Kelly L W, Barden C A, Tiedeman J S, Hatchell D L
Department of Ophthalmology, Duke University Medical Center, Durham, NC 27710.
Exp Eye Res. 1993 Mar;56(3):341-7. doi: 10.1006/exer.1993.1044.
Capillary closure and venous dilatation occur early in diabetic retinopathy, and altered blood rheology may play a role. For example previous studies have shown leukocytes are less deformable, are more activated, and occlude retinal capillaries more often in diabetic subjects. The purpose of this study was to determine if rheologic changes developed in diabetic cats, a model in which we have documented retinal capillary basement membrane thickening, microaneurysms, and intraretinal hemorrhage characteristics of early diabetic retinopathy. Viscosity of blood, plasma and purified erythrocyte suspensions was measured by rotational viscometry and plasma fibrinogen content was determined by heat precipitation. Filterability of blood and purified erythrocyte, mononuclear leukocyte, and granulocyte suspensions was determined at constant flow, measuring the increase in pressure over 2 min relative to the pressure generated by buffer alone. Viscosity of whole blood and plasma, but not erythrocytes, was significantly elevated (P < 0.005) in the diabetic cats over normals at all shear rates studied (450, 225 and 90 sec-1). Furthermore, fibrinogen levels were significantly elevated in diabetic cats compared to normals (P < 0.004), and were positively correlated with the viscosity of whole blood and plasma. The filterability of mononuclear leukocytes and whole blood in diabetic cats was decreased 56% and 74% when compared to normals, P < 0.0006 and P < 0.025, respectively. In contrast, the filterability of granulocytes and erythrocytes was not significantly different between the two groups. These results suggest that the rheologic alterations in diabetes are numerous, and involve both cellular and plasma protein changes.(ABSTRACT TRUNCATED AT 250 WORDS)
在糖尿病视网膜病变早期会出现毛细血管闭合和静脉扩张，血液流变学改变可能起了一定作用。例如，先前的研究表明，糖尿病患者的白细胞变形性降低、活性增强，更常阻塞视网膜毛细血管。本研究的目的是确定糖尿病猫是否会出现血液流变学变化，我们已记录到该模型存在早期糖尿病视网膜病变的视网膜毛细血管基底膜增厚、微动脉瘤和视网膜内出血特征。通过旋转粘度测定法测量血液、血浆和纯化红细胞悬液的粘度，通过热沉淀法测定血浆纤维蛋白原含量。在恒定流量下测定血液、纯化红细胞、单核白细胞和粒细胞悬液的过滤性，测量2分钟内相对于单独缓冲液产生的压力的压力增加。在所有研究的剪切速率（450、225和90秒-1）下，糖尿病猫的全血和血浆粘度显著高于正常猫（P<0.005），但红细胞粘度无显著差异。此外，糖尿病猫的纤维蛋白原水平显著高于正常猫（P<0.004），且与全血和血浆粘度呈正相关。与正常猫相比，糖尿病猫的单核白细胞和全血过滤性分别降低了56%和74%，P分别<0.0006和P<0.025。相比之下，两组之间粒细胞和红细胞的过滤性无显著差异。这些结果表明，糖尿病中的血液流变学改变多种多样，涉及细胞和血浆蛋白变化。（摘要截断于250字）
