Restricted feed intake in lactating primiparous sows. I. Effects on sow metabolic state and subsequent reproductive performance

The effects of feed restriction (60% of anticipated feed intake; Restrict; n=60) during the last week of a 21-day lactation in primiparous sows compared with feeding at 90% of anticipated feed intake (Control; n=60) on sow metabolic state, litter growth and sow reproductive performance after weaning were compared. Metabolisable energy (ME) derived from feed was lower, ME derived from body tissues was higher and litter growth rate was reduced (all P<0.05) in Restrict sows during the last week of lactation. Treatment did not affect weaning-to-oestrus interval, pregnancy rate, ovulation rate, embryonic survival or the number of live embryos (P>0.05) at Day 30 of gestation: However, embryo weight was greater (P<0.05) in Control than in Restrict sows (1.55±0.04vs 1.44±0.04g, respectively). These data suggest the biology of the commercial sow has changed and reproductive performance of contemporary primiparous sows is increasingly resistant to the negative effects of lactational catabolism. Overall, catabolism negatively affected litter weaning weight and embryonic development of the next litter, but the extent to which individual sows used tissue mobilisation to support these litter outcomes was highly variable.     

Nutritional restriction in lactating primiparous sows selectively affects female embryo survival and overall litter development

This study explored the possibility of sex-specific effects on embryonic survival in primiparous sows subjected to restricted feed intake during the last week of lactation and bred after weaning (Restrict; n = 16), compared with control sows fed close to ad libitum feed intakes (Control; n = 17). Restrict sows were in a substantial negative net energy balance at weaning, and lost 13% of estimated protein and 17% of fat mass during lactation, yet the weaning-to-oestrous interval and ovulation rate were not different between treatments. However, embryonic survival at Day 30 of gestation was lower (P < 0.05) in Restrict than Control sows, and selectively reduced the proportion of female embryos surviving (P < 0.01). A decrease in weight and crown-rump length of surviving female (P < 0.05) and male (P < 0.05) embryos was seen in Restrict litters. The mechanisms mediating this sex-specific effect on embryonic loss in feed-restricted sows are unclear. The data presented here indicate that feed-restriction during the last week of lactation in primiparous sows causes a selective decrease in survival of female embryos and limits the growth of all surviving embryos.     

Ontogeny of metabolic effects on embryonic development in lactating and weaned primiparous sows

Using an established experimental paradigm, feed restriction during the last week of lactation in primiparous sows reduces embryonic growth and development and produces female-specific embryonic mortality by Day 30 of gestation. Because this gender-specific loss of embryos at Day 30 was associated with changes in the variation of markers of epigenetic imprinting, the present study sought to establish the ontogeny of such epigenetic affects. Leucocyte DNA of restrict-fed sows exhibited decreased global methylation during the last week of lactation and during the return to oestrus (P < 0.05), but no associated changes in plasma folate and vitamin B(12). Furthermore, no changes in methylation of blastocyst DNA, embryonic sex ratios or development were evident at Day 6 of gestation that would characterise the underlying defects that reduced female embryo survival by Day 30. However, regardless of treatment, embryo recovery rates and synchrony in embryonic development were associated with the stage of development of the recovered embryos (r = 0.68; P < 0.001). The subset of sows classified as bearing litters with superior embryonic development had lower net energy balance over lactation (P < 0.01) and higher ovulation rates (P < 0.005) compared with sows classified as having poorer embryonic development. Collectively, these data suggest that a subset of litters within restrict-fed sows will be most sensitive to the latent epigenetic mechanisms that ultimately trigger gender-specific loss of embryos by Day 30 of gestation, but that these selective mechanisms are not evident by Day 6 of gestation.     

