Changes of physiological and biochemical characteristics of rat erythrocytes after blood loss

In experiments of Wistar male rats, changes are studied of erythrocyte hematological, biochemical (activitities of transport ATPases), and rheological properties (capability for aggregation and deformability) 7 days after bloodletting of 12-15 % of the total blood mass. It has been shown that alongside with an elevation of erythrocyte volume and of the number of immature cells - reticulocytes, there was a statistically significant increase of Na,K-ATPase and Ca-ATPase activities in the whole erythrocytes and their membrane preparations - ghosts, the increment of activity in the case of Na,K-ATPase being essentially higher in the whole cells. This indicates the appearance of an enzyme activator inside the erythrocytes. There are also revealed a decrease of firmness of erythrocyte aggregates, a deceleration of spontaneous aggregation, and an increase of index of erythrocyte deformability. The conclusion is made that changes of erythrocyte rheological properties are interconnected with changes of the Na,K-ATPase activity and are directed to optimization of blood circulation in large vessels and capillary network.     

Changes of gas exchange parameters and of functional-biochemical properties of erythrocytes in dynamics of experimental anemia in rats

In experiments on male Wistar rats, in a specially constructed computerized installation, O₂ consumption by the animals in comparison with changes of hematological, biochemical, and rheological blood properties is studied after anemization—acute blood loss (12–15% of the total blood mass). An increase of the O₂ consumption by the organism and tissues by 18–28% has been revealed for the first 7 days after the blood loss, in spite of a pronounced decrease of hematocrit and of the amount of erythrocytes and hemoglobin in peripheral blood by 20–25% of the initial level. There was a 5–10-fold increase of the content of immature erythrocyte forms—reticulocytes and a progressive rise of cell acidic resistance, which is characteristic of young erythrocyte forms. An increase of O₂ consumption at a decrease of the blood oxygen capacity (a low hemoglobin level) seems to be due to the more efficient transport and yield of O₂ to tissues. At the 3rd and 7th day after the blood loss, activity of Na,K-ATPase has been found to increase by 60% and 20%, respectively. Analysis of the erythrocyte rheological properties has shown that the maximal firmness of aggregates (U_q) and the aggregation rate (1/T) decrease progressively beginning from 3 days after the blood loss; index of deformability (I_max) turned out to be elevated by 7–11%, probably due to an increase of the cell membrane elasticity. The conclusion is made that changes of erythrocyte rheological properties are interconnected with changes of the Na,K-ATPase activity and are directed at optimization of blood circulation in large vessels and the capillary network.     

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。     

Influence of the course of treatment by injections of ozonized saline on rheological properties of erythrocytes in patients with complex pathology

The study was carried out to evaluate rheological properties of erythrocytes by comprehensive methods of piezodynamic aggregometry in a microvolume and gradient ektacytometry in patients with complex pathology before and after every injection of ozonized physiological saline. It has been shown that administration of physiological saline and each session of ozone therapy cause reduction of minimal aggregate strength and spontaneous aggregation rate, microviscosity decreases, and deformability and water permeability of erythrocyte membranes increase. The dynamics of changes in the studied parameters of erythrocytes shows an improvement of the blood rheological properties in the patients not only immediately after the procedure, but and after 2 weeks, 1 and 2 months after the course.     

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.     

Deformability of stored erythrocytes as a criteria for their in vivo survival rate

The loss of deformability observed in erythrocytes stored as whole blood for 36 days (ACD-AG) or as buffy-coat free erythrocyte concentrate (EK) was characterized by measuring their filterability. During the first 3 weeks the index of filterability for ACD-AG erythrocytes increased only slightly and rose to about 140% of its initial value on the 36th day. In contrast, a heavy loss of deformability (increase of the filterability index to more than 600%) was detected for erythrocytes from EK, which, from a rheological point of view, is apt to raise doubts of using this stored blood. An incubation of 1 hour at 37 degrees C in fresh plasma did not result in improving the deformability. A cell volume loss of more than 20% connected with an increase of the inner viscosity to more than 400% was found to be the cause of this decrease of deformability. These rheological differences are also reflected in the 24 hours in vivo survival rate (SR), if the "early loss" of damaged erythrocytes immediately after transfusion is taken into account. Whereas the SR values of 80% for whole blood erythrocytes do not change significantly, the SR values for EK values can be found to reach 54% approximately.     

