斑点肉鸭小肠液中消化酶活性变化探讨

以 0～45日龄斑点肉鸭为研究对象 ,测试 5 ,1 5 ,2 5 ,35 ,45日龄肉鸭小肠液中淀粉酶、脂肪酶、蛋白酶活性随年龄的变化趋势。结果表明 :淀粉酶、蛋白酶活性随日龄增大而升高 ,且 5～ 1 5日龄段显著升高 (P <0 0 5) ;脂肪酶活性在 5～ 1 5日龄段显著降低 ,1 5～ 45日龄段一直维持在较低水平。试验结果对斑点肉鸭饲料中营养的合理配比及外源性消化酶适时添加具有一定的指导作用     

Influence of alpha-linked glucose on sodium-glucose cotransport activity along the small intestine in cattle

Thirteen steers (378+/-23 kg) were used in a split-plot experimental design to evaluate the effect of small intestinal carbohydrate on sodium-glucose cotransport in brush border membrane vesicles prepared from five equidistant sites along the small intestine. The steers consumed 7.2+/-0.4 kg/d ground fescue hay and soybean meal-based supplement and were infused ruminally or postruminally with a partial alpha-amylase starch hydrolysate (914.5+/-8.3 g/d) for 7 d. On d 7, five equidistant 1-m small intestinal sections were harvested and frozen in liquid N for later preparation of brush-border membrane vesicles. Maltase activity of the homogenate and vesicle preparations changed (P < 0.001; lowest in the duodenum, highest in the jejunum) and alkaline phosphatase decreased (P < 0.001) along the small intestine. With respect to the original homogenates, the vesicle preparations were enriched 9.80+/-0.83- and 7.64+/-0.67-fold for alkaline phosphatase and maltase, respectively; enrichments were not different between treatments (P = 0.76 and 0.39, respectively). However, alkaline phosphatase and maltase enrichment changed (P < 0.001) along the small intestine. Recoveries of alkaline phosphatase and maltase activities (25.0+/-0.2% and 19.5+/-0.2%, respectively) in the vesicle preparation were not affected (P = 0.29 and 0.21, respectively) by treatment but changed (P < 0.001) along the intestine. Recovery of protein in the vesicle preparation was 2.60+/-0.01% and was not affected by treatment or intestinal site. Sodium-glucose cotransport activity (220+/-44 pmol x mg(-1) x s(-1)) was not affected (P = 0.34) by treatment but did change (P < 0.001; lowest in the ileum, highest in the proximal and mid-jejunum) along the small intestine. Apparent Km of the sodium-glucose cotransporter for glucose was 62.8+/-5.8 microM. The specific activity of maltase was highest in the jejunum, and sodium-glucose cotransport was highest in the first two jejunal sites. However, duodenal maltase activity was lowest and ileal sodium-glucose cotransport activity was lowest. Sodium-glucose cotransport activity may limit small intestinal starch assimilation in the distal small intestine. It does not seem that glucose arising from carbohydrate hydrolysis regulates activity of sodium-dependent glucose transport in cattle.     

Ganglioneuroma in the small intestine of a juvenile pig

A mass was located in the small intestine of a slaughtered 6-month-old male Landrace-cross pig that had no clinical abnormalities. This egg-shaped well-circumscribed mass was situated in the submucosal and muscular tissue layers and protruded into the lumen. Histopathologically, the tumor comprised discrete or aggregated ganglion and schwannian cells in neuropil-like tissue. Some ganglion cells contained Nissl substance in their cytoplasm. The ganglion cells stained positive for neuron-specific enolase, class III β-tubulin, neurofilament, and synaptophysin; the schwannian cells stained positive for vimentin, S-100 protein, and glial fibrillary acidic protein. The tumor was diagnosed as a ganglioneuroma in accordance with these findings. Here, we have reported detailed immunohistochemical findings in addition to the histopathological features of a swine ganglioneuroma.     

