Rat Fetal Development Research Articles

Effects of 'dedo de moça' pepper extract administration on wistar rat pregnancy and fetal development

Introduction: The dedo de moça pepper is spicy due to capsaicin, which activates receptors in sensory neurons, generating a burning sensation. Studies suggest that capsaicin-sensitive neurons, by releasing neuropeptides, may affect uterine contraction. Objective: To evaluate the effect of chronic administration of capsaicin extract (Cps) during pregnancy in Wistar rats and their fetuses. Methodology: Pregnant female Wistar rats were divided into 4 groups (n = 5/group): Group I – Negative Control; Group II – Positive Control; Group III – Cps 1 – 0.25 mL; Group IV – Cps 2 – 0.5 mL. Exposure was initiated after embryo implantation (3rd day of pregnancy) until full term (20th day of pregnancy), with gavage performed three times per week. Results: On the 20th day, pregnant rats were euthanized, and outcomes evaluated included weight gain, placental morphology, reproductive capacity, and embryonic/fetal development. Ingestion of capsaicin extract resulted in negative impacts on fetal intrauterine growth parameters and placental alterations, with deposition of atypical hyaline material for gestational age and changes in vascular structures. Conclusion: The results indicate that capsaicin extract interfered with placental exchange, leading to intrauterine growth restriction of the fetuses.

Effect of SpikoGen subunit vaccine administration during pregnancy on fetal development of rats.

The effects of coronavirus disease 2019 vaccination on fertility and pregnancy have turned out to be a main topic of public attention. Inactivated or recombinant protein vaccines are a reliable and safe method but mostly suffer from weak immunogenicity just in case formulated with a suitable adjuvant. The purpose of this research was to assess the impacts of new SpikoGen subunit vaccine administration during pregnancy on organogenesis in the rat fetus, which is a novel achievement in teratogenesis studies. In the first group (G1) animals received normal saline. A dose of 25 µg of the vaccine was administered to groups of rats as follows: groups 2, 3, 4, and 5 received two doses of vaccine on different days before and after start of pregnancy. On day 21, after the caesarean process, the effects of the vaccine were estimated by morphological, skeletal, and histological studies. Administration of the SpikoGen vaccine had no significant effect on weight, head diameter, tail length, and length of the fetuses to their tail. There were no malformations, toes and legs were fully developed, and all internal organs of the fetus were completely formed. Also, there was no difference in the overall skeletal opacity and density between the control and treatment groups. The results of this study indicated no negative impacts of the vaccine administration during pregnancy on developing of fetuses in rats.

Teratogenic effect of Aesculus hippocastanum L. extract on fetal development in rats

Teratogenic effect of Aesculus hippocastanum L. extract on fetal development in rats

Effects of melamine and cyanuric acid on placental and fetal development in rats.

Melamine or cyanuric acid alone has low toxicity, but combined exposure to melamine and cyanuric acid was reported to cause unexpected toxicological effects. This study investigated the potential effects and toxic mechanism of combined exposure to melamine and cyanuric acid on placental and fetal development in rats. Exposure to melamine and cyanuric acid caused maternal toxicity manifested by increased abnormal symptoms and decreased body weight gain. Developmental toxic effects included a decrease in placental and fetal weights with increased fetal deaths and post-implantation loss. Melamine and cyanuric acid induced oxidative stress in the developing placenta and fetus. The placentas from rats treated with melamine and cyanuric acid showed shortening of the placental layers with histological changes, decreased cell proliferation, increased apoptotic changes, and decreased insulin-like growth factor (IGF)/IGF-binding proteins (IGFBPs) and placental lactogen (PL) expression levels. Fetuses from melamine- and cyanuric acid-treated dams showed increased apoptotic changes and suppressed cellular proliferation in their livers and vertebrae. Consequently, combined exposure to melamine and cyanuric acid resulted in high levels of oxidative stress and impaired placental development associated with impairment of the IGF/IGFBP and PL systems, resulting in increased apoptotic changes and reduced fetal cell proliferation.

Effects of pseudoephedrine on rat fetal bone development: evaluation by three different methods.

