Effects of feeding fat-coated butyrate on mucosal morphology and function in the small intestine of the pig

As shown earlier, pig rations with high starch and purine content initiate mucosal hypertrophy by stimulating mitotic activity and DNA formation in the small intestine, whereas in the colon butyrate inhibits apoptosis and thus increases crypt depth. It was the aim of this study to combine these effects by targeting fat-coated butyrate into the small intestine where it usually does not occur, and to investigate effects on mucosal development and function. Three groups of five pigs were fed 3.6 kg/day of either a low-energy ration [deficit group, 6.6 MJ metabolizable energy (ME)/kg] or a high-energy ration (13.7 MJ ME/kg) that was supplemented with brewing yeast as a source of purines. The third ration was of high energy and contained purines and was additionally supplemented with coated butyrate (13.5 MJ ME/kg; 29 g calcium butyrate/kg). Rations were fed for 5 days. After killing, tissue samples were obtained from the proximal, medial and distal parts of jejunum for histology. Chyme samples were obtained from the ileum of all animals and used for sucrase determination. Villus size was not changed by feeding, but butyrate had an effect on plica height and area mainly in the medial jejunum. Plica area in the butyrate group (4.2 mm(2)) was significantly higher (p 相似文献   

Influence of creep feeding and weaning on brush border enzyme activities in the piglet small intestine

The activities of the enterocyte brush border enzymes lactase (beta-D galactoside galactohydrolase, EC 3.2.1.23) and sucrase (sucrose alpha-D glucohydrolase, EC 3.2.1.48) were measured at set percentage lengths along the small intestines of 112 piglets killed between 21 and 32 days of age. The influences on these activities of consumption of creep feed and of weaning were recorded. Weaning at three weeks old resulted in large, rapid reductions in lactase activity at most sites along the small intestine; sucrase activity declined temporarily and then recovered. Minimum values were recorded about four to five days after weaning. Similar changes were observed whether or not creep feed was consumed before weaning. Continued consumption of creep feed by unweaned pigs over the 21 to 32 day period also produced small but significant reductions in lactase activities. The large loss of digestive enzyme activities at brush borders in weaned animals coincided with a reduced ability to absorb xylose and to checks in growth rate in otherwise healthy piglets.     

单胃动物小肠内可消化性碳水化合物的吸收及其调控

本文阐述单胃动物小肠内可消化性碳水化合物的吸收及其调控机制。可消化性碳水化合物在单胃动物体内的降解产物主要为葡萄糖、果糖、半乳糖和双糖。葡萄糖、果糖和半乳糖在小肠内,由小肠内绒毛上皮细胞或细胞间隙直接吸收;双糖在双糖酶的作用下水解成单糖形式,为小肠绒毛上皮细胞吸收。其吸收机制可分为3个途径:主动吸收、被动吸收以及通过细胞间隙直接吸收。其中主动吸收是主要的吸收途径。调控小肠可消化性碳水化合物吸收的因素较多,包括吸收面积、Na 电化学梯度、细胞膜脂质成分、转运细胞与非转运细胞比例、转运子周转速率、亲和系数等因素。通过多种因子的调控作用,能有效地促进碳水化合物的吸收,以满足动物体的生长和发育的需要。     

Effect of simulated transport stress on the rat small intestine: A morphological and gene expression study

The present study investigated the effects of simulated transport stress on morphology and gene expression in the small intestine of laboratory rats. Sprague Dawley rats were subjected to 35 °C and 0.1×g on a constant temperature shaker for physiological, biochemical, morphological and microarray analysis before and after treatment. The treatment induced obvious stress responses with significant decreases in body weight (P < 0.01), increases in rectal temperature, serum corticosterone (CORT), serum glucose (GLU), creatine kinase (CK) and lactate dehydrogenase (LDH) levels (P < 0.01), as well as expression of Hsp27/70/90 mRNA (P < 0.05; P < 0.01). The rat jejunum was severely damaged and apoptotic after mimicking transport stress, which may mainly be related to cell death, oxidation reduction and hormone imbalance determined by microarray analysis. The bioinformatics analysis from the present study would provide insight into the potential mechanisms underlying transport stress-induced injury in the rat small intestine.     