谷氨酰胺对肉鸡肠道发育及小肠消化酶活性的影响

将180只1日龄AA肉仔鸡随机分成3组,设3个重复,每组60只,1组为对照组,2、3组为试验组,分别饲喂添加0%、0.2%、0.4%谷氨酰胺的基础日粮,试验期42 d,探讨了外源性谷氨酰胺对AA肉仔鸡小肠生长发育和消化道酶活性的影响.结果表明,在肉鸡饲料中添加外源性谷氨酰胺,能促进小肠的生长发育,显著增加肉鸡十二指肠、空肠和回肠重量、长度以及肠道指数(P＜0.05),提高小肠蛋白酶、脂肪酶、淀粉酶和胰蛋白酶活性(P＜0.05);谷氨酰胺的适宜添加剂量为0.2%.提示谷氨酰胺可作为肠道促生长添加剂在肉鸡饲料中使用,其适宜添加剂量为0.2%.     

Intestinal microbiota differentially affect brush border enzyme activity and gene expression in the neonatal gnotobiotic pig

To study microbial influence on intestinal development pertaining to nutrient digestion, two separate gnotobiotic experiments were performed, each with 16 piglets allocated to four treatment groups: germfree (GF), monoassociation with Escherichia coli, monoassociation with Lactobacillus fermentum or conventionalization with faecal bacteria (CV). Enzyme activity and gene expression of lactase phlorizin hydrolase (LPH) and aminopeptidase N (APN) were measured in isolated enterocytes, harvested on day 14, using specific substrates and quantitative PCR respectively. Enterocytes of CV pigs had reduced APN activity, but had increased gene expression relative to GF, making the specific activity:mRNA (A:G) ratio dramatically lower (p < 0.05). Similarly, LPH A:G ratio was significantly reduced (p < 0.05) in enterocytes of CV pigs as compared with GF. The results of co‐incubation of L. fermentum, E. coli and faecal bacteria with APN indicate a direct relationship between enzyme inactivation and specific A:G ratio in enterocytes. We conclude that enterocyte up‐regulation of APN expression occurs as either a direct response to microbial colonization or as a feedback mechanism in response to reduced enzyme activity through microbial degradation. This mechanism may play a role in ensuring effective competition of the host with the intestinal microbiota for available nutrients.     

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。     

北京雏鸭小肠消化酶活性变化规律研究

北京鸭成熟早,生长发育快,育肥性能好,肉质细嫩,味道鲜美,是我国著名的肉用鸭品种.近年来,关于通过添加外源性消化酶以弥补家禽体内消化酶的不足、降低肠道食糜黏度,从而提高饲料利用率、增强机体代谢水平和免疫力以促进动物生长方面的研究较多[1],但对北京雏鸭内源酶的变化规律未见报道.     

糖萜素对鲫鱼消化酶活性的影响

本试验测定了饲养30d鲫鱼的肠道和肝胰脏中蛋白酶、淀粉酶和脂肪酶的活性。结果表明,在基础饲料中添加1000mg/kg糖萜素能显著提高鲫鱼肠道和肝胰脏中的蛋白酶、淀粉酶和脂肪酶活性(P<0.05),且效果优于基础饲料中添加4mg/kg的黄霉素组。     

Cerebral dopamine, apomorphine and oral activity in the neonatal pig

Neonatal piglets in which oral stimulation associated with feeding was reduced by intragastric tube feeding displayed an increase in stereotyped snout rubbing, licking and chewing behaviour. An investigation of a possible neurochemical basis for this behaviour was made by using sensitive radioenzymatic and micro-fluorimetric assays to estimate the concentrations of the catecholamines and of the dopamine metabolites homovanillic acid (HVA) and 3,4-dihydroxyphenyl-acetic acid (DOPAC) in different brain regions. These observations revealed that the increased non-nutritive oral activity of such piglets did not appear to be caused by an increased release of dopamine in the brain, since it was not associated with increases in the concentrations of the acidic metabolites of dopamine in either the caudate nucleus, the putamen, the nucleus accumbens, the olfactory tubercle, the hypothalamus, or the substantia nigra. The only neurochemical changes observed were small decreases in the concentration of HVA in the putamen and the nucleus accumbens. A lack of effect on catecholamine concentrations in any of the six brain regions examined suggested that the environmental manipulation caused no changes in the development of catecholamine-containing nerve endings.
Subcutaneous injection of apomorphine was found to increase the non-nutritive oral activity of piglets. Apparent conditioning effects of the environment on apomorphine-induced stereotyped behaviour however, prevented any satisfactory testing of possible changes in cerebral dopamine receptor sensitivity following reduced oral stimulation.     

