仔猪胃肠道食糜和血液中酪啡肽的检测及阿片样活性分析     

张源淑  宗亚峰  邹思湘  陈伟华 《畜牧兽医学报》2006,37(10):1063-1066

将24头仔公猪分为对照组(正常哺乳28 d断奶)、试验I组(添喂β-酪啡肽-7)和试验Ⅱ组(添喂酪蛋白酶解物)。试验组于21 d断奶,再连续添喂酪蛋白胃蛋白酶解液或β-酪啡肽-7 10 d,每天2次(共20mL),至32 d,3组动物各随机取6头同时剖杀,取血、胃食糜和空肠食糜。通过所建立的RP-HPLC方法,在胃食糜和空肠食糜中检测到β-酪啡肽-5、β-酪啡肽-7样物质。对照组、酪啡肽-7组和酪蛋白水解液组,β-酪啡肽-7的平均含量分别为21.12±2.38,23.58±7.49、21.81±9.93μg/g胃食糜和16.99±3.48、19.08±2.85、21.36±4.85μg/g肠食糜;胃食糜中-βCM-7的含量高于空肠食糜,试验组均高于对照组。在各组仔猪的血液中未检测到酪啡肽样物质。肠食糜的细胞生物学试验结果表明:与喂仔猪料的对照组比较,试验I组和试验Ⅱ组对细胞腺苷酸环化酶的活性均具有不同程度的抑制作用,抑制率分别为27.9%和89.0%,抑制作用均能被纳洛酮反转,逆转率分别是43.2%和89.07%。提示在21日龄断奶仔猪饲料中添加酪啡肽或酪蛋白酶解物,其肠道中有酪啡肽释放,阿片总活性升高。  相似文献   

Alcalase在酪蛋白磷酸肽生产中的应用研究   总被引：6，自引：0，他引：6  

赵利  王璋  许时婴 《中国奶牛》2002,(5):15-18

本文运用碱性蛋白酶Alcalase水解酪蛋白制备酪蛋白磷酸肽（CPP）。研究了Alcalase作用酪蛋白的最佳条件，探讨了乙醇浓度和酪蛋白水解度（DH）对CPP得率和N／P（摩尔比）的影响。  相似文献   

Comparison of methods for assay of fecal proteolytic activity     

Williams DA  Reed SD 《Veterinary clinical pathology / American Society for Veterinary Clinical Pathology》1990,19(1):20-24

Fecal proteolytic activity (FPA) in ten normal dogs was readily detected either calorimetrically using azocasein substrate or by radial enzyme diffusion into agar gels containing casein substrate. Daily FPA ranged from 17 to 207 azocasein units/g (ACUIG) or 4 to 18 mm of casein hydrolysis, while mean 3-day FPA ranged from 58 to 10 1 ACUIG or 7 to 15 mm. Studies of proteolytic activity remaining after treatment of fecal extracts with a specific trypsin inhibitor indicated that trypsin accounted for 0% to 71% of proteolytic activity. Proteolytic activity decreased steadily in fecal specimens stored at room temperature or above, but there was only slight loss in activity during storage for up to 5 days at 4 degrees C. Proteolytic activity was unaffected by repeated freezing and thawing and samples could be stored for long periods at -2 degrees C without noticeable loss of activity. It is concluded that assays of FPA using either azoprotein substrate or radial enzyme diffusion into agar gels containing casein substrate allow evaluation of exocrine pancreatic function in dogs, provided that several samples are tested. These methods are suitable for application in a variety of species.  相似文献   

ORIGINAL ARTICLE: Bioavailability of lysine for kittens in overheated casein is underestimated by the rat growth assay method*,†     

J. A. Larsen  A. J. Fascetti  C. C. Calvert  Q. R. Rogers 《Journal of animal physiology and animal nutrition》2010,94(5):e102-e108

Growth assays were performed to determine lysine bioavailability for kittens and rats in untreated and heated casein; these values were compared with estimates obtained with an in vitro method. Body weight, food intake, nitrogen and dry matter digestibility, and plasma lysine were determined during an 80‐day growth trial using kittens (n = 16). Body weight and food intake were determined during a 21‐day growth trial using weanling rats (n = 80). The growth data showed bioavailable lysine to be 102.4% and 100.2% (for untreated casein) and 66.1% and 51.7% (for heated casein) for kittens and rats, respectively. There was no relationship between plasma lysine and dietary lysine concentrations for kittens. There were no significant differences in nitrogen or dry matter digestibility among diets for kittens. The chemically reactive lysine content of untreated casein was 99.6%, and of heated casein was 67.1%. Heat treatment of casein resulted in significantly decreased lysine bioavailability as estimated by all methods. For untreated casein, both growth assays showed good agreement with the in vitro method for available lysine. For heated casein, the rat growth assay significantly underestimated bioavailable lysine as determined in kittens while the in vitro method closely approximated this value for the cat.  相似文献   

