Chicory fibre improves reproductive performance of pregnant rats involving in altering intestinal microbiota composition.

AIM: Chicory fibre (CF) is rich in fructan, which always functions as a quality dietary fibre source during mammalian pregnancy; however, its effect on reproductive performance remains unclear. METHODS AND RESULTS: 40 pregnant SD rats were randomly allotted to receive one of four diets: basal diet (control group), basal diet + 5% CF, basal diet + 10% CF, and basal diet + 15% CF, respectively. We found that CF significantly increased the number born alive and total litter birth weight (P < 0·05), increased the expression of intestinal tight junction proteins, mucins and antimicrobial peptides, accompanied by the increase of villi height and the decrease of crypts depth of pregnant SD rats (P < 0·05). We also observed that CF markedly increased the acetic acid, propanoic acid, butyric acid and total SCFAs concentrations in caecum contents and promoted the expression of SCFAs-related receptors (P < 0·05). Notably, rats fed CF increased the relative abundance of Bacteroidetes (P < 0·001), decreased the relative abundance of Firmicutes and Proteobacteria, while markedly lowered the Firmicutes/ Bacteroidetes ratio (F/B ratio) (P < 0·05). Intriguingly, the number born alive and total litter birth weight were positively correlated with some probiotics and negatively correlated with other harmful bacteria by Pearson correlation analysis. CONCLUSION: Collectively, CF can enhance intestinal barrier function and maintain intestinal health, and may improve reproductive performance by altering intestinal microbiota composition. SIGNIFICANCE AND IMPACT OF THE STUDY: Adding suitable dietary fibre to the diet can improve the reproductive performance of sows. Indeed, there exist various problems in the application of traditional dietary fibres, including high insoluble fibre content and anti-nutritional factor level, and mycotoxin contamination. This study demonstrates that dietary CF supplementation improves reproductive performance and intestinal health. Thus, CF can be applied in pregnancy animals as a new dietary fibre additive in animal husbandry.

Serum and tissue pregnanes and pregnenes after dexamethasone treatment of cows in late gestation.

Dexamethasone (DEX) initiates parturition by inducing progesterone withdrawal and affecting placental steroidogenesis, but the effects of DEX in fetal and maternal tissue steroid synthetic capacity remains poorly investigated. Blood was collected from cows at 270 days of gestation before DEX or saline (SAL) treatment, and blood and tissues were collected at slaughter 38 h later. Steroid concentrations were determined by liquid chromatography tandem mass spectrometry to detect multiple steroids including 5α-reduced pregnane metabolites of progesterone. The activities of 3ß-hydroxysteroid dehydrogenase (3ßHSD) in cotyledonary and luteal microsomes and mitochondria and cotyledonary microsomal 5α-reductase were assessed. Quantitative PCR was used to further assess transcripts encoding enzymes and factors supporting steroidogenesis in cotyledonary and luteal tissues. Serum progesterone, pregnenolone, 5α-dihydroprogesterone (DHP) and allopregnanolone (3αDHP) concentrations (all <5 ng/mL before treatment) decreased in cows after DEX. However, the 20α-hydroxylated metabolite of DHP, 20αDHP, was higher before treatment (≈100 ng/mL) than at slaughter but not affected by DEX. Serum, cotyledonary and luteal progesterone was lower in DEX- than SAL-treated cows. Progesterone was >100-fold higher in luteal than cotyledonary tissues, and serum and luteal concentrations were highly correlated in DEX-treated cows. 3ßHSD activity was >5-fold higher in luteal than cotyledonary tissue, microsomes had more 3ßHSD than mitochondria in luteal tissue but equal in cotyledonary sub-cellular fractions. DEX did not affect either luteal or cotyledonary 3ßHSD activity but luteal steroidogenic enzyme transcripts were lower in DEX-treated cows. DEX induced functional luteal regression and progesterone withdrawal before any changes in placental pregnene/pregnane synthesis and/or metabolism were detectable.

Methionine Supply During Late-Gestation Triggers Offspring Sex-Specific Divergent Changes in Metabolic and Epigenetic Signatures in Bovine Placenta.