Ultrastructural changes in the small intestine of neonatal calves with enteric colibacillosis

The small intestines of calves inoculated orally with the enteropathogenic strain of Escherichia coli 0101:K'B41',K99 were examined by electron microscopy at 3, 6, 12, 16, 21, 36, 69, 70 and 72 hours after inoculation. The challenge organism adhered to the mucosa of the distal small intestine from six hours post-inoculation. Bacteria were separated from the microvillous brush border by a gap of 200 to 300 nm in which bacterial fimbriae and the microvillous glycocalyx were seen. Bacteria never were found in epithelial cells but were present in macrophages in the lamina propria from 12 hours. At three and six hours, cytopathic changes were not seen in the small intestine, but from 12 hours epithelial cells on affected villi had blunt and thick microvilli and contained cytoplasmic inclusions. Epithelial cells were seen frequently in the process of extrusion from the villi, either singly, in small groups, or as ribbons of cells. Intervillous bridges, characteristic of villous fusion, were seen frequently from 69 hours.     

屎肠球菌对21日龄AA肉鸡小肠发育和消化酶活力的影响

试验旨在研究21日龄爱拔益加(Arbor Acres, AA)肉鸡日粮中添加不同剂量屎肠球菌对空肠绒毛形态结构及小肠肠道酶活的影响。试验选取600只1日龄AA肉鸡(公鸡),随机分成5组,每组6个重复。对照组(CON组)饲喂基础日粮,抗生素组(Ant组)在基础日粮中添加0.1%金霉素,低(LEF组)、中(MEF组)、高(HEF组)剂量屎肠球菌组分别在基础日粮中添加50、100、200 mg/kg屎肠球菌。结果显示:①相比于CON组,LEF组肉鸡空肠中绒毛高度有显著性增加(P<0.05),Ant组肉鸡空肠中隐窝深度也有显著性增加(P<0.05),其他各处理组间差异不显著(P>0.05)。②与CON组相比,HEF组和Ant组肉鸡肠道中十二指肠中麦芽糖酶活性均显著提高(P<0.05),HEF组和Ant组肉鸡空肠中麦芽糖酶活性也显著提高(P<0.05);相比于CON组,Ant组和HEF组肉鸡空肠中乳糖酶活性显著提高(P<0.05)。LEF组、HEF组和Ant组肉鸡空肠中糜蛋白酶活性与CON组相比显著降低(P<0.05),LEF组、HEF组及Ant组肉鸡十二指肠中脂肪酶活性显著低于CON组(P<0.05)。结果表明,在肉鸡基础日粮中添加50 mg/kg屎肠球菌可显著提高肉鸡空肠绒毛高度。添加屎肠球菌能显著提高其十二指肠和空肠中麦芽糖酶活性,降低糜蛋白酶和脂肪酶活性,且以200 mg/kg添加量效果最明显。     

0～6月龄犊牛小肠pH值及主要消化酶活性的研究

试验对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α-淀粉酶、胰蛋白酶和乳糖酶活性进行了测定,结果发现:犊牛小肠不同部位内容物其pH值不同,回肠pH值高于空肠,回肠和空肠pH值均高于十二指肠;小肠不同部位的α-淀粉酶和胰蛋白酶活性不同,空肠α-淀粉酶和胰蛋白酶活性高于回肠和十二指肠,随着犊牛日龄的增长,活性逐渐增长;小肠不同部位的乳糖酶活性不同,空肠和十二指肠乳糖酶活性高于回肠,随着犊牛日龄的增长,小肠乳糖酶活性逐渐降低。     

鳜胃肠道和肝脏主要消化酶活性的研究

试验分别测定了鳜胃、肠道、肝脏和幽门盲囊中消化酶的活性。结果表明 :鳜消化道中蛋白酶活性大小顺序为 :幽门盲囊 >肠 >胃 >肝脏 ;淀粉酶活性大小顺序为 :肝脏 >幽门盲囊 >胃 >肠 ;脂肪酶活性大小顺序为 :幽门盲囊 >肠 >肝脏 >胃     

