21st Day Of Pregnancy Research Articles

P-glycoprotein functional activity in «soviet chinchilla» rabbits during pregnancy

P-glycoprotein (Pgp, ABCB1-protein) is a membrane transporter protein that plays the key role in pharmacokinetics of drugs with a broad spectrum of action. Substrates of this transporter are some medical drugs (antibacterial, antiretroviral, hypotensive) that are prescribed to pregnant women for long-term intake, sometimes throughout the whole gestation period.
 Aim to study the activity of Pgp on the organism level in rabbits of Soviet Chinchilla breed in pregnancy.
 Materials and Methods. The study was performed on 21 Soviet Chinchilla female rabbits (3000-3500 g). The animals were divided into 3 series. The first series (n=6) included rabbits with 7 days of pregnancy; the second series (n=5) - animals with 14 days of pregnancy; the third series (n=10) - rabbits with 21 days of pregnancy. 7 Days before the study and in the indicated gestation periods, functional activity of Pgp was assessed by the pharmacokinetics of marker transporter substrate – fexofenadine, after its single oral introduction (67.5 mg/kg). Besides, serum concentrations of progesterone, estradiol, testosterone and prolactin were determined by radio immune method
 Results. In all the studied gestational periods, serum concentrations of estradiol, testosterone and prolactin did not significantly differ from those before pregnancy, but the level of progesterone in blood serum was significantly elevated above the norm. On the 7th day of pregnancy pharmacokinetic parameters of fexofenadine did not show any reliable changes as compared to the initial va-lues. On the 14th day of pregnancy a reliable increase in Cmax, AUC0-t, T1/2 of fexofenadine was noted as compared to the parameters before pregnancy, which indicates a decrease in Pgp functional activity on the organism level. On the 21st day of pregnancy Cmax of fexofenadine remained elevated. Other pharmacokinetic parameters of fexofenadine did not show reliable changes. Conclusion. Reduction in Pgp functional activity, determined by the pharmacokinetics of its marker substrate (fexofenadine), was noted in rabbits of Soviet Chinchilla breed on the 14th and 21st days of pregnancy with the underlying significant increase in progesterone level.

The effects of apelin on myometrium contractions in pregnant rats

Apelin, which is a new hormone, is secreted especially in the brain by hypothalamus as well as by many other organs like the stomach, fat tissue, and the heart. For apelin, whose possible effects on many bodily functions like the endocrine system, cardiovascular system and metabolic activities are still under investigation, the reproductive system is also an important target area. The purpose of the present study was to investigate the effects of plasma apelin levels in rats that were in diestrus, pregnancy and lactation periods, and to examine its possible effects on myometrium contractions of pregnant rats and non-pregnant rats that were in diestrus period. The plasma apelin concentrations in female adult Wistar rats were determined with the ELISA method in the diestrus period, and on the 12th, 18th, and 21st days of the pregnancy, and on the 2nd and 10th days of lactation (n=7 for each group). In addition, the effect of apelin at 0.01, 0.1, 1 and 10 μM doses on isometric contractions in the rat uterus on the 21st day of pregnancy and in diestrus period was tested by using isolated organ bath. This protocol was repeated under conditions that were pre-treated with protein kinase C inhibitor in calcium-free medium, and the possible effect of apelin on contractions and the mechanisms that might mediate this effect were investigated. When plasma apelin levels were compared with the rats in diestrus period, the apelin concentrations in the 21-day pregnancy group were high at a significant level (p<0.05); and low at a significant level in the 2-day lactation group (p<0.05). In myometrium contraction trials, it was observed that apelin induced the contractions. Apelin increased the frequency of the myometrium contractions at a significant level when applied at 1 μM and 10 μM concentrations (p<0.05 and p<0.001). Only after the apelin application at 10 μM concentration did the amplitude of the contractions increase at a significant level (p<0.01). In the myometrium of the rats that were on the 21st day of pregnancy, the frequency of the contractions was statistically significant at 0.1 μM, 1 μM and 10 μM doses (p<0.01). In addition, the amplitude of the contractions increased at a statistically significant level at 1 μM and 10 μM dose application (p<0.05 and p<0.01, respectively). The apelin application induced the contractions in calcium-free medium. When apelin was applied after the pre-application with protein kinase C inhibitor, no contractions were observed. The present study showed that apelin levels were increased at the end of pregnancy in rats, and the hormone induced the uterus contractions. This effect does not occur with protein kinase C inhibitor and in calcium-free medium, which shows that protein kinase C pathway might play a role in these mechanism. These findings show that apelin might be an endogenous peptide that plays a role on uterine contractions at birth in rats.

