Dysfunction of membrane-receptor system of blood cells and kidney tissue in experimental diabetes mellitus.

The effect of streptozotocin-induced diabetes mellitus on some parameters of energy metabolism and functional status of cell membranes was studied in experiments on rats. It was found that the development of diabetes mellitus is associated with dramatic changes in the metabolism of blood cells and kidney tissue: inhibition of aerobic ATP synthesis, accumulation of lactate, uncoupling of oxidative phosphorylation, and development of lactic acidosis. Diabetes mellitus leads to restructuring of membrane lipids, changes in microviscosity, and suppression of insulin receptors and membrane-bound Na(+), K(+)-ATPase, and Ca(2+)-ATPase. Sharply increased levels of LPO products and lactic acidosis during DM indicate an imbalance in the LPO-antioxidant system and development of oxidative stress.

[Lipid-proteinic interaction in erythrocytie and placental membranes in women with insulin resistance].

Disturbances of erythrocyte and placental membrane functiond have been studied in placenta of pregnant women with obesity and diabetes mellitus type 2. The results of this study demonstrate significant metabolic impairments in women with insulin resistance. Changes in lipid spectrum of erythrocyte membranes and decreased activity of antioxidant enzymes obviously contribute to the development of fetoplacental insufficiency. This changes point to necessity of the antioxidant therapy in pregnant women with obesity and diabetes mellitus type 2.

[Disfunction of membrane-receptor system of blood cells in children with diabetes mellitus of type I and II].

When metabolic failure in children and adolescents with diabetes, are violations of the structural and functional properties of membrane - the receptor apparatus of cells, accompanied by a decrease in ATP levels, inhibition of activity of membrane-bound enzyme Na+, K(+)-ATPase, a sharp decrease in insulin binding receptor activity and decrease glucose uptake by cells that indicates a decline in cell sensitivity to insulin. Diabetes in children and adolescents occurs with lipid disorders, activation of the processes of lipid peroxidation, manifested increasing concentrations of both primary and secondary products of lipid peroxidation, changes in structural and functional properties of erythrocyte membranes, as well as disturbances in the antioxidant defense system. Changes in the studied indexes depend on the type of diabetes and duration of the disease. Imbalance in the system LPO-AOD in the background shows the development of dyslipidemia, oxidative stress, particularly pronounced in type 2 diabetes.

[Structural organization of red blood cell membranes in pregnant women with gestosis]. / Strukturnaia organizatsiia membran éritrotsitov pri gestozakh.

Activated lipid peroxidation (LPO) was found to occur with decreased antioxidative activity (AOA) in gestosis, by deteriorating the structural and functional properties of cell membranes. This enhanced the permeability of the phospholipid bilayer and altered the function of membranous proteins and the synthesis of biologically active agents, by involving the systems responsible for microcirculatory homeostasis. Enhanced membrane hydrophilicity and increased LPO and AOA are typical of the second and third trimesters of normal pregnancy. Pregnant with gestosis generally show higher microviscosity and hydrophilicity of membranes and enhanced blood LPO.

[The structural status of red blood cell membranes in children with insulin-dependent diabetes mellitus. Examination by spin probe]. / Strukturnoe sostoianie membran eritrotsitov krovi detei, bol'nykh insulinozavisimym sakharnym diabetom. Issledovanie metodom spinovogo zonda.

Using spin probes-stearic acid analogues, the authors investigated the microviscosity and the a/b parameter of red blood cell membranes in children with diabetes mellitus. The structural changes were correlated with altered metabolic measurements. The change in the pathway of insulin in diabetes mellitus led to the structural state of red blood cell membranes.

[Mechanisms of functional disorders of the membrane receptor apparatus in pregnant women with insulin-dependent diabetes mellitus]. / Mekhanizmy narushenii funktsii membranoretseptornogo apparata pri insulinzavisimom sakharnom diabete u beremennykh zhenshchin.

Studies of membrane receptor system in patients with insulin-dependent diabetes mellitus revealed that insulin resistance in pregnant patients with type I diabetes is caused by disordered cellular sensitivity to threshold physiological and submaximal insulin doses, whereas the maximal doses of the hormone normalize glucose consumption by the cells. High insulin doses intensify lipid peroxidation, normalize the status of membranous proteins, reduce the number of thiol groups, reduce AOA level in membranes, and, hence, reduce membranous capacity to bind active peroxide radicals. Structural and functional changes in red cell membranes are associated with reduced affinity of insulin receptors, reduction in the number of insulin-binding sites in membranes, this disordering intracellular effects of insulin.

