Regulatory role of l-proline in fetal pig growth and intestinal epithelial cell proliferation

l-proline (Pro) is a precursor of ornithine, which is converted into polyamines via ornithine decarboxylase (ODC). Polyamines plays a key role in the proliferation of intestinal epithelial cells. The study investigated the effect of Pro on polyamine metabolism and cell proliferation on porcine enterocytes in vivo and in vitro. Twenty-four Huanjiang mini-pigs were randomly assigned into 1 of 3 groups and fed a basal diet that contained 0.77% alanine (Ala, iso-nitrogenous control), 1% Pro or 1% Pro + 0.0167% α-difluoromethylornithine (DFMO) from d 15 to 70 of gestation. The fetal body weight and number of fetuses per litter were determined, and the small and large intestines were obtained on d 70 ± 1.78 of gestation. The in vitro study was performed in intestinal porcine epithelial (IPEC-J2) cells cultured in Dulbecco''s modified Eagle medium-high glucose (DMEM-H) containing 0 μmol/L Pro, 400 μmol/L Pro, or 400 μmol/L Pro + 10 mmol/L DFMO for 4 d. The results showed that maternal dietary supplementation with 1% Pro increased fetal weight; the protein and DNA concentrations of the fetal small intestine; and mRNA levels for potassium voltage-gated channel, shaker-related subfamily, member 1 (Kv1.1) in the fetal small and large intestines (P < 0.05). Supplementing Pro to either gilts or IPEC-J2 cells increased ODC protein abundances and polyamine concentrations in the fetal intestines and IPEC-J2 cells (P < 0.05). In comparison with the Pro group, the combined administration of Pro and DFMO reduced the expression of ODC protein and spermine concentration in the fetal intestine, as well as the concentrations of putrescine, spermidine and spermine in IPEC-J2 cells (P < 0.05). Meanwhile, the percentage of cells in the S-phase and the mRNA levels of proto-oncogenes c-fos and c-myc were increased in response to Pro supplementation, whereas depletion of cellular polyamines with DFMO increased tumor protein p53 (p53) mRNA levels (P < 0.05). Taken together, dietary supplementation with Pro improved fetal pig growth and intestinal epithelial cell proliferation via enhancing polyamine synthesis.     

Effects of Sini decoction on the ultrastructure of small intestinal epithelial cells in rats with intestinal ischemia-reperfusion

AIM: To investigate the effect of Sini decoction (SND)on the ultrastructure of small intestinal epithelial cells in rats with intestinal ischemia-reperfusion. METHODS: Thirty-two Sprague-Dawley rats of both sexes were randomly divided into 4 groups: (1) Control group in which sham operation was performed; (2) Model group in which intestinal I/R was produced by clamping super mesenteric artery(SMA) for 1 hour and declamping SMA for 3 hours; (3) SND1 group in which SD (0.6 g/200 g rat) was given via stomach tube 3 d before intestinal I/R; (4) SND2 group in which SD (1.2 g/200 g rat)was given via stomach tube 3 d before intestinal I/R. A strip of small intestine was taken from distal end of ileum for electron microscopic examination. The two-dimensional structural parameters and three-dimensional structural parameters of mitochondria were calculated. RESULTS: (1)Morphological changes of small intestine: In control group, epithelial cells were orderly arranged, with normal mitochondria and intestinal villi. In model group, the gaps between epithelial cells widened. There were a lot of apoptotic cells. Microvilli were short and swelled. Mitochondria were swelled obviously with broken ridges. Endoplasmatic reticulum was severely dilated. In SND1 and SND2 groups, microvilli and epithelial cells were orderly arranged relatively, mitochondria was slightly swelled. (2) Structural parameters of mitochondria: In model group, there were the least mitochondria and the swelling of mitochondria was severe. In SND1 and SND2 groups, the mitochondria was more than that of model group and the swelling were slight. CONCLUSION: Sini decoction can protect small intestine from ischemia-reperfusion injury without dose-dependent effect.     

Gut growth and glucose tolerance in newborn pigs subjected to prenatal protein restriction and postnatal Glucagon-like Peptides