Supplementation of sows with L-carnitine during pregnancy and lactation improves growth of the piglets during the suckling period through increased milk production

Recent studies showed that piglets of sows fed diets supplemented with L-carnitine grow faster during the suckling period than piglets of control sows fed diets without L-carnitine. This study was undertaken to investigate the effect of L-carnitine supplementation in sows on milk production and milk constituents. An experiment was performed in which two groups of 20 gilts each were fed diets with or without supplemental L-carnitine during pregnancy (0 vs. 125 mg L-carnitine daily/sow) and lactation (0 vs. 250 mg L-carnitine daily/sow). The experiment was continued over two reproductive cycles. L-carnitine-treated sows had larger litters (P<0.01) and higher litter weights (P<0.05) than control sows. Piglets of L-carnitine-treated sows had lower birth weights (P<0.05) but grew faster during the suckling period (P<0.01) and were heavier (P<0.05) at weaning than piglets of control sows. L-carnitine-treated sows had higher milk yields on d 11 and 18 of lactation than control sows (P<0.05). Milk of L-carnitine-treated sows had higher concentrations of total and free carnitine than milk of control sows (P<0.001); concentrations of fat, protein and lactose and the amounts of gross energy in the milk did not differ between the two groups of sows. The amounts of protein (P<0.05) and lactose (P<0.05) were higher in L-carnitine-treated sows than in control sows; the amount of energy secreted with the milk tended to be higher in carnitine-treated sows than in control sows (P<0.10). The study suggests that piglets of carnitine-treated sows grow faster during the suckling period than those of control sows because they ingest more nutrients and energy with the milk.     

Altered epigenetic variance in surviving litters from nutritionally restricted lactating primiparous sows

Feed restriction of primiparous sows during the last week of lactation has been shown to decrease embryonic growth and female embryo survival to Day 30 of gestation. This study sought to determine whether global DNA methylation and epigenetic gene expression of the candidate genes Igf2, Igf2r, and Xist were associated with these treatment effects. Given that these epigenetic traits are expected to be important for embryo viability, changes in variance for these traits at Day 30 were predicted to be reflected in the loss of abnormal embryos at this time. Consistent with this prediction, variance in DNA methylation was reduced (P < 0.001) in Restrict male embryo, and there was a tendency for reduced variance (P < 0.06) in Restrict female embryos. Variation in DNA methylation tended to be correlated (R = 0.42, P < 0.1) with the difference in variance of embryo weights between treatments (P < 0.01), suggesting a relationship between epigenetic changes and embryonic development. Variance in Igf2r expression tended to decrease (P < 0.07) in Restrict female embryos while variance in Xist expression tended to decrease in Restrict male embryos (P < 0.08), suggesting that maternally inherited epigenetic defects may cause female embryonic loss and reduced growth before Day 30 of gestation.     

L-carnitine supplementation of sows during pregnancy improves the suckling behaviour of their offspring

It has been shown that L-carnitine supplementation of sows increases their milk production and the postnatal growth of the suckling piglets. To test the hypothesis that this effect is due to an improved suckling behaviour of the piglets, two experiments with sows were performed. Two groups of thirteen or ten sows each (in experiments 1 and 2, respectively) were fed diets with or without supplemental L-carnitine during pregnancy (125 mg/d) and lactation (250 mg/d). After birth, the litters of all sows were standardised to equal sizes of eleven and nine piglets per litter in experiments 1 and 2, respectively. In experiment 1, the piglets of L-carnitine-supplemented sows had a higher total suckling time per day on days 3, 6 and 9, and greater weight gains during the suckling period, than the piglets of control sows (P<0.05). In experiment 2, all litters were taken away from their mothers and switched to other sows. Half of the control sows and half of the L-carnitine-supplemented sows were given litters born to control sows, the other half of each group being given litters born to L-carnitine-supplemented sows. Piglets born to L-carnitine-supplemented sows had a higher total suckling time per day on day 3 and greater body weight gains during the first 14 d compared with piglets born to control sows (P<0.05). This study shows that piglets born to sows supplemented with L-carnitine are able to suckle for longer, which enables them to obtain more milk and grow faster than piglets born to control sows.     