Amniotic Membrane-Coated Polypropylene Mesh for the Repair of Incisional Hernia: An Experimental Study In a Rat Model of Abdominal Wall Defect

Background: Incisional hernia repairs are among common abdominal wall surgeries, can be primarily required or being reconstructed using a synthetic or biological material. Objectives: This study aimed at evaluating intra-abdominal adhesions and incisional site healing after the repair of the abdominal wall by fresh amniotic membrane-coated polypropylene mesh in comparison to only polypropylene mesh in an experimental rat study. Methods: The study protocol was approved by the Cumhuriyet University Institutional Ethics Committee for Animal Experiments (Sivas-Turkiye, date 24/06/2015). Sixteen pregnant female Wistar-Albino rats (mean weight, 275 g) were anesthetized on the 21st day of pregnancy, and a 1-cm area of the abdominal wall was excised. The pregnancy was terminated, emerging amniotic membranes were dissected, and eight pieces of the 1-cm2 polypropylene mesh were coated with these amniotic membranes without using any suture or adhesive. The polypropylene meshes were sutured on the abdominal wall of eight rats (control group), selected by simple random sampling. For the remaining eight rats, the same procedure was applied with the amniotic membrane-coated polypropylene meshes (experimental group). On the 28th postoperative day, the anterior abdominal wall was opened, and intra-abdominal adhesions were assessed macroscopically by Nair’s adhesion scoring system. Strip-shaped biopsy samples were taken from incision lines for histopathological examination. Results: The experimental group had significantly less intra-abdominal adhesions (i.e., Nair’s score of 2 to 4) compared to the control group (two and six rats, respectively; P = 0.046), and had significantly lower mean score for polymorphonuclear leukocyte infiltration (P = 0.039), hyperemia (P = 0.039), and epithelialization (P = 0.039). The score for the increase in connective tissue (P = 0.018) was significantly higher in the experimental group, and the scores for edema (P = 0.590) and macrophage infiltration (P = 0.590) were similar between the two groups. Conclusions: The use of polypropylene mesh coated with fresh amniotic membrane provides the advantage of decreasing postoperative intra-abdominal adhesions along with less inflammation and higher epithelialization after abdominal wall repair surgery.

Prenatal stress-induced impairments of cognitive flexibility and bidirectional synaptic plasticity are possibly associated with autophagy in adolescent male-offspring

Prenatal stress (PS) brings numerous outcomes on offspring, including anxiety, depression-like behavior and other cognitive disorder. In this study, a rat model of PS was established by using restraint stress for 45min three times per day from the 15th to 21st day of pregnancy. Behavioral tests, including open field test (OPT), elevated plus-maze (EPM) and Morris water-maze (MWM), were performed in adolescent male-offspring. The bidirectional synaptic plasticity, including long-term potential (LTP) and depotentiation (DEP), from the hippocampal Schaffer collaterals to CA1 region was subsequently measured. Furthermore, Western blot assay, immunofluorescence staining and hematoxylin-eosin (HE) staining were employed. The MWM test showed that the cognitive flexibility was remarkably damaged in PS offspring. Meanwhile, PS considerably aggravated the anxiety and depression-like behavior in OPT and EPM. Both LTP and DEP were significantly inhibited by PS. Furthermore, PS considerably altered the expression of synaptic-related proteins NR2A, NR2B and PSD-95 in adolescent male-offspring. Interestingly, PS significantly elevated the autophagy level in the hippocampus of male-offspring. In order to investigate the role of autophagy on the negative impacts of PS in adolescent male-offspring, both in vitro and in vivo studies were performed. It was found that autophagy inhibitors significantly eliminated the alterations in gene expression induced by corticosterone. The results suggest that regulating autophagy may become a new targeted therapy to relieve the damage induced by PS in adolescent male-offspring.

