Clinical Hemorheology and Microcirculation - Volume 28, issue 2

Authors: Vayá, Amparo | Iborra, Jesús | Falcó, Cristina | Moreno, Isabel | Bolufer, Pascual | Ferrando, Fernando | Pérez, María Luz | Justo Aznar,

Article Type: Research Article

Abstract: In major and intermediate thalassemia a decrease in erythrocyte deformability and increased erythrocyte aggregability has been described, but few studies have dealt with the question of rheological red blood cell behaviour in minor β and δβ thalassemia carriers, mostly in δβ, because it is a less common entity. To ascertain whether there are differences in red blood cell behaviour between minor thalassemia and controls and between both types of thalassemia trait β and δβ, we determined erythrocyte deformability and aggregability in 30 β and 30 δβ trait carriers diagnosed both with conventional methods and globin gene analysis, and in 40 …age‐ and sex‐matched controls. Erythrocyte deformability determined by means of the Rheodyn SSD showed a statistically significant lower Elongation Index (EI) at all the shear stresses tested in both thalassemic groups compared with controls (p<0.001). Minor β thalassemia carriers showed lower EI than δβ carriers (p<0.001). Erythrocyte aggregability measured with the Myrenne aggregometer was significantly lower in both thalassemic groups than in controls (p<0.001), although no significant differences could be observed between both thalassemic groups. The rheological alterations found in thalassemia carriers are in part due to microcytosis, hypochromia and the morphological changes that characterize this kind of anaemia. The less altered deformability found in δβ carriers, is in agreement with the fact that it deals with a more benign trait. Show more

Keywords: Thalassemia minor, erythrocyte deformability, erythrocyte aggregability

Citation: Clinical Hemorheology and Microcirculation, vol. 28, no. 2, pp. 71-78, 2003

Authors: Fischler, L. | Meredith, D.O. | Reinhart, W.H.

Article Type: Research Article

Abstract: In most studies fish‐oil had been administered by enteral route. Recently an parenteral marine fish‐oil emulsion has been developed. With an intravenous infusion an immediate effect on the membrane lipid composition of circulating blood cells and endothelial cells may be expected. In this study we assessed the acute effects of a parenteral fish‐oil emulsion on blood rheology and erythrocyte morphology in vitro. Blood from 15 healthy young volunteers was incubated in vitro with increasing concentrations of a parenteral fish‐oil emulsion (Omegaven® ) at 37°C for different time periods (2, 20, and 60 min). Plasma and whole blood viscosity were …measured using a Couette viscometer. Red blood cell morphology was examined by light and scanning electron microscopy. High plasma concentrations of Omegaven® increased whole blood viscosity at high and low shear rate (p<0.01 above 20%vol) and plasma viscosity to a lower extent (p<0.05 at 40%vol). Erythrocytes underwent cell swelling (increase of centrifuged hematocrit) and a dose‐dependent echinocytic shape transformation, which indicates an intercalation of the compound in the outer hemileaflet of the cell membrane. These effects were already apparent after 2 min of incubation and were fully reversible upon wash‐out of Omegaven® . We conclude that the intravenous fish‐oil preparation Omegaven® interacts with the outer hemileaflet of the erythrocyte membrane and may affect membrane functions. At pharmacological concentrations these effects seem to be negligeable. Show more

Keywords: Blood viscosity, eicosapentaenoic acid, erythrocyte membrane, fat emulsions, intravenous, fatty acids, omega‐3, fish oil

Citation: Clinical Hemorheology and Microcirculation, vol. 28, no. 2, pp. 79-88, 2003

Authors: Hilário, Sandra | Saldanha, Carlota | Martins e Silva, J.

Article Type: Research Article

Abstract: The possibility that erythrocytes may function as a reservoir for noradrenaline and adrenaline and as a modulator of circulating catecholamine concentrations had been suggested. The aim of this work was to study the adrenaline effect on erythrocyte membrane fluidity, acetylcholinesterase (AChE) enzyme activity, P50 and erythrocyte deformability and also to verify if the role of adrenaline on erythrocyte properties is sex‐dependent. Blood samples from 42 healthy donors were obtained, and its aliquots incubated 30 min without (control) and with 10−5 M concentrations of adrenaline alone (A1 ) and adrenaline with an α and an β‐blocker (A2 ). Results …demonstrate that initial AChE values in female are higher (p≤0.01) than male values. In female, adrenaline decreases AChE activity either when α and β‐adrenergic receptors are blocked (p≤0.01) or when they are not. In male, adrenaline increases AChE activity when none of adrenergic receptors are blocked. Control values of male and female erythrocyte membrane fluidity are very similar but behaviour became differently (p≤0.05) when adrenaline is present because it decreases male and increases female values. Gender differences in erythrocyte deformability are verified at high shear stress values (p≤0.02). In female we have also registered the existence of an inverse significant correlation (r=−0.62) between membrane rigidity and AChE activity in A2 values. Adrenaline increases p50 values (p≤0.03) in both sexes. Peripheral blood film has shown echinocytes when adrenaline 10−5 M is present. We conclude that in this in vitro study sex‐related differences in erythrocyte acetylcholinesterase enzyme activity, membrane fluidity and erythrocyte deformability under adrenaline influence were found. Show more

Keywords: Adrenaline, erythrocyte, erythrocyte membrane fluidity, acetylcholinesterase enzyme activity, P$_{50}$, erythrocyte deformability, gender

Citation: Clinical Hemorheology and Microcirculation, vol. 28, no. 2, pp. 89-98, 2003

Authors: Bollini, A. | Hernández, G. | Bravo Luna, M. | Cinara, L. | Rasia, M.

