High throughput detection and characterization of red blood cells deformability by combining optical tweezers with microfluidic technique / 生物医学工程学杂志

A high throughput measurement method of human red blood cells (RBCs) deformability combined with optical tweezers technology and the microfluidic chip was proposed to accurately characterize the deformability of RBCs statistically. Firstly, the effective stretching deformation of RBCs was realized by the interaction of photo-trapping force and fluid viscous resistance. Secondly, the characteristic parameters before and after the deformation of the single cell were extracted through the image processing method to obtain the deformation index of area and circumference. Finally, statistical analysis was performed, and the average deformation index parameters (

Hemorheologic Alterations in Patients with Type 2 Diabetes Mellitus Presented with an Acute Myocardial Infarction

BACKGROUND: Hemorheologic indices are known to be related to vascular complications in variable clinical settings. However, little is known about the associations between hemorheologic parameters and acute myocardial infarction (AMI) in type 2 diabetes mellitus (T2DM). The purpose of this study was to demonstrate the changes of hemorheologic environment inside of blood using hemorheologic parameters, especially the elongation index (EI) and critical shear stress (CSS) in diabetics with versus without AMI. METHODS: A total of 195 patients with T2DM were enrolled. Patients were divided into the study group with AMI (AMI+, n = 77) and control group (AMI−, n = 118) who had no history of coronary artery disease. Hemorheologic parameters such as EI and CSS were measured and compared between the two groups. RESULTS: The EI was lower (30.44%±1.77% in AMI+ and 31.47%±1.48% in AMI−, P < 0.001) but the level of CSS was higher (316.13±108.20 mPa in AMI+ and 286.80±85.34 mPa in AMI−, P = 0.040) in the AMI+. The CSS was significantly related to the erythrocyte sedimentation rate (R² = 0.497, P < 0.001) and use of dipeptidyl peptidase-4 inhibitors (R² = 0.574, P = 0.048). CONCLUSION: Diabetics with AMI resulted in adverse hemorheologic changes with lower EI and higher CSS compared to diabetic subjects without AMI. Evaluation of the hemorheologic parameters may provide valuable supplementary information for managing patients with AMI and T2DM.

Effects of exhaustive exercise-induced oxidative stress on red blood cell deformability / 中国应用生理学杂志

<p><b>OBJECTIVE</b>The aim of the present study is to explore the effects of exhaustive exercise-induced oxidative stress on the antioxidant capacity and diformability of rat red blood cells.</p><p><b>METHODS</b>Rats were divided into three group (n = 10): sedentary control (C), exhaustive running exercise (ERE) and moderate running exercise (MRE) groups. Animals in the ERE group started treadmill running at a speed of 20 m/min speed with a 5% gradient, and reached a speed of 25 m/min with gradient 15% in 20 min. Running was continued until exhaustion. MRE group rats running at a speed of 20 m/min with a 5% gradient for 40 min. The levels of free thiol in erythrocyte membrane protein, lipidperoxidation levels and membrane protein components were analyzed. The red blood cell deformability of different groups was also observed.</p><p><b>RESULTS</b>The results showed that red blood cells were damaged by severe oxidative stress and the anti-oxidative capacity decreased significantly under exhaustive exercise conditions. Besides, lipid peroxidation and protein sulfhydryl cross-link based clustering of membrane were found after exhaustive exercise, and polymers high molecular weight (HMW) was formed. The elongation index (EI) was found to decline significantly in the ERE group compared with the C and MRE groups under shear stress (control group, 0.41 +/- 0.01 at 3 Pa and 0.571 +/- 0.008 at 30 Pa; ERE group, 0.314 +/- 0.013 at 3 Pa and 0.534 +/- 0.009 at 30 Pa; P < 0.05 and P < 0.01, respectively).</p><p><b>CONCLUSION</b>These exercise-induced oxidative injure result in a significant decrease in deformability of rat erythrocytes, which in turn leads to dysfunction in the microcirculatory.</p>

Exogenous normal lymph alleviates microcirculation disturbances and abnormal hemorheological properties in rats with disseminated intravascular coagulation

