a clear increase in burying behavior latency accompanied by a decrease in cumulative burying behavior was observed. Similarly, a clear reduction in burying behavior immediately after parturition was found. The number of shocks necessary for displaying the burying behavior were not modified along pregnancy and lactation with the exception of a clear decrease for the 7th lactation day. Changes in locomotor activity were observed at pregnancy, but not along lactation. These changes do not account for the reduction in burying behavior observed at the 14th gestation day. Data related to the reduction in burying behavior observed during gestation are discussed on the possible participation of progestins, while those found during lactation are discussed on the bases of the variations in serotonin and β-endorphins that normally occur during this period.

Cardiovascular and pulmonary effects of betamethasone during midtrimester on fetal rats.

In order to elucidate the effects of corticosteroids on fetal hearts during midtrimester, pregnant rats were injected with a daily dose of betamethasone (1 mg/kg) from the 12th day through the 17th day of pregnancy. The fetal cardiovascular and pulmonary systems were studied on the 21st day of pregnancy (term). The treated fetuses showed the following signs of hydrops fetalis: retarded growth, pale, edematous skin, and decreased movement. The thymus and lung displayed prominent hypoplasia. The morphometry of the treated fetuses revealed: decreased right ventricle mass by 37% and decreased left ventricle mass by 29%. We concluded betamethasone had a significant effect on the developing fetal cardiovascular system, inducing hydrops fetalis. Additionally, beta-methasone caused hypoplasia of the thymus and lung.

Mon 0900 Chemical paralyzation as a potential risk factor for the development of hypothermia in the trauma patient transported from the scene by helicopter

Pregnant rats were kept at a simulated altitude hypoxia (5000 m = pO2 11.38 kPa) for eight hours every day from the 16th to 21st day of pregnancy. The heart musculature of the left ventricle of newborn male rats underwent electron microscopic qualitative and morphometric quantitative examinations on the 2nd, 5th, 11th and 22nd day.—Prenatal hypoxia leads to delayed development of the heart. The reduced weight on the 2nd day compared with that of control animals is compensated on the 22nd day.—Prenatal hypoxia causes matrix disintegration and cristolysis of the mitochondria. Volume density, which is lower on the 2nd day (0.24 : 0.29 (control animals)), reaches that of the controls by the 22nd day. But the specific surface density of the cristae mitochondriales is markedly higher in the animals subjected to hypoxia (2nd day 31.0 : 20.6; 22nd day 44.0 : 38.1).—Prenatal hypoxia causes an increase, in the postnatal period, in the autophagocytosis processes, which normally already exist in the heart musculature; this is recognizable by an increase in the volume density of the autophagic vacuoles (2nd day 0.0049 : 0.0034; 22nd day 0.0098 : 0.0045).The changes observed are regarded as reversible, i. e. as adaptive processes.

Increase in uterine prostaglandin E 2, F 2α, prostacyclin and stability in thromboxane A 2 production during late pregnancy in streptozotocin-induced diabetic rats

This experiment was conducted to determine the effect of diabetes on uterine prostanoids production in near-term rats. The incidence of an insulin therapy was also studied. On the 21st day of pregnancy, uterine PGE2, PGF2 alpha and PGI2 levels showed a significant increase (respectively p<0.05, p<0.01 and p<0.05 in diabetic rats compared to controls whereas TxA2 production remained unchanged. The insulin therapy restored PGE2 levels, the most potent stimulatory factor of the myometrial fiber at control values, whereas it enhanced significantly PGI2 concentrations (p<0.05) and has no effect on PGF2 alpha production; TxA2 levels remaining always unchanged. It is suggested that the increase in uterine protanoids production during diabetes could induced a myometrial hypertonicity and play a role in the disturbance of the fetal development. The maintenance of PGE2 levels to control values by the insulin therapy might contribute to a normal delivery.

Fetal Heart Malformations in Experimental Hyperphenylalaninemia in Pregnant Rats

Abstract Sprague‐Dawley rats were given L‐phenylalanine intraperitoneally from the 8th to 11th day of pregnancy. The hearts of the fetuses were examined on the 21st day of pregnancy. We found that the group given the higher doses of L‐phenylalanine had significantly more heart defects than the group given the lower dose and the controls. Ventricular septal defect was found in 80 % of the fetuses with congenital deformities of the heart. [14C] Leucine uptake by the embryos was significantly lower in the group loaded with L‐phenylalanine than in the controls.The activity of thymidine kinase, one of the rate‐limiting enzymes in DNA synthesis, was significantly lower in the brain and heart tissues of the young rats loaded with L‐phenylalanine than in the controls.Thus, when blood levels of phenylalanine are high in early pregnancy, an amino acid imbalance in the embryo occurs during fetal organogenesis. Also, thymidine kinase decreases, which may hinder DNA synthesis. Both of these mechanisms seem to be involved in the higher incidence of fetal heart malformations in maternal phenylketonuria.