Effects of maternal methyl donor intake during pregnancy on ileum methylation and function in an intrauterine growth restriction pig model

Background Intrauterine growth retardation(IUGR)affects intestinal growth,morphology,and function,which leads to poor growth performance and high mortality.The present study explored whether maternal dietary methyl donor(MET)supplementation alleviates IUGR and enhances offspring’s growth performance by improving intestinal growth,function,and DNA methylation of the ileum in a porcine IUGR model.Methods Forty multiparous sows were allocated to the control or MET diet groups from mating until delivery.After farrowing,8 pairs of IUGR and normal birth weight piglets from 8 litters were selected for sampling before suckling colostrum.Results The results showed that maternal MET supplementation tended to decrease the IUGR incidence and increased the average weaning weight of piglets.Moreover,maternal MET supplementation significantly reduced the plasma concentrations of isoleucine,cysteine,urea,and total amino acids in sows and newborn pig-lets.It also increased lactase and sucrase activity in the jejunum of newborn piglets.MET addition resulted in lower ileal methionine synthase activity and increased betaine homocysteine S-methyltransferase activity in the ileum of newborn piglets.DNA methylation analysis of the ileum showed that MET supplementation increased the methyla-tion level of DNA CpG sites in the ileum of newborn piglets.Down-regulated differentially methylated genes were enriched in folic acid binding,insulin receptor signaling pathway,and endothelial cell proliferation.In contrast,up-regulated methylated genes were enriched in growth hormone receptor signaling pathway and nitric oxide biosyn-thetic process.Conclusions Maternal MET supplementation can reduce the incidence of IUGR and increase the weaning litter weight of piglets,which may be associated with better intestinal function and methylation status.

Mechanisms underlying the role of endoplasmic reticulum stress in the placental injury and fetal growth restriction in an ovine gestation model

Background Exposure to bisphenol A(BPA),an environmental pollutant known for its endocrine-disrupting properties,during gestation has been reported to increase the risk of fetal growth restriction(FGR)in an ovine model of pregnancy.We hypothesized that the FGR results from the BPA-induced insufficiency and barrier dysfunction of the placenta,oxidative stress,inflammatory responses,autophagy and endoplasmic reticulum stress(ERS).However,precise mechanisms underlying the BPA-induced placental dysfunction,and subsequently,FGR,as well as the potential involvement of placental ERS in these complications,remain to be investigated.Methods In vivo experiment,16 twin-pregnant(from d 40 to 130 of gestation)Hu ewes were randomly distributed into two groups(8 ewes each).One group served as a control and received corn oil once a day,whereas the other group received BPA(5 mg/kg/d as a subcutaneous injection).In vitro study,ovine trophoblast cells(OTCs)were exposed to 4 treatments,6 replicates each.The OTCs were treated with 400μmol/L BPA,400μmol/L BPA+0.5μg/m L tunicamycin(Tm;ERS activator),400μmol/L BPA+1μmol/L 4-phenyl butyric acid(4-PBA;ERS antagonist)and DMEM/F12 complete medium(control),for 24 h.Results In vivo experiments,pregnant Hu ewes receiving the BPA from 40 to 130 days of pregnancy experienced a decrease in placental efficiency,progesterone(P4)level and fetal weight,and an increase in placental estrogen(E2)level,together with barrier dysfunctions,OS,inflammatory responses,autophagy and ERS in type A cotyledons.In vitro experiment,the OTCs exposed to BPA for 24 h showed an increase in the E2 level and related protein and gene expressions of autophagy,ERS,pro-apoptosis and inflammatory response,and a decrease in the P4 level and the related protein and gene expressions of antioxidant,anti-apoptosis and barrier function.Moreover,treating the OTCs with Tm aggravated BPA-induced dysfunction of barrier and endocrine(the increased E2 level and decreased P4 level),OS,inflammatory responses,autophagy,and ERS.However,treating the OTCs with 4-PBA reversed the counteracted effects of Tm mentioned above.Conclusions In general,the results reveal that BPA exposure can cause ERS in the ovine placenta and OTCs,and ERS induction might aggravate BPA-induced dysfunction of the placental barrier and endocrine,OS,inflammatory responses,and autophagy.These data offer novel mechanistic insights into whether ERS is involved in BPA-mediated placental dysfunction and fetal development.