Myoelectric activity in the intestine of cows with strangulating obstruction of the distal small intestine

Myoelectric activity in 2 cows instrumented with permanent electrodes in the ileum, cecum, proximal loop of the ascending colon (PLAC), and spiral colon was analyzed after an obstruction developed in the distal small intestine. Results were compared with patterns from a group of 7 normal cows. Myoelectric activity in the ileum immediately orad to the occlusion was characterized by abolition of the migrating myoelectric complex (MMC) and a constant pattern of strong spike bursts of long duration. Cyclic activity was present in all parts of the large intestine, and propagation of phase III activity was evident from proximal to distal. A slight degree of disorganization in phase III propagation was restricted to the spiral colon. Activity cycles tended to be shorter in the cecum and PLAC of both cows with colic than in normal cows, and the intensity of spiking activity was generally lower. Changes in duration of the MMC in the spiral colon (bovine colonic MMC, bcMMC) were inconsistent, but the intensity of spiking activity tended to be lower in phases I and II of both cows compared to controls. The organization of phase III in several spindles typical of the bovine spiral colon was not disrupted, but phase IV of the bcMMC occurred only infrequently. Organized cyclic activity occurred in the large intestine of both cows despite complete disruption of the small intestinal MMC, indicating the presence of mechanisms able to initiate and regulate coordinated myoelectric patterns in the large intestine independent of the small intestine.     

Phase 1 and phase 2 metabolic activities along the small intestine in adult male sheep

Maté, L., Virkel, G., Lifschitz, A., Sallovitz, J., Ballent, M., Lanusse, C. Phase 1 and phase 2 metabolic activities along the small intestine in adult male sheep. J. vet. Pharmacol. Therap. 33 , 537–545. Metabolic activities of several xenobiotic metabolizing enzymes were evaluated in both hepatic and enteric subcellular fractions obtained from Corriedale × Merino crossbreed rams by using a biochemical approach. Microsomes obtained from the different segments of sheep small intestinal mucosa displayed cytochrome P450 (CYP)‐dependent N‐demethylations but not O‐deethylase activities apparently occurred. CYP‐mediated N‐demethylations neither decreased nor increased along the small intestinal mucosa. Percentages of activity for erythromycin N‐demethylase in the small intestine were between 29% (duodenum) and 45% (ileum) from that measured in the liver, whereas those determined for triacetyl‐oleandomycin N‐demethylation ranged between 10% (duodenum) and 15% (jejunum) of the same hepatic activity. Conversely, metabolic rates for aminopyrine and chlorfeniramine N‐demethylations in the gut mucosa ranged between 3% and 7% compared to their respective hepatic enzyme activities. Sheep enteric mucosa also displayed metabolic reactions typically mediated by flavin‐containing monooxygenases (FMOs), carbonyl reductases (CBRs), carboxylesterases (CES), glutathione S‐transferases (GSTs) and uridine diphosphoglucuronyltransferases (UGTs). The FMO‐mediated sulfoxidation of methimazole was 2.6‐fold higher (P < 0.01) in the ileal compared to the duodenal mucosa. Percentages of activity for the microsomal CBR‐dependent biotransformation of menadione were between 12% (ileum) and 19% (duodenum–jejunum) of the total activity measured in the liver; metabolic rates measured in duodenum and jejunum were ～1.7‐fold higher (P < 0.05) than that observed in the ileum. The microsomal CES activity (using p‐nitrophenyl acetate as substrate) was around twofold higher in duodenum (P < 0.05) and jejunum (P < 0.01) in comparison to the ileum. Cytosolic GST‐dependent activities (toward 1‐chloro, 2,4‐dinitrobenzene) were similar in the mucosa of duodenum, jejunum and ileum. Microsomal UGT activities (toward 1‐naphthol) in duodenum and jejunum were three‐ and fourfold higher, respectively, compared to that measured in the ileum. The small intestinal mucosa may play a critical defensive role due to its involvement in the detoxification of toxic compounds prior to absorption. In addition, gut metabolic reactions may contribute to the presystemic metabolism of orally administered drugs. These results are a further contribution to the understanding of the relevance of the extra‐hepatic metabolism of xenobiotics in ruminant species.