Incorporation of Na,K-ATPase into human erythrocyte membranes using liposomes

A procedure for incorporation of isolated cattle brain Na,K-ATPase into erythrocyte membranes by proteoliposomes has been elaborated. The Na,K-ATPase activity of proteoliposome-treated human erythrocytes containing incorporated Na,K-ATPase does not exceed that of control erythrocytes. In the erythrocyte membrane the incorporated enzyme exists in a functionally active state and retains the vector properties of the Na+-pump. Exogenous ATP stimulates 22Na influx and 86Rb efflux in and from the erythrocytes.     

Effects of nitric oxide and prostacyclin on deformability and aggregability of red blood cells of rats ex vivo and in vitro.

Although many diseases of the heart and circulatory system have been linked with insufficient deformability and increased aggregability of red blood cells, there are only a few drugs which can modulate these biological functions of erythrocytes. Here, we show evidences that iloprost, stable prostacyclin analogue and SIN-1, active metabolite of molsidomine which spontaneously releases NO, may be sufficient pharmacological tools for modulating red blood cell deformability and aggregability. Deformability of red blood cells was measured by shear stress laser diffractometer (Rheodyn SSD) and expressed in percent of red blood cell deformability index (DI). MA-1 (Myrenne) erythrocyte aggregometer was used for photometric measurements of aggregability in arbitrary units (MEA) of mean extent of aggregation. Experiments were carried out on rats ex vivo and in vitro using whole rat blood or isolated erythrocytes. Ex vivo SIN-1 (infusion 2 mg/kg/min i.v.) and iloprost (bolus injection 10 microg/kg i.v.) significantly improved erythrocyte deformability and aggregability at 5-15 min after administration. L-NAME (10 mg/kg i.v.)- inhibitor of nitric oxide synthase, and aspirin (1 mg/kg i.v.) caused worsening of deformability of erythrocytes in experiments ex vivo. Studies in vitro also revealed improvement of red blood cell deformability and aggregability by SIN-1 (3 microM, 15 min incubation at 22 degrees C) or iloprost (1 microM, 15 min incubation at 22 degrees C) and this phenomenon appeared not only in whole blood but also in isolated red cells. It is concluded that NO- and prostacyclin-induced improvement of red blood cell deformability and aggregability results from direct action of these compounds on erythrocytes. NO-donors and iloprost could be useful in the treatment of disorders of blood fluidity.     

Na K ATPase activity in mammalian erythrocytes

The effects of membranotropic substances--nonionic detergent Tween-20 and EDTA--on the activity and some properties of Na,K-ATPase from mammalian erythrocytes were studied. It was shown that pretreatment of whole erythrocytes with Tween-20 (5 mg/ml) allows a detection of the enzyme activity, which cannot be detected in intact cells. It was also found that erythrocyte ghosts with a high and stable activity of Na,K-ATPase can be obtained by injections of EDTA (1-2 mM) into the hemolysis medium. Although the enzyme activity in whole erythrocytes and their ghosts was detected by the use of various membranotropic agents, the type of the dependence of the Na,K-ATPase activity on MgCl2 and EDTA concentration in the incubation medium was essentially the same for both cell preparations, the optimal concentrations of MgCl2 and EDTA being 3 and 1 mM, respectively. A rise in MgCl2 concentration above 3 mM caused a decrease of the enzymatic activity. Simple techniques have been developed for the detection of the Na,K-ATPase activity in mammalian erythrocytes which allow the determination of a higher enzymatic activity than those described in literature.     