Fetal protein restriction is potentially associated with organ dysfunctions after birth (e.g. impaired gut growth, glucose tolerance and pancreatic β-cell function). Just after birth, gut growth and maturation is stimulated by enteral food intake, and inhibited by total parenteral nutrition (TPN), in part mediated via differential release of insulino- and intestino-tropic hormones like the Glucagon-Like Peptides 1 and 2 (GLP-1, GLP-2). We hypothesized that short-term co-infusion of GLP-1 and GLP-2 would stimulate pancreatic and intestinal growth in newborn TPN-fed pigs subjected to prenatal protein restriction. Two sows were fed a protein-restricted diet (PR: 8% crude protein during last 50% of gestation) while a third sow was fed a control diet (C: 15% crude protein). PR pigs were killed either at birth (n = 7) or after 3 days TPN with (n = 6) or without (n = 4) intravenous infusion of a mixture of synthetic human GLP-1_7–37 and GLP-2_1–33 (each 50 μg/kg/d). At birth, PR piglets did not show reduced body weight, relative to controls (1.45 vs. 1.50 kg), but significantly reduced weight of the small intestine (18.0 ± 0.6 vs. 21.9 ± 0.5 g/kg, P < 0.001) and a marginally reduced pancreas weight (0.85 ± 0.02 vs. 0.93 ± 0.04 g/kg, P = 0.10). Co-infusion GLP-1 and GLP-2 into PR pigs resulted in increased basal glucose levels (5.3 vs. 4.0 mM), and glucose-stimulated insulin release, but did not have any significant effect on body weight, or weight of internal organs (heart, lungs, spleen, kidneys, adrenals, stomach, colon, liver, intestine, pancreas). We conclude that short-term (3 days) infusion of native GLP-1 and GLP-2 does not stimulate gut growth or glucose tolerance in TPN-fed piglets born from protein-restricted mothers. Moderate maternal protein restriction does however cause significant reduction in intestinal growth in newborn piglets which may decrease the neonatal digestive capacity.     

Intermittent suckling improves post-weaning feed uptake but does not change functional gut characteristics of piglets

Suckling pigs were separated from their dam for 24 h on day 21 (1 × 24 h fasting, n = 10) or day 21 and 24 (2 × 24 h fasting, n = 10). Pigs in the control group (n = 10) were not fasted before weaning. All pigs were weaned on day 28 postpartum. Feed intake during the first 4 days post-weaning was higher (P < 0.05) for pigs exposed to 1 × 24 h fasting compared with controls. Water consumption was not affected by fasting prior to weaning. The difference in post-weaning feed uptake was not reflected in any clinical traits, intestinal morphology, or activity of digestive enzymes (maltase, dipeptidylpeptidase IV, aminopeptidases A and N; P > 0.15). In conclusion, a short period of fasting prior to weaning can increase post-weaning feed uptake, although this had no clinical impact under the present experimental conditions.     

微生物发酵豆粕对断奶仔猪生长、血清指标及肠道形态的影响

本文旨在研究微生物发酵豆粕对仔猪生长及血清指标的影响,并且根据肠道组织形态学的微观变化,评价了不同处理的豆粕对早期断奶仔猪肠道形态的影响.选用60头35日龄断奶体重为(8.62±0.21)kg的同窝杜×长×大仔猪,分为试验组和对照组,每组3个重复,每个重复10头,分别饲喂以普通豆粕为对照组,微生物发酵豆粕为试验组的日粮.试验结果表明:饲喂微生物发酵豆粕使仔猪料重比降低8.39%(P＜0.05),腹泻指数降低39.96%(P＜0.01),血清尿素氮含量降低39.47%(P＜0.01),血清IgG含量降低6.35%(P＜0.05).豆粕经微生物发酵后减轻饲粮中大豆蛋白对肠道的过敏损伤,使肠道维持良好的结构形态,从而促进营养物质的消化吸收.     

主动免疫血管活性肠肽（VIP）对家鸽繁殖性能影响的初探

将３０对青年鸽随机分为三组，第一组用血管活性肠肽（ＶＩＰ）类似物与牛血清蛋白（ＢＳＡ）的偶联物进行主动免疫ＶＩＰ，第二组注射与第一组等量的生理盐水，第三组不做任何处理。在试验的第一阶段，除第三组外，第一、二组鸽在产蛋后立即将书目是拿出，试验结果显示：第一组与第二组鸽月产蛋量和周抱窝数差异不显著。但第一、二组鸽产蛋量与第三组（自然饲养组）差异极显著。在试验的第二阶段（Ｂ处理过程）均不把蛋拿出，则三组     

Dietary mannan oligosaccharide enhances salinity tolerance and gut development of larval cobia

The potential beneficial effects of supplementing live feeds with mannan oligosaccharide (MOS; BioMos®) upon cobia Rachycentron canadum larval performance were examined. Characteristics of fish examined included survival to weaning, growth, ability to withstand osmotic stress and the degree of development of the brush border of the intestine. Live feeds included rotifers (Brachionus plicatilis) and Artemia which were enriched for 24 h with a commercial enrichment media alone or in combination with 0.2% (dry weight basis) MOS. Salinity challenges were performed at 6 days post-hatch (dph) and at 7, 13, and 14 dph (0 and 65 g L^− 1 for 6 dph; 0 and 55^− 1 7+ dph) corresponding to transitions in feeding, to examine the ability of larval cobia to survive stress. Differences (P < 0.05) in survival, favoring cobia receiving MOS-supplemented feeds were discerned at 6 and 7 days post-hatch (dph) when fish were challenged at 0 g L^− 1 and at 13 dph when challenged with 55 g L^− 1 salinity water. Electron microscopy of the mid-intestine of developing larvae revealed that MOS-supplemented diets enhanced (P < 0.05) the height of microvilli while reducing (P < 0.05) the occurrence and size of supranuclear vacuoles. Supplementation of diets with MOS could assist cobia larvae in maintaining allostasis especially when reared at sub-optimal salinities.     

