ethylenethiourea and Abnormalities--Multiple

The aim of this study was to study the effect of vitamin A deficiency (VAD) on the embryological development of anorectal malformations (ARMs) and the enteric nervous system.. Female Sprague-Dawley rats were divided into 3 groups: VAD group, normal group (negative control), and ethylene thiourea (ETU) group (positive control) with a normal diet. On day 20 of pregnancy, cesarean section was performed on all rats. The incidence of ARMs in the fetal rats and Protein gene product 9.5 (PGP9.5) and S-100 protein expression by immunohistochemistry were determined.. The incidence of ARMs in VAD and ETU groups was 64.8% (59/91) and 45.9% (61/133), respectively (P > .05). Anorectal malformations were not found in the normal group. Protein gene product 9.5 and S-100 protein expression in the non-ARM rectums of the VAD group was lower than the ETU (P = .0156 vs P = .0105) and normal groups (P = .0091 vs P = .0024). There was no significant difference in PGP9.5 and S-100 protein expression between ETU and normal groups. In the ARM rectums, PGP9.5 and S-100 protein expression in the VAD group was lower than the ETU group (P < .0001). Protein gene product 9.5 and S-100 protein expression was also lower in ARM than non-ARM rectums in the VAD and ETU groups (P < .0001, P = .0203, and P = .0122, respectively).. Vitamin A deficiency during pregnancy may result in the embryological development of ARMs. Enteric nervous system development may be related to ARMs.

Topics: Abnormalities, Drug-Induced; Abnormalities, Multiple; Anal Canal; Animals; Anus, Imperforate; Diet; Enteric Nervous System; Ethylenethiourea; Female; Gene Expression Regulation, Developmental; Nerve Tissue Proteins; Neurons; Pregnancy; Pregnancy Complications; Random Allocation; Rats; Rats, Sprague-Dawley; Rectum; S100 Proteins; Tail; Teratogens; Ubiquitin Thiolesterase; Vitamin A; Vitamin A Deficiency

Sonic hedgehog (Shh) has been shown to be involved in the morphogenesis of many organ systems including the notochord, floor plate and limbs, as well as in the development of the left-right axis in vertebrates. Recent evidence suggests the Shh cascade plays a crucial role in the development of the foregut and hindgut. We have previously shown that prenatal exposure of fetal rats to ethylenethiourea (ETU) induces hindgut malformations and other abnormalities of the VACTERL association. The aim of this study was to determine the pattern of expression of Shh and its downstream genes during hindgut development in ETU-exposed embryos with anorectal malformations (ARMs). Pregnant Sprague-Dawley rats were mated together overnight and a positive vaginal plug was marked as gD0. On gD10, 1% ETU (125 mg/kg) was given to the experimental group and controls received the same volume of saline. Embryos were collected from both groups at gD12-16. The developing hindgut of each embryo was dissected under magnification and snap frozen. Highly purified RNA was isolated from each hindgut and first strand cDNA was prepared with appropriate negative controls. Reverse transcriptase (RT) polymerase chain reaction (PCR) was done to determine the transcripts of Shh in each sample and quantitative real-time PCR was carried out to show relative quantitative expression of Shh at each time point. Shh was detected in all samples confirming that Shh is active during the process of hindgut development in fetal rats. Relative quantitation demonstrated that Shh expression shows time-dependent changes in the developing hindgut of ETU-exposed rat embryos, and when results were compared with control samples, there was significant decrease in expression on gD14 and 15, when the cloaca normally separates into the rectum and urethra occurs in the rat fetus. The misregulated expression of Shh in the hindgut of ETU-exposed rat embryos suggests that ETU may interfere with Shh signalling. Downregulation at the time of cloacal separation into rectum and urethra indicates that Shh plays a crucial role in the development of hindgut.

Topics: Abnormalities, Multiple; Anal Canal; Animals; Cloaca; Ethylenethiourea; Female; Gene Expression Regulation, Developmental; Hedgehog Proteins; Polymerase Chain Reaction; Pregnancy; Rats; Rats, Sprague-Dawley; Rectum; Trans-Activators

Pregnant Sprague Dawley rats were separated into two groups. In the experimental group, single intragastric doses of ethylenethiourea (ETU) were given on the 11th day of gestation. In the control group, a single intragastric dose of distilled water was given on the same day of gestation. Fetuses were recovered on day 20 of gestation, and were prepared for dissection and light microscopy. A high incidence of axial dysraphic disorders (omphalocele and rachischisis) and imperforate anus with recto-urethral fistula were noted in experimental male rat fetuses obtained from dams subjected to varying doses of ETU.

