Aberrant expression of miR-29a/29b and methylation level of mouse embryos after in vitro fertilization and vitrification at two-cell stage.

Proper epigenetic modifications during preimplantation embryo development are important for a successful pregnancy. We aim to investigate the putative influence of in vitro fertilization (IVF) and vitrification on DNA methylation in mouse preimplantation embryos. The study groups consisted of blastocyst-derived vitrified two-cell embryos, nonvitrified embryos, and a control group of in vivo derived blastocysts. We assessed developmental competence, global DNA methylation, relative expression levels of miR-29a/29b, and their target genes, Dnmt3a/3b. Vitrified embryos had a lower developmental rate as compared with nonvitrified embryos. There was no significant decrease in blastocyst cell numbers among studied groups, whereas there was a steady decline in DNA methylation after IVF and vitrification. The levels of miR-29a/29b upregulated in the experimental groups as compared with the control group. IVF and vitrification caused Dnmt3a/3b downregulations in blastocysts. The results of this study have suggested that a relationship exists between IVF and embryo vitrification with methylation interruptions in the blastocysts.

Interfering Effects of In Vitro Fertilization and Vitrification on Expression of Gtl2 and Dlk1 in Mouse Blastocysts.

BACKGROUND: Embryo vitrification is a key instrument in assisted reproductive technologies (ARTs). However, there is increasing concern that vitrification adversely affects embryo development. This study intends to assess the effect of vitrification on developmental competence, in addition to expressions of long non-coding RNA (lncRNA) gene trap locus 2 (Gtl2) and its reciprocal imprinted gene delta-like homolog 1 (Dlk1), in mouse blastocysts. MATERIALS AND METHODS: In this experimental study, we have designed three experimental groups: control (fresh blastocysts collected from superovulated mice), in vitro fertilization (IVF; blastocysts derived from IVF) and vitrification (IVF derived blastocysts subjected to vitrification/warming at the 2-cell stage). Quantitative reverse transcription polymerase chain reaction (qRT-PCR) was performed to assess the expression levels of Gtl2 and Dlk1 in the blastocysts. RESULTS: The results showed that vitrification group had significantly lower blastocyst and hatching rates compared to the IVF group (P<0.037) and (P<0.041), respectively. Gtl2 was down-regulated and Dlk1 was up-regulated following the IVF and vitrification (P<0.05). CONCLUSION: These results suggested that IVF and vitrification disturbed genomic imprinting and lncRNA gene expressions, which might affect the health of IVF children.

The effect of personal protective equipment on thermal stress: An experimental study on firefighters.

BACKGROUND: Various parameters can affect the performance of firefighters. Thermal stress in firefighters is one of the most important harmful factors, which causes impaired performance and subsequent occupational accidents. Therefore, this study aimed to evaluate the effect of personal protective equipment (PPE) on thermal stress in firefighters. MATERIALS AND METHODS: This descriptive-analytical cross-sectional study was performed on 30 firefighters. Heart rate, metabolism and temperature parameters were measured with and without using PPE in a simulated standard chamber. Then, the two indices of predicted mean vote (PMV) and predicted percentage dissatisfied (PPD) were calculated. Data analysis was performed using SPSS version 22.0. RESULTS: The results showed that PPE-induced weight directly increased heart rate and indirectly led to an increase in metabolism and temperature as well as significant changes in PMV and PPD indices (p < 0.001). In addition, our results showed that the effect of thermal resistance of clothing (Clo) on PMV and PPD indices was very high (p < 0.001). CONCLUSION: The findings of the study indicated that heat stress in firefighters is influenced by PPE weight and thermal resistance of clothing. Therefore, cooling vests can be used to reduce the thermal stress induced by temperature rise resulted from metabolism, PPE weight and thermal resistance of clothing. Reduced thermal stress will lead to the cooling of body temperature to acceptable levels of PMV and PPD.

