果蔬源胰脂肪酶抑制剂的筛选

通过从三油酸甘油酯释放油酸的释放率来判定胰脂肪酶活性的方法,研究并比较了30种果蔬乙醇提取物的减肥作用.30种果蔬70％乙醇提取物对胰脂肪酶作用的测定结果表明:青辣椒乙醇提取物对胰脂肪酶的抑制作用最强,抑制率为46.15％,山竹提取物抑制率为29.87％,白萝卜、柠檬和圣女果提取物对胰脂肪酶的抑制率均达到20％以上.大蒜提取物对胰脂肪酶有较强的促进作用(29.64％),陈皮和山楂提取物对胰脂肪酶的促进率分别为6.38％和7.66％.     

低分子肝素对高脂血症性胰腺炎大鼠VEGF表达的影响

目的 研究低分子肝素对大鼠高脂血症性胰腺炎胰腺微循环的作用机制。方法 将72只健康SD大鼠随机分成假手术组、模型组和治疗组各24只,每组再随机分成四个亚组。先采用高脂饮食建立高脂血症模型,模型组和治疗组制作大鼠急性胰腺炎模型,制模成功后治疗组分别于0、6、12、18 h开始使用低分子肝素皮下注射,各亚组均间隔6 h重复皮下注射一次,每亚组均干预4次;模型组和假手术组同时间点皮下注射等量生理盐水对照。结果 大鼠胰腺血流速度模型组低于假手术组,治疗组高于模型组（P<0.05）;胰腺组织病理学评分模型组高于假手术组,治疗组低于模型组（P<0.05）;模型组各亚组胰腺血管内皮生长因子（VEGF）蛋白表达、VEGF mRNA表达水平均高于假手术组,而治疗组均低于模型组（P<0.05）。结论 大鼠高脂血症性胰腺炎,VEGF与微循环障碍密切相关;低分子肝素可能通过下调胰腺组织VEGF水平来改善胰腺微循环障碍,减轻胰腺组织进一步损害,且早期干预价值更大。     

口服和静脉注射重组hGLP-1类似物对糖尿病大鼠的影响

目的观察口服和静脉注射重组hGLP-1类似物对糖尿病大鼠血糖、胰岛素及胰岛组织病变的影响。方法用链脲佐菌素（STZ）建立SD大鼠糖尿病模型,随机分为模型组、灌胃组和注射组,每组10只,分别给予生理盐水灌胃、重组hGLP-1类似物多肽灌胃、hGLP-1类似物基因重组载体尾静脉注射,观察4周内各组大鼠血糖、胰岛素、胰岛组织病理变化。结果与模型组比较,灌胃组和注射组的血糖水平在给药后1～4周明显下降,而血清胰岛素水平显著升高（P〈0.01）。灌胃组在各时间点的血糖、胰岛素水平与注射组相比,差异无统计学意义（P〉0.05）。HE染色发现,灌胃组和注射组大鼠的胰岛组织病变有所改善。结论重组hGLP-1类似物可降低糖尿病大鼠的血糖、提高血清胰岛素水平。     

Effects of poorly hydrolizable ingredients in mixed feeds on pancreatic exocrine function in chickens

The response of the pancreas to the use of the poorly hydrolysable ingredients (wheat bran and sunflower meal) in the mixed feed diet was shown under the conditions of the chronic experiments on chickens. The proteolytic enzyme activity decreases by 22–36% as compared to the control because of a 10% decrease in the dietary crude protein level. The lipase activity increases by 17–26% due to an increase in the dietary crude fat content, while the amylase activity remains significantly unchanged with an increase in the dietary amount of nonstarch polysaccharides. The process of the pancreatic adaptation to the new dietary feed generally occurs through a change in the activity of pancreatic enzymes rather than the volume of pancreatic juice. This can indicate the fine adjustment of the digestive system to any change in feed quality.     

活性酵素对中华倒刺鲃肝胰脏淀粉酶活性的影响

研究了不同pH值下,在饲料中添加不同浓度的活性酵素饲养中华倒刺鲃(Spinibarbus sinensis Bleeker)29 d,测定中华倒刺鲃外部生长指标以及与鱼生长有密切相关的淀粉酶活性、活力指标。结果表明,活性酵素能够很好地促进中华倒刺鲃的生长,并对其肝胰脏淀粉酶的最适pH值有较大的影响。随着pH值的变化,淀粉酶活性也随之变化。正常情况下其最适pH为6.8~7.7,酶活力为10.97μg/min;在饲料中添加0.2%、0.4%活性酵素时,其最适pH值下,酶活力分别从10.97升为12.38和12.15μg/min;在饲料中添加0.6%活性酵素时,其最适pH值下,酶活力从10.97升为13.87μg/min。     

