Gabert V M, Jensen M S, Weström B R, Pierzynowski S G
Department of Nutrition, Danish Institute of Agricultural Sciences, Research Centre Foulum, Tjele, Denmark.
Int J Pancreatol. 1997 Aug;22(1):39-43. doi: 10.1007/BF02803903.
The results of this study demonstrated that proteolytic enzymes in pancreatic juice from pigs prepared with the pouch method (PM) were nearly fully active or were fully active. When activation with enterokinase was carried out further inactivation and/or breakdown occurred for chymotrypsin C and cathodal trypsin. In addition, some inactivation and/or breakdown of proteolytic enzymes in pancreatic juice occurred during collection of pancreatic juice from PM pigs.
Samples of pancreatic juice were collected from growing pigs using either the PM or the catheter method (CM). An isolated pouch was prepared where the pancreatic duct enters the duodenum, and three pigs were fitted with a pancreatic pouch re-entrant cannula. Three different pigs had a catheter surgically inserted into the pancreatic duct. Pooled 8-h samples of pancreatic juice were analyzed before and after activation with enterokinase. Chymotrypsin, trypsin, and elastase activities were identified in pancreatic juice after separation by electrophoresis in 1% agarose gels at pH 8.6 using N-acetyl-DL-phenylalanine-beta-naphthyl ester (Ac-Phe-beta ne) as a substrate.
This qualitative enzyme assay indicated that a considerable amount of chymotrypsin C, anodal trypsin, chymotrypsins A and B, elastase II, and cathodal trypsin were present in samples of nonactivated pancreatic juice from PM pigs. In contrast, the only active enzymes identified in pancreatic juice from CM pigs were very small amounts of chymotrypsin A and elastase II. The amounts of chymotrypsin C and cathodal trypsin were lower in activated than in nonactivated pancreatic juice from PM pigs. However, there were increases in the amounts of the other enzymes when pancreatic juice from PM pigs was activated. As expected, the activation of pancreatic juice from CM pigs resulted in the measurement of very high amounts of all the proteolytic enzymes. The amounts of anodal trypsin, chymotrypsins A and B, and elastase II were higher in activated pancreatic juice from CM pigs than from PM pigs.
本研究结果表明,采用囊袋法(PM)制备的猪胰液中的蛋白水解酶几乎完全有活性或完全有活性。用肠激酶激活后,糜蛋白酶C和阴极胰蛋白酶会进一步失活和/或分解。此外,从采用PM法的猪收集胰液的过程中,胰液中的蛋白水解酶会发生一些失活和/或分解。
使用PM法或导管法(CM)从生长猪收集胰液样本。在胰管进入十二指肠处制备一个分离的囊袋,三只猪安装了胰囊折返插管。另外三只不同的猪通过手术将导管插入胰管。用肠激酶激活前后对合并的8小时胰液样本进行分析。在pH 8.6的1%琼脂糖凝胶中进行电泳分离后,以N-乙酰-DL-苯丙氨酸-β-萘酯(Ac-Phe-βne)为底物,鉴定胰液中的糜蛋白酶、胰蛋白酶和弹性蛋白酶活性。
这种定性酶分析表明,来自采用PM法的猪的未激活胰液样本中存在大量的糜蛋白酶C、阳极胰蛋白酶、糜蛋白酶A和B、弹性蛋白酶II以及阴极胰蛋白酶。相比之下,在来自采用CM法的猪的胰液中鉴定出的唯一有活性的酶是极少量的糜蛋白酶A和弹性蛋白酶II。来自采用PM法的猪的激活胰液中,糜蛋白酶C和阴极胰蛋白酶的含量低于未激活胰液。然而,来自采用PM法的猪的胰液激活后,其他酶的含量增加。正如预期的那样,来自采用CM法的猪的胰液激活后,所有蛋白水解酶的测量值都非常高。来自采用CM法的猪的激活胰液中,阳极胰蛋白酶、糜蛋白酶A和B以及弹性蛋白酶II的含量高于来自采用PM法的猪的激活胰液。