Superoxide dismutase reduces islet microvascular injury induced by streptozotocin in the rat
Superoxide dismutase reduces islet microvascular injury induced by streptozotocin in the rat
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DOI：
10.1152/ajpendo.1997.273.2.e376
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发表时间：
1997-08-01
影响因子：
5.1
通讯作者：
Kusterer, K
中科院分区：
文献类型：
--
作者：
Enghofer, M;Usadel, KH;Kusterer, K
静脉注射链脲佐菌素（STZ）可导致大鼠永久性糖尿病。我们研究了在这个动物模型中胰岛微循环变化和自由基形成的可能作用。在体内荧光显微镜下进行4小时后，STZ的管理。测量胰腺内分泌和外分泌组织的血管通透性、毛细血管血流量和内皮白细胞粘附。最早的微循环事件是胰岛中血管通透性的增加，在STZ给药后1 h达到峰值，t = 60 min时胰岛和外分泌组织光强度之间的差异为+15.8 +/- 5.6%。3 h后胰岛血流速度显著降低，而外分泌胰腺中的血流不受影响。仅在接受STZ的大鼠中观察到胰岛血流完全停滞。既没有增加白细胞粘附胰岛血管内皮细胞，也没有观察到缺血再灌注现象。预防性给予自由基清除剂超氧化物歧化酶可预防STZ诱导的胰岛微循环损伤。结论：STZ可导致大鼠胰岛内严重的微循环障碍。显然，这些变化至少部分是由氧自由基介导的。
Intravenous administration of streptozotocin (STZ) leads to permanent diabetes mellitus in rats. We investigated the possible role of islet microcirculatory changes and free radical formation in this animal model. In vivo fluorescence microscopy was performed for 4 h after administration of STZ. Vascular permeability, capillary blood flow and endothelial leukocyte adhesion were measured in endocrine and exocrine pancreatic tissue. The earliest microcirculatory event was an increase in vascular permeability in pancreatic islets, with a peak 1 h after STZ administration, The difference between islet and exocrine tissue light intensity was +15.8 +/- 5.6% at t = 60 min. Islet blood flow velocity significantly decreased after 3 h, whereas blood flow in the exocrine pancreas was not affected. Complete stasis of islet blood flow was observed only in rate receiving STZ. Neither increased leukocyte adhesion to islet vascular endothelium nor ischemia-reperfusion phenomena were observed. Prophylactic administration of the radical scavenger superoxide dismutase prevented STZ-induced damage to the islet microcirculation in the initial phase of this model. me conclude that STZ leads to severe microcirculatory disturbances within pancreatic islets in rats. Apparently these changes are mediated at least in part by free oxygen radicals.