Pseudoephedrine (PSE) is an agent that is contained in common cold medications. The agent, which is used to treat cold and cough, is the fourth most prescribed drug group in some countries. During pregnancy, expectant mothers use PSE for colds and other reasons. One out of every four expectant mothers use PSE alone or in combination with other medicines for various reasons. This study was aimed to investigate effects of PSE on long bones development in rat during fetal growth. Pregnant rats were divided into five groups: control and four experimental groups (25mg/kg, 50mg/kg, 100mg/kg, 200mg/kg PSE). Between 1 and 20days of pregnancy, PSE was given to them by gavage. Weights and heights of fetuses isolated by cesarean on the 21st day were measured. Ossification of femur and humerus was examined by three different methods mentioned earlier. Depending on the dose increase, all morphometric data, ossification rate and bone length of the fetuses were decreased. Besides, it was determined that the amount of Calcium in the bone tissue decreased in the analyzes made with SEM-EDX Analysis. The data obtained from this study reveal that the use of PSE during pregnancy disrupts the existing balance in the bone and negatively affects ossification due to the dose increase. In conclusion, we present descriptive and novel data on the effects of PSE use during pregnancy on the bone development of rat fetal long bones.

Investigation of the Effect of Melissa officinalis L. on Fetal Development by Ultrasonography in Rats

Medicinal plants have been used to treat many diseases since prehistoric times. With the discovery of new medicinal plants, new therapeutic areas have emerged. On the other hand, the posology of these plants and indications for use during pregnancy or adolescence are still debated. The use of Melissa officinalis L. (M. Officinalis) in traditional medicine is common, but its effect on fetal development is not clear. Ultrasonographic evaluation of fetal development is critical. Unfortunately, ultrasound probe differences used in pregnancy studies in rats are confusing. Therefore, in the present study, we aimed to search both possible effects of M. officinalis on fetal development, and test the effectiveness of human breast ultrasound probes in the ultrasonographic evaluation of rat fetuses. Rats were randomly divided into Control and M. officinalis groups. M. officinalis was gavaged for 21 consecutive days 24 hours after mating. Rats in the Control group were treated with the extract of M. officinalis. Ultrasonography examination was performed with the superficial probe used in breast examination in humans. Gestational sac diameters, biparietal diameters, crown-rump lengths, and heart rates of fetuses were measured in both groups. According to our results, ultrasonographic measurements on the 15th, 17th, and 20th days of pregnancy were higher in the M. officinalis group than in the Control group. However, both groups had no statistical significance according to all measurements. As a result, it was concluded that M. officinalis extract might not have any effect on the development of rat fetuses in terms of ultrasonographic examination, whereas pregnancy can be diagnosed with human ultrasonography devices and the development of fetuses can be followed in rats.

A primary study on rat fetal development and brain-derived neurotrophic factor levels under the control of electromagnetic fields.

In previous researches, electromagnetic fields have been shown to adversely affect the behavior and biology of humans and animals; however, body growth and brain-derived neurotrophic factor levels were not evaluated. The original investigation aimed to examine whether Electromagnetic Fields (EMF) exposure had adverse effects on spatial learning and motor function in rats and if physical activity could diminish the damaging effects of EMF exposure. In this study, we measured anthropometric measurements and brain-derived neurotrophic factor (BDNF) levels in pregnant rats' offspring to determine if Wi-Fi EMF also affected their growth. These data we report for the first time in this publication. Twenty Albino-Wistar pregnant rats were divided randomly into EMF and control (CON) groups, and after delivery, 12 male fetuses were randomly selected. For assessing the body growth change of offspring beginning at delivery, then at 21 postnatal days, and finally at 56 post-natal days, the crown-rump length of the body was assessed using a digital caliper. Examining BDNF factor levels, an Enzyme-linked immunosorbent assay ELISA kit was taken. Bodyweight was recorded by digital scale. Outcomes of the anthropometric measurements demonstrated that EMF blocked body growth in rats exposed to EMF. The results of the BDNF test illustrated that the BDNF in the EMF liter group was remarkably decreased compared to the CON group. The results indicate that EMF exposure could affect BDNF levels and harm body growth in pregnant rats' offspring. The results suggest that EMF exposure could affect BDNF levels and impair body growth in pregnant rats' offspring.