Background: Nonruminant male and female offspring respond differently to gestational nutrition, with placenta contributing to the underlying mechanisms. However, similar data are lacking in large ruminants. Objectives: The aim of this study was to investigate the impact of methionine supply during late-gestation on metabolism and DNA methylation in placenta from cows carrying male or female calves. Methods: During the last 28 d of pregnancy, cows were individually fed a control diet (CON) or the control diet plus rumen-protected d,l-methionine (MET; 0.9 g/kg dry matter intake). Placentomes collected at term were classified according to cow dietary treatment and offspring sex as follows: Male CON (n = 7), Male MET (n = 7), Female CON (n = 8), and Female MET (n = 8). Calf growth was measured until 9 wk of age. Targeted metabolomics, RT-PCR, global DNA methylation, and activity of selected enzymes in one-carbon metabolism and transsulfuration pathways were performed. Statistics were conducted via ANOVA using MIXED models. Results: At birth, Male MET calves were heavier than Male CON calves (7.6%, P = 0.02), but body mass was similar at 9 wk of age. In contrast, compared with Female CON, Female MET calves had greater body mass at 9 wk of age (6.3%, P = 0.03). Compared with Male CON, placenta from Male MET calves had greater concentrations of tricarboxylic acid (TCA) cycle and transsulfuration intermediates (23-100%, P < 0.05), along with greater 5-methyltetrahydrofolatehomocysteine methyltransferase activity (67%, P = 0.03). Compared with Female CON, placenta from Female MET calves had greater concentrations of one-carbon metabolism intermediates (13-52%, P < 0.05). DNA methyltransferase 3A (DNMT3A) was upregulated (43%, P < 0.01) in placenta from Female MET compared with Female CON calves. Global DNA methylation was lower in placenta from Female MET compared with Female CON calves (45%, P = 0.06). Conclusions: Methionine supply affects placental metabolism, DNA methylation, and body mass of the calf in a sex-specific manner, underscoring its importance as dietary methyl-donor for pregnant cows.

Nutritional evaluation and productivity of supplemented sheep grazing in semiarid rangeland of northeastern Brazil.

Sheep production systems in Brazilian caatinga rangelands require supplementation adapted to changes in floristic and chemical composition as dry seasons progress. Meeting sheep nutritional needs in extensive semiarid systems is challenging because of sheep dietary preferences and habits. The objective of this trial was to evaluate the substitutive effect of concentrate supplementation on grazing sheep in the Brazilian caatinga rangeland and its consequences on performance in different seasons. The trial was conducted from March to August 2013 at Embrapa Goat and Sheep in Sobral, Ceará State, Brazil. Thirty-two Brazilian Somali multiparous ewes were submitted to estrus synchronization and controlled breeding. At the start of the trial, ewes averaged 30.45 + 2.60 kg body weight (BW). Ewes were divided into four groups and individually offered 0, 200, 350, or 500 g supplement head-1 day-1. Intake prediction and digestibility trials were evaluated at three periods: rainy season (April), transition rainy-dry (June), and dry season (August). Sheep weights were taken every 14 days to measure their performance from late gestation until weaning. Ewe BW and body condition score changes were determined too. Lamb BW changes were also measured every 14 days from birth through weaning. A completely randomized design with split plot arrangement using eight replications was used for intake and digestibility measurements. The differences between supplement offered (0, 200, 350, and 500 g sheep-1) and season (rainy, transition rainy-dry, and dry) were submitted to analyses of variance and multiple means were separated, where differences were detected, using the Tukey's test. During lactation up through weaning, ewes supplemented at 500 g day-1 had greater BW than ewes without supplement. Ewes supplemented with 200 g concentrate head-1 day-1 had 9.1% greater (P ≤ 0.05) BW at weaning and their lambs had 19.7% greater birth and 16.6% heavier wean BW despite lower dry matter intake compared to unsupplemented animals. Supplementation with 200 g concentrate increased carrying capacity by 28.8% during the dry season and by 20.5% during the rainy season. This study confirmed that in the dry season, when quality of rangeland forages decreases, supplementation contributes to greater DMI, improves postpartum and lactation BW recovery of ewes, and contributes to greater lamb birth and wean weights. Moreover, supplementation leads to feed substitution effects that may increase rangeland resilience by mitigating overgrazing. Supplementation with 200 g concentrate can also prevent negative energy balance for grazing animals, improving longer postnatal recovery, longer intervals between parturitions, fewer double and is necessary to ensure a better BW at birth to lambs.

