Hofbauer B, Saluja A K, Lerch M M, Bhagat L, Bhatia M, Lee H S, Frossard J L, Adler G, Steer M L
Department of Surgery, Beth Israel Deaconess Medical Center and Harvard Medical School, and Harvard Digestive Diseases Center, Boston, Massachusetts 02215, USA.
Am J Physiol. 1998 Aug;275(2):G352-62. doi: 10.1152/ajpgi.1998.275.2.G352.
Supramaximal stimulation of the pancreas with the CCK analog caerulein causes acute edematous pancreatitis. In this model, active trypsin can be detected in the pancreas shortly after the start of supramaximal stimulation. Incubation of pancreatic acini in vitro with a supramaximally stimulating caerulein concentration also results in rapid activation of trypsinogen. In the current study, we have used the techniques of subcellular fractionation and both light and electron microscopy immunolocalization to identify the site of trypsinogen activation and the subsequent fate of trypsin during caerulein-induced pancreatitis. We report that trypsin activity and trypsinogen-activation peptide (TAP), which is released on activation of trypsinogen, are first detectable in a heavy subcellular fraction. This fraction is enriched in digestive enzyme zymogens and lysosomal hydrolases. Subsequent to trypsinogen activation, both trypsin activity and TAP move to a soluble compartment. Immunolocalization studies indicate that trypsinogen activation occurs in cytoplasmic vacuoles that contain the lysosomal hydrolase cathepsin B. These observations suggest that, during the early stages of pancreatitis, trypsinogen is activated in subcellular organelles containing colocalized digestive enzyme zymogens and lysosomal hydrolases and that, subsequent to its activation, trypsin is released into the cytosol.
用胆囊收缩素类似物蛙皮素对胰腺进行超最大刺激会导致急性水肿性胰腺炎。在这个模型中，超最大刺激开始后不久就能在胰腺中检测到活性胰蛋白酶。用超最大刺激浓度的蛙皮素在体外孵育胰腺腺泡也会导致胰蛋白酶原的快速激活。在当前的研究中，我们使用了亚细胞分级分离技术以及光学和电子显微镜免疫定位技术，来确定胰蛋白酶原激活的位点以及在蛙皮素诱导的胰腺炎过程中胰蛋白酶随后的去向。我们报告说，胰蛋白酶活性和胰蛋白酶原激活肽（TAP，在胰蛋白酶原激活时释放）首先在一个重的亚细胞组分中被检测到。这个组分富含消化酶原和溶酶体水解酶。胰蛋白酶原激活后，胰蛋白酶活性和TAP都转移到一个可溶性区室。免疫定位研究表明，胰蛋白酶原激活发生在含有溶酶体水解酶组织蛋白酶B的细胞质液泡中。这些观察结果表明，在胰腺炎的早期阶段，胰蛋白酶原在含有共定位的消化酶原和溶酶体水解酶的亚细胞器中被激活，并且在其激活后，胰蛋白酶被释放到细胞质溶胶中。