大豆蛋白抗原对断奶仔猪生长性能、小肠消化酶活性及组胺水平的影响

选取88头7日龄＂杜×长×大＂三元杂交仔猪,按体质量和性别随机分成11组,每组8头。仔猪经皮下注射进行免疫,A组（对照组）注射生理盐水,大豆球蛋白（11S）B、C、D免疫组注射11S500μg/kg.w,21日龄时进行二免,23日龄C、D组分别肌肉注射11S2 500、5 000μg/kg.w;大豆球蛋白（11S）E、F组不免疫,23日龄肌肉注射11S2 500、5 000μg/kg.w。β-伴大豆球蛋白（7S）分组同11S。所有仔猪于23日龄断奶,在7、21、35日龄时空腹称重,计算平均日增重。试验结束时,每组选择5头仔猪进行屠宰,取十二指肠近端、空肠中段、回肠近段各2cm,用于测定消化酶活性和组胺水平。结果显示,与对照组相比,免疫500μg/kg.w 11S和7S可显著提高断奶仔猪平均体质量和平均日增重（P〈0.05或P〈0.01）,直接致敏2 500、5 000μg/kg.w的11S和7S可显著降低断奶仔猪的平均体质量和平均日增重（P〈0.05或P〈0.01）;11S可显著降低断奶仔猪十二指肠、回肠中胰淀粉酶、蛋白酶和十二指肠脂肪酶活性（P〈0.05或P〈0.01）,降低十二指肠、回肠组胺水平（P〈0.05或P〈0.01）;而7S显著降低断奶仔猪十二指肠、空肠胰淀粉酶、蛋白酶和十二指肠中脂肪酶活性（P〈0.05或P〈0.01）,降低十二指肠、空肠组胺水平（P〈0.05或P〈0.01）。与免疫组相比,免疫后致敏5 000μg/kg.w的11S可显著降低断奶仔猪的平均体质量和平均日增重（P〈0.05或P〈0.01）、十二指肠、回肠中胰淀粉酶、蛋白酶、十二指肠脂肪酶活性（P〈0.05或P〈0.01）和十二指肠、回肠组胺水平（P〈0.05或P〈0.01）;致敏2 500、5 000μg/kg.w的7S差异不显著（P〉0.05）。对仔猪提前免疫大豆蛋白抗原,能显著提高断奶仔猪的生长性能和小肠中消化酶活性,降低组胺的释放,从而促进仔猪的生长,并且7S的免疫效果明显优于11S。     

大鼠感染微小隐孢子虫后小肠、肾及肺脏病理学变化

将40只SPF级SD大鼠随机均分为地塞米松免疫抑制感染组和对照组n=20,免疫抑制感染组大鼠一次性接种1×106个/L微小隐孢子虫卵囊液1mL,空白对照组接种1mL灭菌生理盐水。于试验结束后宰杀大鼠,立即剖检取小肠、脾、肺,Bouin液固定,常规石蜡切片,HE染色,奥林巴斯显微摄影系统观察并显微摄影。结果显示,免疫抑制感染组大鼠小肠绒毛和肠腺受损严重,数量明显减少,结构模糊,绒毛上皮细胞和肠腺细胞明显肿胀、解体,细胞结构消失;肾脏肾小体数量减少,有的血管球明显萎缩甚至碎解,肾小囊腔明显增大,有的肾小囊壁层细胞的连续性遭到破坏;肺脏肺泡隔明显增厚,充血现象严重,肺泡隔内的细胞萎缩,胞核固缩,细胞结构模糊。试验结果表明,微小隐孢子虫对大鼠小肠、肾和肺等器官的组织结构具有明显损伤作用,进而影响大鼠的消化吸收、泌尿和呼吸等功能。     