Caffeine consumption during early pregnancy impairs oviductal embryo transport, embryonic development and uterine receptivity in mice.

Caffeine consumption has been widely used as a central nervous system stimulant. Epidemiological studies, however, have suggested that maternal caffeine exposure during pregnancy is associated with increased abnormalities, including decreased fertility, delayed conception, early spontaneous abortions, and low birth weight. The mechanisms underlying the negative outcomes of caffeine consumption, particularly during early pregnancy, remain unclear. In present study, we found that pregnant mice treated with moderate (5 mg/kg) or high (30 mg/kg) dosage of caffeine (intraperitoneally or orally) during preimplantation resulted in retention of early embryos in the oviduct, defective embryonic development, and impaired embryo implantation. Transferring normal blastocysts into the uteri of caffeine-treated pseudopregnant females also showed abnormal embryo implantation, thus indicating impaired uterine receptivity by caffeine administration. The remaining embryos that managed to implant after caffeine treatment also showed increased embryo resorption rate and abnormal development at mid-term stage, and decreased weight at birth. In addition to a dose-dependent effect, significant variations between individual mice under the same caffeine dosage were also observed, suggesting different sensitivities to caffeine, similar to that observed in human populations. Collectively, our data revealed that caffeine exposure during early pregnancy impaired oviductal embryo transport, embryonic development, and uterine receptivity, which are responsible for abnormal implantation and pregnancy loss. The study raises the concern of caffeine consumption during early stages of pregnancy.

Role of Estradiol in the Regulation of Prolactin Secretion During Late Pregnancy.

Estrogen action is necessary for evidencing the stimulatory action of mifepristone and naloxone on prolactin (PRL) secretion during late pregnancy. Our aim is to determine the mechanism mediating this facilitator action of estrogens. To investigate the hypothalamic mechanisms involved in estrogen actions in PRL secretion at the end of pregnancy, we measured the effect of pretreatment with the estrogen antagonist tamoxifen on the expression of tyrosine hydroxylase (TH), hormone receptors (ERα and ß, PRs, PRLR(long)), and µ- and κ- opioid receptors (ORs) at mRNA (by semiquantitative RT-PCR) and protein (by western blot for TH, PRLR(long), ERα, PRs, µ- and ORs) levels in extracts of medial basal hypothalamus (MBH) and serum PRL, E2 and P4 levels (by RIA) in mifepristone- and naloxone-treated rats. Tamoxifen administration partially prevented PRL release induced by the combined treatment. TH expression diminished and ERα expression increased in mifepristone-treated rats at mRNA and protein levels and tamoxifen partially prevented these changes with no effect on PRs expression. Mifepristone increased PRLR(long) mRNA levels; this increase was blocked by tamoxifen. Combined tamoxifen and mifepristone treatment decreased µ- and k-ORs mRNA but not protein levels. In conclusion, E2 induces neuroadaptive mechanisms necessary to facilitate PRL release preceding delivery. Acting through ERα, E2 modulates hypothalamic dopaminergic neurons activity, regulating TH, µ- and κ-ORs and PRLR(long) expression, and is necessary for evidencing the effects of P4 withdrawal. Its presence on days 14 and 15 of pregnancy is crucial to facilitate the opioid system modulation of PRL secretion at the end of pregnancy in the rat.

Twin reduction by PGF2α intraluteal instillation in dairy cows.

The objective of this study was to determine whether induced luteolysis of one of the two corpora lutea in twin pregnancies would provoke spontaneous twin reduction. In Experiment 1, 12 post-partum cows with two corpora lutea in the same ovary were assigned to (three cows per group): Group I, Group II, Group III or Group IV receiving into one of the corpora lutea puncture with no treatment, 0.5 mg dinoprost, 1.5 mg dinoprost and 2.5 mg dinoprost, respectively. One of the two corpora lutea showed clear signs of luteolysis on Day 2 and was practically non-detectable on Day 7 after treatment in the three cows of the Group IV. In Experiment 2, 11 cows carrying live twins with two corpora lutea on Day 28 of gestation, eight bilateral and three unilateral, received 2.5 mg dinoprost into one of the corpora lutea. Corpus luteum reduction and embryo reduction after treatment were registered in 10 and 9 cows, respectively. In bilateral twin pregnancies, four cows suffering embryo reduction remained pregnant. In unilateral twin pregnancies, membrane detachment resulted in the death of both cotwins. In conclusion, although observations were based on few animals, there seems to be a mechanism that operates locally to transfer ovarian progesterone to the uterus, and also a quantitative relationship between the amount of progesterone secreted and support of conceptuses, resulting in death of one twin embryonic vesicle when one corpus luteum regresses.