Temporal candidate gene expression in the sow placenta and embryo during early gestation and effect of maternal Progenos supplementation on embryonic and placental development

The present study characterised gene expression associated with embryonic muscle development and placental vascularisation during early gestation in the pig and examined effects of Progenos supplementation in early pregnancy. Tissues were collected from commercial multiparous sows (n = 48) from Days 16 to 49 of gestation. In the placenta, qPCR revealed that vascular endothelial growth factor (VEGFA) expression did not change from Day 17 to 49 of gestation; however, KDR receptor and angiopoietin-1 and -2 expression were differentially regulated, with periods of high expression corresponding to two critical phases of angiogenesis in the pig. In the embryo, the pattern of myogenesis-related gene expression was consistent with available literature. A commercially available nutritional supplement Progenos (20 g day?1 L-arginine) added to the diet of sows from either Day 15 to 29 (P15-29; n = 33), Day 30 to 44 (n = 29) or from Day 15 to 44 (n = 76) of gestation tended to increase (P = 0.058) embryonic growth rate compared with non-supplemented controls (n = 79) and angiogenin expression was higher (P = 0.028) at Day 30 of gestation in placentae from sows on the P15-29 Progenos treatment. These results are consistent with proposed beneficial effects of l-arginine on early embryonic development and placental vascularisation.     

叶酸缺乏对胚胎停育患者绒毛印记基因甲基化的影响

目的 探讨叶酸缺乏对胚胎停育患者绒毛印记基因甲基化的影响.方法 选取2015年4月至2017年4月在陆军总医院263临床部妇科门诊224例胚胎停育患者(研究组)以及同期同比例自愿来陆军总医院263临床部人工流产孕妇(对照组),按照是否叶酸缺乏分为叶酸正常亚组和叶酸缺乏亚组,分析不同组别胰岛素生长因子2、父系表达基因3以及生长因子受体结合蛋白10甲基化状态.结果 对照组叶酸正常亚组IGF2、GRB10的甲基化指数均低于研究组叶酸缺乏亚组、叶酸正常亚组(t值分别为8.21、7.54、6.12、5.29,均P<0.05).对照组与研究组IGF2、GRB10异常甲基化率比较,差异有统计学意义(χ2值分别为6.11、6.34,均P<0.05).研究组组内叶酸缺乏亚组IGF2、GRB10异常甲基化率显著高于叶酸正常亚组(χ2值分别为5.02、5.44,均P<0.05);对照组叶酸正常亚组IGF2、GRB10异常甲基化率均显著低于研究组叶酸缺乏亚组(χ2值分别为6.17、6.43,均P<0.05).结论 叶酸缺乏可能导致IGF2、PEG3基因甲基化程度以及异常甲基化率增高,从而引起胚胎停育.     

Effect of sow vitamin D status at parturition on the vitamin D status of neonatal piglets

The plasma concentrations of calcium, phosphorus, vitamin D, and vitamin D metabolites were determined in cholecalciferol-treated sows and untreated sows at parturition and their piglets (at birth and at 10 days of age) to determine the relationship between sow vitamin D status and neonatal piglet vitamin D status. At birth, there was a high degree of correlation between sow and piglet plasma concentrations of 25-hydroxycholecalciferol (r = 0.944), 24,25-dihydroxycholecalciferol (r = 0.895), and 25,26-dihydroxycholecalciferol (r = 0.737). Neonatal piglet plasma 1,25-dihydroxyvitamin D was low (42.0 +/- 10.2 pg/ml) and was not correlated with maternal plasma 1,25-dihydroxyvitamin D (r = 0.022). Neonatal plasma calcium and phosphorus were significantly correlated (P less than 0.05) with maternal plasma 1,25-dihydroxyvitamin D (r = 0.515 and 0.581, respectively). Parenteral cholecalciferol treatment of sows before parturition proved an effective means of supplementing young piglets with cholecalciferol (via the sow's milk) and its more polar metabolites via placental transport. However, it had no significant effect on either the plasma mineral or 1,25-dihydroxyvitamin D status of the sow or young piglet.     

