Relationships between hemorheology, erythrocyte metabolism, and von willebrand factor in athletes and patients with peripheral arterial disease

The relationship between hemorheology, erythrocyte ATP and 2,3-diphosphoglycerate (2,3-DPG) concentrations, and von Willebrand factor antigen was studied in athletes and peripheral arterial disease patients. Lower blood viscosity, mainly due to a higher erythrocyte deformability, was found in athletes compared to control subjects. Higher 2,3-DPG/Ht levels in athletes were correlated with blood viscosity, erythrocyte deformability, the rigidity index, and erythrocyte suspension viscosity at low shear stress. It is suggested that these relationships might be determined by the predominance of immature erythrocytes in the blood circulation of the athletes. In the group of patients, a decrease in ATP/Ht was related to increased erythrocyte aggregation and a higher erythrocyte suspension viscosity. Moreover, the concentration of von Willebrand factor was positively correlated with the erythrocyte aggregation index, erythrocyte suspension viscosity, and plasma viscosity. The results show that alterations in erythrocyte and plasma rheology may be involved in the modification of the functional state of the vascular endothelium and the development of atherosclerosis.     

肠淋巴液引流对失血性休克大鼠红细胞流变性的影响

目的:观察肠淋巴液引流对失血性休克大鼠红细胞流变性指标以及血液黏度的作用。方法:Wistar雄性大鼠均分为假休克组、休克组(复制失血性休克模型)、引流组(复制失血性休克模型,自低血压1 h引流休克肠淋巴液)。在低血压3 h或相应时间,经腹主动脉取血,检测红细胞参数、红细胞电泳、红细胞沉降率(ESR)以及血液黏度,计算红细胞聚集指数、红细胞变形指数。结果:与假休克组比较,休克组红细胞数量、红细胞比积(HCT)、血红蛋白(Hb)、平均红细胞血红蛋白浓度(MCHC)、红细胞电泳率与迁移率、红细胞变形指数、全血黏度、全血低切与高切相对黏度和还原黏度显著降低,休克组平均红细胞体积、红细胞电泳时间、ESR、血沉方程K值与校正K值、红细胞聚集性指数、血浆黏度显著升高;引流组MCHC、红细胞电泳率与迁移率、全血黏度、全血低切与高切还原黏度均显著降低,引流组红细胞体积分布宽度(RDW-SD)显著增加。同时,引流组HCT、RDW-SD、红细胞变形指数、全血黏度、全血低切与高切相对黏度显著高于休克组;ESR、血沉方程K值与校正K值、红细胞聚集性指数、血浆黏度显著低于休克组。结论:休克肠淋巴液引流可改善失血性休克大鼠红细胞流变行为,从而改善血液流变性。     

杜仲绿原酸对高脂小鼠血液流变学作用研究

旨以研究杜仲绿原酸对高脂高胆固醇诱导的高血脂模型小鼠血液流变学的影响,以昆明小鼠为实验动物,随机分成5组:阴性对照组,模型对照组和低剂量(25 mg/kg BW)、中剂量(50 mg/kg BW)、高剂量(100 mg/kg BW)杜仲绿原酸组,每组10只.后4组饲以高脂饲粮,同时小鼠灌胃杜仲绿原酸4周,实验结束,分别测定各组小鼠血液流变学参数、血清和肝脏的抗氧化酶活性和脂质过氧化产物MDA含量及其总抗氧化能力和羟自由基清除率.高脂血症小鼠的全血粘度、血浆粘度、红细胞压积、血沉、纤维蛋白原、红细胞刚性指数和聚集指数显著降低(P＜0.05),红细胞变形指数显著提高(P＜0.05),小鼠血清和肝脏SOD、GSH-Px水平、总抗氧化能力和羟自由基清除能力均显著升高(P＜0.05),MDA水平显著降低(P＜0.05).在高脂膳食条件下,杜仲绿原酸能有效提高血液的抗氧化防御功能(包括抗氧化力、抗氧化酶活性)、改变血液流变学参数等,降低血液粘度、红细胞刚性和聚集,增强变形能力,使细胞膜的流动性增高,其中以中剂量效果相对较好.     