Associations of serum D-dimer and glycosylated hemoglobin levels with third-trimester fetal growth restriction in gestational diabetes mellitus

BACKGROUND Gestational diabetes mellitus(GDM)is a special type of diabetes that commonly occurs in women during pregnancy and involves impaired glucose tolerance and abnormal glucose metabolism;GDM is diagnosed for the first time during pregnancy and can affect fetal growth and development.AIM To investigate the associations of serum D-dimer(D-D)and glycosylated hemoglobin(HbA1c)levels with third-trimester fetal growth restriction(FGR)in GDM patients.METHODS The clinical data of 164 pregnant women who were diagnosed with GDM and delivered at the Obstetrics and Gynecology Hospital of Fudan University from January 2021 to January 2023 were analyzed retrospectively.Among these women,63 whose fetuses had FGR were included in the FGR group,and 101 women whose fetuses had normal body weights were included in the normal body weight group(normal group).Fasting venous blood samples were collected from the elbow at 28-30 wk gestation and 1-3 d before delivery to measure serum D-D and HbA1c levels for comparative analysis.The diagnostic value of serum D-D and HbA1c levels for FGR was evaluated by receiver operating characteristic analysis,and the influencing factors of third-trimester FGR in GDM patients were analyzed by logistic regression.RESULTS Serum fasting blood glucose,fasting insulin,D-D and HbA1c levels were significantly greater in the FGR group than in the normal group,while the homeostasis model assessment of insulin resistance values were lower(P<0.05).Regarding the diagnosis of FGR based on serum D-D and HbA1c levels,the areas under the curves(AUCs)were 0.826 and 0.848,the cutoff values were 3.04 mg/L and 5.80%,the sensitivities were 81.0%and 79.4%,and the specificities were 88.1%and 87.1%,respectively.The AUC of serum D-D plus HbA1c levels for diagnosing FGR was 0.928,and the sensitivity and specificity were 84.1%and 91.1%,respectively.High D-D and HbA1c levels were risk factors for third-trimester FGR in GDM patients(P<0.05).CONCLUSION D-D and HbA1c levels can indicate the occurrence of FGR in GDM patients in the third trimester of pregnancy to some extent,and their combination can be used as an important index for the early prediction of FGR.

Long-term implications of fetal growth restriction

Fetal growth restriction(FGR),or intrauterine growth restriction(IUGR),is a complication of pregnancy where the fetus does not achieve its genetic growth potential.FGR is characterized by a pathological retardation of intrauterine growth velocity in the curve of intrauterine growth.However,the FGR definition is still debated,and there is a lack of a uniform definition in the literature.True IUGR,compared to constitutional smallness,is a pathological condition in which the placenta fails to deliver an adequate supply of oxygen and nutrients to the developing fetus.Infants with IUGR,compared to appropriately grown gestational age infants,have a significantly higher risk of mortality and neonatal complications with long-term consequences.Several studies have demonstrated how suboptimal fetal growth leads to long-lasting physiological alterations for the developing fetus as well as for the newborn and adult in the future.The long-term effects of fetal growth retardation may be adaptations to poor oxygen and nutrient supply that are effective in the fetal period but deleterious in the long term through structural or functional alterations.Epidemiologic studies showed that FGR could be a contributing factor for adult chronic diseases including cardiovascular disease,metabolic syndrome,diabetes,respiratory diseases and impaired lung function,and chronic kidney disease.In this review we discussed pathophysiologic mechanisms of FGR-related complications and potential preventive measures for FGR.