Safety of classical swine fever virus vaccine strain LOM in pregnant sows and their offspring

The present study aimed to evaluate the safety of the classical swine fever virus (CSFV) vaccine strain LOM in pregnant sows. Pregnant sows with free CSFV antibody were inoculated with a commercial LOM vaccine during early pregnancy (day 38; n = 3) or mid-pregnancy (days 49–59; n = 11). In pregnant sows vaccinated during the early stages of gestation, abortion (day 109) was observed in one case, with two stillbirths and seven mummified fetuses. The viability of live-born piglets was 34.9% in sows vaccinated during mid-pregnancy compared with 81.8% in the control group. Post-mortem examination of the organs of the sows and piglets did not reveal any pathological lesions caused by CSFV; however, CSFV RNA was detected in the organs of several vaccinated sows and their litters. The LOM strain was transmitted from sows with free CSFV antibody to their fetus, but did not appear to induce immune tolerance in the offspring from vaccinated pregnant sows. Side effects were not observed in pregnant sows with antibody to the LOM strain: transmission from sow to their litters and stillbirth or mummified fetuses. The LOM strain may induce sterile immunity and provide rapid, long-lasting, and complete protection against CSFV; however, it should be contraindicated in pregnant sows due to potential adverse effects in pregnant sows with free CSFV antibody.     

Experimental transplacental transmission of porcine cytomegalovirus.

Six serologically negative sows were infected by intranasal instillation of porcine cytomegalovirus (PCMV) between 31 and 85 days of pregnacy. Four sows showed an afebrile anorexia and lethargy 14-25 days after infection and all 6 developed significant increases in indirect immunofluorescent (IIF) antibody titres within 35 days. Virus was recovered from nasal and/or cervical swabs from 2 sows during life and from lung macrophage cultures after death. At term the sows were killed and their fetuses harvested by caesarean section. The number of mummified and stillborn fetuses increased from 4/63 in 6 previous litters to 18/60 in the 6 present litters. Nine of 43 fetuses born alive were reared in isolators for up to 6 weeks but the majority were killed for examination on the day of birth. Virus was isolated from 16 piglets from 4 of the 6 litters examined; it was isolated most frequently from lungs and liver but also from spleen, kidney, brain and nasal mucosa. Unsuckled day-old pigs had insignificant IIF titres, irrespective of whether they were excreting virus or not. The 5 congenital excretors which were reared all died within 7 days but no death occurred among their 4 litter-mates. Post-natal infection of 2 of these piglets reared in contact with congenitally infected pigs was suggested by the recovery of virus from nasal swabs 17 and 27 days after birth and the subsequent rise in IIF titre to 1/256 by day 42.     

Effect of type and timing of oil supplements to sows during pregnancy on the growth performance and endocrine profile of low and normal birth weight offspring

Eighty-eight multiparous sows were used to evaluate whether type and timing of oil supplementation during gestation influences the incidence of low birth weight (LBW). Sows were allocated (eight per treatment) commercial sow pellets (3 kg/d; control diet) or an experimental diet consisting of control diet plus 10 % extra energy in the form of excess pellets, palm oil, olive oil (OO), sunflower oil (SO) or fish oil; experimental diets were fed during either the first half (G1) or second half (G2) of gestation. Growth performance and endocrine profile of LBW (<1.09 kg) and normal birth weight (NBW; 1.46-1.64 kg) offspring were compared. Maternal dietary supplementation altered the distribution curve for piglet birth weight. SOG1 sows had a greater proportion of LBW piglets (P<0.05), whilst it was reduced in the OOG1 group (P<0.05). Growth rate of LBW piglets was lower compared with their NBW siblings (P<0.05) when dietary supplementation was offered in G2 but were similar for G1. At birth, LBW offspring of supplemented animals possessed more fat compared with the control group (P<0.05); LBW offspring of control animals exhibited a more rapid decline in fat free mass/kg prior to weaning. Plasma metabolites and insulin concentrations were influenced by maternal diet and birth weight. In conclusion, maternal dietary supplementation altered the distribution of piglet birth weights and improved the energy status of LBW piglets. Supplementation with MUFA during G1 reduced the incidence of LBW, whereas PUFA had the reverse effect.     