Effect of Weaning Ages on Pancreatic and Intestinal Chymotrypsin Activity in Piglet

Twelve litters of new born piglets were divided randomly into groups Ⅰ, Ⅱ, Ⅲ and Ⅳ, and weaned at 17, 21, 28 and 35 days of age, respectively, to determine the effect of weaning age on pancreatic and intestinal chymotrypsin activity in piglets. The results showed that the relative and specific activity of pancreatic chymotrypsin increased significantly 12h after weaning compared with that of sucking piglets at the same age and then decreased and remained low for 2 - 3 weeks after weaning. Total pancreatic chymotrypsin activity had no change with the increase of pancreas weight during day 18 - 50 regardless of weaning (P ＞0.05). Chymotrypsin activity of jejunum had the same change as that of pancreas during sulking stage.Jejunum chymotrypin activity decreased in the first week post-weaning in the piglets weaned before day 28, but had no change in groups weaned at 28 or 35 days. The earlier the weaning age, the longer the restoring time.Chymotrypsin activity in jejunum is more sensitive to the effects of weaning age than in duodenum and ileum.     

The Role of Nitric Oxide in the Exocrine Pancreatic Function in Chicken

The universal cell mediator nitric oxide (NO) mediating the physiological effects via so-called NO donor compounds prolonging its life time. The concentration of NO metabolites in the pancreatic juice of chicken was determined by the enzymatic sensor. It was found that pancreatic juice from starved birds contains nitrate and no other nitro- or nitroso compounds. After feeding, the NO donors appear in pancreatic juice in concentrations of a few tens of μM. These compounds were present in pancreatic juice for several hours after feeding. It is possible that NO donors promote relaxation of the smooth muscles in the walls of pancreatic ducts. Concentration of NO donors in blood serum also increased 2.5–3.0-fold after feeding and remained high during a few subsequent hours. The preliminary subcutaneous administration of atropine to the birds prevent this increase with no effects on the initial concentrations of NO donors in serum. This suggests that the increase is associated with cholinergic stimulation and, therefore, with the activity of the parasympathetic nervous system. The concentration of trypsin in serum also increased after feeding, and atropine also prevents this increase. It is known that serum trypsin acts as a regulator of pancreatic function. Intravenous administration of trypsin led to an insignificant increase of tryptic activity in serum but induced the increase of NO donor concentration twofold. Apparently, nitric oxide, represented by these compounds, can act as a humoral factor in the regulation of pancreatic function in pancreatic juice and possibly in the blood.     

西洋参皂苷对高脂肪食小鼠脂肪和胰脂肪酶活性的影响

通过体外、体内试验研究了西洋参总皂苷、单体皂苷对胰脂肪酶活性及小鼠体重和子宫周围脂肪组织重的影响。体外试验结果表明：西洋参茎叶总皂苷为0．5g/L时，对胰脂肪酶活性的抑制率为90％；人参皂苷Rc，Rb1，Rb2对胰脂肪酶活性均显示很强的抑制作用，当质量浓度为0．5g/L时抑制率分别为100％、96％、97％；体内试验结果表明：西洋参茎叶皂苷对体重影响变化不大，但可以明显降低子宫周围脂肪质量。这说明西洋参茎叶总皂苷和人参皂苷Rc，Rb1，Rb2可以抑制胰脂肪酶活性。因此西洋参茎叶总皂苷的抗肥胖作用可能是由于西洋参总皂苷中的人参皂苷Rc，Rb1，Rb2抑制小肠吸收食物脂肪的结果。     

Amino acid content of rabbit acrosomal proteinase and its similarity to human trypsin

Rabbit acrosomal proteinase from epididymal spermatozoa of 44 male rabbits was purified by subcellular fractionation, sucrose density gradient centrifugation, and electrofocusing; the specific activity of the purified product was 20,047 units per milligram, a value similar to that observed for pancreatic trypsins from various sources. The molecular weight determined from the amino acid analyses and ultracentrifugation was about 22,000. This rabbit acrosomal proteinase showed great similarity to pancreatic trypsin, especially to human pancreatic trypsin, both in the number of individual amino acids and in the total number of residues. This similarity was confirmed by an antigenic cross reaction between rabbit antiserum to bovine pancreatic trypsin with human, rabbit, rhesus monkey, and bull acrosotnal proteinase.     

