Arshi K, Bendayan M, Ghitescu L D
Département de Pathologie et Biologie Cellulaire, Université de Montréal, Québec, Canada.
Lab Invest. 2000 Aug;80(8):1171-84. doi: 10.1038/labinvest.3780125.
The alteration induced by diabetes on vascular permeability to serum albumin was investigated in the mesentery of streptozotocin-induced hyperglycemic rats. Double-tagged ((125)I and dinitrophenol-haptenated) heterologous albumin was intravenously administered in normal and hyperglycemic animals, and the extravasation of the tracer was evaluated by radioactivity measurements and by morphometry at the ultrastructural level using quantitative protein A-colloidal gold immunocytochemistry. The results demonstrate that diabetes induces a significant increase in the permeability of the mesentery vessels to albumin. This increase is due to a more efficient transport of macromolecules by endothelial plasmalemmal vesicles and not to leakier interendothelial junctions. Passage across the endothelial basement membranes did not appear to be restricted in either the control or diabetic condition. However, in diabetes, the mesothelial basement membrane appeared to become modified and to restrain the passage of albumin toward the peritoneal cavity. After 3 months of diabetes, the rats presented a net increase in the average diameter of the blood vessels localized in the mesentery arcada (macrovascular hyperplasy) and a notable angiogenesis, manifested at the level of the microvasculature in the mesenteric windows.
在链脲佐菌素诱导的高血糖大鼠肠系膜中，研究了糖尿病对血管血清白蛋白通透性的影响。将双标记（（125）I和二硝基苯酚半抗原化）的异源白蛋白静脉注射到正常和高血糖动物体内，并通过放射性测量以及使用定量蛋白A胶体金免疫细胞化学在超微结构水平上进行形态计量学分析来评估示踪剂的外渗情况。结果表明，糖尿病会导致肠系膜血管对白蛋白的通透性显著增加。这种增加是由于内皮细胞质膜小泡对大分子的转运效率更高，而不是内皮细胞间连接更易渗漏。在对照或糖尿病状态下，穿过内皮基底膜的过程似乎均未受到限制。然而，在糖尿病状态下，间皮基底膜似乎发生了改变，并抑制了白蛋白向腹腔的通过。糖尿病3个月后，大鼠肠系膜弓状动脉中的血管平均直径出现净增加（大血管增生），并且在肠系膜窗的微血管水平出现明显的血管生成。