Characteristics of adenosine triphosphatase activity in carp erythrocytes treated with saponin

The activities of Ca-ATPase and Na,K-ATPase in saponin-treated erythrocytes of man, rat and carp were compared. It was shown that at free calcium concentrations lower than 1 microM the activity of Ca-ATPase in carp erythrocytes was by one order of magnitude lower than in rat erythrocytes and 3-4 times lower than in human red blood cells. At [Ca2+] = 0.4 microM the activities of Na,K-ATPase in all species under study were essentially the same. The increase in Ca2+ concentration up to 1 microM resulted in a 2-5-fold activation of Na,K-ATPase in rat and carp erythrocytes, respectively. In all cases studied a further elevation of free calcium concentration was accompanied by a decline of the Na,K-ATPase activity. It was shown that the Pi content in carp erythrocytes is 5-6 times as high as that in mammalian cells. This circumstance is a considerable obstacle to a detailed analysis of mechanisms of ATPase activity regulation in carp erythrocytes by methods used for determination of inorganic phosphate production.     

A Plasmodium falciparum exo-antigen alters erythrocyte membrane deformability

Here we describe a reduced membrane deformability of human erythrocytes when aspirated into 0.6 microns diameter in polycarbonate sieves, after exposure of uninfected cells to spent parasite-culture supernatant. This, taken in concert with a previous observation that intra-erythrocytic development of the parasite P. falciparum decreases host localised membrane deformability, may indicate a biological role for such parasite-induced changes in the rheological properties of the erythrocyte.     

The flow properties of blood and their characterization by hemorheologic methods

In a number of supply disturbances the flow behaviour of blood plays an increasing role in modern therapy concepts. The present paper deals with representing factors, such as haematocrit, aggregation, deformation, which exercise an influence on the complex flow properties of blood under variable conditions. By referring to the example of deformability it is shown how and to what extent different mechanical parameters of individual erythrocytes participate in static or dynamic whole cell deformation. Starting from fundamental quality demands (sensitivity, specificity, value of prediction) to diagnostic measuring technique, haemorheological methods for determining complex flow properties, aggregation and deformation as single phenomena and mechanical properties of individual erythrocytes are presented. Selected examples of application for normal blood, cells altered in vitro or pathological changes measured ex vivo are referred to.     

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.     

肠系膜淋巴管结扎对急性失血大鼠红细胞流变性的影响

目的:观察结扎肠系膜淋巴管(MLD)对急性失血大鼠红细胞流变性的影响。方法:20只Wistar雄性大鼠随机均分为失血组与结扎组。所有大鼠经右侧颈总动脉匀速放血(失血量为全血量的1/4),结扎组失血后结扎MLD,失血组仅在MLD下穿线。记录24h存活情况。24h后,将存活大鼠经左侧颈总动脉迅速放血,测定实验前后的红细胞沉降率(ESR)、红细胞电泳、红细胞压积(Hct),计算红细胞聚集与变形指数。结果:急性失血后24h,结扎组大鼠存活情况(9只)略好于失血组(6只)。急性失血后24h,与实验前相比,失血组与结扎组的ESR、血沉方程K值、校正K值、红细胞电泳时间均显著升高或延长,红细胞变形性降低,失血组的红细胞聚集指数显著升高、红细胞电泳长度与迁移率均显著降低;结扎组的ESR、血沉方程K值、校正K值、红细胞聚集指数、电泳时间较失血组显著降低,红细胞电泳长度与迁移率、变形性较失血组显著升高。结论:急性失血导致大鼠红细胞聚集性升高、红细胞电泳能力及变形性降低,结扎MLD可改善急性失血导致的红细胞流变性异常。     

Effect of pH on the velocity of erythrocyte aggregation

The effect of pH on the velocity of aggregation of human erythrocytes was quantitatively examined with a rheoscope combined with a video-camera, an image analyzer and a computer, in relation to the morphological changes of erythrocytes and their aggregates. (i) With increasing pH of the medium, the velocity of erythrocyte aggregation increased. (ii) The rouleaux formed at high pH were longer in shape and more stable against the increase of shear rate than those formed at low pH. (iii) With increasing pH, the diameter of erythrocyte increased, the (maximum) thickness decreased, and the cell volume decreased. The pH dependency of erythrocyte aggregation may be mainly due to the morphological change of erythrocytes, and partly due to the changes of erythrocyte deformability and of interaction with macromolecules.     