Disturbances of the microcirculation and abnormal hemorheological properties are important factors that play an important role in disseminated intravascular coagulation (DIC) and result in organ dysfunction or failure. In the present study, we established an animal model of DIC using intravenous Dextran 500 in rats, and used exogenous normal lymph corresponding to 1/15 of whole blood volume for injection through the left jugular vein. We found that normal lymph could improve the blood pressure and survival time of rats with DIC. The results regarding the mesenteric microcirculation showed that the abnormality of the diameter of mesenteric microvessels and micro-blood flow speed in the DIC+lymph group was significantly less than in the DIC+saline group. Whole blood viscosity, relative viscosity, plasma viscosity, hematocrit (Hct), erythrocyte sedimentation rate (ESR), and electrophoresis time of erythrocytes were significantly increased in the DIC+saline group compared to the control group. The electrophoretic length and migration of erythrocytes from the DIC+saline and DIC+lymph groups were significantly slower than the control group. Blood relative viscosity, Hct, ESR, and electrophoretic time of erythrocytes were significantly increased in the DIC+lymph group compared to the control group. Whole blood viscosity, relative viscosity and reduced viscosity were significantly lower in the DIC+lymph group than in the DIC+saline group, and erythrocyte deformability index was also significantly higher than in the DIC+saline and control groups. These results suggest that exogenous normal lymph could markedly improve the acute microcirculation disturbance and the abnormal hemorheological properties in rats with DIC induced by Dextran 500.

Hemorheology visualization clinical research in elderly hypertension patients of different Chinese medical syndrome types / 中国中西医结合杂志

<p><b>OBJECTIVE</b>To observe blood flow features in elderly hypertension patients of different Chinese medical syndrome types and to test their correlation with rheological properties of red blood cells (RBCs) by applying micro-channel array flow analyzer (MC-FAN).</p><p><b>METHODS</b>Recruited were 109 elderly hypertension patients were assigned to phlegm-stasis blocking collateral group (35 cases), yin deficiency yang hyperactivity group (42 cases), Shen deficiency group (32 cases) according to Chinese medical syndrome typing. Besides, another 21 elderly healthy subjects were recruited as the control group. The hemorheology visualization testing of elderly hypertension patients was detected using MC-FAN. The erythrocyte deformation index (DI), erythrocyte aggregation index (EAI), and erythrocyte related plasma ATPase activity were observed. The correlation between the transiting time (TT) of blood hemorheology visualization and rheological indicators of RBCs were analyzed.</p><p><b>RESULTS</b>The hemorheology visualization TT was significantly prolonged more in the phlegm-stasis blocking collateral group than in the yin deficiency yang hyperactivity group, the Shen deficiency group, and the control group (P < 0.05). Compared with the control group, the DI was significantly lower in the phlegm-stasis blocking collateral group than in the yin deficiency yang hyperactivity group, the Shen deficiency group, and the control group (P < 0.05) when the shear rate was 100 s(-1). Compared with the control group, the plasma Na+ -K(+) -ATPase activity and the plasma Ca2+ -Mg2+ -ATPase activity were significantly lower in elderly hypertension patients (P < 0.01). Among the three groups, plasma Ca2+ -Mg2+ -ATPase activity was significantly lower in the phlegm stasis blocking collateral group than in the Shen deficiency group (P < 0. 05). The hemorheology visualization TT (10, 30, 60, and 100 microL) was negatively correlated with DI. The hemorheology visualization TT at 100 microL was positively correlated with EAI.</p><p><b>CONCLUSION</b>Changes of hemorheology visualization TT of elderly hypertension patients were significant and correlated with traditional EAI.</p>

The effects of mesenteric lymph drainage on erythrocyte rheology in rats with hemorrhagic shock / 中国应用生理学杂志