Toxic effects of 70% ethanol extract of Moringa stenopetala leaf (Baker f.) Cufod. (Moringaceae) on fetus and placenta of pregnant Wistar rats

BackgroundMoringa stenopetala leaves (Baker f.) Cufod. (Moringaceae) are used as a staple food and traditional medicine for treating various diseases like malaria, hypertension, stomach pain, diabetes, elevated cholesterol, and removing the retained placenta. Its prenatal toxicity study is minimal. Thus, this study aimed to assess the toxic effects of a 70% ethanol extract of Moringa stenopetala leaf on the fetuses and placentas of pregnant Wistar rats.MethodFresh leaves of Moringa stenopetala were collected, dried at room temperature, ground to powder, and extracted using 70% ethanol. For this study, five groups of animals, each containing ten pregnant rats, were used. Groups I–III were experimental groups and treated with 250, 500, and 1000 mg/kg body weight of Moringa stenopetala leaf extract, respectively. Groups IV and V were pair-fed and ad libitum control groups. The extract was given during gestation days 6 to 12. The fetuses were recovered at day 20 of gestation and examined for the presence of developmental delays, gross external malformations, skeletal and visceral defects. Gross and histopathological changes in the placenta were also evaluated.ResultsCompared to the pair-fed control group, maternal daily food intake and weight gain were reduced in the 1000 mg/kg-treated group during the treatment and post-treatment periods. A significantly higher number of fetal resorptions was also seen in the 1000 mg/kg treatment group. The crown-rump length and fetal and placental weights were all significantly reduced in pregnant rats given 1000 mg/kg. However, there were no visible malformations in the visceral organs as well as external genitalia in all the treatment and control groups. About 40.7% of the fetuses in the 1000 mg/kg treated rats had no proximal hindlimb phalanges. In addition, light microscopic investigations of the placenta in the high-dose treated rats revealed structural changes in the decidual basalis, trophoblastic zone, and labyrinthine zones.ConclusionIn conclusion, consumption of M. stenopetala leaves at a higher dose may have toxic effects on the development of rat fetuses. At a higher dose, the plant extract increased the number of fetal resorptions, reduced the number of fetuses, decreased the fetal and placental weights, and alter the placental histopathology. Thus, it is recommended to limit the excess feeding of M. stenopetala leaves during gestation.

Maternal Dietary Carbohydrate Restriction and Mild-to-Moderate Exercise during Pregnancy Modify Aspects of Fetal Development in Rats

To determine whether acute bouts of exercise during pregnancy would predispose the fetus to increased risk if maternal dietary carbohydrate were restricted, untrained pregnant rats were randomly assigned to a 0% (low), 12% (moderate) or 60% (high) glucose diet, and either rested or exercised daily for 20 min from d 16 to term on a rodent treadmill at a mild (15.5 m/min) or moderate (24.3 m/min) intensity. A 3 ՠ3 nested factorial model with and without food intake as a covariate was employed. Both greater exercise intensity and the lower levels of dietary carbohydrate independently decreased term maternal liver and plantaris glycogen concentrations and increased plasma lactate concentrations. However, significant differences due to exercise disappeared (except for plasma lactate) with food intake controlled for in the model, indicating that energy deficits modulated these exercise effects. In contrast, for the offspring, when food intake was controlled for, a restricted level of maternal dietary carbohydrate significantly lowered fetal weight, plasma glucose and insulin concentrations and liver glycogen concentrations measured at term. Exercise alone did not reduce mean fetal weight if nested weights within a litter were used in the statistical analysis. Mild to moderate maternal exercise lowered only fetal plasma glucose concentrations and only if maternal food intake was not controlled for. These results indicate that acute exercise during pregnancy can have detrimental effects on fetal development only if dietary glucose is severely restricted. Otherwise, adequate glucose and energy in the maternal diet in untrained pregnant rats during repeated bouts of acute exercise seem to protect the fetus.

Regulation of Shh/Bmp4 Signaling Pathway by DNA Methylation in Rectal Nervous System Development of Fetal Rats with Anorectal Malformation

ObjectiveTo study the influence of gene methylation in the Shh/Bmp4 signaling pathway on the enteric nervous system in the rectum of rat embryos with anorectal malformations (ARMs). MethodsPregnant Sprague Dawley rats were divided into three groups; two groups treated with either ethylene thiourea (ETU induce ARM) or ETU+5-azacitidine (5-azaC inhibit DNA methylation) and a normal control group. The levels of DNA methyltransferases (DNMT1, DNMT3a, DNMT3b), the methylation status of the Shh gene promoter region and the expression of the key components were detected by PCR, immunohistochemistry and western blotting. ResultsThe expression of DNMTs in the rectal tissue of the ETU and ETU+5-azaC groups was higher than that of the control. The expression of DNMT1, DNMT3a and methylation level of the Shh gene promoter in the ETU group was higher than in the ETU+5-azaC group (P < 0.01). The methylation level of the Shh gene promoter was higher in the ETU+5-azaC group than in the control. The Shh and Bmp4 expression in the ETU and ETU+5-azaC groups were lower than in the control, and their expression in the ETU group was also lower than in the ETU+5-azaC group. ConclusionThe methylation status of genes in the rectum of the ARM rat model may be changed by intervention. The low methylation level of the Shh gene may promote the expression of key Shh/Bmp4 signaling pathway components.