Electrophysiological characterization of electrolyte and nutrient transport across the small intestine in horses

The aim of this study was to characterize the transport mechanisms of electrolytes and nutrients across the jejunum of nine healthy horses electrophysiologically. The stripped mucosa was mounted in Ussing chambers and tissue conductances (G_t) and short circuit currents (I_sc) were continuously monitored. After blocking the sodium and potassium channels with amiloride, tetraethylammonium chloride (TEA) and barium, chloride secretion was stimulated by carbachol and forskolin. Subsequently, chloride channels were inhibited by 4,4′‐diisothiocyanato‐stilbene‐2,2′‐disulfonic acid, 5‐nitro‐2‐(3‐phenylpropylamino)benzoic acid, CFTR_inh‐172, N‐(2‐naphtalenyl)‐(3.5‐dibromo‐2.4‐dihydroxyphenyl)methylene glycine hydrazide (GlyH‐101) and glibenclamide and their dose–response effect was investigated. The response to glucose, l ‐alanine and glycyl‐l ‐glutamine was determined at two different mucosal pH values (pH 7.4 and 5.4 respectively). Mean basal I_sc was ?0.47 ± 0.31 μEq/cm²h and mean G_t was 22.17 ± 1.78 mS/cm². Amiloride and TEA did not alter the baseline I_sc. Barium, carbachol and forskolin significantly increased I_sc. Irrespective of the dose, none of the chloride inhibitors changed I_sc. All nutrients induced a significant increase in I_sc with the increase being significantly higher at pH 7.4 than at pH 5.4. In conclusion, there is evidence that chloride secretion in horses may be different from respective transport mechanisms in other species. The glucose absorption is suggestive of a sodium‐dependent glucose cotransporter 1. However, a decrease in luminal pH did not stimulate current response to peptides as shown for other mammals.     

膨化和膨胀加工技术及其对猪生产性能的影响

随着饲料原料资源的短缺和价格的上涨,加工工艺对降低生产成本,改善猪生产性能的作用日趋明显.传统的膨化工艺具有降低抗营养因子和有害菌数量,并提高营养物质消化率的作用.新型的膨胀工艺除了上述优点外,还能提高产能,降低能耗,并使原料释放营养物质,提高营养物质的消化率.膨胀工艺可破坏非常规原料的纤维成分,增加其应用范围和营养价值.大量的试验结果表明,膨化和膨胀工艺对仔猪、育肥猪和哺乳母猪的生产性能具有提升作用.膨化和膨胀工艺将会在饲料加工和动物营养领域发挥更大的作用.本文针对膨化和膨胀技术巨大的应用潜力及良好的实际效果作一简述.     

犊牛小肠不同部位pH值及蛋白酶活性变化规律的研究

本文对0-6月龄黑白花公犊牛小肠不同部位（十二指肠、空肠和回肠）的pH值及胰蛋白酶和糜蛋白酶活性进行了测定。结果表明,犊牛小肠不同部位的pH值不同．回肠pH值高于空肠,回肠和空肠pH值均显著高于十二指肠：小肠不同部位的胰蛋白酶和糜蛋白酶活性不同．空肠胰蛋白酶和糜蛋白酶活性高于回肠,空肠和回肠胰蛋白酶和糜蛋白酶活性显著高于十二指肠．随着犊牛日龄的增长．活性逐渐增长。     

Effect of acute deficiency of dietary proline on proline balance in the rat small intestine and liver