酸性条件下酪蛋白与高酯果胶稳定体系的研究     

张静  李元瑞  籍保平 《西北农林科技大学学报(自然科学版)》2008,36(6):195-199

【目的】研究酸性条件下酪蛋白的稳定特性。【方法】从牛乳中提取出纯体酪蛋白,对酸性条件下酪蛋白与高酯果胶相互作用的条件和机理进行了测定与分析。【结果】当pH值为4.20,酪蛋白含量为0.6%~1.5%时,高酯果胶添加量(y)与酪蛋白含量(x)之间存在线性关系,线性方程为y=0.333 3x+0.245 8;酪蛋白和高酯果胶有效结合的适宜pH值为3.70~5.30。【结论】在合适的酸度范围内,高酯果胶分子通过空间位阻效应和静电吸引与酪蛋白胶束结合,阻止了酪蛋白胶束之间的聚集沉淀,从而使酪蛋白在酸性条件下也可以相对稳定地存在。  相似文献   

酪蛋白的胰蛋白酶酶解条件的优化   总被引：3，自引：0，他引：3  

王政杨国宇  潘玉善郏自明 《华中农业大学学报》2005,24(6):618-621

用二次回归通用旋转设计、响应面分析法,研究三因素五水平下胰蛋白酶水解酪蛋白的反应,得到了一定条件下酪蛋白在酶作用下水解程度的变化规律。根据回归方程利用统计优选法寻优,确定了最优水解条件：温度为58℃,pH值为7．4,酶底比为0．7％。  相似文献   

组织块种植法体外培养奶牛乳腺上皮细胞     

丁月云  张莉莉  陈莎莎  王恬 《南京农业大学学报》2008,31(4)

为建立成熟的奶牛乳腺上皮细胞体外培养体系,以组织块种植法培养荷斯坦泌乳期成年母牛乳腺组织,观测长出的上皮细胞在各生长时期的形态变化,绘制生长曲线并计算群体倍增时间,用免疫组化技术鉴定乳腺上皮细胞角蛋白18的表达,用SDS-PAGE电泳和免疫印迹分析技术检测乳腺细胞的酪蛋白分泌情况。试验结果表明,此培养体系可获得良好的奶牛乳腺上皮细胞,原代以及传代培养,细胞增殖旺盛,长势良好;细胞骨架蛋白——角蛋白18表达为阳性,且培养的细胞具有分泌牛乳酪蛋白的功能。  相似文献   

改性牦牛乳酪蛋白可食性膜制备的研究     

胡先望  严晓娟  陈朋  吴润  梁宁  张鸣明  宋勇强 《安徽农业大学学报》2014,41(6):922

以牦牛乳酪蛋白作为成膜基质,氢氧化钠调节pH,添加脂肪类物质（如硬脂酸、软脂酸及其混合物）作为阻隔剂,单硬脂酸小分子多元醇酯作为乳化剂,研究各种成分的添加比例、甘油添加量、烘干温度、质量浓度比及成膜工艺参数对成膜的影响;通过正交试验,确定膜组分和成膜工艺的最优组合。结果表明：当酪蛋白含量为2.5%,小分子多元醇酯含量为1%,pH7.0,烘干温度和湿度分别为30℃、40%时,改性膜形成一种新的结晶体,此时形成的膜最优。  相似文献   

牦牛乳酪蛋白降血压肽对高血压大鼠体内降压效果研究     

冯玉萍  ;李倬  ;张福梅  ;陈诚  ;田伟  ;靳冬武  ;龙仕和  ;崔梦楠  ;暴艳敏 《中兽医医药杂志》2014,(3):50-54

目的：观察牦牛乳酪蛋白降血压肽对应激性高血压大鼠（stress induced hypertensive rats,SIHR）和正常Wistar大鼠的降压效果,并与降压药物厄贝沙坦（irbesaran）和卡托普利（Captopril）的作用效果进行比较。方法：采用木瓜蛋白酶、中性蛋白酶水解制备牦牛乳酪蛋白降血压肽,分别以20 mg/kg、40 mg/kg和60 mg/kg剂量的牦牛乳酪蛋白降血压肽一次灌胃,每隔2 h测量SIHR收缩压（SBP）,连续测量8 h;长期实验持续6周,每天60 mg/kg一次灌胃,每隔1周测量SBP一次。结果：SIHR给予牦牛乳酪蛋白降血压肽后,血压均显著下降（P〈0.05）,并均在灌胃后3-6 h达最低,血压下降最大幅度为（27±5.13）mmHg,呈现一定的量效关系;而正常大鼠给予牦牛乳酪蛋白降血压肽后血压无显著变化,服用厄贝沙坦和卡托普利后血压则保持显著下降的趋势。长期灌胃牦牛乳酪蛋白降血压肽可使SIHR血压明显下降（P〈0.05）,并且降压效果稳定。结论：牛乳酪蛋白降血压肽对SIHR有明显的体内降压效果,长期服用可稳定血压,对正常大鼠血压无明显影响。  相似文献   

龙井茶叶中鞣质含量的测定     

范斌  刘步东  李登昌 《中兽医医药杂志》2014,(6):38-40

用干酪素法对龙井茶叶中鞣质含量进行测定。结果表明,龙井茶叶鞣质含量在2.000-11.000μg/m L范围内呈线性关系（R2=0.999 3）;样品平均加标回收率为84.6%,SD为0.226%,RSD为1.8%（n=6）。该方法准确、可靠、重现性好、精密度好,可用于龙井茶叶中鞣质含量的测定。  相似文献