Influence of maternal periuterine and periovarian fat on reproductive performance and fetal growth in rats.

We aimed to evaluate how high-fat diet consumption can interfere with rat reproductive performance and fetal development. High-fat diet (HFD) was initiated in 30-day-old rats, distributed into two groups (n=7 animals/group): Rats receiving a standard diet and rats receiving HFD. At adulthood, the rats were mated, and on day 21 of pregnancy, the females were anesthetized, decapitated, and submitted to laparotomy to obtain visceral and periovarian adipose tissue. The uterine horns were exposed for analysis of maternal reproductive performance. The fetuses and placentas were weighed and analyzed. Pearson's correlation test was used, and p<0.05 was considered significant. There was a significant positive correlation (HFD consumption x increased periovarian fat) and a negative correlation with the implantation, live fetus numbers and lower litter weight. Furthermore, the increased relative weight of periuterine fat was related to the lower number of live fetuses and litter weight. Regarding the fetal weight classification, there was a negative correlation between the relative weight of periovarian fat and the percentage of fetuses appropriate for gestational age and large for gestational age. Therefore, our findings show that HFD maternal intake negatively influenced on reproductive performance and fetal growth.

Effects of nanopolystyrene nanoplastic exposure on the development and neurotoxicity of fetal rats during gestation

Objective: To investigate the effects of polystyrene nanoplastics (PS-NPs) exposure during gestation on the growth and neurotoxicity of fetal rats. Methods: Twenty-seven SD pregnant rats were randomly divided into 9 groups with three rats in each group. The experimental group of PS-NPs was given 0.5, 2.5, 10 and 50 mg/kg of PS-NPs suspension with different particle sizes (25 and 50 nm) by gavage, wihe the control group was given ultrapure water by gavage. The time of gavage is from the 1st to the 18th day of pregnancy. The morphological changes of the placenta were observed; compare the number of male and female fetuses, live/dead/absorbed fetuses, body weight, body length, placental weight, and organ coefficients of kidney, liver, brain and intestine of fetal rats; the prefrontal cortex, hippocampus and striatum of the fetal rats were taken to measure related biochemical indicators. Results: Compared with the control group, the placenta of the PS-NPs exposed group was found to have structural damage, which increased in a dose-dependent manner. The area ratio of trophoblast was significantly increased (P＜0.05), and the area ratio of labyrinth was significantly decreased (P＜0.05); In the prefrontal cortex, hippocampus and striatum of fetal rats, the levels of IL-1β, IL -6 and TNF-α were significantly increased in the 10 and 50 mg/kg PS-NPs exposed group (P＜0.05), and more significantly elevated in the 25 nm group than those in the 50 nm group at 10 mg/kg exposure (P＜0.05) the CAT activity was significantly decreased in 2.5, 10 and 50 mg/kg PS-NPs exposure groups (P＜0.05), while the SOD and GSH-Px activities were significantly decreased in 25 nm exposure groups and 2.5, 10 and 50 mg/kg 50 nm PS-NPs exposure groups (P＜0.05), the MDA content was significantly increased in 10, 50 mg/kg 25 nm PS-NPs exposure groups and 50 mg/kg 50 nm PS-NPs exposure groups (P＜0.05). Conclusion: Maternal PS-NPs exposure during gestation may affect the growth and development of fetal rats by damaging the placental barrier and produce neurotoxicity in fetal rats, causing oxidative stress and inflammatory responses in various brain regions, and smaller particle sizes and higher doses of polystyrene nanoplastic exposure have more significant neurotoxic effects on the offspring.