Introduction Proline is widely found in all types of mammalian tissue, and accounts for about 20% of the amino acids that constitute collagen (A dams 1970). Proline is nutritionally nonessential but biologically it is an important amino acid and consequently mammalian organisms synthesize the required amounts of proline even in the absence of sufficient proline consumption via food. The metabolism of higher animals is unique, and amino acid metabolism differs from one tissue to the next. Some organs are capable of synthesizing nonessential amino acids for use throughout the body. For example, arginine is primarily synthesized in the kidney and then released and distributed throughout the body. Pyrroline-5-carboxylate reductase is the enzyme responsible for the final stage of proline synthesis, and its activity has been confirmed in many important organs and tissue such as the cartilage, liver, small intestine, kidney and thymus gland (H erzfeld et al. 1977; S mith and P hang 1978). However, the different levels of pyrroline-5-carboxylate reductase activity among these organs has led to the belief that different amounts of proline are synthesized in these organs. In order to ascertain biological responses to dietary proline deficiency, it is important to identify the organs that release and distribute proline throughout the body when insufficient proline is consumed through the diet, thus reducing the blood proline concentration. Few studies have investigated this issue, but when ascertaining biological responses to dietary proline deficiency, it is more important to elucidate the effect of dietary proline deficiency on the metabolism of proline and other amino acids that are closely related metabolically to proline, in proline synthesizing organs. One of the most effective ways to assess amino acid metabolism in a target tissue of higher animals is to measure the difference between the arterial and venous concentrations of amino acids. I shikawa (1974) measured arteriovenous differences in order to examine the release of proline from the kidney and small intestine of fasted rats and the uptake of proline by the liver. In a previous study, it was found that when the plasma proline concentration was reduced to the fasting level by the consumption of a proline-deficient diet, proline was released from the kidney (W atanabe et al. 1995, 1997). In the present study, to ensure the induction of dietary proline deficiency, a completely purified diet containing all amino acids except for proline was prepared and fed to rats under experimental conditions. To investigate the role of the small intestine and liver in supplying and ingesting proline when the uptake of proline through food is restricted, the release and uptake of amino acids in the small intestine and liver were assessed by measuring carotid artery–portal vein and portal–hepatic vein differences in proline in rats.     

牛磺酸对镉致大鼠肝肾组织的保护

为了研究牛磺酸对镉致大鼠肝肾组织的保护作用,将50只大鼠按体重随机分为5组:正常对照组、模型组、高、中、低剂量干预组,每组10只。第30天后处死动物,称重,计算进食量、食物利用率、脏器系数。结果:(1)模型组大鼠终重、进食量、食物利用率明显低于对照组(P<0.05);高、中剂量干预组大鼠终重、进食量、食物利用率明显高于模型组(P<0.05);(2)模型组大鼠肝、肾湿重下降明显与对照组(P<0.05);高、中剂量干预组大鼠肝湿重明显高于模型组(P<0.05);高剂量干预组大鼠肾湿重明显高于模型组(P<0.05);且高剂量干预组大鼠肝、肾湿重明显高于低剂量干预组(P<0.05);(3)高剂量干预组肝组织中MDA、GSH、NO含量降低,SOD活性升高与模型组比较(P<0.05);且高剂量干预组SOD活性升高与中、低剂量干预组比较(P<0.05),有一定的剂量反应关系;高剂量干预组GSH含量显著降低与低剂量干预组比较(P<0.05)。表明镉对大鼠体重、进食量、食物利用率、脏器系数、氧化损伤均有不同程度的影响,牛磺酸能有效的拮抗镉对大鼠肝、肾组织的损伤。     

Special sugar expression on apoptotic epithelial cells of Peyer's patches and intestinal villi in rat small intestine

