Trimble E R, Bruzzone R, Gjinovci A, Renold A E
Endocrinology. 1985 Sep;117(3):1246-52. doi: 10.1210/endo-117-3-1246.
The object of the present investigation was to determine whether insulin secreted by the endocrine pancreas and carried in the insulo-acinar portal system has a direct effect on pancreatic enzyme secretion. For this purpose, the isolated rat pancreas was perfused in a nonrecirculating system. The perfusate contained 3 mM glucose, and either caerulein or vaso-active intestinal polypeptide was used to stimulate exocrine secretion. The amount of insulin reaching the exocrine pancreas was reduced by two different experimental procedures. In the first, use was made of streptozotocin-diabetic rats treated with insulin in vivo. Treatment was such that the contents of amylase and lipase, vastly altered in the untreated diabetic state, were normalized before the perfusion studies. In the second procedure, insulin reaching the exocrine pancreas was reduced by antiinsulin serum in the perfusate. In these procedures, the reduced insulin bioavailability was associated with a reduction in caerulein- and vasoactive intestinal polypeptide-stimulated enzyme release, which was shown as a reduction of maximum responsiveness to caerulein without alteration of sensitivity. By contrast, in dispersed pancreatic acini where the insulo-acinar axis was completely disrupted, amylase secretion from diabetic and nondiabetic tissue was identical over a wide range of caerulein concentrations, showing that the secretory defect seen in the perfusion studies was not inherent to the exocrine tissue. The results show that basal insulin secretion has a direct effect on pancreatic enzyme output and that the insulo-acinar axis may play an important role in the regulation of acinar cell function.
本研究的目的是确定内分泌胰腺分泌并通过胰岛-腺泡门脉系统输送的胰岛素是否对胰腺酶分泌有直接影响。为此，在非循环系统中对分离的大鼠胰腺进行灌注。灌注液含有3 mM葡萄糖，使用蛙皮素或血管活性肠肽刺激外分泌。通过两种不同的实验方法减少到达外分泌胰腺的胰岛素量。第一种方法是使用体内用胰岛素治疗的链脲佐菌素糖尿病大鼠。治疗方式使得在灌注研究之前，未治疗的糖尿病状态下大幅改变的淀粉酶和脂肪酶含量恢复正常。第二种方法是在灌注液中加入抗胰岛素血清，减少到达外分泌胰腺的胰岛素。在这些实验中，胰岛素生物利用度的降低与蛙皮素和血管活性肠肽刺激的酶释放减少有关，表现为对蛙皮素最大反应性的降低，而敏感性未改变。相比之下，在胰岛-腺泡轴完全中断的分散胰腺腺泡中，在广泛的蛙皮素浓度范围内，糖尿病和非糖尿病组织的淀粉酶分泌相同，这表明灌注研究中看到的分泌缺陷并非外分泌组织所固有。结果表明，基础胰岛素分泌对胰腺酶输出有直接影响，胰岛-腺泡轴可能在腺泡细胞功能调节中起重要作用。