Allopregnanolone and social stress: regulation of the stress response in early pregnancy in pigs.

This experiment investigated whether allopregnanolone, a neurosteroid metabolite from progesterone, modulates the stress response during early pregnancy. Twenty-five nulliparous sows (Sus scrofa) were allocated to one of three treatments: pregnant, ovariectomized or ovariectomized administered daily intravenously with alfaxalone as a synthetic allopregnanolone analog. On days 5, 12 and 19 of pregnancy, all sows were subjected to social stress by submitting them individually to a resident-intruder test, acting as the intruder. Blood samples were collected to analyze plasma progesterone, allopregnanolone, cortisol and adrenocorticotropic hormone (ACTH) concentrations. On day 26, 10 sows across the three treatments were subjected to a dexamethasone suppression test followed by a corticotrophin-releasing hormone administration to test the functionality of their hypothalamo-pituitary-adrenal (HPA) axis through cortisol release. Pregnant sows returned more rapidly to baseline cortisol concentrations following the resident-intruder test (p = 0.006). However, there were no other differences in cortisol or ACTH concentrations according to treatment or day, or to the HPA responsivity test on day 26. Allopregnanolone concentration in pregnant sows was higher than in ovariectomized sows (p < 0.001), but stable during the first third of pregnancy. Allopregnanolone concentration was correlated with longer resident-intruder test duration (pregnant: r = 0.66, p = 0.0003; ovariectomized: r = 0.47, p = 0.03), reflecting lower aggressiveness, and with progesterone concentration (r = 0.25, p = 0.03). Alfaxalone administration raised plasma allopregnanolone concentration in alfaxalone-administered sows but resulted in little behavioral and physiological effects. These findings did not support the hypothesis that the stress response of the female pig changes in the first third of pregnancy. Allopregnanolone was associated with lower aggression in social encounters.

Fishmeal supplementation during ovine pregnancy and lactation protects against maternal stress-induced programming of the offspring immune system.

BACKGROUND: Prenatally stressed offspring exhibit increased susceptibility to inflammatory disorders due to in utero programming. Research into the effects of n-3 PUFAs shows promising results for the treatment and prevention of these disorders. The purpose of this study was to investigate whether maternal fishmeal supplementation during pregnancy and lactation protects against programming of the offspring's immune response following simulated maternal infection. METHODS: In order to accomplish this, 53 ewes were fed a diet supplemented with fishmeal (FM; rich in n-3 PUFA) or soybean meal (SM; rich in n-6 PUFAs) from day 100 of gestation (gd 100) through lactation. On gd135, half the ewes from each dietary group were challenged with either 1.2 µg/kg Escherichia coli lipopolysaccharide (LPS) endotoxin to simulate a bacterial infection, or saline as the control. At 4.5 months of age the offspring's dermal immune response was assessed by cutaneous hypersensitivity testing with ovalbumin (OVA) and candida albicans (CAA) 21 days after sensitization. Skinfold measurements were taken and serum blood samples were also collected to assess the primary and secondary antibody immune response. RESULTS: Offspring born to SM + LPS mothers had a significantly greater change in skinfold thickness in response to both antigens as well as a greater secondary antibody response to OVA compared to all treatments. CONCLUSIONS: Supplementation during pregnancy with FM appears to protect against adverse fetal programming that may occur during maternal infection and this may reduce the risk of atopic disease later in life.

Prenatal ethanol exposure disrupts intraneocortical circuitry, cortical gene expression, and behavior in a mouse model of FASD.