<p><b>OBJECTIVE</b>To observe the effects of mesenteric lymph drainage on erythrocyte rheology and blood viscosity in hemorrhagic shock rats.</p><p><b>METHODS</b>Wistar rats were randomly divided into sham-shock group, shock group (establishing hemorrhagic shock model), drainage group (establishing hemorrhagic shock model plus drainaging shock mesenteric lymph from hypotension 1 h). At 3 h of hypotension or corresponding time, blood samples were harvested from the abdominal aorta for determining the erythrocytic parameters, erythrocyte electrophoresis, erythrocyte sedimentation rate (ESR) and blood viscosity, and the erythrocytes aggregation index and erythrocyte deformability index were calculated.</p><p><b>RESULTS</b>Compared with the sham-shock group, the red cell contents, hematocrit (HCT), hemoglobin (Hb), mean corpuscular hemoglobin concentration (MCHC), erythrocyte electrophoretic rate and mobility, erythrocyte deformability index, whole blood viscosity, whole blood relative or reduced viscosity at low and high shear rates in shock group were observably lower, and mean corpuscular volume, electrophoretic time of erythrocyte, ESR, K value of equation and K value of emendation, erythrocytes aggregation index, plasma viscosity in shock group were increased markedly; the MCHC, erythrocyte electrophoretic rate and mobility, whole blood viscosity, whole blood relative viscosity at low and high shear rates in drainage group were reduced, and the red blood cell volume distribution width -SD (RDW-SD) was increased remarkably. At the same time, in drainage group, the HCT, RDW-SD, erythrocyte deformability index, whole blood viscosity and relative viscosity at low and high shear rates were higher, the ESR, K value of equation and K value of emendation, erythrocytes aggregation index, plasma viscosity were lower than that of shock group.</p><p><b>CONCLUSION</b>The results indicate that the mesenteric lymph drainage could improve the erythrocyte rheological behavior, as a result, improve the hemorrheological properties in hemorrhagic shock rats.</p>

Changes of blood viscosity and erythrocyte rheology in acute hypoxic hypoxia mices / 中国应用生理学杂志

<p><b>OBJECTIVE</b>To observe the changes of blood viscosity and erythrocyte rheology in mice after acute hypoxic hypoxia (AHH).</p><p><b>METHODS</b>Thirty-two Kui-ming mice were randomly divided into control group, AHH group (duplicating AHH model, and divided into 5 min, 8 min, 11 min subgroups), the blood sample was taken out from heart after neck dislocation at corresponding times, for detecting the blood viscosity and erythrocyte rheology indices.</p><p><b>RESULTS</b>Compared with control group, the whole blood viscosity at different shears, whole blood reduced viscosity, whole blood relative viscosity were lower and the erythrocytes aggregation index was higher in AHH 5 min group; the electrophoresis time was longer and the electrophoresis length, migration of erythrocyte were lower in AHH 8 min and AHH 11 min groups. The whole blood reduced viscosity, whole blood relative viscosity, erythrocytes aggregation index in AHH 8 min group were higher, and the erythrocyte deformability index was lower significantly than that of AHH 5 min group, respectively.</p><p><b>CONCLUSION</b>These data suggested that the AHH could induce the blood viscosity and electrophoresis ability.</p>

The influence shuxuetong on the membrane viscoelasticity of erythrocyte taken from patients with chronic pulmonary heart disease / 生物医学工程学杂志

The present paper was aimed to explore the effect of Shuxuetong on the membrane viscoelasticity of erythrocyte taken from the acute phase patients suffering from chronic pulmonary heart disease. The membrane viscoelasticity of erythrocyte was taken from the acute phase patients suffering from chronic pulmonary heart disease. The changes of membrane viscoelasticity of erythrocyte after treated with shuxuetong were detected by micropipette aspiration technique. The results showed that the Shuxuetong of certain concentration could cause the decrease of membrane elastic modulus and viscous coefficients in acute phase patients suffering from chronic pulmonary heart disease. The study offers experimental evidences that the comprehensive treatment of pulmonary heart disease should involve the drug or measure to improve the erythrocyte deformability.

The effect of sildenafil on the elasticity of erythrocytes in homozygous sickle cell disease.

Purpose: One of the features of homozygous sickle cell disease (HbSS) is the impaired elasticity of the erythrocyte membrane that could impede microcirculatory blood flow and cause hypoxia and tissue damage. We investigated the effect of sildenafil, a phosphodiesterase 5 (PDE5) inhibitor that inhibits the breakdown of cyclic guanosine monophosphate (cGMP) resulting in vasodilatation, on the elasticity of HbSS erythrocyte. Materials and Methods: Blood samples from ten HbSS patients in steady state was exposed to different doses (5, 10, 20, and 40 μg/mL) of sildenafil and the elasticity of the erythrocytes measured at native hematocrit with the BioProfiler. An equal number of subjects with normal hemoglobin (HbAA) served as the control group. Results: There was a marginal increase in elasticity with 5 μg/mL of the drug and this became significant (P < 0.05) with the 10 μg/mL dose. Thereafter, gradual nonsignificant decreases were observed with the 20 and 40 μg/mL doses. A similar trend was observed for the control group. The elasticity values for the HbSS subjects at native hematocrit were significantly (P < 0.05) less when compared with the corresponding concentrations for the HbAA controls. This was reversed at a corrected hematocrit of 45%. Conclusion: The result of this study shows that sildenafil caused an initial increase in erythrocyte membrane elasticity in both HbSS and HbAA subjects, and this later decreased with increasing concentration of the drug possibly due to the dual effect of cyclic adenosine monophosphate (cAMP).