Thromboembolic risk factors in kidney transplantation: hemorheologic examination in secondary polycythemia

Cardiovascular risk factors will increase the lethality of kidney patients being under dialysis treatment and after transplantation. This risk is additionally increased after transplantation by secondary polycythemia. The paper investigates the rheological properties of the blood of 20 patients affected by secondary polycythemia after kidney transplantation, 10 patients without polycythemia after kidney transplantation and 19 test persons. Plasma viscosity, erythrocyte aggregation and whole blood viscosity were determined. As a result, an increase of erythrocyte aggregation without their deformability being changed could be found in patients affected by polycythemia after kidney transplantation. The reduced thrombocyte aggregation identified in these patients can be explained by the influence of therapy.     

Oscillating viscometer--evaluation of a new bedside test

A viscometer for bedside blood measurements was developed, consisting of an oscillating resonator probe mounted directly into a disposable vacutainer tube for blood withdrawal. It was tested in vitro on blood samples with variable hematocrits (20-60%), increasing fibrinogen concentrations (0-20 g/l), increasing concentrations of an admixed radiographic contrast medium and erythrocyte suspensions in dextran 40 and dextran 70. Results were compared with those obtained with a conventional Couette viscometer. Oscillating viscometry yielded generally higher values than Couette viscometry, and had a good sensitivity for changes in hematocrit with a good correlation between the two methods (r=0.96, p<0.0001). Oscillating viscosity depended on the resonator frequency, it was higher at 3900 Hz than at 215 Hz, suggesting a viscoelastic behavior of blood. Erythrocyte aggregation, induced by increasing fibrinogen concentrations or dextran 70, affected oscillating viscometry. At a high frequency, i.e. a smaller penetration depth of the shear wave, oscillating viscosity tended to decrease, which suggests a depletion of the boundary layer from erythrocytes when they aggregate. At low frequency with a deeper shear wave penetration (about 50 microm), erythrocyte aggregation increased oscillating viscosity. Bedside tests in 17 patients with coronary heart disease and 10 controls confirmed the easy practicability of the test and showed lower oscillating viscosity in these patients despite higher fibrinogen concentrations presumably due to increased erythrocyte aggregation. We conclude that oscillating viscometry is an interesting bedside test, which is capable of providing new information on the biorheology of the erythrocyte-poor boundary layer near the vessel wall.     

Erythrocyte deformation in simulated weightless human and rabbits

Effect and mechanism of simulated weightlessness (SWL) in humans and rabbits erythrocyte deformation were studied. Erythrocyte deformation and membrane fluidity in humans and rabbits, and erythrocyte morphology and hemorreology indices in control and HDT rabbits were measured. The results were a decrease in erythrocyte deformation and membrane fluidity in humans and rabbits during SWL, a significant increase in abnormal erythrocyte, blood viscosity, hematocrit, fibrinogen, and red blood cell aggregation index in HDT rabbits. These results show that the changes in erythrocyte shape, increase of erythrocyte internal viscosity and changes in erythrocyte visco-elasticity may be causing the decrease of erythrocyte deformation in SWL humans and rabbits.     

Blood rheology in acute mountain sickness and high-altitude pulmonary edema.

The role of blood rheology in the pathogenesis of acute mountain sickness and high-altitude pulmonary edema was investigated. Twenty-three volunteers, 12 with a history of high-altitude pulmonary edema, were studied at low altitude (490 m) and at 2 h and 18 h after arrival at 4,559 m. Eight subjects remained healthy, seven developed acute mountain sickness, and eight developed high-altitude pulmonary edema. Hematocrit, whole blood viscosity, plasma viscosity, erythrocyte aggregation, and erythrocyte deformability (filtration) were measured. Plasma viscosity and erythrocyte deformability remained unaffected. The hematocrit level was lower 2 h after the arrival at high altitude and higher after 18 h compared with low altitude. The whole blood viscosity changed accordingly. The erythrocyte aggregation was about doubled 18 h after the arrival compared with low-altitude values, which reflects the acute phase reaction. There were, however, no significant differences in any rheological parameters between healthy individuals and subjects with acute mountain sickness or high-altitude pulmonary edema, either before or during the illness. We conclude that rheological abnormalities can be excluded as an initiating event in the development of acute mountain sickness and high-altitude pulmonary edema.     