[Recording of surface potential changes in erythrocyte membranes from patients with insulin-dependent diabetes mellitus using a spin probe method]. / Registratsiia metodom spinovogo zonda izmenenii poverkhnostnogo potentsiala membran éritrotsitov krovi bol'nykh insulinzavisimym sakharnym diabetom.

Changes in surface potential of erythrocyte membranes were studied by a positively charged analog as a spin probe. Insulin-dependent diabetes mellitus (IDDM) patients demonstrated a significant increase (by 16 +/- 2.0 mV) in negative surface potential as compared to the control. An important role of this phenomenon in pathogenesis of IDDM is discussed.

[Structural changes in erythrocyte membranes in diabetes mellitus using spin labelled fatty acids]. / Issledovanie s pomoshch'iu spin-mechenykh zhirnykh kislot strukturnykh izmenenii v membranakh éritrotsitov pri sakharnom diabete.

Microviscosity and polarity of erythrocyte membranes of the blood of patients suffering from diabetes were studied by ESR using spin-labeled fatty acids. Structural changes were discovered 0.6-0.8 nm from the membrane surface in the lipid bilayer of erythrocytes obtained from patients' blood. No essential immobilization of the acyl chains of phospholipids was found in deeper layers as compared with the control. The bilayer polarity at different depth was not essentially changed either.

[Role of changes in insulin-binding activity and energy metabolism in the pathogenesis of experimental crush syndrome]. / Rol' izmenenii insulinsviazyvaiushchei aktivnosti i énergeticheskogo obmena v patogeneze éksperimental'nogo krash-sindroma.

Study of the effect of the crush syndrome on cell metabolism and insulin-binding activity revealed a new aspect of the pathogenesis of the syndrome, namely, a marked reaction of the mononuclear receptor apparatus. Accumulation of lactate in the tissues and the development of acidosis probably play an important role in disturbance of the insulin-binding activity of the plasma membrane. Reduction of the level of tree adenine nucleotides and ATP in particular may be of essential importance in the late stages of compression. Of importance in the pathogenesis of the crush syndrome was the binding of insulin with its receptors and the subsequent intensification of metabolic disorders and reduction of phosphorylation, which in turn may be the cause of reduced transmission of the signal to the receptors, i. e. disorder of the postreceptor action of insulin.

[The state of erythrocyte membranes in diabetes mellitus]. / Sostoianie membran éritrotsitov pri sakharnom diabete.

Study of red cell membranes in diabetics has shown that physicochemical shifts in the red cell membrane lipid bilayer, elevated lipid peroxidation, and disordered thiol compound metabolism are among the crucial aspects in the pathogenesis of diabetes mellitus. EPR spectroscopy in complex with other biochemical methods will help monitor the adequacy of therapy.

[Correction of metabolic disorders by magnetic-laser irradiation (experimental study)]. / Korrektsiia metabolicheskikh narushenii magnitolazernym oblucheniem (éksperimental'noe issledovanie).

Five series of experiments were conducted on a model of hepatic insufficiency caused by obstructive jaundice to study the effect of semiconductor infrared laser in a range of 800-900 nm with a static magnetic field on some metabolic changes in the organism. Wistar rats weighing 200-250 g were used. The region of the liver was irradiated through an intact epilated skin. The results provide evidence that a definite role in the pathogenesis of hepatic insufficiency is played by intensification of LPO processes and diminution of antioxidant defence which leads, in turn, to reduction of the insulin-receptor interrelations and sharp decrease of hepatic cell metabolism.

[The insulin receptor function of mononuclear leukocytes in pregnant women with diabetes mellitus]. / Sostoianie insulinovykh retseptorov mononuklearov u beremennykh zhenshchin, bol'nykh sakharnym diabetom.

Investigation of the insulin-binding activity of insulin receptors (IR) in insulin treated pregnant women with insulin dependent diabetes mellitus with different requirement in insulin has shown that insulin-dependent diabetes in pregnant women in characterized by heterogeneity. Insulin therapy gets to normal the activity of insulin receptors in patients with diabetes mellitus with an increased affinity to IR, and causes no increase in the level of IR in patients in whom it was not raised. Insulin-binding activity in the latter may be associated with metabolic derangement caused by insulin insufficiency.