MicroRNA-138 Regulates Spinal Cord Development by Activating the Shh in Fetal Rats

Introduction: Dysregulation of spinal cord development can lead to serious neuronal damage and dysfunction, causing significant health problems in newborns. MiRNA-138 appears to be crucial for proliferation, differentiation, and apoptosis of cells. However, the regulation of miRNA-138 and downstream molecules in embryonic spinal cord development remain elusive. The aim of this experiment is to determine whether overexpression of miRNA-138 or RNA interference (RNAi) can regulate the development of spinal cord in fetal rats. Methods: Two plasmid vectors including pLenti-III-mico-GFP (miRNA-138 open reading frame [ORF]) and pLenti-III-miR-Off (miRNA-138 short hairpin) were constructed and injected into the tail vein of rats on the 14th day of pregnancy. Hematoxylin-eosin (HE) staining was used to observe the cell morphology. QRT-PCR, Western blot, and immunostaining confirmed the regulatory relationship between miRNA-138 and downstream molecules sonic hedgehog (Shh). Results: Overexpression of miRNA-138 increased neuron regeneration significantly and decreased neuronal apoptosis when compared with the control. Silencing of miRNA-138 increased neuronal apoptosis and spinal cord atrophy significantly. Furthermore, miRNA-138 ORF treatment effectively increased the expression level of miRNA-138 and also upregulated the level of Shh. Comparatively, knockdown of miRNA-138 downregulated Shh levels in myelodysplastic regions. Conclusion: These findings indicated that miRNA-138 overexpression could protect the spinal cord development of fetal rats, and the underlying mechanisms were associated with Shh expression. The present study provides a novel strategy to promote the molecular mechanism of embryonic spinal cord development.

Di-2-ethylhexyl phthalate-induced miR-155–5p promoted lipid metabolism via inhibiting cAMP/PKA signaling pathway in human trophoblastic HTR-8/Svneo cells

Di-2-ethylhexyl phthalate (DEHP) has been proven to boost miR-155–5p level in trophoblasts, but how DEHP-induced miR-155–5p regulates trophoblastic functions is unclear. For in vivo experiments, DEHP was administered to pregnant Sprague-Dawley (SD) rats at various dosages. After birth, the development of rat fetuses was evaluated. The morphology of the placentae was evaluated using HE staining. miR-155–5p level in placentae was measured utilizing RT-qPCR. Placental cAMP/PKA pathway activation and lipid metabolism levels were assessed using WB, RT-qPCR, and ELISA. For in vitro experiments, DEHP, miR-155–5p inhibitor, or cAMP/PKA inhibitor were applied to treat HTR-8/Svneo cells. Cell viability and functions were investigated utilizing WB, RT-qPCR, CCK-8, transwell assay, plate colony formation assay, and flow cytometry. Besides, the cAMP/PKA pathway activation and lipid metabolism levels in HTR-8/Svneo cells were detected via ELISA, WB, and RT-qPCR. DEHP resulted in fetal malformations and abnormal placental histopathology. DEHP also promoted placental miR-155–5p expression, the cAMP/PKA inactivation, and lipid metabolism in placentae. miR-155–5p knockdown abrogated DEHP-induced proliferative, migrative, and invasive inhibition in HTR-8/Svneo cells. Moreover, miR-155–5p downregulation abolished DEHP-induced inactivation of the cAMP/PKA pathway and enhanced lipid metabolism. Additionally, DEHP-induced miR-155–5p facilitated lipid metabolism by inhibiting the cAMP/PKA signaling pathway in HTR-8/Svneo cells. The current study reveals that miR-155–5p plays an indispensable role in DEHP-induced trophoblastic toxicity by promoting lipid metabolism via inhibiting the cAMP/PKA signaling pathway, indicating miR-155–5p might be a promising therapeutic target for DEHP exposure during pregnancy.

EFEK PEMBERIAN EKSTRAK KAYU SECANG (CAESALIPINIA SAPPAN L.)TERHADAP HISTOPATOLOGI FETUS DAN PLASENTA TIKUS PUIH

Histomorphological assessment of the placenta and fetus was more effective in assessing fetal development on a research scale for determined an active substance during the gestation period in experimental animals. The placenta and fetus connect in the development process. This study aimed to analyze the effect of giving ethanol extract of sappanwood on white rats’ placenta and fetal organs, which were examined histologically at 20 days pregnant rats. The pregnant rats were divided into six groups: The negative group was given aquadest, and treatment groups were given an ethanolic Sappan wood extract 100;200;300;400;500 mg/kg BW. Euthanized with CO2 and cesarian section was performed on pregnant rats on the 20th gestational day. Observation to record fetal body weight, body length, mean placental weight, and the histology of the placental area. Histomorphometry was used to measure the area of the fetal placental region. The group with sappan wood extract had no statistically significant difference in fetal body weight, fetal body length, fetal tail length, the weight placenta, and histomorphometry of the placenta compared to the control group (p &gt; 0.05); this showed that the ethanolic extract of sappan wood does not have a toxic effect on the development of the placenta, which can interfere with fetal development during pregnancy. Sappan wood extract had a nontoxic effect on the placenta and fetal rat development on histological examination, even at the highest dose of 500 mg.kg-1 bw.