Topics: Abnormalities, Drug-Induced; Abnormalities, Multiple; Animals; Anus, Imperforate; Ethylenethiourea; Female; Fetal Diseases; Hernia, Umbilical; Lumbosacral Region; Male; Pregnancy; Rats; Rats, Sprague-Dawley; Spinal Dysraphism

The effects of ethylenethiourea (ETU) were investigated using rat (Wistar-imamichi) embryos cultured from days 11 to 13 of gestation or cultured rat embryonic cells extracted on day 11. Malformations in cultured embryos at the concentration of 30 micrograms/ml of ETU were found in the head and tail, which were severely affected, as well as the limb and face. All embryos exposed to 150 and 300 micrograms/ml of ETU had malformed heads, tails, limbs, and facial configurations. Protein contents of the cultured embryos were decreased dose-dependently at the concentrations ranging from 30 to 300 micrograms/ml. In the histological studies of the cultured embryos with ETU, thinner neuroepithelium in head was observed. In the embryonic cells extracted on day 11 of gestation, ETU dose-dependently inhibited the differentiation of midbrain (MB) cells into neurons and that of limb bud (LB) cells into chondrocytes at the concentrations ranging from 30 to 600 micrograms/ml of ETU. The concentrations of ETU that inhibited the production of differentiated foci by 50% (IC50) were 170 micrograms/ml in LB cells of day 11, and greater than 600 micrograms/ml in LB cells on day 12 of development. Therefore, differentiation of MB cells was more sensitive to ETU than the differentiation of LB cells. These results indicated that there was a reasonable correlation of ETU induced changes in cultured whole embryos and embryonic cells.

Topics: Abnormalities, Multiple; Animals; Cell Differentiation; Cells, Cultured; Embryo, Mammalian; Ethylenethiourea; Gestational Age; In Vitro Techniques; Rats; Rats, Inbred Strains; Teratogens

Nine groups of 66 pregnant rats, grouped by gestation days 11 to 19, were subjected to a single, intragastric administration of ethylenethiourea (ETU). Cesarean section was performed on gestation day 20. No dam died following the ETU treatment, although a mortality as high as 21.2% was noted among the fetuses in this group; the remaining live fetuses were found to suffer from a high incidence of myeloschisis associated with hindbrain crowding. Exencephaly and abnormally enlarged head with occipital bossing due to the herniation of the mesencephalic tectum, with and without dilation of the mesencephalic and 4th ventricles, were induced among the fetuses of the dams given ETU at gestation days 12 and 13. Various degrees of hydranencephaly and dysplastic hydrocephalus were found among the fetuses of dams treated by ETU from gestation days 14 to 18. From the histological features of these malformations of the central nervous system (CNS), a possible mechanism in the induction of myeloschisis with hindbrain crowding induced by ETU is discussed, and compared with the previously reported similar malformations induced by trypan blue.

Topics: Abnormalities, Multiple; Animals; Arnold-Chiari Malformation; Brain; Central Nervous System; Ethylenethiourea; Female; Hydranencephaly; Hydrocephalus; Imidazoles; Maternal-Fetal Exchange; Microcephaly; Pregnancy; Rats; Rats, Inbred Strains; Spinal Cord

Teratogenic potential of ethylenethiourea (ETU) was investigated in SLC-ICR mice after its reaction with sodium nitrite. ETU was given orally in doses of 400 mg/kg on various days of pregnancy in combination with 200 mg/kg NaNO2 at varied intervals. When NaNO2 was given to females immediately after their treatment with ETU on day 6 or 8 of pregnancy, fetal survival was significantly decreased. Various types of malformations were observed in the living fetuses from mothers treated on day 6, 8, or 10 of pregnancy, but not on day 12. The teratogenicity disappeared when NaNO2 was given 2 h after the treatment with ETU.

Topics: Abnormalities, Drug-Induced; Abnormalities, Multiple; Animals; Drug Synergism; Ethylenethiourea; Female; Fetal Death; Fetus; Gestational Age; Imidazoles; Lung; Mice; Nitrites; Pregnancy; Sodium Nitrite; Time Factors