饲粮营养水平对绒山羊小肠感应因子mRNA相对表达量、血液理化指标及激素含量的影响

本试验旨在适当降低饲粮氮水平条件下,通过饲粮添加N-氨甲酰谷氨酸(NCG)及小肠灌注葡萄糖,研究其对绒山羊小肠感应因子mRNA相对表达量、血液理化指标及激素含量的影响。选用27只体况良好、装有永久性瘤胃和十二指肠瘘管的内蒙古白绒山羊羯羊,按年龄和体重相近原则随机分成9组,每组3只。饲粮分为3个处理:低氮[粗蛋白质(CP)10.5%]、低氮+NCG(0.20 g/d)和高氮(CP 13.5%);每个处理的山羊分别进行3个水平的十二指肠葡萄糖灌注:0、20和40 g/d。饲养试验(15 d预试期、15 d正试期)结束后,屠宰取空肠和十二指肠组织,通过实时定量PCR法测定营养感应因子mRNA相对表达量,测定血液理化指标、血清和空肠相关激素含量。结果表明:1)在基础饲粮条件(无葡萄糖灌注)下,随着饲粮氮水平的下降,空肠和十二指肠钠-葡萄糖共转运载体1(SGLT1)的mRNA相对表达量,血浆尿素氮、葡萄糖含量,血清瓜氨酸、胰岛素含量,血清和空肠胰高血糖素样肽1(GLP-1)、胰高血糖素样肽2(GLP-2)和促胰岛素肽(GIP)含量减少,而空肠和十二指肠溶质载体家族7成员9(SLC7A9)、溶质载体家族7成员1(SLC7A1)的mRNA相对表达量增加。2)增加适宜过瘤胃葡萄糖后,随着饲粮氮水平的下降,SGLT1、味觉受体1型1、味觉受体1型2、味觉受体1型3 mRNA相对表达量呈增加趋势。3)低氮饲粮条件下灌注20 g/d葡萄糖,额外饲喂NCG能够缓解饲粮氮水平降低引起的空肠和十二指肠SGLT1 mRNA相对表达量,血浆尿素氮、葡萄糖含量,血清瓜氨酸含量,血清和空肠GLP-1、GLP-2和GIP含量的下降。结果提示,适当降低饲粮氮水平,补饲NCG和增加过瘤胃葡萄糖(十二指肠灌注20 g/d)对绒山羊机体代谢及肠道营养物质感应均有促进作用。     

Composition of individual nucleobases in diets containing different products from bacterial biomass grown on natural gas, and digestibility in mink (Mustela vison)

The objectives of the present study were to quantify the amount of nucleic acids, to examine the nucleobase composition and to determine the digestibility of individual nucleobases in diets containing various products from bacterial biomass grown on natural gas, including autolytic and hydrolytic fractions, using mink (Mustela vison) as a model animal. The diets consisted of cod fillet (control), commercial basic BioProtein, and five experimentally produced autolytic and hydrolytic fractions of the bacterial protein meal as protein sources. Each diet was assigned to four adult male mink, housed individually in cages equipped for controlled feeding and quantitative collection of faeces. Faeces were collected for 4 days, and the individual nucleobases in diet and faeces were analysed by HPLC after hydrolysis using HClO(4). The content of nucleobases in the diets containing bacterial protein meal was 37% to 205% higher than in the control diet. The nucleobase-nitrogen in the control diet amounted to 4.3% of the total nitrogen content, whereas the experimental bacterial protein diets contained from 7.4% to 17.4% of the total N content in the form of nucleic acids. The various methods used to produce the bacterial protein fractions clearly affected both the amount of nucleic acids and the molar proportions of the individual nucleobases. The average digestibility of the nucleobases was 95%, and all the individual nucleobases were highly digestible. Uracil showed the highest digestibility (on average 96.8%), whereas thymine showed the lowest digestibility (on average 93.6%).     

Insect (black soldier fly larvae) oil as a potential substitute for fish or soy oil in the fish meal-based diet of juvenile rainbow trout (Oncorhynchus mykiss)

Alternative sources of fish oil (FO) are one of the major problems in aquaculture; therefore, the goal of the present study was to examine insect (black soldier fly larvae) oil (BSLO) as a potential replacer of fish/soy oil in juvenile rainbow trout (initial average weight of 32 ± 0.15 g) feed. Four diets were formulated wherein FO (control diet) was completely replaced with either soybean oil (SO) or BSLO, and an additional BSLO-based diet supplemented with 1.5% bile acid (BSLO + BA) were fed to the fish for 10 weeks. Growth performance of the BSLO fed group was similar (P > 0.05) to that of the FO and SO fed groups, however, the fish fed BSLO + BA diet registered the lowest growth (P < 0.05). Oil sources did not (P > 0.05) affect the major nutrient content of whole-body, however, the fatty acid composition of the muscle and liver was influenced (P < 0.05), with the highest 14:0, 16:0, and total saturated fatty acid detected in BSLO or BSLO + BA fed trout compared to the others (P < 0.001). No significant differences were observed in eicosapentaenoic acid + docosahexaenoic acid (EPA + DHA) or total n-3 polyunsaturated fatty acid (PUFA) content in muscle among the groups, whereas, the highest EPA:DHA and n-3:n-6 ratios were detected in the FO group. Gene expression for fatty acid binding protein (fabp), fatty acid synthase (fas), and Δ5 desaturase in the liver was lower in FO (P < 0.05), while BSLO + BA registered the highest Δ6 expression (P = 0.006). Supplementation of BA in the BSLO diet increased superoxide dismutase (SOD) and catalase (CAT) activities compared to the other groups (P < 0.05). In conclusion, BSLO could serve as a substitute for FO and SO in rainbow trout diet without negatively impacting growth performance, whole-body composition and nutrient retention, and modulate the expression of fatty acid metabolism-related genes in rainbow trout.     