Influence of caffeine administered at 45°C on bone tissue development

Caffeine is one of the world's most commonly ingested alkaloids which easily permeates the placenta. The teratogenic and embryotoxic influence of large doses of caffeine has been established in many experimental studies on animals. The objective of this work was to assess the influence of caffeine, administered at 45 °C, on the development of the bone tissue of rats, with particular reference to elemental bone composition using an X-ray microprobe. The research was conducted on white rats of the Wistar strain. The fertilized females were divided into two groups: an Experimental Group (Group E) and a Control Group (Group C). The females in Group E were given caffeine orally (at 45 °C) in 30 mg/day doses from the 8th to the 21st day of pregnancy. The females in Group C were given water at the same temperature. The fetuses were used to assess the growth and mineralization of the skeleton. A qualitative analysis of the morphology and mineralization of bones was conducted using the alcian-alizarin method. For calcium and potassium analysis, an X-ray microprobe was used. By staining the skeleton using the alcian-alizarin method, changes in 52 of Group E fetuses were observed. The frequency of the development variants in the Group E rats was statistically higher, compared with Group C. Receiving caffeine at a higher temperature may result in different pharmacodynamics and significantly change tolerance to it. In Group E, a significant decrease in the calcium level, as well as an increase in the potassium level, was observed. The X-ray microprobe can be a perfect complement to the methods which enable determination of the mineralization of osseous tissue.

Influence of chronic prenatal hypoxia on the specialized contact apparatus of rat heart ventricles during ontogeny

Background. During prenatal development embryonic mammalian heart undergoes deep dynamic changes due to size, structure and functions. Pathological intrauterine hypoxia influences fetal development generally and cardiogeny particularly, it affects the structure and function of the heart muscle and can lead to a variety of cardiovascular abnormalities and congenital heart defects. It is known that as a result of chronic intrauterine hypoxia during the stages of prenatal ontogeny specialized intercellular apparatus of cardiomyocytes is damaged, which plays a role not only in the mechanical connections of the cardiomyocytes, but also in the electric cooperatives, metabolic conversions, the homeostasis of the ionic balance and transport morphogenetic signaling molecules which are involved into the mechanisms of cardiogeny. It contributes to the development of diseases that may be associated with impaired local distribution of specialized intercellular junctions, and manifests as arrhythmias and cardiac conduction.Objective. To determine the effects of chronic prenatal hypoxia on the structure and distribution of specialized intercellular junctions of typical cardiomyocytes in the rat ventricular myocardium at the stages of prenatal ontogeny and to evaluate morphometric parameters of intercalated disks in the postnatal period.Materials and methods. White rats were used as a material. Intrauterine hypoxia was modelled by intraperitoneal injection of sodium nitrite from 10th to 21st day of pregnancy. Hearts were investigated by the transmission electron microscopy during the stages of prenatal and postnatal ontogeny and in adult animals. Morphometric and statistical methods were applied. Pairwise comparisons between means of different groups were performed using Student’s t-test where, for each couple of normally distributed populations, the null hypothesis that the means are equal was verified.Results. The average length of desmosomes on the 20th day of embryogenesis is lower in experimental group by 31,3% (p <0,05) in the left ventricle and 30,8% (p <0,05) in the right ventricle than parameters in the control group. The slowdown of growth of the profile length density of fascia adhaerens in the myocardium increases on the 20th day of cardiogeny and it was lower by 32,9% (p <0,05) in the left ventricle and 37,3% (p <0,05) in the right ventricle as compared with the control. During normal prenatal cardiogeny ventricular level of communicative contacts in cardiomyocytes respectably increases and shows a significant increase in nexus mean length from 14th to 18th day of embryogenesis by 75,5% in the control and insignificant increase in the left ventricle in experimental group – 23,6%. The increase in value of the convolution index of intercalated disc of rats with hypoxic myocardial damage as compared with the corresponding value in the neonatal period was 85,4% (p <0,05) in the left ventricle and 52,3% (p <0,05) in the right ventricle.Conclusion. It was established that the alterative influence of intrauterine hypoxia factor is associated with the formation delay of the mechanical and electrical contacts between the contractive cardiomyocytes of the left and right ventricles of rat heart at the stages of prenatal ontogeny. The increasing complexity of the geometry of the intercalated disc is characterized by slower growth of convolution index.