Dietary dihydroartemisinin supplementation alleviates intestinal inflammatory injury through TLR4/NOD/NF-κB signaling pathway in weaned piglets with intrauterine growth retardation

The aim of present study was to evaluate whether diets supplemented with dihydroartemisinin (DHA) could alleviate intestinal inflammatory injury in weaned piglets with intrauterine growth retardation (IUGR). Twelve normal birth weight (NBW) piglets and 12 piglets with IUGR were fed a basal diet (NBW-CON and IUCR-CON groups), and another 12 piglets with IUGR were fed the basal diet supplemented with DHA at 80 mg/kg (IUGR-DHA group) from 21 to 49 d of age. At 49 d of age, 8 piglets with similar body weight in each group were sacrificed. The jejunal and ileal samples were collected for further analysis. The results showed that IUGR impaired intestinal morphology, increased intestinal inflammatory response, raised enterocyte apoptosis and reduced enterocyte proliferation and activated transmembrane toll-like receptor 4 (TLR4)/nucleotide-binding and oligomerization domain (NOD)/nuclear factor-κB (NF-κB) signaling pathway. Dihydroartemisinin inclusion ameliorated intestinal morphology, indicated by increased villus height, villus height-to-crypt depth ratio, villus surface area and decreased villus width of piglets with IUGR (P < 0.05). Compared with NBW piglets, IUGR piglets supplemented with DHA exhibited higher apoptosis index and caspase-3 expression, and lower proliferation index and proliferating cell nuclear antigen expression in the intestine (P < 0.05). Dihydroartemisinin supplementation attenuated the intestinal inflammation of piglets with IUGR, indicated by increased concentrations of intestinal inflammatory cytokines and lipopolysaccharides (P < 0.05). In addition, DHA supplementation down-regulated the related mRNA expressions of TLR4/NOD/NF-κB signaling pathway and upregulated mRNA expressions of negative regulators of TLR4 and NOD signaling pathway in the intestine of piglets with IUGR (P < 0.05). Piglets in the IUGR-DHA group showed lower protein expressions of TLR4, phosphorylated NF-κB (pNF-κB) inhibitor α, nuclear pNF-κB, and higher protein expression of cytoplasmic pNF-κB in the intestine than those in the IUGR-CON group (P < 0.05). In conclusion, DHA supplementation could improve intestinal morphology, regulate enterocyte proliferation and apoptosis, and alleviate intestinal inflammation through TLR4/NOD/NF-κB signaling pathway in weaned piglets with IUGR.     

Effect of lipid source and bile salts in diet of Atlantic salmon, Salmo salar L., on astaxanthin blood levels

A study was conducted to determine the effects of dietary lipid and bile acids on astaxanthin absorption in Atlantic salmon (Salmo salar L.). Fish with an average weight of 1500 g were fitted with a dorsal aorta cannula and fed diets containing herring oil, soybean lecithin, lard, or herring oil supplemented with taurocholic acid (2.5 g/kg diet). Each fish was fed all of the experimental diets in successive order to minimize the effect of individual variation. At a given time following the feeding of each diet, blood was collected and analyzed for astaxanthin. Soybean lecithin significantly lowered the absorption of astaxanthin compared to fish fed herring oil. A 20% (p < 0.12) increase in blood astaxanthin was observed when the fish were fed the diet supplemented with taurocholic acid. Feeding lard significantly increased the blood astaxanthin level compared to the control group. It appears that altering the micellar structure by stimulating micellar (taurocholic acid) or mixed micellar (lecithin) systems did not increase the apparent absorption of astaxanthin. However, increasing the phospholipid level may have actually decreased the absorption possibly by lowering the astaxanthin solubility in the micelles. The increased apparent absorption of astaxanthin with lard is possibly linked to the increased content of 16:0, 18:1n − 9 or 18:2n − 6 fatty acids in this diet, or a reduction in very long chain monoenes (20:1n − 9 and 22:1n − 9). This suggests that the solubility of astaxanthin is higher in diets containing higher levels of 16:0 or 18:1n − 1, or alternatively, that reductions in longer chain monoenes (20:1n − 9 and 22:1n − 9) increase the micellar solubility of this pigment.