Evaluation of various protein sequences on the nutritional carry-over from gestation to lactation with first-litter sows.

First-litter sows and their progeny were used to evaluate the interaction effects of three gestation crude protein levels (9, 13, or 17%) and two lactation protein levels (12 or 18%) on sow reproduction and litter performance. Diets were formulated to contain the desired protein level by altering the ratio of corn and soybean meal. Daily rations of 1.82 kg were individually fed during gestation and were offered ad libitum to the sows by 7 days postpartum. Litters were equalized to eight pigs each by 1 week of age and held constant to weaning (28 days). Sows fed the 9% protein diet gained less during gestation than those fed the 13 or 17% protein diets. Progeny parturition data were similar for the three gestation protein levels. Sows fed the 18% protein lactation diet and their litters performed similarly in regards to feed intake and progeny performance regardless of previous gestation protein level, while those sows fed the 12% protein lactation diet had decreasing lactation weight losses, but increasing fed intakes and litter gains as the level of gestation protein increased from 9 to 17%. There were significant gestation by lactation protein level sequence interactions on sow feed intakes and litter gains, suggesting a nutritional carry-over effect from gestation to lactation. Sows fed the 17% protein gestation diet had the greatest tissue buffer while those fed the 9% protein gestation diet had the least. These results further demonstrate that dams fed a 9% protein gestation diet perform similarly to those fed higher gestation diets, if the lactation dietary protein level is adequate to meet the lactation amino acid requirements.     

The development of acid and pepsin (EC 3.4.23.1) secretory capacity in the pig; the effects of age and weaning. 1. Studies in anaesthetized pigs

The development of gastric secretory capacity of hydrochloric acid and pepsin (EC 3.4.23.1) was studied in thirty-eight Large White X Landrace pigs from the litters of six sows (three pairs of two), 9-38 d of age. The pigs of each pair of sows were born within 24 h of each other. The pigs of a litter were paired according to sex and size and cross-fostered, i.e. one pig from each pair was allocated to each sow. One litter from each pair was reared entirely by the sow (milk-fed, MF) whereas the other litter was reared by the sow for 21 d, but was allowed access to solid food (210 g crude protein (nitrogen X 6.25)/kg) at 12 d and was entirely dependent on solid food after 21 d (creep-fed, CF). Following a 14-18 h fast, pigs were anaesthetized (Halothane-sodium pentobarbitone) and their stomachs perfused at a constant rate with Ringer solution. Gastric secretion was stimulated by intravenous infusion of betazole hydrochloride (Histalog) at 3 mg/kg per h for 2 h. Hydrochloric acid and pepsin were measured in the perfusate which was collected at 15-min intervals. There were significant positive correlations between stomach weight and body-weight for both MF and CF pigs. The slope of the regression line for CF pigs was significantly greater than that for MF pigs (P less than 0.01). There were significant positive correlations between maximal acid output and stomach weight for both MF and CF pigs. There were significant positive correlations between maximal pepsin output and stomach weight for both MF and CF pigs. The slope of the regression line for CF pigs was significantly different from that for MF pigs (P less than 0.01). There were also significant positive correlations between maximal pepsin output per unit stomach weight and stomach weight for both MF and CF pigs. The pattern of development of pepsin secretory capacity in both CF and MF pigs was different from that for acid secretion. Maximal outputs of acid per unit stomach weight for MF and CF pigs remained relatively constant. Maximal outputs of pepsin per unit stomach weight and per unit body-weight increased with age for both MF and CF pigs. The results indicate that pigs given access to solid food before weaning and weaned on to solid food have heavier stomachs and greater acid and pepsin secretory capacity than pigs fed entirely on sows' milk.     