Toxicological effects of the Morinda citrifolia L. fruit extract on maternal reproduction and fetal development in rats

Morinda citrifolia L., also known as Noni, is widely used plant in folk medicine for various therapeutic purposes. However, reports on its effects during pregnancy are limited. Therefore, the objective of this study was to evaluate the effects of the M. citrifolia fruit extract on maternal performance and fetal development during pregnancy in rats. Pregnant Wistar rats (n = 12/group) were treated from gestational days (GD) 0–21 with water (control group) or the aqueous extract of M. citrifolia fruit at doses of 200, 400, or 750 mg/kg, orally. During pregnancy, clinical signs of toxicity, maternal weight, feed intake, and water consumption were noted. On GD 21, the rats were anesthetized and blood was collected to evaluate various biochemical parameters. During laparotomy, reproductive performance parameters were recorded, and fetuses were weighed and the anomalies analyzed. Reduced placental efficiency and fetal growth restriction were observed in the group treated with 400 mg/kg of M. citrifolia extract. The highest dose (750 mg/kg) augmented aspartate aminotransferase concentration and preimplantation losses, while reducing the number of live fetuses. Furthermore, both doses (400 and 750 mg/kg) of the plant extract caused fetal anomalies. In conclusion, consumption of high doses of the M. citrifolia aqueous extrac during pregnancy leads to maternal hepatotoxicity, anti-implantation effects, intrauterine growth restriction and fetal abnormalities, indicating that the plant fruit extract can be harmful to both the mother and the fetus.

The Developmental Toxicity of Thymus schimperi Essential Oil in Rat Embryos and Fetuses.

Background In Ethiopian traditional medicine, the aerial parts of Thymus schimperi are widely used to treat diseases such as gonorrhea, cough, liver disease, kidney disease, hypertension, stomach pain, and fungal skin infections. In addition, they have been used as vegetables to flavor a broad variety of food products. However, there is an insufficient investigation of the toxic effect of Thymus schimperi essential oil. The aim of this study was, therefore, to evaluate the developmental toxicity of the essential oil of Thymus schimperi leaves on developing rat embryos and fetuses. Methods Essential oil of the aerial parts of Thymus schimperi was extracted by hydrodistillation. Pregnant Wistar albino rats were randomly divided into five groups. The doses 65 mg/kg, 130 mg/kg, and 260 mg/kg of the essential of Thymus schimperi were administered by force feeding to the III–V groups, respectively. Groups I and II were negative and ad libitum control groups. The embryos and fetuses were revealed on days 12 and 20 of gestations, respectively. The embryos were examined for developmental delays or growth retardation. Gross external, skeletal, and visceral anomalies in the fetuses were examined. Results In this study, the developmental scores of the number of implantation sites, crown-rump length, the number of somites, and morphological scores were significantly lower while the score of fetal resorptions was increased in a 12-day-old rat embryos treated with 260 mg/kg of the Thymus schimperi essential oil. There was also a significant delay in the development of the otic system, olfactory system, and a reduction in the number of branchial bars in 12-day-old embryos treated with 130 mg/kg and 260 mg/kg of the essential oil. However, external morphological examinations of rat fetuses revealed no detectable structural abnormalities. The fetal skull, vertebrae, hyoid, forelimb, and hindlimb ossification centers did not differ significantly across all the groups. Furthermore, there were no skeletal or soft-tissue malformations as a result of the essential oil treatment. Although the difference was not statistically significant, fetuses of the high-dose treatment group had a reduced number of ossification centers in the caudal vertebrae and hind limp phalanges. Conclusion The essential oil of Thymus schimperi at high doses has a detrimental effect on the development of rat embryos and fetuses. Its developmental toxicity is evidenced by significant delays in fetal and embryonic development, a decrease in the number of implantation sites, and an increase in fetal resorption. Furthermore, administration of the essential oil in higher doses resulted in a significant decrease in placenta weight and litter weight. In addition, the present study provided evidence that using the Thymus schimperi essential oil in a high dose could affect the developing embryo and fetus. Thus, it is recommended to discourage the use of Thymus schimperi essential oil in high doses.