Changes of erythrocyte deformability in rats acclimatized to hypoxia and its molemechanism / 中国应用生理学杂志

<p><b>OBJECTIVE</b>To observe the changes of erythrocyte deformability in rats acclimatized to hypoxia and its molemechanism.</p><p><b>METHODS</b>Male rats were randomly divided into three groups (n = 10): normal control group, acute hypoxia group and hypoxia acclimatization group. Animals were exposed to hypoxia for 0, 1, 28 d, blooded from their hearts after anaesthetized, respectively. Erythrocyte deformability, membrane fluidity, cholesterin and total lipid, lipid components of erythrocyte membrane, erythrocyte membrane ATPase and the concentrations of Na+ and Ca2+ were measured respectively. The two-dimensional electrophoresis maps of the rats erythrocyte membrane protein were achieved. The different protein spots were founded by image master 2D elite and identified by mass spectrum.</p><p><b>RESULTS</b>(1) In acute hypoxia group, the deformability, membrane fluidity, the content of membrane cholesterin and total lipid were declined. The content of phosphatidylserines (PS), sphingomyelin (SM) in erythrocyte membrane lipids were increased, phosphatidylcholine (PC) reduced. The activity of ATP enzymes reduced and the concentration of Na+ and Ca2+ in erythrocyte increased. The two-dimensional electrophoresis maps of the rats erythrocyte membrane protein were achieved. Four of the seven protein spots selected increased and three of them showed no change. (2) In hypoxia acclimatization group, the deformability, membrane fluidity, the content of membrane cholesterin and total lipid were increased than those in acute hypoxia group, similar to normal group. The content of PS, SM in erythrocyte membrane lipids were reduced, PC increased. The activity of ATP enzymes induced and the concentration of Na+ and Ca2+ in erythrocyte increased after hypoxia acclimatization. Four of those protein spots mentioned increase and three declined after hypoxia acclimatization. They were respectively proved by mass spectrum to be alexin binding protein, aquaporin chip, membrane inhibitor reactive lysis, phospholipids scramblase, glucose transferase, aminophospholipid translocases, ATP-dependent floppase, the latter three proteins were associate with the overturning of erythrocyte membrane lipids.</p><p><b>CONCLUSION</b>Acute hypoxia caused the corresponding damage of erythrocyte deformability, erythrocyte membrane fluidity, erythrocyte membrane proteins erythrocyte expression, the activity of membrane ATPase and the concentration of Na+ and Ca2+ in erythrocyte. The parameters above were improved after hypoxia acclimatization, so hypoxia acclimatization effected positively in the damage to erythrocyte due to acute hypoxia. The three membrane proteins might play important roles in the deformability improved by hypoxia acclimatization, which included phospholipids scramblase, aminophospholipid translocases and ATP-dependent floppase.</p>

Effect of mesenteric lymph duct ligation on erythrocyte rheology in acute hemorrhagic rats / 中国应用生理学杂志

<p><b>OBJECTIVE</b>To observe the effects of mesenteric lymph duct (MLD) ligation on erythrocyte rheology in acute hemorrhagic rats.</p><p><b>METHODS</b>Twenty male Wistar rats were randomly divided into hemorrhage group and ligation group (n = 10). Blood (one fourth of body whole blood volume) was withdrawn through right common carotid arteries after rats were anesthetized. In ligation group, the MLD was ligated after hemorrhage, and only threading under the MLD in hemorrhage group. The survival situation at 24 h was recorded. After 24 h, survival rats were anesthetized again, blood sample was withdrawn through left common carotid artery rapidly. And the erythrocyte sedimentation rate (ESR), electrophoresis of erythrocytes, hematocrit (Hct) were determined in blood samples of before and after hemorrhage, the erythrocytes aggregation and deformability indices were calculated.</p><p><b>RESULTS</b>It showed that the ligation group survival (9 rats alive) was slightly better than that in hemorrhage group (6 rats alive). The results of erythrocyte rheology indices showed that the ESR, K value of equation, K value of emendation and electrophoresis time in hemorrhage group and ligation group were higher or longer than those before hemorrhage, the erythrocyte deformability was reduced significantly, respectively. And the erythrocytes aggregation index in hemorrhage group was increased, the electrophoresis length and migration of erythrocyte in hemorrhage group were lower than those before hemorrhage, respectively. But compared with hemorrhage group, the ESR, K value of equation, K value of emendation, erythrocytes aggregation index and electrophoresis time in ligation group were lower, the electrophoresis lenght, migration and deformability of erythrocyte were increased significantly.</p><p><b>CONCLUSION</b>The results indicate that the higher erythrocyte aggregation ability, lower electrophoresis function and deformability are caused by acute hemorrhage in rats, and the MLD ligation can improve the abnormal erythrocyte rheology.</p>

