Clinical Hemorheology and Microcirculation - Volume 20, issue 1

Authors: Khaled, S. | Brun, J.F. | Cassanas, G. | Bardet, L. | Orsetti, A.

Article Type: Research Article

Abstract: We previously reported a higher blood viscosity at corrected hematocrit (45%) (explained by a higher value of erythrocyte rigidity) in football players with low serum zinc (Zn) and thus presumably Zn deficiency; subjects with low serum zinc had also an impairment in performance. This interventional study was undertaken in order to assess the effects of zinc supplementation (compared to placebo) on blood rheology and performance either at rest or during exercise. Ten male healthy volunteers (age: 26 \pm 1.3 yr; weight 67.9 \pm 2.24 kg; height 177 \pm 3 cm) received at random order …either zinc (20 mg/day) and placebo, according to a double blind cross‐over procedure, during seven days. In each case on the eighth day they performed a 25 min submaximal exercise‐test. At rest blood viscosity at corrected hematocrit 45% (\gamma=1000 s^{-1} ) was lower after Zn (3.56 \pm 0.14 vs. 4.13 \pm 0.16 mPa.s, p=0.009 ), explained by a lower RBC rigidity index ‘k’ according to Quemada’s equation (1.65 \pm 0.07 vs. 1.84 \pm 0.08 , p=0.03 ). Hematocrit and plasma viscosity were unchanged, but RBC aggregation was decreased (laser retrodiffusion‐derived aggregation time ‘Ta’ 3.52 \pm 0.51 vs. 2.75 \pm 0.59 , p=0.02 ). The increase in blood viscosity during exercise is lower after Zn than placebo. Blood viscosity at corrected hematocrit 45% remains unchanged during exercise after Zn, yet it increases after placebo. RBC rigidity index ‘k’ remains lower during exercise after Zn. The rating of perceived exertion (Borg’s scale) at the 20th minute of exercise is lower after zinc (5.6 \pm 0.4 vs. 6.6 \pm 0.4 , p=0.008 ). This study confirms that Zn improves erythrocyte deformability, decreases the exercise‐induced acute increase in blood viscosity, and improves exercise tolerance. Since Zn deficiencies are not unfrequent in sportsmen, these findings may be potentially relevant to sports nutrition. Show more

Keywords: Zinc supplement, erythrocyte deformability, erythrocyte aggregation, rheology, exercise

Citation: Clinical Hemorheology and Microcirculation, vol. 20, no. 1, pp. 1-10, 1999

Authors: Ramakrishnan, S. | Grebe, R. | Singh, M. | Schmid‐Schönbein, H.

Article Type: Research Article

Abstract: The hemorheological parameters, plasma viscosity, hematocrit, erythrocyte aggregation and deformability of blood samples obtained from plasmacytoma patients are measured by capillary viscometer, microcentrifuge, Myrenne aggregometer, and filtrometer, respectively. These parameters are significantly altered in patients compared to those of normal subjects. The plasma viscosity and erythrocyte aggregation are increased, whereas erythrocyte deformability and hematocrit are decreased. Based on these parameters the hemorheological risk factor profiles are developed and by their overall risk factors, the patients with low and high risk factors are identified.

Keywords: Plasmacytoma, erythrocyte aggregation and deformability, plasma viscosity, hematocrit, risk profile

Citation: Clinical Hemorheology and Microcirculation, vol. 20, no. 1, pp. 11-19, 1999

Authors: Ramakrishnan, S. | Grebe, R. | Singh, M. | Schmid‐Schönbein, H.

Article Type: Research Article

Abstract: The effects of two local anaesthetics, procain and tetracaine, on erythrocyte aggregation and deformability under in vitro conditions are analysed. Fresh blood samples from healthy volunteers are obtained by venepuncture in test tubes containing heparin as anticoagulant. After centrifugation, plasma and cells are separated and buffy coat is discarded. The erythrocyte suspensions for aggregation and deformability measurement are prepared at hematocrit 34 and at 8% in buffered medium containing glucose and albumin, respectively. A part of the suspending medium in these samples is replaced by an equal volume of anaesthetic solution to obtain its final concentration ranging from 0.001 to …1 g/l. The results show that with the increase of anaesthetic concentration the deformability index and the aggregation index are reduced. The change in erythrocyte shape may contribute to the decrease in aggregation. The combined effect of these parameters may affect blood flow under varied experimental conditions. Show more

Keywords: Erythrocyte aggregation and deformability, local anaesthetic, procain, tetracaine

Citation: Clinical Hemorheology and Microcirculation, vol. 20, no. 1, pp. 21-26, 1999

Authors: Ehrly, A.M. | Bauersachs, R.M.

Article Type: Research Article

Citation: Clinical Hemorheology and Microcirculation, vol. 20, no. 1, pp. 27-30, 1999

Authors: Dobberstein, H. | Solbach, U. | Weinberger, A. | Wolf, S.