The temperature of caffeine administered during pregnancy and foetal morphometric parameters

Background: Caffeine is one of the most frequently ingested (at various temperatures) xenobiotics by people. A number of studies have confirmed the negative effect of high doses of caffeine ingested during pregnancy both for the mother and the developing foetus. The aim of this study was to evaluate the relationship between caffeine’s toxicity on development and the administered solution’stemperature. Materials and methods: The research was conducted on rats. The fertilised females were randomly divided into two main groups: an experimental (E) and a control group (C). The experimental groups received caffeine (30 mg/day) in10 (E1), 25 (E2) and 45°C (E3). The females in the control group were given water at the same temperature (C1, C2 and C3). On the 21st day of pregnancy, the pregnant females were killed by decapitation using a specially prepared laboratory guillotine and were assessed morphometric parameters of foetuses. Results and Conclusions: Based on this work showed that: the embryotoxic effect of caffeine was only confined to a reduction in the number of offspring; the greatest changes in the morphometric parameters occurred in foetuses whose mothers received caffeine at 10°C; in the control groups, the greatest changes were observed in foetuses whose mothers were given water at 10°C during pregnancy.

Placental oxidative stress and decreased global DNA methylation are corrected by copper in the Cohen diabetic rat

Fetal Growth Restriction (FGR) is a leading cause for long term morbidity. The Cohen diabetic sensitive rats (CDs), originating from Wistar, develop overt diabetes when fed high sucrose low copper diet (HSD) while the original outbred Sabra strain do not. HSD induced FGR and fetal oxidative stress, more prominent in the CDs, that was alleviated more effectively by copper than by the anti-oxidant vitamins C and E. Our aim was to evaluate the impact of copper or the anti-oxidant Tempol on placental size, protein content, oxidative stress, apoptosis and total DNA methylation. Animals were mated following one month of HSD or regular chow diet and supplemented throughout pregnancy with either 0, 1 or 2ppm of copper sulfate or Tempol in their drinking water. Placental weight on the 21st day of pregnancy decreased in dams fed HSD and improved upon copper supplementation. Placental/fetal weight ratio increased among the CDs. Protein content decreased in Sabra but increased in CDs fed HSD. Oxidative stress biochemical markers improved upon copper supplementation; immunohistochemistry for oxidative stress markers was similar between strains and diets. Caspase 3 was positive in more placentae of dams fed HSD than those fed RD. Placental global DNA methylation was decreased only among the CDs dams fed HSD. We conclude that FGR in this model is associated with smaller placentae, reduced DNA placental methylation, and increased oxidative stress that normalized with copper supplementation. DNA hypomethylation makes our model a unique method for investigating genes associated with growth, oxidative stress, hypoxia and copper.

Validation of the gastroschisis experimental model and the influence of the mother's diet enriched with glutamine in the fetal morphology

To validate the gastroschisis experimental model in female rats and the effects on the glutamine fetal morphology during pregnancy. Twelve pregnant rats Wistar were separated in two groups: Group I (n = 6 rats, 71 fetuses) took glutamine and Group II (n = 6 rats, 75 fetuses) took isocaloric supplementation. At the 18th day of pregnancy, female rats were taken to hysterotomy and the fetuses which were selected for the act of gastroschisis were partially removed from the womb and by the laparotomy technique, the exclusion of the intestine was done. After that, fetuses were put in the womb cavity again and the rats' abdomen sutured. At the 21st day of pregnancy, date before delivery, by C-section ordinary animals and the ones with gastroschisis were removed and studied separately. The morphometrical parameters studied were the body weight (PC); the intestine weight (PI); the intestine length (CI) and its relations (PI/PC, PI/CI e PC-PI). The intestine weight (PI) and the intestine length (CI) were different in fetuses with gastroschisis (p<0.05), however no difference between the groups regarding supplementation with glutamine. The gastroschisis experimental model is valid and reproducible. The nutritional therapy with glutamine did not change the morphometrical parameters.

Ação da melatonina sobre a dinâmica sanguínea de ratas prenhes e sobre a histogênese do baço e do timo da prole

Investigou-se a influência da melatonina sobre o hemograma de ratas prenhes e dos filhotes e sobre a histogênese e morfometria do baço e do timo dos filhotes. A melatonina foi administrada na dose 0,5mg/kg de peso corporal, dissolvida em 0,1mL de etanol e diluída em 0,3mL de solução salina. Para análise do hematócrito, contagem total de hemácias e contagem total e diferencial dos leucócitos, amostras de sangue foram coletadas no sétimo, 14ºe 21ºdias de prenhez e aos 10 dias de nascimento dos filhotes. Cortes histológicos do baço e do timo da prole foram utilizados para histoquímica e morfometria. A ausência da melatonina promoveu alterações no hemograma apenas no terço final da gestação, sem interferir no hemograma dos filhotes, e induziu modificações morfológicas e morfométricas no timo e no baço nos primeiros dias de vida dos filhotes. Concluiu-se que a melatonina materna é importante para a modulação do hemograma em ratas prenhes e para o desenvolvimento normal do baço e do timo dos filhotes.

