Clinical Hemorheology and Microcirculation - Volume 16, issue 5

Authors: Le Dévéhat, C. | Khodabandehlou, T. | Vimeux, M. | Aouane, F.

Article Type: Research Article

Abstract: The hemorheological properties and transcutaneous oxygen pressure “TcPO2” are studied in both 20 healthy subjects and 36 insulin-dependent diabetic “IDD” patients without micro and macroangiopathy. Patients are classified on the basis of having HbA1C values either persistently below 7.5% (D1 : 23 with good metabolic control) or persistently above 7.5% (D2 : 13 with poor metabolic control). RBC aggregation is shown to be more important in patients while TcPO2 values are decreased. Impairements are more marked in diabetics of group D2 than either those of group D1 or the healthy subjects. These results suggest that a poor metabolic control is …associated with abnormalities in both RBC aggregation and TcPO2. Furthermore, the effects of a 3-year intensive insulin therapy is studied. In this study, 34 IDD patients are selected on the basis of having a poor metabolic control. The therapy is found to improve the HbA1C level in 68% of patients (D3 n=23) while 32% (D4 n=11) remained with a persistent poor metabolic control. In group D3, RBC aggregation and TcPO2 are shown to be improved consistently with HbA1C decrease. In contrast, in group D4, both hemorheologic and microcirculatory disturbances persist despite of the intensive insulin therapy. These results confirm that disturbances in RBC aggregation and TcPO2 can be resulted from a poor and chronic metabolic control. Besides, they underline that beneficial effects on these parameters, can be obtained from an intensive insulin therapy. Show more

Keywords: insulin-dependent diabetes, glycemic control, RBC aggregation, TcPO2

DOI: 10.3233/CH-1996-16511

Citation: Clinical Hemorheology and Microcirculation, vol. 16, no. 5, pp. 677-683, 1996

Authors: Caimi, G.

Article Type: Research Article

Abstract: In 31 VAD subjects (mean age 66.9 ± 7.0 years) and in 20 VAD subjects with NIDDM (mean age 67.6 ± 7.2 years), we evaluated whole-blood filtration (VBC - according to the Reid method), mean erythrocyte aggregation (MEA - employing the aggregometer MA1 of Myrenne), erythrocyte membrane fluidity (marking intact red blood cells with 10-[1-pyrene] decanoic acid), red cell membrane protein lateral mobility (marking intact red blood cells with pyrene-3-maleimide), total red cell calcium content (using an atomic absorption spectrophotometer) and cytosolic red cell Ca2+ content (employing Fura 2-AM), and the relationships between them. In both groups, compared to …controls, we observed a decrease of VBC, an increase of MEA, a decrease of the erythrocyte membrane fluidity and of the red cell membrane protein lateral mobility. As regards the red cell calcium content, we observed that, in VAD subjects with and without NIDDM, the total red cell calcium content is not different from controls, while only in VAD subjects with NIDDM, in comparison with normal controls, an increase in cytosolic red cell Ca2+ content is present. In normals and in VAD subjects with and without NIDDM, VBC and MEA are not related to the parameters reflecting the membrane dynamic properties nor to the red cell calcium content. Show more

Keywords: Vascular atherosclerotic disease, Non-insulin-dependent diabetes mellitus, Whole-blood filtration, Erythrocyte aggregation, Erythrocyte membrane, Erythrocyte calcium

DOI: 10.3233/CH-1996-16512

Citation: Clinical Hemorheology and Microcirculation, vol. 16, no. 5, pp. 685-699, 1996

Authors: Modesti, Pietro Amedeo

Article Type: Research Article

Abstract: Endothelin-1 (ET-1) is a 21 amino acid peptide endowed with a powerful vasoconstrictor activity. The molecular structure and biological activities of endothelin were explored in several studies starting soon after its discovery in 1988, but only recently has the availability of specific ET-1 antagonists allowed its physiological activities to be explored. It is now becoming evident that circulating ET-1 plays a key role in the continuous adaptation of vessel wall tone, of both resistence and capacitance vessels. On the other hand, in addition to the ability to control blood flow, ET-1 synthesis is in turn controlled by blood flow itself, …thus making the connection between ET-1 and peripheral circulation particularly close. This review will focus on recent knowledge about the physiological role of circulating endothelin-1. Show more

Keywords: Endothelin physiology, Haemodynamics, Vasoactive substances, Dynamic forces, Gene regulation

DOI: 10.3233/CH-1996-16513

Citation: Clinical Hemorheology and Microcirculation, vol. 16, no. 5, pp. 701-711, 1996

Authors: Isogai, Y. | Ikemoto, S. | Tanaka, H.

Article Type: Research Article

Abstract: The pathogenesis of diabetic microangiopathy has been considered to be closely related with abnormal viscous blood flow and hypercoagulability in microcirculation. This study aims to find good indices for forecasting the incidence of aggravation of microangiopathy in diabetes. Two kinds of devices have been applied to investigate the rheologic property in diabetics, especially the viscoelasticity in anticoagulation and clotting state of blood. OP-Rheometer system for non-clotting blood and a viscoelastorecorder (VER) for clotting process were used to observe each significance of viscoelasticity for contribution to microangiopathy respectively. The abnormality in viscoelasticity of the blood was well correlated with plasma fibrinogen …and the severity of microangiopathy. In VER maximum value of dynamic rigidity modulus (G'm) was a good index for hypercoagulable state which includes high plasma viscosity, the increased plasma fibrinogen, high red cell aggregation and the severity of retinopathy. To correlate in vivo study with in vitro examination tests, we observe the intravascular erythrocyte aggregation (IEA) in bulbar conjunctiva by a biomicroscopy. There was a good correlation of IEA to G'm and other hemorheological factors. In conclusion, elevation of both viscoelasticity of blood and clotting process (G'm) and high grade IEA suggest the increase of the incidence of aggravation on diabetic microangiopathy. Show more

Keywords: viscoelasticity, diabetes mellitus, microangiopathy, coagulation, intravascular erythrocyte aggregation

DOI: 10.3233/CH-1996-16514

Citation: Clinical Hemorheology and Microcirculation, vol. 16, no. 5, pp. 713-735, 1996