[Role of protein kinases of human red cell membrane in deformability and aggregation changes].

The proteomic analysis has showed that red cell membrane contains several kinases and phosphatases. Therefore the aim of this study was to investigate the role of protein kinases of human red cell membrane in deformability and aggregation changes. Exposure of red blood cells (RBCs) to some chemical compounds led to change in the RBC microrheological properties. When forskolin (10 microM), an adenylyl cyclase (AC) and a protein kinase A (PKA) stimulator was added to RBC suspension, the RBC deformability (RBCD) was increased by 20% (p < 0.05). Somewhat more significant deformability rise appeared after RBC incubation with dB-AMP (by 26%; p < 0.01). Red cell aggregation (RBCA) was significantly decreased under these conditions (p < 0.01). Markedly less changes of deformability was found after RBC incubation with protein kinase stimulator C (PKC)--phorbol 12-myristate 13-acetate (PMA). This drug reduced red cell aggregation only slightly. It was inhibited red cell tyrosine phosphotase activity by N-vanadat and was obtained a significant RBCD rise and RBCA lowering. The similar effect was found when cells were incubated with cisplatin as a tyrosine protein kinase (TPK) activator. It is important to note that a selective TPK inhibitor--lavendustin eliminated the above mention effects. On the whole the total data clearly show that the red cell aggregation and deformation changes were connected with an activation of the different intracellular signaling pathways.

[Techniques for experimental and clinical studies of erythrocyte deformability].

Deformability is an important property of red blood cells and ensures the efficiency of their transport in the microcirculatory vascular system, as well as tissue oxygenation. A study of erythrocyte deformability uses different methods: filtration through about 5.0-microm pores, laser difractometry techniques and a focus of attention has recently been on a procedure for measuring the deformability of erythrocytes in a flow microchamber. The authors have developed a procedure for the recording of erythrocyte deformability and for the computer-aided treatment of an obtained image to have an accurate quantitative assessment of this important microrheological property of the cells. Comparison of the suspension viscosity of erythrocytes at high shift rates and the erythrocyte lengthening index (ELI) in the flow microchamber yielded a high correlation (p = -0.917; p < 0.01). That of ELI in the fractions of young and old cells also supported the high sensitivity of the procedure. Analysis of changes in the degree of erythrocyte deformability (in accordance with ELI), by applying three values of shift strain, revealed an almost linear relationship of the lengthening of fixed cells to the applied shift pressure. The known rheomodulator pentoxiphylline caused a significant erythrocyte deformability increase that was recorded by both methods (in the flow microchamber and at viscosimetry of erythrocyte suspensions with the hematocrit being equal to 40%). Thus, findings suggest that the method for the recording of erythrocyte deformability in the flow microchamber with the computer-aided analysis of images allows one to adequately measure this property of red blood cells.

[Rheological of blood and oxygen transport in long-term adaptation to muscular load]. / Reologicheskie svoistva krovi i transport kisloroda pri dolgovremennoi adaptatsii k myshechnym hagruzkam.

The blood viscosity became reduced after a long-term muscular adaptation in dogs. The main adaptation mechanism is associated with an autoregulated haemodilution and improvement of the red blood cells' microrheology (deformities and aggregation). The findings suggest that reduction in the haemodilution and the blood oxygen capacity are accompanied by a heightened efficiency of the oxygen transport. A sufficient correlation exists between the blood fluidity parameters and the oxygen balance in the body. Value of the optimum haematocrit in oxygen transport, is discussed.

[Analysis of rheologic changes in blood based on a hemorheologic profile concept]. / Analiz reologicheskikh izmenenii krovi na osnove kontseptsii gemoreologicheskogo profilia.

Changes in blood rheology were studied in 106 female hypertensive patients. Basic parameters of blood rheology were recorded: total blood viscosity, plasma viscosity, Hct, erythrocyte aggregation and deformability, fibrinogen, albumin/globulin ratio, and Hct/eta ratio. This set of parameters was presented as the hemorrheological profile. Blood and plasma viscosities were increased in hypertensive patients in comparison with the controls. Therapy with pentoxifylline (600-800 mg/day for 4 weeks) or angiotensin II receptor antagonist losatran (50 mg/day for 4 weeks) resulted in positive changes in the hemorrheological profile.

[Hemorheological profiles in patients with arterial hypertension and bronchial asthma]. / Gemoreologicheskie profili u patsientov s arterial'noí gipertenzieí i bronkhial'noí astmoí.

Hemorheological parameters were studied in patients with essential hypertension (men and women) and those with bronchial asthma. The rheological findings were established as a hemorheological profile. The latter is a set of macro- and microrheological parameters under various pathological conditions. The data show that blood viscosity was increased and correlate with blood pressure in hypertensive patients. There were more significant changes in the male populations of the two groups. The main cause of decreased blood fluidity and oxygen transport efficiency under these conditions is associated with hemoconcentration, elevated plasma levels of protein and increased plasma viscosity. The findings suggest that with the concept of a hemorheological profile one can correct rheological disturbances under various clinical conditions.