作者机构：
[Zhu, H. L.; Hou, Y. Q.; Ding, B. Y.; Hu, L. L.; Zhang, J.] Wuhan Polytech Univ, Hubei Key Lab Anim Nutr & Feed Sci, Wuhan 430023, Peoples R China.
通讯机构：
[Ding, B. Y.] W;Wuhan Polytech Univ, Hubei Key Lab Anim Nutr & Feed Sci, Wuhan 430023, Peoples R China.
关键词：
broiler;enzyme supplementation;dietary metabolizable energy level;growth performance;digestive parameter
摘要：
The study was performed to evaluate the effects of enzyme supplementation on performance and digestive parameters of broilers fed corn-soybean diets from 1 to 21 d of age. A total of 480 one-day-old Cobb broilers were allocated to 1 of 4 treatments, with 6 replicate pens per treatment and 20 birds per pen. The experiment consisted of a 2 × 2 factorial arrangement of treatments with 2 dietary ME levels (high ME, energy 1, 12.13 MJ/kg or low ME, energy 2, 11.92 MJ/kg) and 2 levels of supplemental enzyme (including xylanase, 1,800 IU/g, β-glucanase, 500 IU/g, and α-amylase, 800 U/g; 0 or 0.1% of diet). Enzyme supplementation had no effect on average daily weight gain, feed intake, and feed:gain. However, enzyme supplementation decreased the relative weight of the pancreas (d 7 and 21) in broilers fed the high ME diet. Low dietary ME level increased pancreatic lipase (d 7, P = 0.015), trypsin (d 14, P = 0.01; d 21, P = 0.014), amylase (d 21, P = 0.027), and pepsin (d 7, P = 0.001; d 21, P = 0.042) activity, but reduced pancreatic lipase (d 14, P = 0.03; d 21, P = 0.004) and amylase (d 14, P = 0.027) activity. Enzyme supplementation resulted in an increase in pancreatic amylase (d 7, P = 0.023), trypsin (d 7, P = 0.02; d 21, P = 0.004), lipase (d 21, P = 0.001), pepsin (d 7, P = 0.001; d 14, P = 0.004; d 21, P = 0.001), and maltase (d 14, P = 0.011, in ileum) activity. Moreover, broilers fed low dietary ME and enzyme supplementation diets had an increase in pancreatic lipase (d 21, P = 0.001) and pepsin (d 7, P = 0.001) activity. Low ME diets reduced jejunum villus height and jejunum and ileum crypt depth (d 7, 21). However, enzyme supplementation, especially enzyme supplementation in low ME diets, increased jejunum and ileum villus height and villus surface area. This suggested enzyme supplemented with low ME diet might be more effective to improve the activity of digestive enzymes and the absorptive capacity of the small intestine.
摘要：
Pro-inflammatory cytokines play a critical role in many models of liver injury. In addition, aspartate (Asp) plays an important role in many biological and physiological processes including liver physiology. We hypothesized that Asp could alleviate lipopolysaccharide (LPS)-induced liver injury. Forty-eight weanling pigs were assigned to four treatments including: (1) non-challenged control; (2) LPS challenged control; (3) LPS+0.5% Asp; (4) LPS+1.0% Asp. After 20-d feeding with control (0% Asp), 0.5% or 1.0% Asp supplemented diets, pigs were injected with saline or LPS. At 4 (early phase) and 24 h (late phase) post-injection, blood and liver samples were obtained. Asp attenuated liver injury indicated by reduced serum aspartate aminotransferase activity and increased ratio of serum alanine aminotransferase and aspartate aminotransferase at 24 h, and less severe histological liver damage induced by LPS challenge at 4 or 24 h. In addition, Asp supplementation to LPS challenged pigs decreased mRNA expressions of tumor necrosis factor (TNF)-alpha and cyclooxygenase-2 linearly and quadratically at 4 h, and increased mRNA expressions of these pro-inflammatory mediators linearly and quadratically at 24 h. Finally, Asp decreased mRNA expression of toll-like receptor 4 (TLR4) signaling related genes (TLR4, myeloid differentiation factor 88, IL-1 receptor-associated kinase 1, TNF-alpha receptor-associated factor (6), nucleotide-binding oligomerization domain protein (NOD) signaling related genes (NOD1, NOD2 and receptor-interacting serine/threonine-protein kinase 2) and nuclear factor-kappa B p65 linearly or quadratically at 4 h. However, Asp increased mRNA expressions of these signaling molecules linearly or quadratically at 24 h. These results indicate that, at early and late phases of LPS challenge, Asp exerts opposite regulatory effects on mRNA expression of hepatic pro-inflammatory cytokines and TLR4 and NOD signalling related genes, and improves liver integrity. (C) 2014 Elsevier Inc. All rights reserved.
