THE CHANGE OF AGGREGATION PROPERTIES OF ERYTHROCYTES UNDER THE INFLUENCE OF PENTOXIFYLLINE AND SUM-55 COMPOUND WITH THE STIMULATION OF AN ENTRANCE OF CALCIUM INTO A CELL

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Purpose of the work was to study the effect of SUM-55 compound and pentoxifylline on aggregation parameters in changes of the concentration of calcium in erythrocytes. Material and methods of the study: as a potential equalizer high blood viscosity syndrome studied compound BMS-55 (1,3-dimethyl-7-(2-hydroxi-3-piperidinepropyl-1)-8-phenyl aminoxanthan of hydrochloride, RF patent no 2344137) and a drug with hemorheological activity of pentoxifylline ("Aventis", Germany). The experiments were performed on 50 white male outbred rats, weighed 270-300 g. Blood sampling was carried out from the abdominal aorta under a light ether anesthesia. Each series, the suspension of washed red cells were divided and incubated for 15 minutes at 37°C with the compounds at a final concentration 1h10-4 mol/l. Binding of calcium in the medium was performed using the Ca2+ chelator - EGTA (1 mM) (Sigma, USA). Increase of Ca2+ concentrations in the cell was achieved by incubating the cells with calcium ionophore A 23187 (3.0 mM) (Sigma, USA). The degree of platelet aggregation was measured with semiautomatic type aggregometer MA1 (Myrenne, Germany). Statistical analysis was performed using a table editor Microsoft Excel and «Statistika 6.0» software package Results: at the first stage, in order to avoid a possible chelating effect of the SUM-55 compound we evaluated its impact on the parameters of platelet aggregation in comparison with EGTA. Binding of calcium in the medium using the Ca2+ chelator, EGTA (1 mM) was accompanied by a decrease in the degree of aggregation (p>0.05). The compound SUM-55 and pentoxifylline in a complex with EGTA resulted in a slight increase in platelet aggregation, compared with the samples incubated with EGTA alone, but the received data is not statistically significant. To further confirm the data obtained erythrocyte aggregation was studied using a light microscopy, with further image video record. EGTA, the compound SUM-55 and pentoxifylline did not change the index of platelet aggregation (PA). Increase of Ca2+ into the erythrocytes by incubation of the cells with calcium ionophore A 23187 (3.0 mM) significantly stimulated cell aggregation. Thus, at a shear rate of 600 sec-1 in the degree of aggregation of two time intervals increased more than 5 times. At low speed - 3 sec-1 in two timeslots active components increased by 90% and nearly 3 times, respectively (p<0.05). The SUM-55 compound at a shear rate of 600 sec-1 reduced the degree of aggregation of erythrocytes, as compared with the samples incubated with only the ionophore, 71% (p <0.05) and 61% (M5 and M10), a comparator 33% (p <0.05) and 40% (M5 and M10). With decreasing shear rate 3 s-1 effect of SUM-55 compound on platelet aggregation rate decreased slightly and amounted to 63%, 60% (p<0.05), respectively, time intervals - 5 and 10 seconds. Pentoxifylline reduces the degree of platelet aggregation by 40% and 46% (M15 and M110) (p> 0.05). Conclusions: pentoxifylline and SUM-55 compound affect the regulation of platelet aggregation by acting on the complex of intracellular cascades of reactions caused by the participation of ionized calcium, which can activate a variety of kinases and phosphatases, resulting in phosphorylation or dephosphorylization of key proteins of the membrane cytoskeleton. And the findings received are confirmed by the absence of a chelating ability of pentoxifylline and SUM-55 compound.