褐藻酸钠硫酸酯对血液流变学和血小板聚集的影响

褐藻酸钠硫酸酯(Sodium Alginate Sulfates SAS)是以褐藻酸为原料经磺化、酯化而成的硫酸酯多糖的钠盐系列物(Ⅰ、Ⅱ、Ⅲ、Ⅳ)。本文研究了SAS对兔和大鼠血液流变学和血小板聚集的影响,结果发现:SAS静注5mg/kg能够显著降低高切、低切下的全血比粘度,降低血细胞压积,降低红细胞聚集指数,提高红细胞沉降率,从而改善血液的流变特性。实验中还发现,SAS体内外均可缩短大鼠红细胞电泳时间,体内还可以缩短大鼠血小板电泳时间,而体外则可延长血小板电泳时间。SAS体外可诱导兔、大鼠血小板聚集,能够促进ADP诱导的血小板聚集,而对AA诱导的血小板聚集则无促进作用。结果提示:静注SAS能够改善血液的流变特性,增加红细胞和血小板表面电荷,抑制红细胞及血小板间的粘附和聚集,从而使其具有一定的抗血栓作用。同时还提示,SAS在体内循环和代谢的过程中,结构可能发生了变化,从而使其体内、体外的作用特征出现了相对立的结果。     

The mechanism of erythrocyte sedimentation in Westergren's examination.

The authors deduced the equation that describes the sedimentation of erythrocytes as the function of time, hematocrit, hemoglobin and some plasma protein concentrations and the citrate viscosity and density. This values served to describe plasma and erythrocyte density, plasma viscosity, erythrocyte aggregation and the influence of suspension concentration on the erythrocyte sedimentation rate. The influence of citrate on blood dilution (the reduction of hematocrit and plasma protein concentrations) was also considered. A good agreement between the observed and predicted values was obtained.     

Changes in blood viscosity after administration of vitamin E in the rabbit

Vitamin E is an essential factor to maintain biological membranes stability and its lack may affect membranes structures and reduce erythrocyte life-span. Vitamin E also play a role in the maintenance of a normal platelet aggregation. A.A. studied the effects of a ten days supply of d-1-alpha tocopherol acetate (50 mg/Kg/die) on blood viscosity in 8 rabbits. Results obtained show a significant reduction of blood viscosity on 6th day of treatment in the male rabbits and a progressive reduction of values from the 6th till the 10th day in female rabbits. The most significant decrease of blood viscosity were obtained at the lowest shear-rates, due to an increased red cells deformability to the antioxidative action of vitamin E on the erythrocytes membrane and to a reduced red cells aggregation. Such modifications on the red blood cells caratheristics can be determined by vitamin E through different mechanism: a) inhibiting red cell membrane's polyunsaturable fatty acids oxidation; b) by removal of abnormal lipids from erythrocyte membrane; c) physical and chemical stabilization of membrane's surface.     

华法林联合肝素对瓣膜置换术后患者微循环的影响

目的:研究华法林联合肝素对瓣膜置换术后患者微循环的影响,评价其有效性及安全性。方法:选择2014年1月-2015年6月我院收治的瓣膜置换术患者60例,随机分为实验组和对照组,每组30例。对照组患者瓣膜置换术后第二天口服华法林治疗,实验组患者瓣膜置换术后当天即皮下注射低分子肝素钙,术后第二天口服华法林抗凝治疗。两组患者均于术后7 d、14 d空腹取外周静脉血,检测红细胞比容、血沉、全血还原比粘度、血浆比粘度以及红细胞聚集指数。结果:与对照组相比,实验组患者术后7d、14 d血沉值、全血比粘度水平、全血还原比粘度水平、血浆比粘度和红细胞聚集指数均显著降低,差异具有统计学意义(P0.05);两组患者术后7 d、14 d血细胞比容比较,差异无统计学意义(P0.05)。结论:和单独应用华法林相比,瓣膜置换术后采用联合应用华法林及肝素能更好改善患者微循环,值得临床推广。     

