Schneditz D, Kainz T, Moser M, Kenner T
Institute of Physiology, University of Graz, Austria.
Basic Res Cardiol. 1987 Jul-Aug;82(4):388-95. doi: 10.1007/BF01907026.
The influence of isotonic or hypotonic dilution on viscoelastic properties of blood is examined. The viscous, as well as the elastic, properties of blood samples diluted with isotonic saline or pure water, respectively, and of undiluted whole blood samples are compared by means of a dynamic capillary viscosimeter (OCR-D, A. Paar K.G., Austria). The dilution (approximately 17% of the total blood volume) was performed isovolemically and retained the same rbc count. The rbc swelling observed as a consequence of changes in plasma osmolarity was tracked by the high resolution density measurement, according to the mechanical oscillator technique. Since no significant rbc swelling was found in the dilution with isotonic saline, viscoelastic resistance of blood was efficiently reduced in the observed range of shear rates (2 s-1-100 s-1). This decrease is due to reduced plasma protein concentration, which also lowers plasma viscosity by approximately 18%. Although plasma viscosity is significantly decreased in hypotonic dilutions (-12%), flow properties of the rbc suspensions are, in general, significantly impaired. This is due to the osmotic rbc swelling (hematocrit = +8%), which increases viscous resistance within the suspending fluid, as well as elastic resistance of the rbc due to a loss in rbc deformability. It can be concluded that isotonic dilution leads to a decrease in the viscosity of blood, whereas hypotonic dilution--in an order of magnitude which may occur during resorption of water--leads to increased viscous and elastic resistance of the blood.
研究了等渗或低渗稀释对血液粘弹性的影响。分别用等渗盐水或纯水稀释的血液样本以及未稀释的全血样本的粘性和弹性特性，通过动态毛细管粘度计（OCR-D，奥地利A. Paar K.G.公司）进行比较。等容进行稀释（约占全血总体积的17%）并保持相同的红细胞计数。根据机械振荡器技术，通过高分辨率密度测量追踪由于血浆渗透压变化而观察到的红细胞肿胀。由于在等渗盐水稀释中未发现明显的红细胞肿胀，在观察到的剪切速率范围（2 s⁻¹ - 100 s⁻¹）内，血液的粘弹性阻力有效降低。这种降低是由于血浆蛋白浓度降低，这也使血浆粘度降低了约18%。尽管在低渗稀释中血浆粘度显著降低（-12%），但红细胞悬浮液的流动特性总体上显著受损。这是由于渗透性红细胞肿胀（血细胞比容 = +8%），这增加了悬浮液中的粘性阻力以及由于红细胞变形性丧失导致的红细胞弹性阻力。可以得出结论，等渗稀释导致血液粘度降低，而低渗稀释——在水吸收过程中可能出现的数量级上——导致血液的粘性和弹性阻力增加。
