The changes in digestive enzymes and hormones of gilthead seabream larvae (Sparus aurata, L 1758) fed on Artemia nauplii enriched with free methionine

Variations in digestive enzymes and hormones during the larval development of gilthead seabream (Sparus aurata) fed on live prey (Artemia nauplii) enriched with free methionine were investigated for 16 days (from day 24 to day 40). Prior to initiation of the experiment, newly hatched larvae were transferred from incubators to fiber glass tanks (300 l) with black walls and fed with same diets until day 24. Each experiment was performed in triplicate. In the experimental group, the content of the free methionine in the Artemia nauplii was increased by adding a 5.3 mM free methionine solution to the culture water during a 16-h enrichment period. The larvae of both the control and enriched-methionine groups were sampled four times, with 4-day intervals between samplings, during a 16-day period. The larvae in the control group had a significantly lower growth than those of the methionine group at the end of the study (P < 0.05). The highest trypsin activity and leucine aminopeptidase N/leucine–alanine peptidase ratios were observed in the control group. A significant difference between bombesin activities in the treatment groups was not found at 5th minute after the initiation of feeding (P > 0.05), but they were significant at 15th minute post-initiation of feeding (P < 0.05). A significant difference between the cholecystokinin levels of the treatment groups was found (P < 0.05).     

Effects of dietary medicinal herbs and Bacillus on survival, growth, body composition, and digestive enzyme activity of the white shrimp Litopenaeus vannamei

The basal diet (C), with 0.20% medicinal herbs (M) and 0.30% Bacillus (BM1), with 0.10% medicinal herbs and 0.15% Bacillus (BM2), and with 0.30% Bacillus (B), was used to feed white shrimps (Litopenaeus vannamei) (1.91 ± 0.03 g) in order to assess survival, growth, body composition, and digestive enzyme activity. At the end of the feeding trial, survival ranged from 95.83 to 98.33% with no significant difference (P > 0.05) among all groups. Growth measured as weight gain was significantly (P < 0.05) higher in shrimp fed with BM2, BM1, and M compared to that of C. However, no significant differences were found among B, BM1, and M. In the case of specific growth rate, the shrimp fed with BM1 and BM2 exhibited significantly (P < 0.05) higher values than that of C. The contents of body moisture, crude protein, and ash seemed to be unaffected by the feed supplements, though lipid content was found to be significantly (P < 0.05) different among the treatments. The shrimp fed with BM1 and BM2 had the lowest and highest lipid contents, respectively. The digestive enzyme activity assessed using shrimp hepatopancreas revealed that the activities of amylase and protease in shrimp fed with BM2 were significantly (P < 0.05) higher than those of C at the end of the 2nd and 6th weeks. However, better performance of the specific amylase activity was shown by the shrimp fed with B at the end of the 8th week.     

水牛乳β-酪蛋白基因多态性与消化性能及抗氧化性能的关联研究

本研究以水牛乳β-酪蛋白(β-CN)基因多态性分析结果为依据,从水牛乳中分离并纯化出具有活性的β-酪蛋白亚型.采用体外消化模型分析其在胃肠道中的消化性能;根据水解液的抗氧化活性来分析生物活性肽的释放.高效液相色谱法(HPLC)结果显示,水牛乳中β-CN有A和B两种等位基因.消化性能结果显示A等位基因更利于β-酪蛋白在肠...     

八点黑獭兔消化器官形态结构的研究

分别对30～40日龄、60～90日龄、120～150日龄、180日龄以上4个阶段八点黑獭兔消化管的长度进行测定并对其有关结构进行观察描述。结果显示：40～90日龄期间消化管处在不断的生长发育中,并研究发现结肠狭窄部（长度4-5cm）,回盲口与盲结口分开,直肠长度5-6cm,胃容积的大小与供料多少有密切关系。研究结果为我国家兔解剖学补充了新的内容。     

神经干细胞和神经细胞的拉曼光谱研究

[目的]从光谱学角度分析神经干细胞（NSCs）与神经细胞（NCs）的光谱区别,为临床应用提供一定的试验参考依据。[方法]通过体外培养NSCs和NCs,应用激光共焦显微拉曼光谱仪测定2种细胞的拉曼光谱。[结果]NSCs与NCs的拉曼特征峰主要出现在600～1800 cm-1的波数范围和2850～3 000 cm-1波数范围内,拉曼光谱的峰位和相对峰强存在一定差异。NSCs的拉曼峰646、2917 cm-1与NCs的拉曼峰652、2908 cm-1处存在较大差异。NCs核中B型DNA胸腺嘧啶和酪氨酸含量相对更丰富。NSCs核中具有NO2成分,而NCs核中NO2较少或没有。NSCs与NCs核内部酰胺Ⅲ、C-H键、类胡萝卜素、C-H键、CH2键、CH3基团的结构不发生明显变化。NSCs较NCs的DNA、酪氨酸、蛋氨酸、腺嘌呤、苯基丙氨酸、胡萝卜素、酰胺Ⅲ等含量更丰富,其中以胡萝卜素和酰胺Ⅲ的相对含量最高。[结论]从光谱学角度研究NSCs与NCs,是一种新的干细胞研究方法。     