Effects of dietary Bacillus amyloliquefaciens supplementation on growth performance,intestinal morphology, inflammatory response, and microbiota of intra-uterine growth retarded weanling piglets

Background: The focus of recent research has been directed toward the probiotic potential of Bacillus amyloliquefaciens(BA) on the gut health of animals. However, little is known about BA's effects on piglets with intra-uterine growth retardation(IUGR). Therefore, this study investigated the effects of BA supplementation on the growth performance,intestinal morphology, inflammatory response, and microbiota of IUGR piglets.Methods: Eighteen litters of newborn piglets were selected at birth, with one normal birth weight(NBW) and two IUGR piglets in each litter(i.e., 18 NBW and 36 IUGR piglets in total). At weaning, the NBW piglet and one of the IUGR piglets were assigned to groups fed a control diet(i.e., the NBW-CON and IUGR-CON groups). The other IUGR piglet was assigned to a group fed the control diet supplemented with 2.0 g BA per kg of diet(i.e., IUGR-BA group). The piglets were thus distributed across three groups for a four-week period.Results: IUGR reduced the growth performance of the IUGR-CON piglets compared with the NBW-CON piglets. It was also associated with decreased vil us sizes, increased apoptosis rates, reduced goblet cel numbers, and an imbalance between pro-and anti-inflammatory cytokines in the smal intestine. Supplementation with BA improved the average daily weight gain and the feed efficiency of the IUGR-BA group compared with the IUGR-CON group(P < 0.05). The IUGR-BA group exhibited increases in the ratio of jejunal vil us height to crypt depth, in ileal vil us height, and in ileal goblet cel density. They also exhibited decreases in the numbers of jejunal and ileal apoptotic cel s and ileal proliferative cel s(P < 0.05). Supplementation with BA increased interleukin 10 content, but it decreased tumor necrosis factor alpha level in the smal intestines of the IUGR-BA piglets(P < 0.05). Furthermore, compared with the IUGR-CON piglets, the IUGR-BA piglets had less Escherichia coli in their jejunal digesta, but more Lactobacil us and Bifidobacterium in their ileal digesta(P < 0.05).Conclusions: Dietary supplementation with BA improves morphology, decreases inflammatory response, and regulates microbiota in the smal intestines of IUGR piglets, which may contribute to improved growth performance during early life.

Antenatal taurine reduces cerebral cell apoptosis in fetal rats with intrauterine growth restriction

From pregnancy to parturition, Sprague-Dawley rats were daily administered a low protein diet to establish a model of intrauterine growth restriction. From the 12th day of pregnancy, 300 mg/kg taurine was daily added to food until spontaneous delivery occurred. Brain tissues from normal neonatal rats at 6 hours after delivery, neonatal rats with intrauterine growth restriction, and neo- natal rats with intrauterine growth restriction undergoing taurine supplement were obtained for fur- ther experiments. The terminal deoxyribonucleotidyl transferase （TdT）-mediated biotin-16-dUTP nick-end labeling assay revealed that the number of apoptotic cells in the brain tissue of neonatal rats with intrauterine growth restriction significantly increased. Taurine supplement in pregnant rats reduced cell apoptosis in brain tissue from neonatal rats with intrauterine growth restriction. Immu- nohistochemical staining revealed that taurine supplement increased glial cell line-derived neuro- trophic factor expression and decreased caspase-3 expression in the cerebral cortex of intrauterine growth-restricted fetal rats. These results indicate that taurine supplement reduces cell apoptosis through the glial cell line-derived neurotrophic factor-caspase-3 signaling pathway, resulting in a protective effect on the intrauterine growth-restricted fetal rat brain.

Intrauterine growth restriction alters growth performance, plasma hormones,and small intestinal microbial communities in growing-finishing pigs

