胰组织结构提示多肽胰岛素的正常转运经淋巴而非门脉途径

目的　探讨胰岛多肽激素释放形式和细胞外正常转运途径的结构基础。方法　对大鼠和人胰尾部组织进行了光镜 (LM )和透射电镜 (TEM)观察。结果　胰组织主要由腺泡构成的腺小叶和分隔腺小叶的结缔组织所组成。胰腺的导管、血管和淋巴管 ,有髓和无髓神经纤维 ,均穿行于胰结缔组织内。在胰岛周围的结缔组织间隙内也可见到完整的膜包分泌颗粒 (2 0 0～ 5 0 0nm)。胰腺的毛细血管为窗孔 (5 0nm)型。结论　胰组织结构特点提示 :胰岛多肽激素的释放形式 ,可能是连同颗粒膜的整体释放而非传统认为的胞吐分泌 ;释放入胰组织液中的多态胰岛素或分泌颗粒 ,更易进入淋巴而非门脉血液

The Structural Feature of Pancreatic Tissue Indicated Normal Transporting for Polypeptide Insulin Passing Through Lymphatic Not Portal Vessel Route

Objective To explore the structural foundations of releasing pattern and extracellular normal transport route of polypeptide hormones of pancreatic islets. Methods The nomal tissue of the rat and human pancreatic tails were observed by light and transmission electron microscope (LM/TEM). Results The pancreatic tissue is chief composed of glandular lobules formed with acinus and connective tissue separating these lobules. Pancreatic ducts, blood and lymphatic vessels, myelinated and unmyelinated nerve fibers, passed within connective tissue. The secretory granules (200~500nm) wrapped with membrane were also seen in the connective tissue space around pancreatic islet cells. The blood capillary in pancreas is fenestrated (50nm) type. Conclusion The structural features of pancreatic tissue suggest that the releasing pattern of polypeptide hormones of pancreatic islets can be a whole releasing together with granular membrane not exocytosis as considered. The polypeptide insulin or secretory granule released into pancreatic tissue fluid is easy entering into lymph of pancreas rathcr than into blood of hepatic portal vein.