Hypoxic exercise training causes erythrocyte senescence and rheological dysfunction by depressed Gardos channel activity

Despite enhancing cardiopulmonary and muscular fitness, the effect of hypoxic exercise training (HE) on hemorheological regulation remains unclear. This study investigates how HE modulates erythrocyte rheological properties and further explores the underlying mechanisms in the hemorheological alterations. Twenty-four sedentary males were randomly divided into hypoxic (HE; n = 12) and normoxic (NE; n = 12) exercise training groups. The subjects were trained on 60% of maximum work rate under 15% (HE) or 21% (NE) O(2) condition for 30 min daily, 5 days weekly for 5 wk. The results demonstrated that HE 1) downregulated CD47 and CD147 expressions on erythrocytes, 2) decreased actin and spectrin contents in erythrocytes, 3) reduced erythrocyte deformability under shear flow, and 4) diminished erythrocyte volume changed by hypotonic stress. Treatment of erythrocytes with H(2)O(2) that mimicked in vivo prooxidative status resulted in the cell shrinkage, rigidity, and phosphatidylserine exposure, whereas HE enhanced the eryptotic responses to H(2)O(2). However, HE decreased the degrees of clotrimazole to blunt ionomycin-induced shrinkage, rigidity, and cytoskeleton breakdown of erythrocytes, referred to as Gardos effects. Reduced erythrocyte deformability by H(2)O(2) was inversely related to the erythrocyte Gardos effect on the rheological function. Conversely, NE intervention did not significantly change resting and exercise erythrocyte rheological properties. Therefore, we conclude that HE rather than NE reduces erythrocyte deformability and volume regulation, accompanied by an increase in the eryptotic response to oxidative stress. Simultaneously, this intervention depresses Gardos channel-modulated erythrocyte rheological functions. Results of this study provide further insight into erythrocyte senescence induced by HE.     

Effect of some nickel compounds on red blood cell characteristics

The effect of certain inorganic and coordinated nickel compounds on the resistance to different destructive substances, rheological properties, and functional activity of healthy human red blood cells (RBC), was investigated. It is shown that nickel compounds affect the erythrocyte membrane lipid bilayer, as well as membrane proteins to various extents, depending on the type of compounds used. In general, the acceleration of erythrocyte aging was observed to be more pronounced in young erythrocytes. The observed results suggest that nickel compounds decrease water permeability across erythrocyte membranes. Almost all the investigated nickel compounds decrease erythrocyte thermostability, deformability, and the rate of O₂ release by erythrocytes.     

Biochemical,biophysical and haemorheological effects of dimethylsulphoxide on human erythrocyte calcium loading

The studies using dimethylsulphoxide (DMSO) and/or the 4-bromo-calcium ionophore A23187 (Br-A23187) often neglect the precise knowledge of some of their biochemical, biophysical and haemorheological effects. The aim of the present study was to evaluate these effects on erythrocytes after whole blood incubations with DMSO or Br-A23187 dissolved in DMSO. There were no significant differences between the different aliquots in the values of P(50), pH, erythrocyte deformability, erythrocyte membrane fluidity, haemoglobin and intracellular Ca(2+) concentrations ([Ca(2+)](i)). Aliquots with DMSO (independently of the presence of Br-A23187 or added Ca(2+)) had lower erythrocyte aggregation indexes and higher plasma concentrations of K(+)], Na(+)] and Ca(2+) than the aliquots without DMSO (independently of the presence of added Ca(2+)). Aliquots with added calcium (without the presence of Br-A23187 in DMSO) had a significantly higher erythrocyte acetylcholinesterase activity. Our data shows that calcium loading, the usual objective of Br-A23187 incubations, cannot be fulfilled with the studied experimental conditions. The coherence between our results and those obtained by other authors with different biological systems and different modulators of the rise on [Ca(2+)](i) suggests a non-specific effect of DMSO, disabling the action of the modulator. It can be reasoned that the decreased erythrocyte aggregation (without significant changes on the deformability or membrane fluidity) can result either from the decrease of the hydrogen bonding contribution to erythrocyte aggregation or the increased ionic strength influence on the erythrocyte membrane surface.     

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.