Background: The interaction of the gut microbiota with key metabolic and physiological processes may be associated with poor growth outcomes in animals born with intrauterine growth restriction(IUGR).Results: Growth performance, plasma hormone concentrations, and intestinal microbiota composition were analyzed in IUGR pigs and in normal birth weight(NBW) pigs when the NBW pigs reached 25, 50, and 100 kg of body weight(BW). Compared to NBW pigs, IUGR pigs had lower initial, weaned, and final BW, and lower average daily gain and average daily feed intake in all the considered time points. In the 25 kg BW group, IUGR pigs had higher concentrations of plasma ghrelin and pancreatic polypeptide(PP), but lower insulin concentration than NBW pigs, while the situation was reversed in the 50 kg BW group. As compared to NBW pigs, IUGR pigs had higher microbial alpha diversity in the jejunum and ileum;in the 50 and 100 kg BW groups, IUGR pigs had higher Firmicutes abundance but lower Proteobacteria abundance in the jejunum, and lower Lactobacillus abundance in the jejunum and ileum;in the 25 kg BW group, IUGR pigs showed higher unclassified Ruminococcaceae abundance in the ileum;and in 25 and 50 kg BW groups, IUGR pigs showed lower Ochrobactrum abundance in the jejunum.Spearman's correlation revealed that Lactobacillus was negatively correlated with growth performance, while unclassified Ruminococcaceae was positively correlated. Predictive metagenomic analysis detected significantly different expression of genes in the intestinal microbiota between IUGR and NBW pigs, suggesting different metabolic capabilities between the two groups.Conclusions: Growing-finishing IUGR pigs showed lower growth performance, higher microbial alpha diversity, and differences in plasma hormone concentrations compared to NBW pigs. Alterations in the abundance of Firmicutes,Proteobacteria, Ruminococcaceae, Lactobacillus, and Ochrobactrum in the small intestine may be associated with IUGR, and may therefore serve as a future target for gut microbiota intervention in growing-finishing IUGR pigs.

Effect of Bushen Yiqi Huoxue Recipe on Placental Vasculature in Pregnant Rats with Fetal Growth Restriction Induced by Passive Smoking

Interactions of vascular endothelial growth factor （VEGF） with receptors VEGFR1/Fltl and VEGFR2/Flk1, and those of angiopoietins （Ang-1, Ang-2） with receptor Tie2 play important roles in placental angiogenesis. This study investigated vascular morphology and expression of these angiogenic factors in rat placenta on the day 15, 18, 21 of gestation （D 15, D 18 and D21）. The rats were randomly assigned into 3 groups： normal group, model group [fetal growth restriction （FGR） model], and Bushen Tqi Huoxue （BYHR） recipe treatment group （BYHR group, the pregnant rats with FGR were treated with BYHR recipe）. Morphological analysis indicated that during initial villous formation, fetal nucle- ated erythrocytes （FNEs） appeared in maternal blood sinus （MBS）. Subsequently, FNEs were sur- rounded by endothelial cells to form fetal capillary （FC） and then by trophoblast cells to form villi. As pregnancy proceeded, FC density increased progressively with increasing endothelial identification staining （EIS） in normal and BYHR groups. Whereas, villous formation was suppressed, normal in- crease in FC density was impaired and EIS was weakened in model group. Quantitative PCR analysis showed that VEGF and Flkl mRNA increased over gestation in all groups, indicating that VEGF might play a pivotal role in FC growth during late gestation. VEGF mRNA was increased on D15, while de- creased on D21 in model group as compared with normal group and BYHR group. Immunohistochemi- cally, Ang-2 protein was highly expressed in FNEs, gradually disappeared as villi matured, and decreased over gestation in all groups, indicating that Ang-2 might play a pivotal role in villous formation, which was further supported by decreased Ang-2 mRNA and protein expression in model group on D 15. Ang-1 mRNA, Tie2 mRNA and Ang-1/Ang-2 ratio increased from D15 to D18 in all groups as placenta matured. Ang-1 mRNA, Tie2 mRNA and Ang-1/Ang-2 ratio were decreased on D18 in model group as compared with normal and BYHR groups, indicating delayed maturity of FGR placenta. Alterations in angiogenic factors may result in altered placental vasculature and cause placental insufficiency. BYHR recipe could balance the angiogenic factors to promote the formation and maturation of FGR placental vasculature.

Antioxidant capacity and concentration of redox-active trace mineral in fully weaned intra-uterine growth retardation piglets