Effects of taurine on hemorheology of rats with type 2 diabetes / 中国应用生理学杂志

<p><b>OBJECTIVE</b>To observe the effects of taurine on hemorheology and oxidative stress of diabetic rats.</p><p><b>METHODS</b>40 rats were divided into control group, diabetes group and treatment group at random. Diabetic model was reproduced by intraperitoneal injection of streptozotocin. After having been treated with taurine for 8 weeks, glycosylated hemoglobin (HbA1c) and the serum contents of glucose, superoxide dismutase(SOD), malondialdehyde (MDA) were measured. The changes of hemorheology in different groups were detected respectively.</p><p><b>RESULTS</b>Compared with control group, the content of glucose, MDA and HbA1c in diabetic rats was increased, the activity of SOD was decreased, the levels of whole blood viscosity and the aggregation index of red blood cells and hematocrit were increased and RBC deformability index was decreased in diabetic rats. Moreover, taurine was able to apparently reduce high blood glucose and HbA1c (P < 0.05), markedly elevated the activity of SOD, lowered the content of MDA (P < 0.01); and taurine also could significantly reduce the levels of whole blood viscosity and the aggregation index of red blood cells and hematocrit in the meanwhile, and increase RBC deformability index (P < 0.05 or P < 0.01).</p><p><b>CONCLUSION</b>Taurine could enhance the ability of oxidation resistance, improve blood rheology property in diabetic rats, at the same time it could be beneficial to prevent and cure the development of diabetic blood vessel complication.</p>

Usefulness of Frozen-thawed-deglycerolized Red Blood Cells as Quality Control Materials for Red Blood Cell Deformability Test / 대한진단검사의학회지

BACKGROUND: The red blood cell (RBC) deformability test is a useful method for measuring the ability of RBCs to adapt their shape to the flow conditions. Using this test, several investigators have shown the relationship between RBC deformability and numerous clinical conditions. For the quality control (QC) of RBC deformability test, we evaluated whether frozen-thawed-deglycerolized RBCs can be used as QC materials. METHODS: Packed RBCs were frozen with 40% (wt/vol) glycerol and stored at -80degrees C for 3 months. For 10 different frozen RBC panels, RBCs were thawed, deglycerolized and stored at 4degrees C for 4 weeks. Using microfluidic ektacytometer, we measured RBC deformability of the thawed RBCs. The stability of thawed RBCs was tested once a day for 28 days of storage time and was analyzed by simple regression analysis. The precision of the test using thawed RBCs was analyzed for 7 days of storage time by calculation of CV values of intra-assay (10 measurements/assay) and between-day measurements. RESULTS: Frozen-thawed-deglycerolized RBCs were stable for 1 week. Within-run and between-day precisions of the RBC deformability test during 7 days of storage of thawed RBCs were 1.4-2.9%, and 1.9-2.8%, respectively. CONCLUSIONS: Frozen-thawed-deglycerolized RBCs used in RBC deformability test showed satisfactory within-run and between-run precisions and stability for one week after thawing, and may be used as QC materials for this test.

Effect of congrong powder preparation on erythrocyte parameter and index of blood rheology in rats / 中国中药杂志

<p><b>OBJECTIVE</b>To observe the effect of Congrong powder preparation on erythrocyte parameter and the index of blood rheology in healthy rats.</p><p><b>METHOD</b>The 50 rats were randomly divided into 5 groups ( physiological saline group, testosterone propionate group, large-dose administered group, moderate-dose administered group, small-dose administered group). Blood were taken to determine erythrocyte parameter and the index of blood rheology.</p><p><b>RESULT</b>Congrong powder preparation had no effect on erythrocyte parameter. There was an increase in whole blood viscosity, whole blood reduction viscosity, and in the erythrocyte rigidity index in the large-dose administered group.</p><p><b>CONCLUSION</b>Congrong powder can influence deformability and some related characters of erythrocytes.</p>

Changes in erythrocyte aggregation and deformability in diabetes mellitus: a brief review.