The Mediating Role of A2A Adenosine Receptors in the Mitochondrial Pathway of Apoptotic Hippocampal Cell Death, Following the Administration of MDMA in Rat.

INTRODUCTION: The 3,4-methylenedioxymethamphetamine (MDMA, ecstasy) is a popular recreational drug and a major source of substance abuse, which ultimately leads to sensations of well-being, elation and euphoria, moderate derealization/depersonalization, and cognitive disruptions, as well as intense sensory awareness. The mechanisms involved in memory impairment induced by MDMA are not completely understood. METHODS: The current study used 40 Sprague-Dawley rats, weighted 200 to 250 g. Experiments were performed in four groups, each containing 10 rats. The first group of rats was used as the control, treated with dimethyl sulfoxide (DMSO). The second group was treated with MDMA. The third group was treated with MDMA and CGS (the adenosine A2A receptor agonist, 2-[p-(2-carboxyethyl) phenethylamino]-5'-N-ethylcarboxamidoadenosine) (CGS 21680) and the fourth group was treated with MDMA and SCH (the A2A receptor antagonist [7-(2-phenylethyl)-5-amino-2-(2-furyl-) pyrazolo-[4, 3-e]-1, 2, 4 triazolo [1,5-] pyrimidine]) (SCH 58261). The drugs in all groups were administrated intraperitoneally (i.p.) once a day for 7 days. In 5 rats of each group, following perfusion, samples were taken from hippocampi to investigate apoptosis. Accordingly, the samples were stained using the terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL) assay kit, and studied by light microscopy. In other rats, fresh tissue was also removed to study the expression of bax and bcl-2 by Western blotting technique. RESULTS: It was observed that the coadministration of MDMA with CGS reduced bax expression and prevented apoptosis of hippocampal cells. The coadministration of MDMA and SCH increased bax expression, and also increased the frequency of hippocampal cell apoptosis. CONCLUSION: The results of the current study showed that administration of CGS with MDMA decreased the common side effects associated with MDMA.

The Effects of Chlorpromazine on Reproductive System and Function in Female Rats.

BACKGROUND: Chlorpromazine (CPZ), an antipsychotic drug, is associated with increased risk of sexual dysfunction through increasing prolactin levels. The current study evaluates the effect of CPZ-induced hyperprolactinemia on ovarian follicular growth, gonadotropins, and alteration of ovarian source hormones. MATERIALS AND METHODS: In this experimental study, animals were divided into four groups, control and CPZ (n=8 per group). In the treated groups, CPZ was administered by gavage at doses of 3, 10 and 30 mg/kg per day for 28 days. On day 29 the animals were killed after which histopathological and histomorphometric analyses of the ovaries were performed. We evaluated the levels of prolactin serum, luteinizing hormone (LH), follicle-stimulating hormone (FSH), estradiol (E2) and progesterone. RESULTS: The ovaries of the test groups showed numerous atretic follicles of various sizes. CPZ caused a significant difference between the test groups and the control group (P<0.05) on the amount of atresia and the size of the normal corpora lutea (CL). The increased dysfunction of the ovaries from the different groups depended on the amount of CPZ administered. The serum concentrations of prolactin and progesterone significantly increased (P<0.05), while the serum concentrations of estradiol, LH and FSH notably decreased (P<0.05), depending on the CPZ dose. CPZ-induced animals had unsuccessful mating and decreased pregnancy rate. CONCLUSION: The present findings suggest that CPZ-induced disturbances not only depend on prolactin level but the increased prolactin level is largely dose-dependent.

Chlorpromazine-Induced Hyperprolactinemia on Rat's Uterus.