螺旋粉虱成虫消化系统的形态学与组织学研究

应用解剖学和组织学方法研究了螺旋粉虱(Aleurodicus dispersus Russell)成虫消化系统的形态和组织结构。结果显示,螺旋粉虱成虫消化系统由前肠、滤室、中肠、后肠、瓶形孔和一对唾液腺组成。前肠部分主要是食道;中肠包括胃和肠道;后肠分为回肠、结肠和直肠,其中直肠前部有一段膨大的直肠囊;一对唾液腺并行分布在食管下神经节的两侧,呈肾形。消化道管壁从腔内向外依次由黏膜层、肌层和浆膜层等3层结构组成。PAS染色在中肠的胃和肠道中阳性反应最强烈,其次是食道,而在唾液腺和后肠中基本呈阴性;PAS染色阳性部位位于黏膜层,胃和肠道腔内内容物也有阳性反应,而食道腔内无阳性物质。AB染色在后肠中阳性反应最明显,其它部位均呈阴性;AB染色阳性部位位于黏膜层,而肠腔有絮状弱阳性物质。碱性磷酸酶在唾液腺和后肠染色呈阳性,位于整个唾液腺、后肠的黏膜层和肌层;而前肠和中肠染色呈弱阳性,位于黏膜层。     

鸟类消化系统形态学研究进展

从消化道形态结构与食性、食物质量、能量、生态类型等方面的关系,对国内外鸟类消化系统形态学研究现状进行综述,并对未来研究工作进行展望,以期为相关研究者提供科学的借鉴。     

褶纹冠蚌消化系统组织学研究

[目的]研究褶纹冠蚌消化系统的组织学结构,探讨其结构与功能的关系。[方法]运用组织学方法对褶纹冠蚌消化系统的结构进行观察。[结果]褶纹冠蚌的消化道由唇瓣、口、食道、胃、肠、直肠和肛门组成。消化道管壁大都有许多皱褶,黏膜上皮主要为纤毛柱状细胞,在唇瓣、食道、胃、肠和直肠还有少量的黏液细胞,纤毛和黏液细胞在食物的运输中起重要作用。消化腺为复管状腺,腺管上皮有消化细胞和嗜碱性细胞2种类型,消化细胞内含许多囊泡和颗粒。[结论]该研究可为褶纹冠蚌的消化生理研究提供理论依据,同时为其摄食、组织病理研究奠定基础。     

三种饲料对卵形鲳鲹幼鱼消化酶活性的影响

[目的]探讨饵料与卵形鲳鲹幼鱼消化酶活性的关系。[方法]以浮性饲料、沉性饲料、鱼浆加鳗粉喂养卵形鲳鲹幼鱼21d后,比较了3种饵料对胃、肠、肝胰脏和幽门盲囊消化酶活性的影响。[结果]胃、肠和幽门盲囊蛋白酶均以摄食鱼浆加鳗粉组增加幅度最大,肝胰脏蛋白酶以摄食浮性饲料增加幅度最大,蛋白酶活性均以摄食沉性饲料增加幅度最小。胃淀粉酶以摄食沉性饲料组增加幅度最大,肠、肝胰脏和幽门盲囊淀粉酶均以摄食浮性饲料增加幅度最大,淀粉酶活性均以摄食鱼浆加鳗粉组增加幅度最小。胃、肠、肝胰脏和幽门盲囊脂肪酶均以摄食鱼浆加鳗粉增加幅度最大,均以摄食浮性饲料增加幅度最小。[结论]该研究结果对合理配合饲料养殖有一定的指导作用。     

2种纤维源对鹅肠道正常菌群定植的影响

[目的]探讨鹅日龄和消化道部位对正常菌群定植规律的影响以及正常菌群定植与消化纤维的关系。[方法]以吉林白鹅为试验动物,试验期间饲喂以羊草和玉米秸为纤维源的日粮。采用稀释滴种法对0～56．00日龄雏鹅消化道6个部位（腺胃、十二指肠、空肠、回肠、盲肠和直肠）靠近黏膜的内容物及黏膜的8种细菌（双歧杆菌、乳酸杆菌、真杆菌、消化球菌、类杆菌、肠球菌、葡萄球菌和大肠杆菌）进行分离、培养、鉴定、计数。[结果]雏鹅出壳前其消化道是无菌的,出壳后约6h,就可以在腺胃中查出细菌。随后需氧菌及兼性厌氧菌大量繁殖后,出现厌氧菌的繁殖高峰,46．00日龄左右雏鹅消化道完成定植过程;羊草组细菌数量比玉米秸秆组少,但乳酸杆菌和双歧杆菌的相对含量比玉米秸秆组高;大肠杆菌的优势部位为腺胃,肠球菌和乳酸杆菌的优势部位为回肠,葡萄球菌、真杆菌、类杆菌、消化球菌、双歧杆菌的优势部位为盲肠。[结论]日龄、消化道部位和纤维源显著影响各种菌的定植规律。