Background： The redox status of intra-uterine growth retardation（IUGR） piglets post-weaning has been poorly studied.Methods： Newborns from twenty-four sows were weighted, weaned at 21 d and fed a starter diet until sampling.Sampling was done at 14 d post-weaning. A piglet was defined as IUGR when its birth weight was 2 SD below the mean birth weight of the total population. At weaning, eighteen piglets with nearly equal body weight from each category（i.e. IUGR or normal birth weight（NBW） piglets） were selected and then allocated to two treatments,consisted of six replicates with each pen having three piglets.Results： Compared with NBW group, IUGR significantly decreased average daily gain（P 〈 0.001）, average daily feed intake（P = 0.003）, and feed efficiency（P 〈 0.001） of piglets during the first two weeks post-weaning. IUGR decreased the activities of total antioxidant capacity（P = 0.019）, total superoxide dismutase（T-SOD, P = 0.023）,and ceruloplasmin（P = 0.044） but increased the levels of malondialdehyde（P = 0.040） and protein carbonyl（P = 0.010） in plasma. Similarly, the decreased activities of T-SOD（P = 0.005）, copper- and zinc-containing superoxide dismutase（Cu/Zn-SOD, P = 0.002）, and catalase（P = 0.049） was observed in the liver of IUGR piglets than these of NBW piglets. IUGR decreased hepatic Cu/Zn-SOD activity（P = 0.023） per unit of Cu/Zn-SOD protein in piglets when compared with NBW piglets. In addition, IUGR piglets exhibited the decreases in accumulation of copper in both plasma（P = 0.001） and liver（P = 0.014）, as well as the concentrations of iron（P = 0.002） and zinc（P = 0.048） in liver. Compared with NBW, IUGR down-regulated m RNA expression of Cu/Zn-SOD（P = 0.021） in the liver of piglets.Conclusions： The results indicated that IUGR impaired antioxidant capacity and resulted in oxidative damage in fully weaned piglets, which might be associated with the decreased levels of redox-active trace minerals. This study highlights the importance of redox status in IUGR offspring and provides a rationale for alleviating oxidative damage by dietary interventions aiming to supplement trace minerals and to restore redox balance in the future.

Growth restriction effects during solidification of aluminium alloys

The effects of solute elements during solidification on the grain size are very important and can be quantified by the growth-restriction parameter Q,and Q possesses the better correlation with the grain size. Based on the constitutional undercooling generated by the growth of an adjacent grain during the initial solidification,the growth-restriction parameter Q is deduced and a comprehensive physical basis of Q is obtained by using an initial solute distributing equation. For the alloys with more potent nucleants,Q is a suitable predictor of the grain size. For less potent nucleants,the relative grain size(RGS) is a more accurate prediction of the grain size. This prediction coincides with the experimental behaviors for Al-Ti and Al-Cu alloys with lower solute content.

Concentrations of Polybrominated Diphenyl Ethers in Maternal Blood,Placental Size,and Risk for Fetal Growth Restriction:A Nested Case-control Study

Objective To explore the effects of prenatal exposure to polybrominated diphenyl ethers(PBDEs)on placental size and birth outcomes.Methods Based on the perspective Wenzhou Birth Cohort,this nested case-control study included 101 fetal growth restriction(FGR)and 101 healthy newborns.Maternal serum samples were collected during the third trimester and measured for PBDEs by gas chromatography tandem mass spectrometry.The basic information of mother-newborn pairs was collected from questionnaires,whereas the placental size and birth outcomes of newborns were obtained from hospital records.Results A total of 19 brominated diphenyle ether(BDE)congeners were detected in maternal serum samples.Higher concentrations of BDE-207,-208,-209,and∑19PBDEs were detected in FGR cases than in controls.Increased BDE-207,-208,-209,and∑19PBDEs levels in maternal serum were related to decreased placental length,breadth,surface area,birth weight,birth length,gestational age,and Quetelet index of newborns.After adjusting for confounders,BDE-207 and∑19PBDE concentrations in maternal serum were significantly associated with an increased risk of FGR.Conclusion A negative association was found between PBDE levels in maternal serum and placental size and birth outcomes.Prenatal PBDE exposure may be associated with elevated risk of the incidence of FGR birth.