Use of X-ray microprobe to diagnose bone tissue demineralization after caffeine administration

Caffeine is a methylxanthine which permeates the placenta. In studies on animals, it has been shown to produce teratogenic and embryotoxic effects in large doses. The objective of this study was to assess the influence of caffeine on the development of bone tissue, with particular reference to elemental bone composition using an X-ray microprobe. The research was conducted on rats. The fertilized females were randomly divided into an experimental and a control group. The experimental group was given caffeine orally in 30 mg/day doses from the 8th to the 21st day of pregnancy, while the control group was given water. The fetuses were used to assess the growth and mineralization of the skeleton. On the basis of double dyeing, a qualitative analysis of the bone morphology and mineralization was conducted. For calcium and potassium analysis, an X-ray microprobe was used. In 67 fetuses from the experimental group, changes in skeleton staining with the alcian-alizarin method were noticed. The frequency of the development of variants in the experimental group was statistically higher. In the experimental group,a significant decrease in the calcium level, as well as an increase in the potassium level, was observed. The X-ray microprobe's undoubted advantage is that is offers a quick qualitative and quantitative analysis of the elemental composition of the examined samples. Employing this new technique may furnish us with new capabilities when investigating the essence of the pathology process.

Efeito da administração pré-natal da dexametasona em ratas sobre os perfis glicídicos e hematológicos materno e da prole

Avaliou-se o efeito da administração de dexametasona no início e no meio da gestação de ratas, sobre os perfis glicídicos e hematológicos materno e da prole. Os animais foram submetidos aos seguintes tratamentos: dexametasona do primeiro ao sétimo dia e placebo do oitavo ao 14º dia; placebo do primeiro ao sétimo dia e dexametasona do oitavo ao 14º dia; dexametasona do primeiro ao 14º dia e placebo do primeiro ao 14º dia de gestação. A dexametasona foi administrada por via intraperitoneal, na dose de 0,8mg/kg. Foram coletadas amostras de sangue no sétimo, 14º e 21º dias de gestação, e de sangue e tecido hepático da prole no quinto, 10º e 15º dias pós-natal. Para a verificação das reservas de glicogênio hepático da prole, cortes histológicos foram corados pelo ácido periódico de Schiff. Os resultados apontam para um efeito tempo-dependente da administração de dexametasona durante a gestação, levando a alterações temporais distintas na hematologia e na concentração plasmática de carboidratos nas matrizes e na prole.

Evaluation of cell proliferation and apoptosis in placentas of rats with severe diabetes

The aim of this work was to analyze the cell proliferation and apoptosis indexes on the 18th and 21st days of pregnancy of diabetic rats and to correlate with maternal glycemia and perinatal outcomes. Placentas from 20 Wistar rats were collected and divided into four experimental groups: control and diabetic of 18 and 21 days of pregnancy. The cell proliferation was analyzed using the PCNA expression and apoptosis by the TUNEL method. It was observed that PCNA and TUNEL indexes decreased from day 18 to 21 of pregnancy in the placentas of diabetic rats and these values were lower than control groups. Diabetic dams presented higher percentage of small for pregnancy age (SPA) fetuses. However, there was no difference between the PCNA and TUNEL indexes in SPA and N-SPA fetuses in all the groups and these indexes were not correlated to maternal glycemic. Thus, placental cell proliferation and apoptosis did not interfere in the intrauterine growth restriction.

