ИСТИНА

Diabetes mellitus (DM) is a group of systemic metabolic diseases, characterized by high blood sugar level in the blood of patients, because the pancreas does not produce enough insulin (insulin-dependent diabetes mellitus, abbreviated IDDM), or because cells do not respond to the insulin that is produced (non-insulin-dependent diabetes mellitus, abbreviated NIDDM). DM is gaining higher and higher social problem due to the quickly growing number of Earth population suffering from it and due to severe alterations of vitally important systems of the human organism involved including the cardiovascular system. Diabetes without proper treatments can cause many complications: hypoglycemia, diabetic ketoacidosis, or nonketotic hyperosmolar coma, chronic renal failure and diabetic retinopathy. The major long-term DM complications are related to the damage to blood vessels and capillaries (causes microangiopathy) and impairment of deformability properties of erythrocytes. Presence of concomitant diseases (arterial hypertension and etc.) leads to impairment of blood rheological properties, in particular to decreases of erythrocytes deformability. This leads to doubling the risk of cardiovascular diseases. It is obvious that control and monitoring of DM complications is very important, in particular deformability properties of erythrocytes, which are expected to be impaired in DM patients. The main goal of this work was to estimate the alterations of these parameters for rat and human blood in case of NIDDM and IDDM with and without concomitant arterial hypertension as well as patients with arterial hypertension without DM. In this work, we conducted measurements based on diffractometry techniques. Laser diffractometry is a convenient, fast and relatively simple technique for measuring the erythrocyte deformability. The essence of this technique is in obtaining and subsequent analysis of the diffraction patterns from a highly diluted suspension of erythrocytes at rest and shear flow [1]. Dependence of the diffraction pattern elongation on shear stress characterizes the ability of erythrocytes to deform. All experimental measurements were performed with human blood drawn from practically healthy volunteers, patients with DM (with and without concomitant arterial hypertension), patients with arterial hypertension, as well as with rat blood in such cases. The experimentally obtained results show that the deformability of erythrocytes is impaired in case of DM diseases of both types. For instance, the ability of human erythrocytes to deform in shear flow decreases by about 8-10% (in cases of both IDDM and NIDDM) in comparison with that in the control group. It was shown that the reduction of erythrocyte deformability in case of DM is mainly related with an increase of erythrocyte membranes rigidity. Deformability of human erythrocytes in case of DM with concomitant arterial hypertension decreases by about 20% in comparison with that in the control group. Deformability alterations in the erythrocytes of DM rats are quantitatively different from those in human DM patients. This may be due to the fact that DM rats do no suffer from concomitant diseases and complications characteristic of human DM patients.