Diabetes mellitus (DM) is a metabolic disorder characterized by varying or persistent hyperglycemia either due to insufficient production of insulin by pancreas or improper utilization of the glucose. Erythrocytes remain in hyperglycemic environment throughout their life span and thus are subjected to series of compositional changes, which in turn affect their flow properties through alteration of deformation at individual level and aggregation at collective level. This brief review summarizes the changes in biochemical parameters primarily contributing to the erythrocyte deformability and aggregation as measured by various techniques, of blood samples obtained from diabetic subjects. The significant changes in erythrocyte aggregation and deformability, in comparison with that of control subjects show the relevance of these measurements. These changes are further supported by in vivo observations of blood flow through microvessels. Finally the relevance of these in combination with other clinical parameters is suggested.

The significance of erythrocyte fragment count to predicting hemolysis in roller pumps / 生物医学工程学杂志

Hemolysis in blood pumps has been measured by various in vitro tests, in which normalized index of hemolysis (NIH) was established. As NIH is complicated and difficult to calculate, erythrocyte fragment count (EFC) is proposed in the present study to predict hemolysis in roller pumps. Five paired in vitro tests were conducted using the POLYSTAN pediatric pump (group A) and COBE pump (group B). Ten whole blood samples (400ml) were circled in the roller pump for 16 hours. Erythrocyte fragments count and plasma-free hemoglobin (FHb) were measured before pumping and every 2 hours through circulation after 4 hours pumping. The morphological changes of erythrocyte were observed by scanning electron microscope. Simple linear regression analysis showed the two groups' EFC and FHb levels increased linearly during a long period of pumping, and the coefficient of determination (R2) was 0.64. These data suggested that Erythrocyte fragments count could be used as an index in evaluating the in vitro hemolytic properties of blood pumps.

Blood rheology analysis of 23436 samples and establishment of reference range by sitting and lying position / 中国应用生理学杂志

<p><b>AIM</b>To establish reference range of blood theology for different gender by sitting and lying in healthy populations.</p><p><b>METHODS</b>In 31 volunteers blood were drawed in the postures of sitting and lying to measure blood rheology. Data (between July 2002 and July 2006) of 32854 samples (23436 check-up, 6553 out-patient,2865 in-patient) were collected. Differences between different postures and different gender were compared by Independ-Sample t-test with SPSS 13.0 software and each reference range of blood rheology was established.</p><p><b>RESULTS</b>In sitting and lying postures 12 parameters of blood rheology showed great significance (P < 0.01). 8 parameters such as whole blood viscosity, blood reduce viscosity, plasma viscosity, hematocrit, were decreased by 9.33% on average while posture was changed from sitting to lying. But index of erythrocyte deformability, erythrocyte electrophoresis presented inverse correlation and were increased by 6.49% on average with the same posture change.Various parameters of blood theology in different gender showed great significance (P < 0.01).</p><p><b>CONCLUSION</b>There is significant difference in various parameters of blood rheology in the posture change from sitting to lying. Reference ranges of blood theology of different postures are established which may be used to decrease the rate of misdiagnosis by 8-10 percent.</p>

Assessment of Hemorheological Deformability of Human Red Cells Exposed to tert-Butyl Hydroperoxide, Verapamil and Ascorbate by Ektacytometer / 대한진단검사의학회지