摘要：
谷氨酰胺(L-glutamine,Gln)是肠细胞和免疫细胞等细胞快速分化的优先底物,可刺激细胞增殖,能调控基因表达和细胞信号通路。Gln不仅作为肠上皮细胞的主要能量物质,为小肠上皮细胞的分化和增殖提供能量,而且还可通过调节谷氨酰胺酶活性、相关细胞信号通路和蛋白合成等促进肠上皮细胞的增殖,但其作用机理还不清楚。mTOR(哺乳动物雷帕霉素靶蛋白,mammalian target of rapamyc
摘要：
Chlorogenic acid, a natural phenolic acid present in fruits and plants, provides beneficial effects for human health. The objectives of this study were to investigate whether chlorogenic acid (CHA) could improve the intestinal barrier integrity for weaned rats with lipopolysaccharide (LPS) challenge. Thirty-two weaned male Sprague Dawley rats (21 +/- 1 d of age; 62.26 +/- 2.73 g) were selected and randomly allotted to four treatments, including weaned rat control, LPS-challenged and chlorogenic acid (CHA) supplemented group (orally 20 mg/kg and 50 mg/kg body). Dietary supplementation with CHA decreased (P < 0.05) the concentrations of urea and albumin in the serum, compared to the LPS-challenged group. The levels of IFN-gamma and TNF-alpha were lower (P < 0.05) in the jejunal and colon of weaned rats receiving CHA supplementation, in comparison with the control group. CHA supplementation increased (P < 0.05) villus height and the ratio of villus height to crypt depth in the jejunal and ileal mucosae under condictions of LPS challenge. CHA supplementation decreased (P < 0.05) intestinal permeability, which was indicated by the ratio of lactulose to mannitol and serum DAO activity, when compared to weaned rats with LPS challenge. Immunohistochemical analysis of tight junction proteins revealed that ZO-1 and occludin protein abundances in the jejunum and colon were increased (P < 0.05) by CHA supplementation. Additionally, results of immunoblot analysis revealed that the amount of occludin in the colon was also increased (P < 0.05) in CHA-supplemented rats. In conclusion, CHA decreases intestinal permeability and increases intestinal expression of tight junction proteins in weaned rats challenged with LPS.
摘要：
The intestine has a high requirement for ATP to support its integrity, function and health, and thus, energy deficits in the intestinal mucosa may play a critical role in intestinal injury. Aspartate (Asp) is one of the major sources of ATP in mammalian enterocytes via mitochondrial oxidation. We hypothesized that dietary supplementation of Asp could attenuate lipopolysaccharide (LPS)-induced intestinal damage via modulation of intestinal energy status. Twenty-four weanling piglets were allotted to one of four treatments: (1) nonchallenged control, (2) LPS-challenged control, (3) LPS+0.5% Asp treatment, and (4) LPS+1.0% Asp treatment. On day 19, pigs were injected with saline or LPS. At 24 h postinjection, pigs were killed and intestinal samples were obtained. Asp attenuated LPS-induced intestinal damage indicated by greater villus height and villus height/crypt depth ratio as well as higher RNA/DNA and protein/DNA ratios. Asp improved intestinal function indicated by increased intestinal mucosal disaccharidase activities. Asp also improved intestinal energy status indicated by increased ATP, ADP and total adenine nucleotide contents, adenylate energy charge and decreased AMP/ATP ratio. In addition, Asp increased the activities of tricarboxylic acid cycle key enzymes including citrate synthase, isocitrate dehydrogenase and alpha-oxoglutarate dehydrogenase complex. Moreover, Asp down-regulated mRNA expression of intestinal AMP-activated protein kinase alpha 1 (AMPK alpha 1), AMPK alpha 2, silent information regulator 1 (SIRT1) and peroxisome proliferator activated receptor gamma coactivator-1 alpha (PGC1 alpha) and decreased intestinal AMPK alpha phosphorylation. These results indicate that Asp may alleviate LPS-induced intestinal damage and improve intestinal energy status. (C) 2014 Elsevier Inc. All rights reserved.