Expression of soluble vascular endothelial growth factor receptor-1 and placental growth factor in fetal growth restriction cases and intervention effect of tetramethylpyrazine

Objective:To investigate the expression of soluble vascular endothelial growth factor receptor-1(sFlt-1) and placental growth factor(PLGF) in the fetal growth restriction(FGR) cases and the intervention mechanism of tetramelhylpyrazine.Methods:A total of 60 fetal growth restriction cases that admitted lo our hospital were randomly divided into ligustrazine intervention group(group A) and nutritional support group(group B).A total of 50 healthy pregnant women were also enrolled as control group(group C).Expression level of maternal serum sFlt1,FLGF and fetal growth parameters including HC,AC,FL,BPD,EFW as well as placenta PLGF,sFlt-1 mRNA expression were recorded and compared among the three groups.A total of 15 SD rats were selected and were divided into lliree groups.TMP group,alcohol and tobacco group and blank control group.Three groups of rats were dissected on the twentieth day of gestation.Result:Expression level of sFlt-1 and PLGF in group A was not significantly different from that of group C(P>0.05):but significant difference in SFlt1 and PLGF expression level was observed between group C and group B(P<0.05).Before treatment.HC,AC,FL,BPD and EFW of group A and group B were significant lower than those of group C.hut after treatment,those parameters in group A were significantly improved(P<0.05).In the animal experiment there was no significant difference in sFlt-1 between treatment group and FGR group without treatment or control group(P>0.05).There was significant difference in PLGF between FGR group with treatment and FGR group without treatment or control group(P<0.01).Conclusions:PLGF level is decreased and sFlt-1 increased in patients suffered from fetal growth restriction,and FGR rats show increased sFlt-1 and decreased PLGF.thus they can be indicator of the fetal growth restriction.Ligustrazinc can effectively improve sFlt-1,PLGF expression level in fetal growth restriction cases,which can be used as treatment for FGR.

Low maternal leptin levels in preeclamptic women with fetal growth restriction

Objective: We hypothesized that preeclamptic women with intrauterine growth restriction (IUGR) would have lower concentrations of leptin compared to women with normal fetal growth. Methods: A crosssectional study was performed in 20 cases of IUGR and 20 normal fetuses born to women diagnosed with preeclampsia. Blood samples were collected from mothers at term gestation and with fetal birth weight less than 2500 grams would categorized as IUGR. The subjects were recruited by consecutive sampling conducted in Hasan Sadikin Hospital and several network hospitals during the period of September-November 2012. Results: A significant difference (p = 0.015) in maternal serum leptin levels was found between IUGR (22.1 ng/ml) and normal fetuses (36.5 ng/ml). Serum levels of leptin in preeclamptic women with IUGR were lower than normal fetuses. Spearman correlation test between maternal serum leptin levels and birth weight in IUGR did not demonstrate a significant correlation, with r = -0.321 (p = 0.168). Conclusion: The maternal leptin concentrations in IUGR are lower than the normal fetus in preeclampsia cases, but there was not enough evidence to support that leptin is associated with birth weight in IUGR.

Impairments of spatial learning and memory in rat offspring with fetal growth restriction

Objective： Throughout the world, fetal growth restriction（FGR） is one of the most severe complications occurring during pregnancy. It is subsequently associated with neurologic abnormalities in chldren. Our aim was to investigate the spatial learning and memory ability of rat offspring born With FGR. Methods：A rat model of FGR was constructed using the method of passive smoking. Spatial learning and memory were studied in rat offspring born with FGR by assessing the animals＇ performance using the Morris water maze task. Results： At 1- and 2- months of age, both female and male offspring rats showed impairment of performance, while at 4 months of age, only female rats showed impaired performance. The FGR offspring spent a longer time swimming and used inefficient strategies（P〈 0.05, respectively）. However, there were no significant maze performance FGR effects in the 4 month old male rats. In all groups of FGR offspring, irrespective of age or sex, the time spent in the platform quadrant by the rat was significantly less than that in the control group（P〈 0.05）. Conclusion： The Morris water maze performance decreased in rat offspring born with FGR. It is suggested that FGR can cause impairments of spatial learning and memory in young animals.