Evolution of Elevated Plus Maze Test (Anxiety) and Porsolt Swimming Test (Depression) Parameters in Wistar Female Rats Treated with Low Dose of Toluene from the 4th to 14th day of Pregnancy: Implication of Progesterone to Protect GABAergic route

Background: The endocrinal and physiological consequences, following the sub chronic administration of toluene (Tol), were examined in pregnant Wistar rats. Methods: A quarter of lethal dose concentration (LD50) of toluene was injected daily in IP to pregnant rats between the 4th and the 14th day of pregnancy. Virgin female rats were also used as a basis of comparison and obey to the same experimental protocol. Blood samples and recordings of sequences of behavior in elevated plus maze was made in 7th, 14th and 21st day of pregnancy. The measurement of the serum levels of progesterone were carried out at the 7th day of gestation (3rd day of treatment), the 14th day (last day of treatment) and one week after delivery (14th day after discontinuation of therapy). After delivery, which occurs at the 21st day, we tested the effectiveness of a GABAergique agonist, the clonazepam, during the forced swimming test. Results: Our results showed that the application of toluene neurotoxic stress during 10 days caused endocrine (plasma progesterone) and behavior (anxiety) disruption that appear to be irreversible in virgin female rats treated with toluene. For cons, the same treatment associated with pregnancy revealed a healing effect 14 days after stopping treatment. Inefficiency of both clonazepam and toluene treatment in virgin female rats was observed. This treatment was effective in pregnant rats treated only with toluene. Conclusion: Pregnancy appears to play a moderating effect on harmfulness and neurotoxicity of toluene, by protecting GABAergic route. Progesterone, as a neuroactif steroid, plays an important role in this protection

Effect of alcohol on the endocrine glands of pregnant Wistar rats

Background: An investigation was conducted to determine the effect of alcohol on some endocrine glands of pregnant Wistar rats.Methods: Thirty female Wistar rats divided into 2 groups of 15 each were used. Group 1 served as control while group 2 was exposed to 2g/kg body weight 30% ethanol during pregnancy. At the 7th, 14th and 21st days of pregnancy, 5 pregnant rats respectively, were selected from each group and sacrificed after determination of their body weights. After the sacrifice, some endocrine glands: pituitary, adrenal, ovary, thyroid, pancreas and placenta were dissected out, observed grossly and weighed. Relativeweights (%) of the organs were also determined.Results: The results of the investigation showed that alcohol consumption during pregnancy increased the absolute and relative weights of adrenal gland and placenta and decreased the absolute and relative weights of thyroid glands. However, alcohol consumption had no observable effect on the absolute and relative weights of the pituitary gland, ovary and pancreas during the three weeks of pregnancy.Conclusions: Alcohol could be mediating its effect on the fetus(es) through the effect on the adrenal and thyroid glands, and placenta of Wistar rats.

Pre-clinical validation of a vaginal cream containing copaiba oil (reproductive toxicology study)

The aims of this study was to evaluate the effects of oil-resin of Copaiba (Copaifera duckei Dwyer), aired in vaginal cream on the reproductive performance of female rats (Rattus norvegicus). To determine the components of the C. duckei oleoresin, gas chromatography coupled with mass spectrometry (CG-MS) was used, and considering the trans-caryophyllene sesquiterpene as a phytochemical marker in the oleoresin. Due to the extensive use of copaiba oleoresin in the suppository form for gynecological infections, an evaluation was carried out on the effects of copaiba oleoresin (Copaifera duckei Dwyer), delivered in a vaginal cream, on the reproductive performance of female Wistar rats. For this purpose, three groups (n=5-6/group) of female rats were treated as follows: 1--vaginal cream of copaiba oleoresin (28.6 mg/kg), 2--base vaginal cream and 3--control (physiological saline 0.9%), administered intravaginally, for 30 days before pregnancy, and from day zero to day 20 during pregnancy. Laparotomy was performed on the 21st day of pregnancy, followed by the determination of reproductive variables: number of live and dead fetuses, mass of the fetuses and placentas, number of implantations and resorptions, number of corpora lutea, pre- and post-implantation loss, and analyses of the fetuses with regard to external and internal anomalies and/or malformations (skeletal and visceral). The trans-caryophyllene present in the sample is suggested as a phytochemical marker and the results of this study demonstrate an absence of maternal toxicity and foetotoxicity embryofoetotoxicity at the dose administered, corresponding to ten times the recommended dose for use in humans. Accordingly, no significant statistical difference was observed between the treated and control groups, for the variables analyzed. Thus, it is concluded that the vaginal cream containing 2.5% copaiba oleoresin is safe during gestation, in female rats (Rattus norvegicus) of the Wistar strain.