Amino acid availability affects amino acid flux and protein metabolism in the porcine mammary gland

A kinetic model was used to examine transmembrane flux kinetics of lysine, methionine and valine across the porcine mammary gland (MG) under dietary amino acid (AA) limiting, adequate and excess conditions. Lactating sows (3 per treatment) were offered three diets: lysine-deficient [LD, 4.9 lysine and 9.9 valine (g/kg diet)], adequate (Control, 9.7 and 10.2) and valine-excess (VE, 9.8 and 13.4). On d 18 of lactation, 2-(15)N-lysine, 5-methyl-(2)H(3)-methionine and 1-(13)C-valine were infused into a jugular vein for 20.5 h. Milk and arterial and mammary venous blood samples were collected at 2- and 1-h intervals, respectively. Compared with Control, milk yield and litter growth rate decreased (P < 0.05) in sows fed the LD diet. Model estimates of mammary protein synthesis (PS), breakdown (PB) and net PS decreased (P < 0.05) in sows fed the LD diet. Net uptake of lysine decreased (P < 0.05) in sows fed the LD diet as a result of decreases in inward and outward transport of lysine. Inward transport of methionine tended to be reduced (P < 0.10) in sows fed the LD diet, resulting in a decrease in net methionine uptake. In sows fed the VE diet, PB was reduced (P < 0.05) and PS unchanged compared with Control. Outward transport of valine and net lysine uptake were reduced (P < 0.05), but net valine uptake was unchanged in sows fed the VE diet compared with Control. In conclusion, the kinetic model provided estimates of PS that were similar to empirical measurements of milk protein output and mammary protein accretion. Transport of lysine and methionine by the porcine MG is closely linked to regulation of mammary PS. Lysine availability has little effect on the transmembrane flux of valine.     

Rapeseed glucosinolates and iodine in sows affect the milk iodine concentration and the iodine status of piglets.

I in the chain sow diet --> blood serum of sow --> sow milk --> piglet serum was investigated in two experiments with a total of eighty-one sows and their piglets. In experiments conducted during the last trimester of gravidity and the 28 d of lactation, diets with glucosinolates (1.9 mmol/kg diet via 100 g ground rapeseed/kg diet (Expt 1) and 2.1 and 4.2 mmol/kg diet via 75 and 150 g rapeseed press cake/kg diet (Expt 2)) were compared with control groups without rapeseed products. From 0 to 600 microg I/kg was added to sow diets during lactation. Diets without supplementary I decreased the I concentration particularly in milk and piglet serum. The presence of rapeseed and rapeseed press cake were indicated by a thiocyanate concentration increase, mainly in sow serum. The diets with glucosinolates decreased the milk and piglet serum I concentration. Spot urine and faeces samples from sows eating the rapeseed-press cake diets had increased I concentration. The sows' serum I and thyroxine did not respond to glucosinolates (Expt 1) or these diets caused an increase in concentration (Expt 2). Both these criteria seem unsuitable for the diagnosis of I status of adult animals. Glucosinolates and their degradation compounds may affect the thyroid and the mammary glands resulting in lower I milk transfer and higher renal and intestinal I excretion.     

Inoculation of female American black bears (Ursus americanus) with partially purified porcine zona pellucidae limits cub production

The present 2-year study investigated the feasibility of using porcine zona pellucidae (pZP) as antigen for immunocontraception in American black bears. Sows, 3-6 years of age, were administered either two doses of 250 microg pZP with Freund's adjuvant (n = 10) or adjuvant alone (n = 5), one in April and one in May, and were kept away from the boars until June. Serum samples were collected before injections and before denning (November). The presence of sows with cubs at side was observed during premature emergence from denning. First-year results indicated that anti-pZP antibody titres in vaccinated sows were 2.5-9.0-fold (range) higher compared with non-vaccinated sows and that the vaccinated sows were threefold less likely to become pregnant (P = 0.167). Control and vaccinated bears produced 1.6 and 0.2 cubs per sow, respectively (P = 0.06). The second-year study investigated the feasibility of using pZP sequestered in a controlled-release pellet and a water-soluble adjuvant (QS-21) to avoid regulatory problems associated with Freund's adjuvant. Sows in the treatment group (n = 22) were administered a single dose of an emulsion of 250 microg pZP and 150 microg QS-21 plus a pellet containing 70-90 microg pZP for delayed release as booster dose. Control sows (n = 5) received the QS-21 adjuvant in pellet alone. Serum samples were collected before inoculations (April) and before denning (November). Seven cubs were born to the five control sows, but none was born to the 22 vaccinated sows (P < 0.001). Anti-pZP antibody mean absorbance ratios in control sows remained at background levels, whereas vaccinated sows had ratios fourfold higher than controls. Two-dimensional polyacrylamide gel electrophoresis and immunohistochemical localisation confirmed immunoreactivity of sera from inoculated bears. We conclude that cub production in the American black bear can be effectively limited with either two injections of 250 microg pZP or a single inoculation of partially purified pZP sequestered in controlled-release pellets.     