Action of hydroxyethyl starch on the flow properties of human erythrocyte suspensions

Hydroxyethyl starch (HES) has often been used as a plasma expander, but questions still remain concerning the mechanisms by which it produces changes in the rheological properties of blood and erythrocyte (RBC) suspensions under various flow conditions. The present investigation has shown that the dynamic viscosity of HES (232,000 and 565,000 daltons) solutions rises in a nonlinear fashion with increasing HES concentration, and for a given concentration of HES exhibits Newtonian behavior at shear rates between 0.15 to 124 sec-1. At low (less than 0.9 sec-1) shear rates the apparent viscosity of a 40% RBC suspension increases with lower concentrations of HES because of RBC aggregation. At higher concentrations of HES, increases in suspension viscosity are due to an increase in the viscosity of the continuous phase since the RBC are largely disaggregated. At high (greater than 36 sec-1) shear rates the relative viscosity (eta/eta O) of RBC suspensions slowly decreases with increasing HES concentration. At low shear rates eta/eta O increases and then decreases with increasing HES concentration. Evidence of the concentration-dependent effects of HES on RBC aggregation is provided not only by the viscometric analysis but also from measurements of erythrocyte sedimentation rate (ESR) and the zeta sedimentation ratio (ZSR). HES is a more potent aggregating agent in phosphate buffered saline (PBS) than it is in plasma. Polymer size has only a slight effect on the extent of RBC aggregation produced, but does have a significant effect on the concentration of polymer at which maximum aggregation occurs. The viscosity-corrected electrophoretic mobility of RBC in HES rises monotonically with the concentration of HES in the suspending medium. Decreases in the extent of RBC aggregation with increasing polymer concentrations probably result from an increase in the electrostatic repulsive forces between the cells.     

Pharmacological concentrations of arginine influence human whole blood viscosity independent of nitric oxide synthase activity in vitro

l-Arginine, the natural precursor of NO, is infused in patients to restore endothelial function. Concentrations up to 7.5 mM l-arginine have been measured after parenteral administration. We investigated whether such high concentrations of amino acids influence blood viscosity in vitro. Incubation of whole blood from healthy volunteers with l-arginine, d-arginine, which has no effect on stereospecific NO synthases (NOS), the NOS substrate L-AME, the NOS inhibitor L-NNA, the amino acids l-lysine and l-glutamic acid, and finally NaCl dose-dependently decreased (up to 30% at 10(-2) M) low shear viscosity, which is primarily determined by erythrocyte aggregation. In contrast, the lipophilic NOS inhibitor L-NAME had no effect on low shear viscosity. All molecules failed to influence high shear viscosity, which is primarily determined by red cell deformability, and the erythrocyte shape remained unaltered. We conclude that high concentrations amino acids may decrease blood viscosity at low shear rate independent of NOS activity. This effect may contribute to the improved blood flow after intravascular administration of l-arginine.     

Measurement of erythrocyte orientation in flow by spin labeling III--erythrocyte orientation and rheological conditions

The measurements of erythrocyte orientation, obtained through a spin labeling technique, are compared with a phenomenological model. Several rheological conditions are varied: hematocrit, suspending medium viscosity, blood age, artificial reversible aggregation. We found that the onset of orientation is very sensitive to any variation of these conditions, and that its measurement would be a good method to assess erythrocyte deformability. A critical shear rate for the orientation process is then determined and compared to the corresponding parameter obtained from viscosity measurements of identical suspensions. A close qualitative relationship is found between the two sets of values of the critical shear rate.     