BACKGROUND: Hyperprolactinemia is a common side effect of antipsychotic drugs that requires further investigation. The current study was designed to evaluate dose-dependent effect of chlorpromazine (CPZ) on hormonal changes and uterine horn histological structure in rats. Moreover, the mammary glands were analyzed to show hyperprolactinemia-induced histological changes. METHODS: Albino Wistar rats (n = 32) were divided into four groups. The first group was set as a control. In the three drug-treated groups (eight rats in each group), CPZ was administered by a gavage at doses of 3, 10, and 30 mg/kg/day for 28 days. One day after the last administration of the drug, the animals were sacrificed. Histopathological and histomorphometrical analyses of the uterine horns and mammary glands were carried out to evaluate dose-dependent effect of CPZ on histological structure. Serum levels of prolactin (PRL), estradiol, progesterone, follicle-stimulating hormone (FSH), and luteinizing hormone (LH) were also evaluated. RESULTS: Remarkable (P < 0.05) elevation was observed in CPZ-administrated animals' uterine horn endometrium, myometrium, and perimetrium thicknesses, and the mammary glands were observed with galactorrhea features. The serum level of progesterone and PRL significantly (P < 0.05) increased, while the serum concentration of LH, FSH, and estradiol was notably (P < 0.05) decreased depending on administrated CPZ dose. No histological and biological changes were occurred in the control animals. CONCLUSION: The present findings suggest that CPZ-induced disturbances not only depend on PRL level and increased PRL level largely depends on administrated doses of the CPZ.

Effect of purine nucleoside analogue-acyclovir on the sperm parameters and testosterone production in rats.

BACKGROUND: Acyclovir (ACV), a synthetic purine nucleoside analogue derived from guanosine, is known to be toxic to gonads and the aim of this study was to evaluate the effect of ACV on the sperm parameters and testosterone production in rat. MATERIALS AND METHODS: In this experimental study, forty adult male Wistar rats (220 ± 20 g) were randomly divided into five groups (n=8 for each group). One group served as control and one group served as sham control [distilled water was intraperitoneally (i.p.) injected]. ACV was administered intraperitoneally in the drug treatment groups (4, 16 and 48 mg/kg/day) for 15 days. Eighteen days after the last injection, rats were sacrificed by CO2 inhalation. After that, cauda epididymides were removed surgically. At the end, sperm concentrations in the cauda epididymis, sperm motility, morphology, viability, chromatin quality and DNA integrity were analyzed. Serum testosterone concentrations were determined. RESULTS: The results showed that ACV did not affect sperm count, but decreased sperm motility and sperm viability at 16 and 48 mg/kg dose-levels. Sperm abnormalities increased at 48 mg/kg dose-level of ACV. Further, ACV significantly increases DNA damage at 16 and 48 mg/kg dose-levels and chromatin abnormality at all doses. Besides, a significant decrease in serum testosterone concentrations was observed at 16 and 48 mg/ kg doses. CONCLUSION: The present results highly support the idea that ACV induces testicular toxicity by adverse effects on the sperm parameters and serum level of testosterone in male rats.

Toxic effect of acyclovir on testicular tissue in rats.

BACKGROUND: Acyclovir (ACV), a synthetic purine nucleoside analogue, is known to be toxic to gonads. OBJECTIVE: The current study evaluated cytotoxicity of ACV on histopathological changes in testis tissue and serum testosterone and lipid peroxidation concentrations of male rats. MATERIALS AND METHODS: Animals were divided into five groups. One group served as control and one group served as control sham. In the drug treated groups ACV administered for 15 days. 18 days after the last injection, animals were sacrificed. Histopathological and histomorphometrical analysis of the testis was carried out. Serum levels of testosterone and Lipid Peroxidation and potential fertility of animals was evaluated. RESULTS: Male rats exposed to ACV had significant reduction in serum testosterone concentrations at 16 and 48mg/kg dose-levels (p<0.01). ACV induced histopathological changes in the testis and also increase the mean number of mast cells in peritubular or interstitial tissue in the testis at at 16 and 48mg/kg dose-levels (p<0.01). In addition ACV caused increase of serum level of Lipid Peroxidation at 48mg/kg dose-level (p<0.05). As well ACV decreased potential fertility in male rats. CONCLUSION: The present results highly support the idea that ACV has adverse effect on the reproductive system in male rat.