In utero ethanol exposure from a mother's consumption of alcoholic beverages impacts brain and cognitive development, creating a range of deficits in the child (Levitt, 1998; Lebel et al., 2012). Children diagnosed with fetal alcohol spectrum disorders (FASD) are often born with facial dysmorphology and may exhibit cognitive, behavioral, and motor deficits from ethanol-related neurobiological damage in early development. Prenatal ethanol exposure (PrEE) is the number one cause of preventable mental and intellectual dysfunction globally, therefore the neurobiological underpinnings warrant systematic research. We document novel anatomical and gene expression abnormalities in the neocortex of newborn mice exposed to ethanol in utero. This is the first study to demonstrate large-scale changes in intraneocortical connections and disruption of normal patterns of neocortical gene expression in any prenatal ethanol exposure animal model. Neuroanatomical defects and abnormal neocortical RZRß, Id2, and Cadherin8 expression patterns are observed in PrEE newborns, and abnormal behavior is present in 20-d-old PrEE mice. The vast network of neocortical connections is responsible for high-level sensory and motor processing as well as complex cognitive thought and behavior in humans. Disruptions to this network from PrEE-related changes in gene expression may underlie some of the cognitive-behavioral phenotypes observed in children with FASD.

Impact of 5-azacytidine on rat decidual cell proliferation.

The DNA demethylating agent 5-azacytidine (5-azaC) has a teratogenic influence during rat development influencing both the embryo and the placenta. Our aim was to investigate its impact on early decidual cell proliferation before the formation of placenta. Thus, female Fischer rats received 5-azaC (5 mg/kg, i.p.) on the 2nd, 5th or 8th day of gestation and the decidual tissues were harvested on gestation day 9. They were then analysed immunohistochemically for expression of cell proliferation marker proliferating cell nuclear antigen (PCNA) in decidual cells and for global DNA methylation using the coupled restriction enzyme digestion, random amplification and pyrosequencing assays. We found that 5-azaC administered on the 5th and 8th (but not on 2nd) day of gestation led to increased PCNA expression in decidual cells compared with untreated controls. No significant changes in DNA methylation were detected, with either method, in any of the treated rat groups compared with untreated controls. Thus, we conclude that 5-azaC can stimulate decidual cell proliferation without simultaneously changing global DNA methylation level in treated cells.

Effects of exposure to nanoparticle-rich diesel exhaust on pregnancy in rats.

Pollutants from burning of diesel fuel are hazardous to human health. Nanoparticles in diesel exhaust potentially have profound impact on fetal development and maternal endocrine function during pregnancy due to their ability to penetrate deeply into the body. To investigate the effects of nanoparticle-rich diesel exhaust (NR-DE) on pregnancy, pregnant rats were exposed to NR-DE, filtered diesel exhaust (F-DE) or clean air for 19 days of gestation. Relative weights of maternal liver and spleen to body weight were significantly lower in the NR-DE and F-DE groups than those in the control group. The serum concentration of maternal progesterone was significantly lower, while those of luteinizing hormone (LH) and corticosterone were significantly higher in the NR-DE and F-DE groups than those in the control group. The serum concentration of estradiol-17ß was significantly higher in the F-DE group than that in the control group. The levels of cytochrome P450 side-chain cleavage enzyme, 3ß-hydroxysteroid dehydrogenase and LH receptor mRNA in the corpus luteum were significantly lower in the NR-DE and F-DE groups than those in the control. In fetuses, body weight and crown-rump length were significantly greater and shorter, respectively, in both males and females in the NR-DE and F-DE groups than those in the control group. These results demonstrate that exposure of pregnant rats to NR-DE and F-DE suppresses the function of corpora lutea and stimulates the function of the adrenal cortex, suggesting a risk of spontaneous abortion associated with maternal hormonal changes.

Effect of treatment with human chorionic gonadotropin on day 5 after timed artificial insemination on fertility of lactating dairy cows.

