胰腺内外分泌部微血管内皮细胞不同生物学特性的研究

Study on the different biological characteristics of microvascular endothelial cells in endocrine and exocrine portion of pancreas

目的了解正常生理状态、急性水肿性胰腺炎(AEP)胰腺内外分泌部微血管内皮细胞生物学特性的异同。方法应用荧光免疫组织化学染色和共聚焦激光扫描显微镜技术,观察32只正常、AEP Wistar大鼠胰腺内外分泌部微血管内皮细胞VE-cadherin的表达及其变化。结果在胰腺外分泌部,正常鼠微血管内皮细胞的VE-cadherin位于内皮细胞连接处,AEP时微血管内皮细胞VE-cadherin的表达减少且分布异常,并贯穿于整个疾病过程中;而在内分泌部,正常大、中胰岛毛细血管球血管内皮无VE-cadherin阳性染色,小胰岛内有弥漫性染色,其AEP时的表现与生理状态下的比较无明显变化。结论实验结果显示了大、中胰岛及小胰岛血管内皮细胞生物学的特殊性,这种特殊性可能与其相应内环境以及功能的特殊性相关。

Objective To understand whether there are some differences of the biological characteristics of microvascular endothelial cells between endocrine and exocrine pancreas in normal and acute edematous pancreatitis （AEP） rats. Methods The AEP model of Wistar rats was induced by subcutaneous injection of caerulein. The frozen pancreas was sectioned into 50 μm and 5μm, then the tissue was incubated with anti-VE-cadherin mAb and subsequently with TRITC-conjugated secondary antibody. Expression of VE-cadherin of microvascular endothelial cells at pancreas islet and exocrine pancreas were observed with confocal laser scanning microscope and fluorecence microscope. The collection of images was analyzed with Image Pro Plus system, and compared fluorecence intensities with normal and AEP groups. Results In pancreatic exocrine region, VE- cadherin localization of the normal rats was defined and continuous along entire border of each endothelial cell in microvessels. In the course of AEP, VE-cadherin immunoreactivity was no longer confined to the intercellular junction of endothelium in microvessels. In the endocrine area, VE- cadherin immunoreactivity was absent in capillaries of the sinusoidal capillary glomerulus in the normal or AEP intermediate and large islets, but in small islets VE-cadherin stain was obvious and diffusive in both groups rats. Conclusion VE-cadherin immunoreactivity differs between exocrine and endocrine region, and intermediate-large islets and small islets. These evidences support that biological properties of islet capillary endothelial cell are special, and it maybe relate particularity of endo-circumstance and functions of islet.