Characteristics of 18F-FDG and 18F-FDOPA PET in an 8-year-old neutered male Yorkshire Terrier dog with glioma: long-term chemotherapy using hydroxyurea plus imatinib with prednisolone and immunoreactivity for PDGFR-β and LAT1

An 8-year-old neutered male Yorkshire Terrier dog presented with head pressing, vestibular ataxia, neck tenderness, and no oculocephalic reflex. A demarcated lesion in the pons was identified on MRI. The patient was tentatively diagnosed with a glioma and was treated with hydroxyurea plus imatinib and prednisolone. After 30 days of therapeutic treatment, the patient showed a clear improvement in neurological signs, which lasted for 1117 days. On day 569 after the initiation of treatment, ¹⁸F-fluorodeoxyglucose (FDG)-positron emission tomography (PET) was performed with no significant findings on visual analysis. The average and maximal standardized uptake values (SUVs) were 1.92 and 2.29, respectively. The tumor-to-normal-tissue (T/N) ratio was 0.97. The first evidence of clinical deterioration was noticed on day 1147. On day 1155, 3,4-dihydroxy-6-[¹⁸F]-fluoro-l-phenylalanine (¹⁸F-FDOPA)-PET was performed. High uptake of ¹⁸F-FDOPA was observed in the intracranial lesion. The mean and maximal SUVs of the tumor were 1.59 and 2.29, respectively. The T/N ratio was 2.22. The patient was euthanized on day 1155 and histopathologic evaluations confirmed glioma (astrocytoma). This case shows that chemotherapy with hydroxyurea plus imatinib may be considered in the treatment of canine glioma. Furthermore, this is the first case describing the application of ¹⁸F-FDG and ¹⁸F-FDOPA in a dog with glioma.     

Serum biochemical parameters and amino acids metabolism are altered in piglets by early-weaning and proline and putrescine supplementations

The study was to investigate the effect of early-weaning stress and proline (Pro) and putrescine (Put) supplementations on serum biochemical parameters and amino acids (AA) metabolism in suckling and post-weaning pigs. Blood and small intestinal mucosa were harvested from suckling piglets at 1, 7, 14, and 21 d of age and piglets on d 1, 3, 5, and 7 after weaning at 14 d of age, as well as from piglets received oral administration of Pro and Put from 1 to 14 d old. In suckling piglets, the serum glucose, albumin and total cholesterol levels were increased (P < 0.05) with increasing age, whereas the serum globulin, urea nitrogen (BUN), alkaline phosphatase (ALP) and aspartate aminotransferase (AST) levels were lowered (P < 0.05). The concentrations of most serum AA and the AA transporters related gene expressions were highest in 7-d-old piglets (P < 0.05), whereas the phosphorylation status of the mammalian target of the rapamycin (mTOR) signaling pathway in the small intestine increased in piglets from 1 to 21 d old (P < 0.05). Weaning at 14 d old increased (P < 0.05) the BUN and triglycerides levels in serum, as well as jejunal solute carrier family 7 member 6 (SLC7A6), ileal SLC36A1 and SLC1A1 mRNA abundances at d 1 or 3 post-weaning. Weaning also inhibited (P < 0.05) the phosphorylation levels of mTOR and its downstream ribosomal protein S6 kinase 1 (S6K1) and 4E-binding protein-1 (4EBP1) in the small intestine of weanling pigs. Oral administration of Put and Pro decreased (P < 0.05) serum ALP levels and increased (P < 0.05) intestinal SLC36A1 and SLC1A1 mRNA abundances and mTOR pathway phosphorylation levels in post-weaning pigs. Pro but not Put treatment enhanced (P < 0.05) serum Pro, arginine (Arg) and glutamine (Gln) concentrations of weaning-pigs. These findings indicated that early-weaning dramatically altered the biochemical blood metabolites, AA profile and intestinal mTOR pathway activity, and Pro and Put supplementations improved the AA metabolism and transportation as well as activated the intestinal mTOR pathway in weanling-pigs. Our study has an important implication for the broad application of Pro and Put in the weaning transition of piglets.     