Lactating sows and suckling piglets preferentially incorporate RRR- over all-rac-alpha-tocopherol into milk,plasma and tissues

Synthetic vitamin E, all-rac-alpha-tocopherol, contains eight different stereoisomers, only one of which, RRR-alpha-tocopherol, occurs naturally. The objective of this investigation was to evaluate the relative abilities of these two vitamin E forms to enrich piglet tissues when fed as alpha-tocopheryl acetates to sows during pregnancy and lactation. alpha-Tocopherol delivery to fetuses and to suckling piglets was monitored by feeding 150 mg each of d(3)-RRR-alpha- and d(6)-all-rac-alpha-tocopheryl acetate to three pregnant sows daily from 7 d before to 7 d after giving birth. Labeled and unlabeled vitamin E concentration ratios were measured in sow plasma and milk, and in piglet (n = 9) plasma and tissues at birth, 7 and 21 d. At birth, despite elevated sow plasma deuterated alpha-tocopherol concentrations, no labeled alpha-tocopherol was detected in piglet plasma or tissues. Sow plasma and milk d(3)-alpha- to d(6)-alpha-tocopherol concentrations were 2:1, leading to a 2:1 ratio in suckling piglet plasma and tissues. In piglets at d 7 compared with birth, most tissues contained a 10-fold increase in total alpha-tocopherol; the highest deuterated vitamin E concentrations were in the liver, followed by the lung, heart, kidney, muscle, intestine and brain. In conclusion, pigs discriminate between RRR- and all-rac-alpha-tocopherol with a preference for RRR-alpha-tocopherol; thus, the official bioequivalence ratio of 1.36:1 RRR- to all-rac-alpha-tocopherol is underestimated. After initiation of suckling, piglet plasma and tissues demonstrated a dramatic increase in vitamin E concentrations, emphasizing the limited placental vitamin E transfer and the importance of milk for enhancing the vitamin E status of the newborn.     

不明原因胚胎停育绒毛和蜕膜组织芳香烃受体和细胞色素P4501A1蛋白的表达及意义

目的:探讨芳香烃受体(aryl hydrocarbon receptor,AhR)和细胞色素P4501A1(cytochrome P4501A1,CYP1A1)蛋白在胚胎停育患者绒毛及蜕膜中的表达。方法:分别选取30例不明原因胚胎停育患者作为病例组和30例正常早期妊娠人工流产妇女作为对照组,采用免疫组织化学方法检测2组患者绒毛和蜕膜组织中AhR和CYP1A1蛋白表达水平。结果:绒毛组织中,病例组AhR蛋白表达水平(0.58±0.03)高于对照组(0.25±0.04),病例组CYP1A1蛋白表达水平(0.60±0.01)高于对照组(0.22±0.03),差异均有统计学意义(P0.05)。蜕膜组织中,病例组AhR蛋白表达水平(0.56±0.03)高于对照组(0.26±0.04),病例组CYP1A1蛋白表达水平(0.57±0.01)高于对照组(0.24±0.03),差异均有统计学意义(P0.05)。结论:胚胎停育患者绒毛和蜕膜组织中AhR和CYP1A1蛋白表达明显增高,可能与不明原因胚胎停育的发生有关。