Article Type: Research Article

Abstract: Hyperviscosity syndrome leads to vascular disturbances in different organs. In the retina typical ophthalmoscopic changes can be found including dot and blot hemorrhages, retinal and optic nerve head edema, and increased diameter of retinal veins. In this study we examined the retinal microcirculation in patients with hyperviscosity syndrome. Nineteen patients (14 patients with Waldenstroem’s macroglobulinemia, two patients with kryoglobulinemia, three patients with plasmacytoma) were examined. All patients underwent a video fluorescein angiography. In all angiograms the arteriovenous passage time (AVP) and the arm retina time (ART) were quantified. In addition, hematocrit (Hct) and plasma viscosity (ETA) were measured. In patients …with hyperviscosity syndrome AVP was significantly prolonged in comparison to healthy volunteers (AVP: 2.5 \pm 1.3 s vs. 1.5 \pm 0.4 s; p<0.01 ). The ART showed no significant differences. Plasma viscosity was doubled in patients as compared with reference values (ETA: 2.57 \pm 1.5 mPa\, s vs. 1.24 \pm 0.08 mPa\, s; p<0.01 ). In this study we showed an increase in plasma viscosity as well as an increase in arteriovenous passage time. This may result in retinal circulatory disturbances and may cause the typical fundus changes in patients with hyperviscosity syndrome. Show more

Citation: Clinical Hemorheology and Microcirculation, vol. 20, no. 1, pp. 31-35, 1999

Authors: Landgraf, H.

Article Type: Research Article

Citation: Clinical Hemorheology and Microcirculation, vol. 20, no. 1, pp. 37-40, 1999

Authors: Lawall, H. | Angelkort, B.

Article Type: Research Article

Abstract: Increased rheological parameters and disturbances of capillary perfusion are often observed in both types of diabetes. It is assumed that these alterations might be involved in the development and progression of diabetic microangiopathy. It has been shown elsewhere, that erythrocyte rigidity, erythrocyte and platelet aggregation, plasma viscosity and leucocyte adhesion are increased. By methods of microcirculation capillary perfusion can be investigated and in vivo no significant alterations can be found at rest. During reactive hyperemia flow reduction diminishes capillary perfusion in various organs. In this presentation hemorheological parameters and erythrocyte velocity in nailfold capillaries are investigated in both types of …diabetes under various conditions. Plasma viscosity and spontaneous platelet aggregation are often increased, especially in patients with diabetes type 2 and in diabetic foot lesions. Improvement of the metabolic situation by insulin application reduces the elevated parameters and improves capillary perfusion. Long‐term type 1 diabetics tend to show increased rheological factors and reduced capillary perfusion. Although an association between some hemorheological parameters and capillary perfusion seems to exist, a strong correlation cannot be found. Show more

Citation: Clinical Hemorheology and Microcirculation, vol. 20, no. 1, pp. 41-47, 1999

Authors: Spitzer, S. | Münster, W. | Sternitzky, R. | Bach, R. | Jung, F.

Article Type: Research Article

Abstract: Purpose, Material and Methods: The aim of this study was to investigate the influence of direct intraarterial application of the contrast agents Iodixanol‐270 and Iopentol‐150 on the capillary perfusion. This was accomplished through continuous recording of the capillary perfusion in the nailfold capillaries of the right hand before and after a bolus injection of 20 ml of contrast agent into the right axillary artery. Results: After injecting 20 ml of Iodixanol‐270, which has a high viscosity compared to the plasma viscosity, a statistically significant decrease in the erythrocyte velocity of 60.8% from 0.439\pm 0.273 mm/s to 0.172\pm …0.090 mm/s was observed already 10 s after the injection (p=0.0001 ). The decreased velocity was maintained until the end of the observation period of 6 min. In contrast to this finding, no change in the erythrocyte velocity was observed after injection of 20 ml of the low‐viscous Iopentol‐150 (p=0.1508 ). Conclusions: The erythrocyte velocity in cutaneous capillaries therefore strongly depends on the viscosity of the contrast agent. Show more

Keywords: Cutaneous microcirculation, radiography, contrast media, non‐ionic, erythrocyte velocity

Citation: Clinical Hemorheology and Microcirculation, vol. 20, no. 1, pp. 49-55, 1999

Authors: Toth, K. | Nemes, J. | Czopf, L. | Kapronczay, P. | Kesmarky, G. | Juricskay, I.

Article Type: Research Article

Abstract: It is known from previous studies that hemorheological parameters are altered in patients with essential hypertension. The hemorheological and hemodynamical effects of doxazosin, a selective alpha‐1‐adrenoreceptor blocker agent, was examined in twenty patients (mean age: 54 \pm 10 years) with essential hypertension. Hemorheologic (hematocrit, fibrinogen, plasma and whole blood viscosity) and hemodynamic (cardiac output and index, total peripheral resistance) parameters and plasma lipids were determined. The measurements were carried out before the beginning of the treatment, after 1 week and after 12 weeks treatment periods. Besides significant reduction of blood pressure and total peripheral resistance (p<0.001 ), …a decrease in cholesterol (p <0.001 ) and triglyceride (p<0.01 ) levels and a beneficial effect on hemorheological parameters was detected. Fibrinogen and plasma viscosity decreased significantly (p <0.01 ). Hematocrit value was also lower after one week (p<0.001 ), then an increase could be seen. Whole blood viscosity showed similar changes as hematocrit, but the degree of its final increase was slighter, which was supported by the significantly lower value of corrected blood viscosity (p <0.05 ). Show more

Keywords: Essential hypertension, blood rheology, plasma lipids, doxazosin

Citation: Clinical Hemorheology and Microcirculation, vol. 20, no. 1, pp. 57-61, 1999