Article Type: Research Article

Abstract: The objective of this study was to emphasise the potential power of simple and inexpensive haemorheological tests as predictors of hypertensive gestational disorders through a retrospective study. Blood samples of 195 primigravids with gestational age 18–23 weeks were studied. For data processing pregnant women were allocated into 3 groups, based on difference of SBP and DBP values measured at first and last consultation, and presence of proteinuria and oedema: Normotensive pregnants (n=149), hypertensive pregnants; n=26 and preeclamptic pregnants; n=20. Whole blood viscosity, plasma viscosity, erythrocyte rigidity and aggregability, haemoglobin, hematocrit, total protein, albumin and fibrinogen were assayed. Increased relative viscosity …(ηr ) (p<0.01), decreased erythrocyte deformability (p<0.05), lower O2 release (p<0.01) and birth weight (p<0.01), showed a negative correlation with filterability index in preeclamptics. There was a decrease of erythrocyte deformability in hypertensive women. Erythrocyte deformability and blood viscosity could be an early indicator in preeclamptics, and erythrocyte deformability in hypertensive ones, therefore they could be considered alert factors in order to decide a thorough control in these patients to prevent further complications. Show more

Keywords: Pregnancy hypertension, haemorheology, blood viscosity, erythrocyte deformability, erythrocyte aggregation

Citation: Clinical Hemorheology and Microcirculation, vol. 28, no. 2, pp. 99-105, 2003

Authors: Karul, Aslıhan B. | Karadag, Fisun | Kozacı, Didem | Altun, Cagatay

Article Type: Research Article

Abstract: The aim of this study is to investigate if erythrocyte fragility is altered in chronic obstructive pulmonary disease (COPD) due to oxidative stress. Fasting blood samples were collected into both plain tubes and tubes with K3 EDTA and analyzed in two hours for hematologic indexes and erythrocyte osmotic fragility (EOF). Malondialdehyde (MDA) concentrations in serum were detected in terms of TBARS (thiobarbituric acid reactive substances), spectrophotometrically. Thirty‐nine clinically stable male COPD patients with mean age 67±8 were prospectively studied. The control subjects consisted of healthy males with mean age 64±12. Pulmonary function tests of COPD patients revealed …severe airway obstruction whereas they were normal for control group. Normal pH with mild hypoxemia and hypercapnia were detected in arterial blood gas analyses. Hemoglobin, haematocrit and mean corpuscular volume values of two groups were similar. Mean serum MDA concentration was 1.09±0.11 μmol/l in COPD patients and 0.95±0.06 μmol/l in the control group (p=0.336). EOF was 33.06±1.24% in COPD group and 33.17±1.55% in controls (p=0.453). There was no correlation between EOF and MDA concentrations of COPD patients (r=−0.18, p=0.924). EOF and MDA did not correlate with severity of COPD (p>0.05). We conclude that markers of oxidative stress are not increased and erythrocyte osmotic fragility is not altered in stable COPD patients with normal arterial pH. Show more

Citation: Clinical Hemorheology and Microcirculation, vol. 28, no. 2, pp. 107-112, 2003

Authors: Wei, Lei | Muller, Sylvaine | Ouyang, JingPing | Stoltz, Jean‐François | Wang, Xiong

Article Type: Research Article

Abstract: Vasodilator‐stimulated phosphoprotein (VASP), an actin filaments‐associated protein expressed mainly in focal adhesions and dynamic membrane regions of endothelial cells (ECs), serves as a substrate for cAMP and cGMP‐dependent protein kinases. In this work, we studied the effect of laminar shear stress in vitro on the location and expression of the VASP as well as its phosphorylation associated with actin reorganisation in human umbilical endothelial cells (HUVECs). The distributions of VASP and microfilaments were observed by a fluorescent double staining. The level of VASP expression in cells was quantified by western blot. Experiments showed that, after exposure to a shear stress …of 10 dyn/cm2 for 24 h, besides the elongation and orientation of the cells, and spots of VASP were found along thick stress fibres, particularly at their two extremities. Western blot data showed conversions up to 11.4% and 8.9% of the 46 kD non‐phosphorylated form VASP to its 50 kD phosphorylated form after exposures of 1 h and 4 h respectively to the same shear stress. The shear stress of 15 dyn/cm2 had qualitatively the same effect as that of 10 dyn/cm2 , but with a lower magnitude. However, the shear stress of 2 dyn/cm2 had much slower and weaker effects on the same tendency. These results suggest that a laminar shear stress can induce VASP translocation and phosphorylation that proceed actin filaments rearrangement along with the flow direction in HUVECs. Show more

Keywords: VASP, phosphorylation, shear stress, endothelial cells

Citation: Clinical Hemorheology and Microcirculation, vol. 28, no. 2, pp. 113-120, 2003