PATHOGENETIC MECHANISMS IN DIABETIC VASCULAR DISEASE

本申请中提出的研究的长期目标 阐明糖尿病损伤血管的机制 并导致临床上显著的血管疾病。 越来越多 有证据表明：1）许多晚期并发症 糖尿病与葡萄糖代谢为山梨醇的增加有关 通过酶醛糖还原酶，和2）醛糖还原酶连接的， 糖尿病引起的血管损伤和山梨醇代谢是 经调制的。 设计了实验方案 实现以下具体目标：1）阐明 胰岛素缺乏与高血糖无关，反之亦然， 糖尿病血管病变的发病机制，2）阐明 肌醇和Na/K-ATP酶组织水平降低的作用 在介导糖尿病诱导的血管内皮细胞增殖中的活性 渗透性，3）评估性别 类固醇和甲状腺激素可以调节糖尿病诱导的 多元醇代谢和血管功能完整性的改变， 4)确定造成aldo增加的机制， 糖尿病大鼠红细胞中酮还原酶活性，5） 确定红细胞中醛酮还原酶活性 与醛酮还原酶活性和/或血管 糖尿病患者坐骨神经、主动脉和眼睛的通透性变化 大鼠，6）探讨醛酮 红细胞还原酶活性、青春期和血糖控制 在人类糖尿病患者中。 在大鼠中的研究将广泛使用新方法， 我们实验室开发的程序， 评估激素、药物制剂的直接影响， 代谢底物对组织代谢和血管 体内渗透性。 激素和代谢的直接影响 在新的制粒中评估基质对这些参数的影响 在皮肤腔室中形成的组织，其中测试物质 局部应用于组织。 评估血管通透性 通过125 I-白蛋白的渗透。 醛酮还原酶活性（以 与环境多元醇水平相反）的红细胞和组织的浓度。 通过测量半乳糖醇在 与半乳糖体外孵育。 定量组织多元醇 作为它们的丁烷硼酸酯衍生物， 色谱/质谱法。 Na/K-ATP酶活性 用同位素法测定。 需要获得的信息 从这些实验中应该提供重要的新见解 糖尿病血管疾病的发病机制。

The long term objective of the studies proposed in this application is to elucidate the mechanism(s) by which diabetes injures vessels and causes clinically significant vascular disease. A growing body of evidence indicates that: 1) many of the late complications of diabetes are linked to increased metabolism of glucose to sorbitol by the enzyme aldose reductase, and 2) aldose reductase-linked, diabetes-induced vascular damage and sorbitol metabolism are hormonally modulated. The experimental protocols are designed to achieve the following specific aims: 1) to elucidate the role of insulin deficiency independent of hyperglycemia, and vice versa, in the pathogenesis of diabetic vascular disease, 2) to clarify the roles of decreased tissue levels of myo-inositol and Na/K-ATPase activity in mediating diabetes-induced increases in vascular permeability, 3) to assess potential mechanisms by which sex steroids and thyroid hormone may modulate diabetes-induced alterations in polyol metabolism and vascular functional integrity, 4) to identify the mechanism(s) responsible for increased aldo- keto reductase activity in erythrocytes of diabetic rats, 5) to determine whether aldo-keto reductase activity in erythrocytes correlates with aldo-keto reductase activity and/or vascular permeability changes in sciatic nerve, aorta, and eyes in diabetic rats, 6) to investigate the relationship between aldo-keto reductase activity in erythrocytes, puberty, and glycemic control in human diabetics. The studies in rats will make extensive use of new methods and procedures developed in our laboratory which make it possible to assess direct effects of hormones, pharmacologic agents, and metabolic substrates on tissue metabolism and vascular permeability in vivo. Direct effects of hormones and metabolic substrates on these parameters are assessed on new granulation tissue formed in skin chambers in which test substances are applied topically to the tissue. Vascular permeability is assessed by permeation of 125I-albumin. Aldo-keto reductase activity (as opposed to ambient polyol levels) of red cells and tissues is assessed by measurement of galactitol accumulation during incubation with galactose in vitro. Tissue polyols are quantified as their butaneboronate derivatives using electron ionization gas chromatography/mass spectrometry. Na/K-ATPase activity is assessed by use of isotopic method. The information to be gained from these experiments should provide important new insights into the pathogenesis of diabetic vascular disease.