西洋参总皂苷及单体皂苷对胰脂肪酶活性的影响

首次对西洋参部皂苷及各单体皂进行了降脂活性的研究。结果表明：西洋参总皂苷较人参总皂苷对体外胰脂肪酶活性的抑制作用强，在0．5mg/mL浓度时抑率分别为90％和35．2％；人参皂苷Rc,Rb1,Rb2对胰脂肪酶少性均有很强的抑制作用，在0．5mg/mL浓度时抑制率分别为100％、96％、97％、初步揭示出它们具有被开发为降血脂新药的良好前景。     

桔梗抗肥胖机理试验研究

用含有桔梗水提取物的高脂肪饲料饲喂小鼠，结果表明：含5％桔梗水提取物的高脂肪饲料与对照组比较，小鼠体重和子宫周匀明显下降；同时肝脏中三酰基甘油的水平也有所降低。研究认为：桔梗总皂苷能抑制胰脂肪酶活性，可以使胰脂肪酶的活性抑制在41．7％水平上；桔梗皂苷D、桔梗皂苷A和桔梗皂苷C可分别使其活性抑制在34．8％、3．3％和5．2％的水平上。而菊糖对胰脂肪酶活性没有抑制作用，也不能抑制高脂肪饲料引起的小鼠肥胖和脂肪肝。因此，桔梗抗肥胖作用可能是由于桔梗皂苷类成分抑制胰脂肪酶活性，从而抑制对食物脂肪的吸收。     

Enhanced activity and altered specificity of phospholipase A2 by deletion of a surface loop

Protein engineering and x-ray crystallography have been used to study the role of a surface loop that is present in pancreatic phospholipases but is absent in snake venom phospholipases. Removal of residues 62 to 66 from porcine pancreatic phospholipase A2 does not change the binding constant for micelles significantly, but it improves catalytic activity up to 16 times on micellar (zwitterionic) lecithin substrates. In contrast, the decrease in activity on negatively charged substrates is greater than fourfold. A crystallographic study of the mutant enzyme shows that the region of the deletion has a well-defined structure that differs from the structure of the wild-type enzyme. No structural changes in the active site of the enzyme were detected.     

Differences in adrenergic recognition by pancreatic A and B cells

The adrenergic control of glucose homeostasis is mediated in part through variations in the release of pancreatic hormones. In this study, purified pancreatic A and B cells were used to identify the recognition and messenger units involved in the adrenergic regulation of glucagon and insulin release. Catecholamines induced beta-adrenergic receptor activity in A cells and alpha 2-adrenergic receptor activity in B cells. The two recognition units provoked opposite variations in the production of cellular cyclic adenosine monophosphate, the beta-adrenergic unit enhancing the nucleotide's permissive effect on amino acid-induced glucagon release and the alpha 2-adrenergic unit inhibiting that upon glucose-induced insulin release. In both cell types, catecholamines interact powerfully with the synergistic control of hormone release by nutrient- and (neuro)hormone-driven messenger systems.     

肠道条件和粒径对加工山核桃体外消化的影响

根据健康成人和胰腺外分泌功能不全(exocrine pancreatic insufficiency, EPI)人群的肠道条件,设置不同的胆盐浓度、肠道pH和胰脂酶浓度,分析加工山核桃基质降解率(matrix degradation rate,MDI)、脂肪和蛋白质消化率、总酚和抗氧化活性,探究不同肠道条件和粒径大小对加工山核桃体外消化的影响。结果显示,粒径大小对加工山核桃体外消化影响最显著,小颗粒加工山核桃MDI、抗氧化活性以及脂肪和蛋白质消化率均高于大颗粒加工山核桃。pH和胆盐浓度与脂肪消化和抗氧化活性相关,pH 7,胆盐浓度为10 mmol·L^-1时,脂肪消化效果更好;胰脂酶浓度越高,脂肪和蛋白质消化率越高。因此,EPI人群可适量摄入补充益生元、胰酶制剂,提高对山核桃制品营养素消化利用率。     

猪胰脏中胰酶的制备新工艺技术研究

以猪胰脏为原料,采用单因素试验研究胰酶制备的不同工艺路线、不同提取溶剂、提取激活温度、时间、pH和沉淀剂种类对三酶活力和收率及其他品质的影响,并通过正交试验优化得胰酶制备的工艺条件为:提取溶剂为25%乙醇(原料量的2倍,V·m-2),保护剂为1.0%氯化钠和1.0%甘油,激活剂为0.2%CaCl2和1.0%胰酶原粉;提...     

Environmental dependence of activity of porcine pancreatic lipase in a complex with polymers

It is established that the activity of porcine pancreatic lipase in a complex with the polyelectrolytes sodium polystyrene sulfonate and polydiallyldimethylammonium chloride depends on the presence of salts and environmental temperature.     

A NOTE ON SERUM CHOLINESTERASE VARIABILITY IN MALE AND FEMALE RATS

(1) The serum cholinesterase activity of mature female rats is three to five times as great as that found in mature male rats. Mice sera exhibit similar sexual variations in activity, but to a lesser degree. (2) Immature female rats and probably senile female rats possess a low serum cholinesterase activity, in the same range as that of the mature male rats.     