BACKGROUND: Normal erythrocyte is deformable and this facilitates blood flow in the capillaries. Oxidative stress reduces the deformability of erythrocytes, and influences on blood flow in microcirculation. The objective of this study was to investigate the deformability of erythrocytes exposed to oxidative stress, the protective effects of verapamil and ascorbic acid against oxidative damages in erythrocytes, and the value of the microfluidic ektacytometer, RheoScan-D (RheoMeditech, Korea) in clinical application. METHODS: Effects of oxidative stress on erythrocytes were investigated using tert-butyl hydroperoxide (tBHP). Before exposure to tBHP, the erythrocytes were pretreated with verapamil and ascorbic acid to examine their protective effect against oxidative damages. The deformability of erythrocytes was measured by the microfluidic ektacytometer, RheoScan-D. RESULTS: When treated with tBHP, the deformability of erythrocytes was decreased (P<0.01) and methemoglobin (metHb) formation and mean corpuscular volume (MCV) of erythrocytes were increased (P<0.01, P<0.05) compared to those of the untreated control cells. Compared to the tBHP treated cells, pretreatment with verapamil increased the deformability of erythrocytes (P<0.01) and decreased metHb formation (P<0.01) and MCV (P<0.05). Likewise, pretreatment with ascorbic acid increased the deformability of erythrocytes (P<0.01) and decreased metHb formation (P<0.01). CONCLUSIONS: Oxidative stress reduces the deformability of erythrocytes and the deformability could be one of markers for oxidative damage. Verapamil and ascorbic acid have protective role against tBHP induced oxidative stress. The ektacytometer, RheoScan-D used in this study is convenient for clinical measurement and could be used in various fields of clinical medicine.

Erythrocyte deformability and its variation in diabetes mellitus.

Erythrocyte deformability improves blood flow in the microvessels and in large arteries at high shear rate. The major determinants of RBC deformability include cell geometry, cell shape and internal viscosity (i.e., mean cell hemoglobin concentration and components of the erythrocyte membrane). The deformability is measured by several techniques but filtration of erythrocytes through micro-pore membranes and ektacytometry are two sensitive techniques to detect changes in erythrocytes under varied experimental and diseased conditions. Diabetes mellitus (DM) is a metabolic disorder, characterized by varying or persistent hyperglycemia, which induces several changes in the erythrocyte membrane and its cytoplasm, leading to alteration in the deformability. A decreasing trend of deformability in these patients is observed. The shape descriptor form factor, as determined by processing of erythrocyte images, increases with the increase of blood glucose levels and shows a pattern similar to filtration time of erythrocyte suspensions through cellulose membranes. Fluidity of the membrane as measured in erythrocytes of these patients is decreased. With prolonged diabetic conditions the deformability of erythrocytes is further decreased, which may complicate the flow of these cells in microvessels.

Effect of Xuesaitong drop pills on experimerntal thrombosis and thrombolysis in rats / 中国中药杂志

<p><b>OBJECTIVE</b>To study the effect and the mechanism of Xuesaitong drop pills (total saponins in Radix Notoginseng; XDP) on experimental thrombosis, thrombolysis and blood theology.</p><p><b>METHOD</b>First, the rats were randomly divided into five groups: control, XDP (90, 30, 10 mg x kg(-1)), Xuesaitong tablet (XP) 30 mg x kg(-1). Then the effect of the drugs on thrombus and thrombosis was studied after the ratsthrombosis was induced by the arteriovenous shunt. Second, the rats were randomly divided into seven groups: model, XDP (90, 30, 10 mg x kg(-1)), XT (90, 30 mg x kg(-1)), lumbrukinase capsule. Then the effect of the drugs on thrombus and thrombosis was studied after the rats'thrombosis was induced by the electrical stimulation of common carotid artery. Third, the rats were randomly divided into six groups: control, model, XDP (80, 40 mg x kg(-1)), XT (40, 20 mg x kg(-1)). Then the effect of the drugs on blood circulation promoting was observed after the rats'acute blood stasis induced by adrenalin and icy water.</p><p><b>RESULT</b>XDP 90, 30 mg x kg(-1) could notably lighten the wet-weight and dry-weight of thrombus in the arteriovenous shunt model in rats in a dose-dependent manner (P < 0.01). XDP 90 mg x kg(-1) with intragastric administration for 3 days had the satisfactory effect on thrombolysis after the rat's thrombosis was induced by the electrical stimulation of common carotid artery (P < 0.01). XDP 80, 40 , 20 mg x kg(-1) reduced significantly erythrocyte aggregation (P < 0.01) and decreased the whole blood viscosity at low shear rate (P < 0.05). XDP 80, 40 mg x kg(-1) reduced the whole blood viscosity at high shear rate and plasma viscosity (P < 0.05). XDP 80 mg x kg(-1) decreased the whole blood viscosity at high shear rate (P < 0.05).</p><p><b>CONCLUSION</b>XDP can significantly inhibit the thrombosis and has the satisfactory effect on thrombolysis. One kind of the mechanism is related to the effect on blood rheology.</p>