Reproductive management programs that synchronize ovulation can ovulate a smaller than normal follicle, potentially resulting in inadequate progesterone (P4) concentrations after artificial insemination (AI). Ovulation of the dominant follicle of the first follicular wave with human chorionic gonadotropin (hCG) treatment can produce an accessory corpus luteum and increase circulating P4 concentrations. This manuscript reports the results of 2 separate analyses that evaluated the effect of hCG treatment post-AI on fertility in lactating dairy cows. The first study used meta-analysis to combine the results from 10 different published studies that used hCG treatment on d 4 to 9 post-AI in lactating dairy cows. Overall, pregnancies per artificial insemination (P/AI) were increased 3.0% by hCG treatment post-AI [34% (752/2,213) vs. 37% (808/2,184); Control vs. hCG-treated, respectively]. The second study was a field research trial in which lactating Holstein cows (n=2,979) from 6 commercial dairy herds were stratified by parity and breeding number and then randomly assigned to one of 2 groups: control (no further treatment, n=1,519) or hCG [Chorulon i.m.: 2,000 IU (in 3 of the herds) or 3,300 IU (in 3 herds); n=1,460] on d 5 after a timed AI (ovulation synchronized with Ovsynch, Presynch-Ovsynch, or Double-Ovsynch). In a subset of cows, the hCG profile and P4 changes were determined. Treatment with hCG increased P4 (4.3 vs. 5.3 ng/mL on d 12). Pregnancies per AI were greater in cows treated with hCG (40.8%; 596/1,460) than control (37.3%; 566/1,519) cows. Interestingly, an interaction among treatment and parity was observed; primiparous cows had greater P/AI after hCG (49.7%; 266/535) than controls (39.5%; 215/544). In contrast, older cows receiving hCG (35.7%; 330/925) had similar P/AI to controls (36.0%; 351/975).Thus, targeted use of hCG on d 5 after TAI enhances fertility about 3.0% (based on meta-analysis) to 3.5% (based on our field trial). Surprisingly, this fertility-enhancing effect of hCG was very large in first-lactation cows but not observed in older cows in the field study. Future research is needed to confirm these intriguing results and to determine why older cows did not have improved fertility after hCG treatment.

On determining the BMD from multiple outcomes in developmental toxicity studies when one outcome is intentionally missing.

Public health concerns over the occurrence of developmental abnormalities that can occur as a result of prenatal exposure to drugs, chemicals, and other environmental factors has led to a number of developmental toxicity studies and the use of the benchmark dose (BMD) for risk assessment. To characterize risk from multiple sources, more recent analytic methods involve a joint modeling approach, accounting for multiple dichotomous and continuous outcomes. For some continuous outcomes, evaluating all subjects may not be feasible, and only a subset may be evaluated due to limited resources. The subset can be selected according to a prespecified probability model and the unobserved data can be viewed as intentionally missing in the sense that subset selection results in missingness that is experimentally planned. We describe a subset selection model that allows for sampling pups with malformations and healthy pups at different rates, and includes the well-known simple random sample (SRS) as a special case. We were interested in understanding how sampling rates that are selected beforehand influence the precision of the BMD. Using simulations we show how improvements over the SRS can be obtained by oversampling malformations, and how some sampling rates can yield precision that is substantially worse than the SRS. We also illustrate the potential for cost saving with oversampling. Simulations are based on a joint mixed effects model, and to account for subset selection, use of case weights to obtain valid dose-response estimates.

The toxic effects of nickel chloride on liver, erythropoiesis, and development in Wistar albino preimplanted rats can be reversed with selenium pretreatment.

The exposure to nickel chloride (NiCl2) can cause hematotoxicity and hepatotoxicity and canaffect development. The present study pertains to the protective effect of selenium (Se) against NiCl2-induced toxicity in preimplanted Wistar albino rats. The subcutaneous (s.c.) administration of 25 or 50 mg/kg of NiCl2 to Wistar albino rats on day 3 of gestation induced an immediate and significant decrease in maternal body weight and anemia 2 days after treatment. In addition, an increase in plasma aspartate aminotransferase (AST) was observed. These effects were maintained on day 20 of gestation. Moreover, a significant increase in plasma alanine aminotransferase (ALT) levels was observed with the administration of 25 mg/kg of NiCl2. Conversely, administration of 50 mg/kg of NiCl2 by s.c. injection increased erythropoiesis at day 20 of gestation and decreased platelets counts. In addition, administration of 100 mg/kg of NiCl2 markedly reduced the maternal body weight and number of live fetuses and increased fetal loss, predominantly at the end of the experimental period. All dose levels of NiCl2 caused an alteration in the hepatic histoarchitecture. When 0.3-mg/kg Se was injected s.c. with 100-mg/kg NiCl2, the levels of plasma AST and ALT and the structure of the liver were restored. Administration of 20 mg/L/day of NiCl2 in the drinking water significantly reduced the maternal body weight at day five of gestation as well as erythropoiesis during the exposure period. The present study suggests that Se can counteract the nocuous effect of nickel on the liver; however this antioxidant did not prevent alterations in development and erythropoiesis.

