Keim V, Rohr G
Institute of Applied Physiology, University of Marburg, FRG.
Pancreas. 1987;2(5):562-7. doi: 10.1097/00006676-198709000-00012.
The secretion of newly synthesized pancreatic enzymes was studied in pancreatic duct cannulated rats after intravenous injection of 100 microCi of [35S]methionine. Secretion rate was stimulated by intravenous infusion of either cerulein (0.2 microgram/kg h) or carbachol (10 nmol/kg h) starting simultaneously with or 180 min before the injection of the labeled methionine. Secretory proteins were analyzed by sodium dodecyl sulfate (SDS) gel electrophoresis or by nondenaturing gel electrophoresis followed by determination of the radioactivity associated with the individual proteins. Similar to unstimulated controls in all experiments, an early secretion of newly synthesized trypsinogen and chymotrypsinogen was found, whereas amylase and lipase were secreted only after a certain lag period. The results suggest that the intracellular transit of endoproteases is faster than that of other enzymes, irrespective of whether or not secretagogues were applied.
在静脉注射100微居里的[35S]蛋氨酸后，对胰管插管大鼠新合成的胰腺酶分泌情况进行了研究。从注射标记蛋氨酸的同时或之前180分钟开始，通过静脉输注雨蛙素（0.2微克/千克·小时）或卡巴胆碱（10纳摩尔/千克·小时）来刺激分泌率。分泌蛋白通过十二烷基硫酸钠（SDS）凝胶电泳或非变性凝胶电泳进行分析，随后测定与各个蛋白质相关的放射性。在所有实验中，与未受刺激的对照组相似，发现新合成的胰蛋白酶原和糜蛋白酶原早期分泌，而淀粉酶和脂肪酶仅在一定延迟期后才分泌。结果表明，无论是否应用促分泌剂，内切蛋白酶在细胞内的转运速度都比其他酶快。