Examination of the molecular control of ruminal epithelial function in response to dietary restriction and subsequent compensatory growth in cattle

Background： The objective of this study was to investigate the effect of dietary restriction and subsequent compensatory growth on the relative expression of genes involved in volatile fatty acid transport, metabolism and cell proliferation in ruminal epithelial tissue of beef cattle. Sixty Holstein Friesian bulls（mean liveweight 370 ± 35 kg;mean age 479 ± 15 d） were assigned to one of two groups：（i） restricted feed allowance（RES; n = 30） for 125 d（Period 1） followed by ad libitum access to feed for 55 d（Period 2） or（ii） ad libitum access to feed throughout（ADLIB; n = 30）. Target growth rate for RES was 0.6 kg/d during Period 1. At the end of each dietary period, 15 animals from each treatment group were slaughtered and ruminal epithelial tissue and liquid digesta harvested from the ventral sac of the rumen. Real-time q PCR was used to quantify m RNA transcripts of 26 genes associated with ruminal epithelial function. Volatile fatty acid analysis of rumen fluid from individual animals was conducted using gas chromatography.Results： Diet × period interactions were evident for genes involved in ketogenesis（BDH2, P = 0.017）, pyruvate metabolism（LDHa, P = 0.048; PDHA1, P = 0.015） and cellular transport and structure（DSG1, P = 0.019; CACT, P = 0.027）. Ruminal concentrations of propionic acid（P = 0.018） and n-valeric acid（P = 0.029） were lower in RES animals, compared with ADLIB, throughout the experiment. There was also a strong tendency（P = 0.064）toward a diet × period interaction for n-butyric with higher concentrations in RES animals, compared with ADLIB, during Period 1.Conclusions： These data suggest that following nutrient restriction, the structural integrity of the rumen wall is compromised and there is upregulation of genes involved in the production of ketone bodies and breakdown of pyruvate for cellular energy. These results provide an insight into the potential molecular mechanisms regulating ruminal epithelial absorptive metabolism and growth following nutrient restriction and subsequent compensatory growth.

Effect of behavior training on learning and memory of young rats with fetal growth restriction

Objective: To investigate the effect of behavior training on the learning and memory of young rats with fetal growth restriction (FGR). Methods: The model of FGR was established by passive smoking method to pregnant rats. The new-born rats were divided into FGR group and normal group, and then randomly subdivided into trained and untrained group respectively. Morris water maze behavior training was performed on postnatal months 2 and 4, then learning and memory abilities of young rats were measured by dark-avoidance testing and step-down testing. Results: In the dark-avoidance and step-down testing, the young rats’ performance of FGR group was worse than that of control group, and the trained group was better than the untrained group significantly. Conclusion: FGR young rats have descended learning and memory abilities. Behavior training could improve the young rats’ learning and memory abilities, especially for the FGR young rats.

Intrauterine growth restriction and genetic determinantsexisting findings, problems, and further direction

Fetal growth is determined largely by the nutrient supply, placental transport function, and growth hormones. Recently, gene mutation and expression, especially of those genes associated with the proteins that are related to the fetal growth, have been reported to play an important role in the development of intrauterine growth restriction(IUGR). Fetal growth epigenetics, a new concept in fetal growth, has resulted from studies on fetal programing. This paper outlines the findings of our serial studies on IUGR, and summarizes data on IUGR animal models, placental function in transferring nutrients, cell proliferation dynamics in IUGR, and experimental treatment of IUGR. We review genetic approaches to IUGR, especially those relating to growth factor genes, angiotensinogen genes and other gene mutations. We also discuss the epigenetics of fetal growth and future study directions on fetal growth restriction. These should be valuable in elucidating the mechanisms employed by the fetus and in helping to develop interventional strategies that might prevent the development of IUGR.

Impact of dietary L-arginine supply during early gestation on myofiber development in newborn pigs exposed to intra-uterine crowding