Our previous study clarified that the apical regions of both the follicle-associated epithelium (FAE) of Peyer's patches and the intestinal villi are the only adhesion sites of indigenous bacteria in rat jejuno-ileum. To survey the ligands against bacterial lectins, sugar expression patterns on epithelial cells were lectin-histochemically investigated using 21 lectins in the jejuno-ileal Peyer's patches of rats. As a result, (D-glcNAc)(2-4), detected by Solanum tuberosum (STL) and by Lycopersicon esculentum (LEL), and beta-D-gal(1-3)-D-galNAc detected by Peanut agglutinin (PNA), were strongly expressed on the brush borders of the apical regions of the FAE and the intestinal villi. On the other hand, neither sugar was expressed on the brush borders of the basal regions of both FAE and intestinal villi. The positive intensities for the lectins correlated with the progression of epithelial apoptosis in the FAE and in the intestinal villi. Moreover, the double staining with lectin histochemical method and the in situ nick end-labeling method could simultaneously detect the strong expression of both sugars and nuclear DNA fragmentation in epithelial cells at the late apoptotic stage. Other sugar expression patterns in the intestinal villi were similar with those in the FAE. There were no lectins specific for M cells in the FAE. From these findings, the possible sugars of ligands against some indigenous bacterial lectins, expressing specially on the apoptotic epithelial cells, might be narrowed down in rat jejuno-ileum.     

大菱鲆幼鱼对几种蛋白质源中营养物质的表观消化率及膨化处理对其产生的影响

本试验旨在研究大菱鲆(Scophthalmus maximus L.)对秘鲁红鱼粉、豆粕、葵花粕和玉米蛋白粉中干物质、粗蛋白质、氨基酸和总能的表观消化率,以及膨化处理对其产生的影响。试验饲料由70%基础饲料和30%待测蛋白质源组成,并添加0.1%的三氧化二钇(Y2O3)作为外源指示剂,将其分别制作成正常颗粒料和膨化颗粒料。将平均体重为(8.98±0.01)g的大菱鲆幼鱼随机分成10组,每组3个重复,每个重复40尾鱼,按照不同处理分别投喂相应饲料,喂养2周后采用后肠挤压法收集粪便样品至第6周。结果表明:大菱鲆幼鱼对4种蛋白质源中干物质、粗蛋白质、总氨基酸和总能的表观消化率分别为22.33%~65.50%、48.97%~85.28%、47.70%~84.14%和44.50%~81.16%。其中,秘鲁红鱼粉的各营养物质的表观消化率均显著高于3种植物蛋白质源(P0.05);3种植物蛋白质源中以豆粕中粗蛋白质的表观消化率最高,葵花粕次之,玉米蛋白粉最低;各待测蛋白质源中总氨基酸表观消化率的变化趋势与粗蛋白质表观消化率基本一致。经膨化处理后,大菱鲆对4种蛋白质源中营养物质的表观消化率均得到改善,尤其是3种植物蛋白质源,效果显著(P0.05),膨化处理后4种蛋白质源中干物质、粗蛋白质、总氨基酸和总能的表观消化率分别为24.26%~70.87%、57.20%~85.33%、68.27%~87.09%和49.23%~84.35%。由此得出,膨化处理能够提高大菱鲆幼鱼对秘鲁红鱼粉、豆粕、葵花粕和玉米蛋白粉中营养物质的表观消化率。     

小肽的吸收与转运及其营养作用

随着动物营养学研究的发展,蛋白质营养的研究也在逐步深入,由原来的粗蛋白营养发展到氨基酸营养,进一步发展到现在的小肽营养。本文就小肽的吸收、转运、营养及其在动物生产中的应用,以及目前小肽研究领域中存在的问题等方面进行阐述。     

小肠铁吸收的细胞机制

几乎所有有机体都需要铁来满足生长需要。Fe2 +/Fe3+之间的氧化还原电位使铁在许多的生化过程中发挥着重要作用 ,包括电子转移、基因调控、氧的结合和转移以及细胞的生长和分化。但过量铁沉积又会对细胞产生一定的毒性作用 ,如游离Fe2 +能够促进自由基的产生从而对脂肪、蛋白质以及DNA产生损伤作用。在吸收、利用与排泄整个代谢过程中 ,铁的肠道吸收是控制体内铁的动态平衡最重要的环节。铁在小肠中的吸收位置主要在小肠近端 ,小肠近端上皮细胞是在小肠绒毛上被发现的高度特异性的、具有吸收功能的细胞 ,控制着日粮铁进入体内的通道。但…     

The effect of otic vehicle and concentration of dexamethasone on liver enzyme activities and adrenal function in small breed healthy dogs