The role of estrogen receptors, erbB receptors, vascular endothelial growth factor and its receptors, and vascular endothelial growth inhibitor in the development of the rat mammary gland

We identified the localization and distribution of cell-specific epidermal growth factor receptors (EGFRs: erbB-1, erbB-2, erbB-3, erbB-4), vascular endothelial growth factor (VEGF), VEGF receptors [VEGFRs: VEGF-R1 (flt-1), VEGF-R2 (flk-1/KDR), VEGF-R3 (flt-4)], vascular endothelial growth inhibitor (VEGI), and estrogen receptor (ER), and determined whether or not these growth factors in rat mammary glands are functional. Thirty-five adult female Spraque-Dawley rats were randomly divided into five groups, each of which were at the 7th, 14th, and 21st day of pregnancy; 7th day post-delivery; and 7th day after weaning. It was determined that erbB, VEGF and its receptors, VEGI, and ER stained at different intensities. Intense staining was observed, in particular, in erbB receptors during pregnancy and involution, and also in VEGF and its receptors during lactation, while ER stained during the last periods of pregnancy and lactation. In conclusion, the expression of erbB, VEGF and its receptors, and ER were determined at varying intensities at different sites of the mammary gland during pregnancy, lactation, and involution periods.

Study of Density of Interstitial Cells of Cajal in the Terminal Intestine of Rats with Anorectal Malformation

Intestinal constipation is one of the most commonly occurring complaints in the postoperative period after correction of anorectal malformation (ARM). An abnormal density of interstitial cells of Cajal (ICC) is one potential cause. The objective of this study was to analyze the density of ICC in the terminal intestine of fetuses of rats with anorectal anomaly induced by ethylenethiourea (ETU). The fetuses were distributed into three groups: Group A--normal fetuses obtained from pregnant female rats that did not receive ETU; Group B--fetuses with no ARM, obtained from pregnant rats that received ETU, and Group C--fetuses with ARM, obtained from pregnant rats that received ETU. ETU was administered on the 11th day of pregnancy at a dose of 125 mg/kg. The fetuses were extracted by means of laparotomy on the 21st day of pregnancy. The terminal intestine of the fetuses was removed and analyzed by immunohistochemistry to evaluate ICC. Statistically significant differences were found between groups A, B and C regarding the density of ICC. Group A presented with the highest density, followed by groups B and C. There is a lower density of ICC in the terminal intestine of rats with ARM.

Teratogenicity of Mimosa tenuiflora seeds to pregnant rats

Bone and other malformations caused by the ingestion of Mimosa tenuiflora are common in ruminants in the Brazilian semiarid. The aim of this research was to study the teratogenic effects of M. tenuiflora in Wistar rats ( Rattus novergicus). The experimental group had 15 females and was fed, from the 6th to the 21st day of pregnancy, with a ration containing 10% of M. tenuiflora seeds. The control group, with 10 females, was fed with the same ration without seeds. There were no differences in weight gains, and food and water consumption between treated and control rats. Ninety bone malformations were observed in 40 of the 101 fetuses born in the experimental group, and four malformations were observed in three of the 58 fetuses born in the control group ( p<0.05). The weight and number of ossification centers of the fetuses from the experimental group were higher than those from the control group ( p<0.05). It is concluded that the seeds of M. tenuiflora are teratogenic to rat fetuses.

Effects of prenatal stress on male offspring sexual maturity

Prenatal stimulations have been shown to have long-term effects on at reproductive activity. We evaluated the influence of the prenatal stress on the hypothalamic-pituitary-gonad (HPG) axis in male offsprings from mothers with high number of offsprings per litter (HNL) and low number of offsprings per litter (LNL) after hypothesizing that the number of offsprings per litter may modify the effect of the prenatal stress on the HPG of adult offsprings. Pregnant Wistar rats were used for this study. Immobilization (IMO) stress was used, 30 min, 3 times per week, from the 5th to 21st day of pregnancy. The weight of adrenal and gonads, and the corticosterone (COR), testosterone (TES) and luteinizing hormone (LH) plasmatic levels were analyzed in the male offspring at 30, 45 and 70 days of age. The offspring males coming from LNL showed a decrease in testicle weight and TES levels, without changes in the plasmatic LH levels. However, the offspring of HNL showed a decrease of LH levels. It is possible to conclude that in LNL prenatal stress would produce alterations to gonadal level, while in HNL the effect of stress would be evident at pituitary level.