Background: Intra-uterine crowding(IUC) observed in hyperprolific sows impairs myofiber hyperplasia and overall fetal growth. Arginine supplementation(ARG) in gestation diets has been shown to positively affect litter and muscle development. The study objective was to assess whether the effect of ARG on offspring characteristics, with special emphasis on myofiber hyperplasia, differs under IUC conditions from these responses,because in that situation growth retardation is particularly prevalent due to reduced fetal nutrient supply.Unilateral oviduct ligation(OL) was used as a model for an uncrowded and hyperprolificacy(IN) as a model for a crowded intra-uterine environment.Methods: Five OL and five IN sows were fed a diet supplemented daily with either 43 g L-alanine(Ctrl) or 25 g L-arginine from d 14 to 28 of gestation in a cross-over design(two periods: 5^( th) and 6^( th) parity). At farrowing, two male and two female offspring, respectively, with a low and intermediate birth weight(BtW) were selected. After euthanization, the Semitendinosus muscle(STM) was removed and weighed, and the light and dark portions(STM_d and STM_l) were prepared for myofiber histochemistry using ATPase staining and the entire STM for gene expression analysis of myogenesis-related genes using RT-qPCR. In addition, various organs were removed and weighed. Data were analyzed using the MIXED model in SYSTAT.Results: No effect of either IUC or dietary treatment was found in litter characteristics. Offspring of ARG sows displayed a greater muscle area in STM(P < 0.01) as a result of the greater myofiber hyperplasia(P < 0.01). The increase was more distinct in the STM_l(P < 0.05) than in the STM_d(P = 0.131). Offspring of OL sows were heavier at birth(P < 0.01), had a heavier STM(P < 0.05), liver(P < 0.01) and kidney(P < 0.05), but when expressed relative to birth weight, these differences were absent. In addition, IUC had an effect(P < 0.05) on the expression of one of the myogenesis-related genes investigated.Conclusions: Independent from the extent of IUC, ARG improved Bt W, muscle and organ weights and myofiber hyperplasia in offspring.

Glucose Metabolic and Gluconeogenic Pathways Disturbance in the Intrauterine Growth Restricted Adult Male Rats

Objective To explore the molecular mechanism of type 2 diabetes in intrauterine growth restricted adult rats through determination of blood glucose and expression of gluconeogenic enzymes in liver.Methods Male intrauterine growth restriction(IUGR) offspring induced by maternal protein-malnutrition and normal controls were studied.The body weights of offspring rats were weighted from birth to 12 weeks of age.Fasting plasma glucose and insulin levels were determined by glucose oxidase method and enzyme-linked immunosorbent assay(ELISA) respectively at 1 week,8 weeks,and 12 weeks.Peroxisome proliferator-activated receptor-γ coactivator-1α(PGC-1α),phosphoenolpyruvate carboxykinase(PEPCK),and glucose-6-phosphatase(G6Pase) mRNA and protein levels in liver were measured by real time RT-PCR and Western blot in newborn rats(Week 1) and adult rats(Week 12).Results Birth weights of IUGR rats were significantly lower than those of controls until 4 weeks later,when IUGR rats caught up to controls.Between 8 and 12 weeks,the growth of IUGR rats surpassed that of controls.No significant differences were observed in blood glucose and insulin levels at newborn rats between the two groups.However,by the end of 8 weeks IUGR rats developed hyperinsulinemia and high insulin resistance index.At the age of 12 weeks,IUGR rats had mild fasting hyperglycemia.In addition,hepatic PGC-1α mRNA and protein levels as well as hepatic mRNA levels of PEPCK and G6Pase at Week 1 and Week 12 in IUGR rats were all significantly higher than those of controls(P<0.05).Conclusions As a result of intrauterine malnutrition,the expression of gluconeogenic genes is exaggerated in offspring.This change stays through adulthood and may contribute to the pathogenesis of type 2 diabetes.

Compensatory growth in hybrid tilapia (Oreochromis mossambicus×O. niloticus) reared in seawater, following restricted feeding

Hybrid tilapia weighing 7.71 g were reared in seawater at 24.0-29.0℃ for 8 weeks. The controls were fed to satiation twice a day throughout the experiment, whereas treatment groups were fed at 0.5%, 1.5% or 3.0% body weight per day for 4 weeks, and then to satiation for the remainder of the experiment. During the first 4-week period, there was a curvilinear relationship between growth rate and ration size. Fish fed 0.5% and 1.5% rations displayed compensatory growth response of 2 weeks duration during realimentation. The weight-adjusted growth rate of fish fed at 3% ration was not significantly different from that of the controls by the end of the experiment, when none of the treatment groups had caught up in body weight with the controls. Hyperphagia was observed for the first 2 weeks of realimenatation in fish previously fed at 3% ration, but persisted for the whole realimentation period in groups previously fed at 0.5% and 1.5% rations. None of the feed restricted groups showed improved digestibility, feed efficiency, or protein and energy retention efficiency.