Vitamin D deficiency inhibits pancreatic secretion of insulin

The effects of a vitamin D deficiency on insulin and glucagon release was determined in the isolated perfused rat pancreas by radioimmunoassay of the secreted proteins. During a 30-minute period of perfusion with glucose and arginine, pancreases from vitamin D-deficient rats exhibited a 48 percent reduction in insulin secretion compared to that for pancreases from vitamin D-deficient rats that had been replenished with vitamin D. Vitamin D status had no effect on pancreatic glucagon secretion. This result, along with the previously demonstrated presence in the pancreas of a vitamin D-dependent calcium-binding protein and cytosol receptor for the hormonal form of vitamin D, 1,25-dihydroxyvitamin D3, indicates an important role for vitamin D in the endocrine functioning of the pancreas.     

硒对雏鸡胰腺的生物学效应

大量的研究结果证实,硒对维持雏鸡生长和胰腺外分泌机能具有专一的作用。胰腺是雏鸡硒缺乏的靶器官,而骨骼肌、心肌、肝脏和其它组织在维生素E 充足时,不受缺硒的影响。硒缺乏的雏鸡,即使喂给足够的维生素 E,胰腺也发生变性和纤维化。与补硒鸡相比,硒缺乏鸡血清中生育酚较低,粪中的中性脂类和胆汁较多,血清谷草转氨酶活性升高,胰脂酶和胰蛋白酶活性较低。此结果归因于胰腺的变性和脂酶的缺乏,从而降低了脂肪的水解,破坏了脂类和维生素 E 吸收所必需的脂类——胆汁微胶粒的形成。在日粮中加入胆汁酸,仅仅部分地改善脂肪的消化和维生素 E 的吸收。补饲游离的脂肪酸和单油酸甘油脂,增加了鸡的维生素E 吸收和存活时间,但不能防止胰腺的纤维化。生物化学研究还表明,酶原活性降低,溶酶体酶中的组织蛋白酶和酸性磷酸酶活性升高。硒是谷胱甘肽过氧化物酶(GSH—Px)的重要组分,此酶与鸡的渗出性素质相关;而且日粮中的硒含量与血清中 GSH—Px 活性高度相关,但是,Contor 报道,GSH—Px 与胰腺萎缩没有相关性。组织化学的研究揭示了由于巨噬细胞的侵润,而导致溶酶体的酶增多。在变性的胰腺中未获得溶酶体破坏的证据,由此证明,硒防止胰腺纤维化的作用,不在于保护胰腺细胞中溶酶体的膜。胰腺变性的病理组织学损伤,开始是在胰腺细胞内形成空泡和透明体,胰腺泡成带现象消失。其次,在胰腺泡之间出现成纤维细胞,全部细胞质基本上都皱缩了,因而扩大了胰腺泡的中央腔。最后,胰腺泡呈现由小的浓染的核所组成的细胞轮,并完全被纤维组织包围。内分泌胰岛显得非常明显,但内分泌机能不紊乱,β-胰岛细胞也不受缺硒的影响。尽管组织学观察到透明体,但线粒体的呼吸机能未受影响。胰腺的组织学检查证明,大麦和硒蛋氨酸是最有效的硒源,就予防胰腺变性的效力而言,硒蛋氮酸是亚硒酸钠和硒代胱氨酸的四倍。严重的胰腺变性常常继发渗出性素质,在防止鸡的渗出性素质中,植物源性硒的生物学活性比动物源性高,硒代胱氨酸比蛋氨酸活性大,但不如亚硒酸钠有效。     

硒和蛋氨酸对雏鸡营养性胰腺萎缩及某些生化指标的影响

用京白Ⅲ系雏鸡进行2×2因子试验(添加蛋氮酸O,0.3％,硒O,0.2PPM),研究了饲粮硒和蛋氨酸缺乏与适量对雏鸡胰腺萎缩(NPA)及胰谷胱甘肽过氧化物酶(GSH-Px)和谷胱甘肽(GSH)的影响。结果表明,雏鸡耗硒一周后出现胰腺变性。缺硒使雏鸡胰、肝脏GSH-Px活性、GSH含量显著降低(P<0.05),GSH/GSSG比例降低。缺硒时1—4周血浆及四周的胰GSH-Px活性、胰硒含量在缺蛋氨酸组显著高于加蛋氨酸组。四周时胰脏GSH含量、GSH/GSSG比例显著低于加蛋氨酸组(P<0.01)。缺硒饲粮中添加蛋氨酸可使缺硒引起的NPA病变程度减轻。