Nano-TiO2retarded fetal development by inhibiting transplacental transfer of thyroid hormones in rats

The potential environmental toxicity of nano-TiO2to rat fetal development is associated with retention of thyroid hormones in the placenta.

The Role of Sorting Nexin 17 in Cardiac Development

Sorting nexin 17 (SNX17), a member of sorting nexin (SNX) family, acts as a modulator for endocytic recycling of membrane proteins. Results from our previous study demonstrated the embryonic lethality of homozygous defect of SNX17. In this study, we investigated the role of SNX17 in rat fetal development. Specifically, we analyzed patterns of SNX17 messenger RNA (mRNA) expression in multiple rat tissues and found high expression in the cardiac outflow tract (OFT). This expression was gradually elevated during the cardiac OFT morphogenesis. Homozygous deletion of the SNX17 gene in rats resulted in mid-gestational embryonic lethality, which was accompanied by congenital heart defects, including the double-outlet right ventricle and atrioventricular and ventricular septal defects, whereas heterozygotes exhibited normal fetal development. Moreover, we found normal migration distance and the number of cardiac neural crest cells during the OFT morphogenesis. Although cellular proliferation in the cardiac OFT endocardial cushion was not affected, cellular apoptosis was significantly suppressed. Transcriptomic profiles and quantitative real-time PCR data in the cardiac OFT showed that SNX17 deletion resulted in abnormal expression of genes associated with cardiac development. Overall, these findings suggest that SNX17 plays a crucial role in cardiac development.

Effects of intrauterine infection in different periods on the placenta and endometrial blood vessel formation of pregnant mice and the growth and development of fetal rats

Objective: To investigate the effects of intrauterine infection in different periods on the placenta and endometrial blood vessel formation of pregnant rats and the growth and development of fetal rats.Methods: According to the random number table method, 32 pregnant rats were divided into the early infection group, the mid-term infection group, the late infection group and the control group, with 8 rats in each group. On the 3rd, 9th and 15th day of pregnancy, lipopolysaccharide was injected intraperitoneally to construct intrauterine infection models. The pregnant rats in the control group were intraperitoneally injected with the same dose of 0.9% sodium chloride solution. On the 18th day of pregnancy, the inflammatory factors [interleukin-6 (IL-6), tumor necrosis factor-α (TNF-α)], the blood vessel density of placenta and endometrium in the placental tissues of pregnant rats, dead fetus + absorbed fetus, the inflammatory factors IL-6, TNF-α and oxidation reaction indicators [malondialdehyde (MDA) and myeloperoxidase (MPO)] in the fetal rat lung and brain tissues were detected.Results: The changing trend of IL-6 and TNF-α levels in the placental tissues of pregnant rats with intrauterine infection in different periods was: the control group &lt; the late infection group &lt; the mid-term infection group &lt; the early infection group, the differences were statistically significant (p &lt;.05). The changing trend of fetal rat weight, placental weight and placental coefficient in the intrauterine infection groups in different periods was: the control group &gt; the late infection group &gt; the mid-term infection group &gt; the early infection group, the differences were statistically significant (p &lt; .05). The blood vessel density of placenta and endometrium, the mean number of fetuses, brain coefficient and lung coefficient in the late infection group were significantly increased in comparison with the early infection group and the mid-term infection group. The total number and the ratio of dead fetus + absorbed fetus, the levels of IL-6, TNF-α, MDA and MPO in brain and lung tissues were significantly reduced, and the differences were statistically significant (p &lt; .05). The blood vessel density of placenta and endometrium, brain coefficient and lung coefficient of pregnant rats in the mid-term infection group were significantly increased in comparison with the early infection group, and the differences were statistically significant (p &lt; .05). There was no statistically significant difference in the other indicators between the two groups (p &gt; .05).Conclusions: Intrauterine infection in different periods can inhibit placental and endometrial angiogenesis, and affect the survival rate of fetal rats and the growth and development of brain and lung. The reason may be related to the aggravation of fetal inflammatory responses and oxidative stress. The earlier the intrauterine infection occurs, the severer the adverse effects on the fetal rats will be.