Adverse influence of coumestrol on secretory function of bovine luteal cells in the first trimester of pregnancy.

Coumestrol is one of a few biologically active substances present in leguminous plants, which are widely used as fodder for ruminants. Depending on the doses, coumestrol acts on the reproductive processes as an estrogen-like factor or antiestrogen to evoke a decrease in ovulation frequency, elongation of estrous cycle duration. The aim of the current investigations was to study the influence of coumestrol on secretory function of luteal cells obtained from first trimester of pregnant cows. Luteal cells (2.5 × 10(5) /mL) from 3rd to 5th, 6th to 8th, and 9th to 12th week of pregnancy were preincubated for 24 h and incubated with coumestrol (1 × 10(-6) M) for successive 48 h and the medium concentrations of progesterone (P4), oxytocin (OT), prostaglandin (PG) E2 and F2α were determined. Moreover, the expression of mRNA for neurophysin-I/oxytocin (NP-I/OT; precursor of OT) and peptidyl-glycine-α-amidating mono-oxygenase (PGA, an enzyme responsible for post-translational OT synthesis) was determined after 8 h of treatment. Coumestrol did not affect P4 secretion but increased the secretion of OT from the cells collected at all stages of gestation studied. Hence, the ratio of P4 to OT was markedly decreased. Simultaneously, coumestrol increased the expression of NP-I/OT mRNA during 9th to 12th weeks of pregnancy, and mRNA for PGA during 3rd to 5th and 9th to 12th weeks of gestation. Furthermore, coumestrol decreased PGE2 secretion from luteal cells in all studied stages of pregnancy, while it affected PGF2α metabolite (PGFM) concentration only from week 3 to 5 of pregnancy. Obtained results suggest that coumestrol impairs secretory function of the corpus luteum (CL) and this way it can affect the maintenance of pregnancy in the cow.

A teratologic suppressor role for p53 in benzo[a]pyrene-treated transgenic p53-deficient mice.

DNA damage may mediate birth defects caused by many drugs and environmental chemicals, therefore p53, a tumour suppressor gene that facilitates DNA repair, may be critically embryoprotective. We have studied the effects of the environmental teratogen, benzo[a]pyrene, on pregnant heterozygous p53-deficient mice. Such mice exhibited between 2- to 4-fold higher embryotoxicity and teratogenicity than normal p53-controls. Fetal resorptions reflecting in utero death were genotyped using the polymerase chain reaction and found to be increased 2.6-fold and 3.6-fold respectively with heterozygous and homozygous p53-deficient embryos. These results provide the first direct evidence that p53 may be an important teratological suppressor gene which protects the embryo from DNA-damaging chemicals and developmental oxidative stress.

Administration of lopinavir/ritonavir association during rat pregnancy: maternal and fetal effects.

PURPOSE: To evaluate the effects of the association of lopinavir and ritonavir administered during the whole period of rat pregnancy. METHODS: 62 Wistar rats of the EPM-1 variant weighing about 200 g were randomly divided into five groups: two controls (Ctrl = stress control, n = 10; and Ctr2 = drug vehicle control, n = 10) and three experimental ones which were treated with an oral solution of lopinavir/ritonavir (Exp1 = 12.8/3.2 mg/kg b.w., n = 14; Exp2 = 38.4/9.6 mg/kg b.w., n = 14; Exp3 = 115.2/28.8 mg/kg b.w., n = 14) from 'day 0' up to the 20th day of pregnancy. Maternal body weight was recorded at the start of the experiment and on the 7th, 14th and 20th day thereafter. At term (20th day), upon laparotomy and hysterotomy, the rats were anesthetized and the amount of implantations, reabsorptions, living fetuses, placentae and intrauterine deaths were recorded. The collected fetuses and placentae were weighed and the concepts were examined under a stereoscope microscope for external malformations. RESULTS: An apparent dose-unrelated lethal effect of the antiviral association on the pregnant rats was observed; notwithstanding, the body weight gain of the surviving rats had no changes, independent of the considered group. It was noted that the quantitative and qualitative intrauterine content of living term rats was indistinguishable from that of the controls. CONCLUSION: There was some degree of deleterious effects of the administration of the lopinavir/ritonavir association on pregnant rats; such effects eventually led to maternal death. However, neither the surviving rats showed toxicity nor did their concepts present any detectable change which could be related to the drug association.

