Zaporožskij Medicinskij Žurnal (Aug 2017)
Lipid metabolism in streptozotocin induced experimental diabetes and it’s correction with niacin-oxyethylidendiphosphonatogermanate
Abstract
Introduction. The development of approaches for effective control of diabetes-induced deterioration of lipid metabolism and plasma glucose level could be implemented by the applying of germanium-contained biologically active substances. Among others such compound as niacin – oxyethylidendiphosphonatogermanate (MIGU-4) should be mentioned, which is able to correct effectively the lipid layers of liver mitochondrial membranes on models of streptozotocin – induced diabetes. Aim. To investigate the dynamic changes of the total cholesterol, total phospholipids level along with their molar ratio; fractions of phospholipids of both erythrocyte membranes and liver mitochondria membranes in experimental diabetes mellitus and to investigate the mentioned indices under conditions of complex correction by MIGU-4 and insulin. Materials and Methods. Diabetes was induced in male Wistar rats with streptozotocin injection (50.0 mg/kg., i. p.). ED50 of MIGU-4 (25.0 mg/kg, i. p.) was used. Cellular membranes were obtained from erythrocytes, and mitochondrial membranes were obtained through differential centrifugation of liver tissue. Lipid extracts were isolated from 1 g of erythrocyte mass and from 200 mg of liver tissue; phospholipids fractionation was carried out by method of ascending one-dimensional thin-layer chromatography. Content of certain phospholipids was estimated by method of spots “burning out” using the 72 % chloride acid at 200 0С up to their complete bleaching with the consequent determination of lipids phosphate. The level of total phospholipids was calculated by summing up all fractions content. Results. The total cholesterol level substantially elevated along with the decreasing of phospholipids content in both erythrocyte and mitochondrial membranes obtained from liver tissue in two weeks after experimental streptozotocin diabetes induction in rats. It resulted in an increase of the cholesterol/ phospholipids ratio. These changes reached the maximal expression of mentioned deteriorations during the second month from the moment of diabetes induction. This was paralleled by a shift of phospholipids fractions which manifested in the increase of fractions which were relatively resistant to oxidation (lysophosphatidylcholine, sphingomyelin) along with the drastic dropping down of fractions which were easily oxidized (phosphatidylcholine, phosphatidylethanolamine), and that indicated violation of membrane fluidity maintaining compensatory mechanisms. Separate administration of insulin and MIGU-4 slightly decreased the negative influence of diabetes-induced deteriorations on both total phospholipids and their fractions content. Combined administration of insulin and MIGU-4 was resulted in significant prevention of the diabetes-induced disturbances of total and fractional phospholipids as well as disturbances of cholesterol/ phospholipids coefficient. Conclusions. The application of MIGU-4 prevents the streptozotocin diabetes-induced lipid metabolism disturbances in a form of total phospholipids and their fractions content violation in cellular and mitochondrial membranes.
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