磷对铝胁迫紫花苜蓿幼苗根系生长和生理特征的影响

为了探究磷对铝胁迫下紫花苜蓿幼苗生长和生理特征的影响,分别用不含和含200 μmol·L^-1磷（P）、100 μmol·L^-1铝（Al）、200 μmol·L^-1 P+100 μmol·L^-1 Al的简易 ［Ca（NO₃）₂］营养液（pH=4.5）处理铝敏感紫花苜蓿品种‘Wl440’幼苗。结果表明,在铝处理中添加磷后,苜蓿幼苗根系和叶片中的铝含量分别比铝处理降低81.53%和61.47%,苜蓿幼苗的根长和根系活力显著提高,叶片电导率和丙二醛（MDA）含量显著下降;光合生理得到明显改善,与铝处理相比,磷添加处理幼苗叶片的叶绿素含量、蒸腾速率、气孔导度和光合速率明显提高,光系统Ⅱ和光系统I的电子传递速率增加;磷添加处理明显提高了铝胁迫苜蓿根系的草酸和苹果酸含量,体内有机酸螯合铝离子的能力增强,光合能力提高。因此,磷能够通过增加根系有机酸含量,改善铝胁迫苜蓿光合系统,从而缓解苜蓿铝毒害。     

BCG诱导RAW264.7细胞脂肪酸氧化对细胞自噬和促炎因子表达的调控作用

旨在探究脂肪酸氧化（fatty acid oxidation,FAO）对BCG介导的RAW264.7细胞自噬和促炎因子表达的调控作用。用BODIPY染色和游离脂肪酸定量试剂盒检测BCG感染后RAW264.7细胞中脂滴聚集情况以及脂肪酸含量;Western blot检测BCG感染对肉毒碱棕榈酰基转移酶1A （CPT-1A）表达的影响;Etomoxir （100 μmol·L^-1）预处理细胞2 h后,BCG感染细胞6 h,检测RAW264.7细胞中BCG存留量,并用Western blot方法检测自噬相关蛋白（Beclin1、LC3-II）和溶酶体蛋白（Rab7）的表达情况;用免疫荧光方法和mRFP-GFP-LC3荧光双标腺病毒分别检测自噬小体聚集和自噬流;荧光定量PCR和ELISA分别检测促炎因子IL-1β、IL-6和TNF-α mRNA表达情况以及在细胞培养上清中的含量。结果显示,BCG感染促进RAW264.7细胞中脂滴聚集和CPT-1A的表达,而游离脂肪酸含量降低;Etomoxir预处理抑制了细胞中BCG存活,并上调了Beclin1、LC3-II和Rab7表达,且细胞中出现大量自噬小体聚集,自噬流增强,却抑制了促炎因子IL-1β、IL-6和TNF-α mRNA表达与分泌。综上表明,抑制FAO可促进BCG感染诱导的RAW264.7细胞自噬,并抑制BCG感染引起的炎症反应。     

Evaluation of vegetable protein in canine diets: Assessment of performance and apparent ileal amino acid digestibility using a broiler model

Recent technological advances in the human food industry with respect to meat processing have decreased the availability of animal proteins to the pet food industry which typically formulates diets with an excess of animal protein. In the long term, this is not sustainable; thus, alternative protein sources need to be investigated. This study examined three canine diets, comparing a typical animal protein‐based diet (control) with two experimental diets where the animal protein was substituted in part with vegetable protein (formulated based either on total protein or amino acid content) using a broiler model. Each diet was fed to six cages each containing two birds from day 15, 18 cages in total (36 birds). Excreta were collected from days 19 to 21. On day 23, birds were euthanized and weighed, and their ileal digesta were collected and pooled for each cage. In addition, one leg per cage was collected for evaluation of muscle mass. Results showed no significant difference in animal performance (feed intake or live weight gain) or muscle to leg proportion across the diets. Birds fed the control diet and the diet balanced for amino acid content exhibited the greatest coefficients of apparent metabolizability for nitrogen (p < .001). Birds fed the diets that contained partial replacement of animal with vegetable protein generally had greater ileal digestibility of amino acids compared to birds fed the control (animal protein) diet. Analysis of excreta showed no dietary difference in terms of dry matter content; however, birds fed the diet balanced for total protein and the diet balanced for amino acid content had significantly greater excreta nitrogen than the control (p = .038). Overall, the study suggests vegetable proteins when formulated based on amino acid content are a viable alternative to animal proteins in canine diets.     

猪油酸-急性肺损伤模型的建立

试验以猪为试验对象建立油酸-急性肺损伤模型。对油酸的注射剂量、宰杀方式进行比较优选;然后选取12头50日龄的猪,随机分为对照组和油酸组;处理后观察猪的呼吸状况,并在处理后不同时相点（1、3和6 h）宰杀猪,对肺组织的结构变化和肺含水量进行观察分析。结果表明,与对照组相比,注射适量油酸后,猪呼吸方式由胸腹式呼吸变为急促的腹式呼吸,呼吸频率明显升高;在注射后的3个时相点剖检发现,油酸组猪的肺组织出现典型急性肺损伤的病理形态。因此,在本试验条件下,以0.05 ml/kg体重,少量分次,耳静脉注射油酸成功建立了油酸-急性肺损伤模型,为进一步开展有关猪肺损伤及肺免疫防御的研究奠定了基础。