Complex impairment of peripheral blood flow in CHF including restricted microcirculation, attenuated regulatory mechanisms and impaired hemorheological properties caused the reduced oxygen utilization contributing to symptoms and advance of heart failure.

Cancer progression is associated with activation of blood coagulation. Blood coagulation process, platelet hemostasis and hemorheological properties were evaluated in patients with solid tumors (n = 27) before and after surgery and in healthy control (n = 20). The main features of blood coagulation process in cancer patients were elevated intensity and shortened period of contact phase of coagulation and inhibited fibrinolysis stage. Such prothrombotic state was fixed before surgery as well as in early postoperative period in spite of preventing thromboprophylactic treatment. Platelets depletion within the high level of spontaneous and ADP-induced platelet aggregation was fixed in cancer. The main cause of blood viscosity decrease in cancer patients was dramatic fall of Hct, because blood viscosity adjusted by Hct 40% was increased owing to the rise of plasma viscosity and substantially worsened RBC microrheological properties. The results of our study indicated close correlation between hemorheological and hemostasis parameters; these interrelations were more numerous and strong in cancer. In cancer patients the combination of a high aggregation activity of platelets, reduced number of erythrocytes (Hct), an increase of RBC aggregation and plasma viscosity caused impairment of blood oxygen transportation efficacy that provoke hypoxia in the microcirculation favoring thrombosis, settlement of tumor and metastasis.

No abstract

The review discusses published data on the effect of hydrogen sulfide on the functioning of the cardiovascular system. Hydrogen sulfide has become the third gas molecule, along with NO and CO, which was classified as gasotransmitters – signaling molecules, a unique feature of which is their ability to easily penetrate the cell membrane due to their good solubility in lipids. Signal transduction with the participation of gasotransmitters significantly differs from classical concepts – there is no need for either special membrane receptors or transport systems, gasotransmitters realize their effect practically in the zone of their biosynthesis, which makes such regulation fast and accurate. In the cardiovascular system, hydrogen sulfide has shown a pronounced cardioprotective effect, especially pronounced in conditions of hypertension and myocardial ischemia. Along with NO, hydrogen sulfide is the most important regulator of vascular tone, while it affects both the properties of the endothelium and regulates the contractility of vascular smooth muscle cells. The role of H2 S in the pathogenesis of arterial hypertension and the therapeutic potential of this gasotransmitter and its derivatives in arterial hypertension treatment both in animal models and in clinical studies have been demonstrated. Experimental data confirming the participation of hydrogen sulfide in the processes of angiogenesis and in the pathogenesis of atherosclerosis were published. For the cardiovascular system, the main function of which is the oxygen supply to organs and tissues, the ability of this gasotransmitter to influence the blood system and act as an oxygen sensor seems to be important. Hydrogen sulfide affects the functional properties of platelets, thrombus stability and microvascular thrombolysis; there is experimental evidence of the effect of H2S on the microrheological properties of erythrocytes and the process of erythrogenesis. And although the mechanisms of the effect of hydrogen sulfide have not yet been sufficiently studied, there is evidence that all gasotransmitters are in close interaction and their joint action gives a synergistic effect.

Введение. Микрореологические свойства эритроцитов — их деформируемость и агрегация в значительной степени определяют текучесть цельной крови и ее кислородотранспортный потенциал. При этом эритроциты — это клетки-мишени, на которые действуют сигнальные молекулы. Последние могут регуляторно изменять микромеханические свойства эритроцитов и реологию крови в целом. К сигнальным молекулам относятся и газотрансмиттеры (ГТ) — такие соединения, как оксид азота (NO), сульфид водорода (H2S) и монооксид углерода (CO). Доноры ГТ могут быть основой для разработки лекарственных препаратов для коррекции реологических свойств крови. Цель работы: изучение изменений микрореологических характеристик эритроцитов под влиянием доноров трех газотрансмиттеров — NO, H2S и CO. Материалы и методы. Эритроциты и их восстановленные тени инкубировали с нитропруссидом натрия (НПН, 100 мкмоль) — донором NO, гидросульфидом натрия (NaHS, 100 мкмоль) — донором H2S и трикарбонилхлор (глицинат) рутением (II) (CORM-3, 50 мкмоль) — донором СО. После этого регистрировали деформируемость эритроцитов (ИУЭ), их агрегацию (ПАЭ) и вязкость суспензий (ВС). Результаты. Установлено, что под влиянием всех трех доноров ГТ происходят заметные изменения микрореологических характеристик эритроцитов и их теней (в среднем на 13–16%; p < 0,05). Важно заметить, что сдвиги ИУЭ, ПАЭ и ВС под влиянием доноров газотрансмиттеров были сходными по величине, и суммарная разница их микрореологических эффектов на три разных донора ГТ не превышала 3%. Заключение. На основании полученных данных и их анализа можно заключить, что эритроциты качественно и количественно примерно одинаково отвечают на действие трех разных доноров ГТ положительными изменениями их микрореологических характеристик и особенно агрегации, которая снижалась более чем на 30%. Background. Erythrocytes microrheological properties (deformability and aggregation) largely determine the fluidity of whole blood and its oxygen transport potential. At the same time erythrocytes are target cells for signaling molecules acting. The latter can regulate erythrocytes micromechanical properties and blood rheology in general. Signaling molecules also include gasotransmitters (GT) — compounds such as nitrogen oxide (NO), hydrogen sulfide (H2S) and carbon monoxide (CO). GT donors can form the basis of drugs for blood rheology correction. Objectives: to study the changes of erythrocytes microrheological characteristics under the influence of donors of three gasotransmitters — NO, H2S and CO. Materials/Methods. Erythrocytes and their restored shadows were incubated with sodium nitroprusside (SNP, 100 μmol) — NO donor, sodium hydrosulfide (NaHS, 100 μmol) — H2S donor, and with tricarbonylchlor (glycinate) ruthenium (II) (CORM-3, 50 μmol) — CO donor. Thereafter we registered erythrocytes deformability (ED), their aggregation (EA) and suspensions viscosity (SV). Results. All three GT donors noticeably changed microrheological characteristics of erythrocytes and their shadows (on average by 13–16%; p < 0.05). It’s important that the shifts of ED, EA, and SV under the influence of gasotransmitter donors were similar in magnitude, and the total difference in their microrheological effects on three different GT donors did not exceed 3%. Conclusions. Erythrocytes qualitatively and quantitatively approximately equally responded to the action of three different GT donors by positive changes in their microrheological characteristics and especially by aggregation that decreased by more than 30%.