Functional and structural changes in the surface of human erythrocytes after UV irradiation with rays of various wavelengths. IV. Changes in the physicochemical properties of autotransfused UV-irradiated blood

Properties of erythrocyte surface were investigated for patients with ischemic heart disease in the course of treatment with the UV-irradiated blood autotransfusion (UVIBA). Application of methods of light-scattering, photometry and cytochemistry revealed rapid and significant changes in deformability and aggregation properties of the erythrocytes immediately following each UVIBA procedure, which was accompanied by considerable blood viscosity decrease.     

Effects of daily management stress on haematology and blood rheology of the gilthead seabream

Haematological and haemorheological responses against a moderate management stress, applied for 2 weeks, have been studied in the gilthead seabream ( Sparus aurata ). The stress application leads to a significant reduction in circulating erythrocytes, which caused decreased blood viscosity. Although erythrocyte osmotic fragility showed a trend inversely related to the duration of management stress, no significant change in cell dimensions, aggregation and deformation indices was observed. Consequently, the decrease in oxygen transport capacity attributable to haematocrit reduction, is not compensated by a qualitative change in the microrheological behaviour of erythrocytes, since the blood viscosity decreases as a direct result of the decline in red blood cell number.     

Relationships between Thyroid Hormones, Blood Rheology, and Lipid Profile in Athletes

The interrelation of thyroid hormones with blood rheology and lipid profile was studied in athletes (N = 12). A decrease in blood viscosity in the athletes was caused by a lower erythrocyte rigidity index, which correlated with an increased reticulocyte count (P = 0.022), a decreased mean concentration of hemoglobin per cell (MCHC) (P = 0.006), and an increased level of thyrotropin (TTH) (P = 0.040). By multiple regression analysis, MCHC was found to be the primary correlate of the erythrocyte rigidity index (P = 0.044). The interrelation of TTH with the rigidity index was explained by a positive correlation of TTH with the reticulocyte count (P = 0.022). The level of triiodothyronine (T₃) was similar in the athletes and the control subjects and negatively correlated with total cholesterol (Ch) (P = 0.033) and low-density lipoprotein cholesterol (LDL Ch) (P = 0.048), which both correlated positively with blood and plasma viscosity and erythrocyte aggregation (P < 0.05 or 0.01). Thus, the decrease in LDL Ch in the athletes, which was closely related with the higher blood and plasma fluidities and with erythrocyte aggregation, was at least partly due to the effect of T₃.     

肝郁脾虚证模型大鼠血流变及TXB_2、PGFla的变化（英文）

目的：探查中医肝郁脾虚证模型的血流变及相关调节因子的状态。方法：采用慢性束缚应激＋过度疲劳＋饮食失节法建立大鼠肝郁脾虚证模型,测定大鼠造模三周、自然恢复一周时的血流变和血浆TXB2、PGF1a。结果：与正常组相比,模型组大鼠造模三周150/s、38/s、10/s、5/s切变率下的全血粘度、还原粘度均显著升高（P〈0.001）,红细胞聚集指数显著降低（P〈0.001）,红细胞压积显著升高（P〈0.01）,红细胞变形指数无显著性差异（P〉0.05）;血浆TXB2显著升高（P〈0.001）,6-keto-PGF1a显著降低（P〈0.05）,TXB2/PGF1a显著升高（P〈0.01）;模型组大鼠第四周150/s、38/s、10/s、5/s切变率下的全血粘度、还原粘度仍显著升高（P〈0.001或P〈0.01）;红细胞聚集指数显著降低（P〈0.001）;红细胞压积与变形指数无显著性差异（P〉0.05）;血浆TXB2和TXB2/PGF1a显著降低（P〈0.05）,6-keto-PGF1a显著升高（P〈0.05）。结论：肝郁脾虚证大鼠存在血液高粘和血栓易形成状态,恢复期血液高粘同时伴有扩血管因素的加强。提示肝郁脾虚证有血流变的异常和血浆TXB2-PGI2的平衡失调,主要涉及到血小板和血浆因素的参与。