Effect of melatonin supplementation on pregnancy outcome in Wistar-Kyoto and Sprague-Dawley rats.

Although melatonin supplementation is known to influence numerous physiological functions, little is however known of its effects on pregnancy outcome. This study investigated the effects of melatonin supplementation on pregnancy outcome in Wistar-Kyoto (WKY) and Sprague-Dawley (SD) rats aged 12-13 weeks. Upon confirmation of proestrus, each female rat was housed overnight with a male of the same strain. On the next morning, following confirmation of mating (vaginal smear), WKY female rats were isolated into individual metabolic cages and given 0, 25, 50 or 100 mg/kg per day of melatonin in drinking water from day 1 of pregnancy to day 21 postpartum. SD females were given 0 or 100 mg/kg per day of melatonin. Maternal weight, duration of pregnancy, litter size, birth weight and body weight of pups up to day 42, and pup mortality were recorded. Data were analyzed using ANOVA for repeated measures. Compared to controls, maternal weight gain during pregnancy was significantly lower in melatonin-supplemented dams (P < 0.01). Litter size was significantly smaller in melatonin-supplemented dams (P < 0.01). Mean birth weight of pups was significantly lower only in pups of dams given 100 mg/kg per day of melatonin (P < 0.001). Mean body weight of pups of dams given melatonin was significantly lower than controls (P < 0.01). Pup mortalities were 9.5% and 21.6% in WKY dams given 25 and 100 mg/kg per day of melatonin respectively, and all pup deaths occurred after day 21 of weaning. The results suggest that melatonin supplementation during antenatal and postpartum period appears to adversely affect litter size, pup growth and mortality in WKY and SD rats. The precise mechanism causing the death is not clear.

The novel effect of hCG administration on luteal function maintenance during the estrous cycle/pregnancy and early embryo development in the pig.

Two independent experiments were performed on cyclic (Experiment I) and pregnant (Experiment II) gilts to examine the effect of human Chorionic Gonadotropin (hCG) administration on day 12 of the estrous cycle/pregnancy on ovarian and endometrial secretory function. Animals were divided into hCG Group (injection of 750 IU hCG) and Control Group (injection of saline). In Experiment I, the prolonged lifespan of the corpus luteum (CL), extended progesterone (P4) production (P < 0.05) and delayed luteolysis were found. In hCG Group increased ratio of PGE2:PGFM during 12 hrs period on day 15 (P < 0.05) of the estrous cycle was observed. In both experiments, higher concentrations of E2 in hCG treated gilts (P < 0.05) on days 14-15 of the estrous cycle/pregnancy were found. In Experiment II, hCG injection did not affect P4, PGE2 and PGFM concentrations in blood plasma, but reduced the number of resorbed embryos on day 30 of pregnancy. In the pregnant hCG treated gilts the immunostaining against von Willebrand Factor (vWF) demonstrated an enhanced (P < 0.05) angiogenesis in CLs and endometrium. Furthermore, the flow cytometry revealed an increased (P < 0.05) viability of cells in CLs of hCG Group. An augmented expression of Steroidogenic Acute Regulatory Protein (STAR; P < 0.05) and LH/hCG receptor mRNA (P < 0.05) in CLs of hCG Group were observed, but an elevated concentration of protein was confirmed only for STAR (P < 0.05). Our studies revealed, for the first time, that administration of hCG affects PGE2:PGFM ratio during the estrous cycle as well as the development of conceptuses through enhanced angiogenesis and decreased luteal apoptosis in early pregnant pigs.