Dexamethasone 0.1% in propylene glycol vehicle has been shown to cause adrenal suppression and increased liver enzyme concentrations in normal dogs. The objectives of this study were to determine if these effects are concentration or vehicle dependent and to evaluate a dexamethasone 0.01% solution. Twenty-one privately owned normal dogs were included in this double-blinded study. Chemistry panels and adrenocorticotropin hormone (ACTH) stimulation tests were performed on day 0 and 15. Dogs were randomly assigned treatment with dexamethasone 0.01% in saline, 0.1% in saline, or 0.1% in a commercial preparation (Tresaderm®: Merial, Duluth, GA, USA) in each ear twice daily for 2 weeks. Nineteen dogs completed the study. After 2 weeks of treatment, all dogs receiving dexamethasone 0.01% in saline had normal ACTH stimulation tests and liver enzyme values. In contrast, four of seven dogs (57.14%) receiving dexamethasone 0.1% in saline experienced adrenal suppression, and four of six dogs (66.67%) receiving Tresaderm® experienced adrenal suppression with three of those dogs (50%) experiencing marked adrenal suppression. No dogs receiving dexamethasone 0.1% in saline had increased liver enzyme concentration, while one of six dogs (16.67%) experienced a slight elevation in alkaline phosphatase. In conclusion, it appears that adrenal suppression caused by otic dexamethasone is concentration and perhaps vehicle dependent. Veterinarians who formulate dexamethasone 0.1% otic solutions should be cognizant of potential adrenal suppression similar to that seen with Tresaderm® although not to the same degree. Dexamethasone at 0.01% did not cause adrenal suppression or liver enzyme alterations after 2 weeks of treatment.     

Ultrasonographic examination of the small intestine, large intestine and greater omentum in 30 Saanen goats

The small and large intestine of 30 healthy Saanen goats were examined ultrasonographically using a 5.0 MHz-linear transducer. The goats were examined on the right side, from the eighth rib to the caudal aspect of the flank. The small and large intestine could be easily differentiated. The descending duodenum could be imaged in 19 goats, and the jejunum and ileum seen in all goats. The jejunum and ileum were most often seen in cross-section and rarely in longitudinal section in the ventral region of the right flank. The intestinal contents were usually homogenously echoic, and active motility was observed in all the goats. The diameter of the small intestine was 0.8–2.7 cm (1.6 [0.33] cm). The spiral ansa of the colon was imaged in all the goats, and in 21 the caecum was also seen. Both these sections of large intestine were most commonly seen in the dorsal region of the right flank. The spiral ansa of the colon was easily identified by its spiral arrangement of centripetal and centrifugal gyri, which had a garland-like appearance. Because of intraluminal gas, only the wall of the colon closest to the transducer could be imaged. The diameter of the spiral colon ranged from 0.8 to 2.0 cm (1.1 [0.24] cm). Usually only the wall of the caecum closest to the transducer could be imaged and it appeared as a thick, echoic, slightly undulating line. The greater omentum could be seen in all the goats.     

吉林白鹅小肠形态学发育规律

应用组织切片技术对11～53日龄吉林白鹅小肠绒毛高度、绒毛宽度、隐窝深度和肌层厚度进行测定。结果显示,小肠各段绒毛高度及宽度随日龄增加整体上呈增长趋势,空肠绒毛最长,回肠绒毛高度、宽度在39日龄达到峰值,早于空肠和十二指肠。回肠隐窝深度11～53日龄随日龄增加而增加,十二指肠和空肠隐窝深度在39日龄达到峰值,39～53日龄变浅。小肠各段肌层厚度与日龄呈正相关,回肠的肌层厚度在46日龄达到高峰,十二指肠和空肠的肌层厚度在53日龄达到高峰。小肠各段绒毛高度/隐窝深度的比值随日龄增加而增加,53日龄时空肠的绒毛高度/隐窝深度的比值最高。