The role of nicotinamide in the correction of renal function in diabetic nephropathy
Hyperglycemia of diabetes mellitus leads to the activation of the polyol way of oxidation of glucose with the activation of the enzymes of aldose reductase and sorbitol dehydrogenase and of their coenzymes NADPH and NAD, which triggers the mechanism of formation of sorbitol. The consequences of these changes lead to microangiopathy of the tissues of the kidneys, which may be one of the pathogenetic mechanisms of diabetic nephropathy. In an accessible literature, the role of coenzymes of sorbitol pathway in the development of diabetic nephropathy is not sufficiently defined. The purpose of the study was to study the content of NAD and NADPH coenzymes, their correlation, and their role in the mechanism of kidney damage in diabetes mellitus and to predict the possible correction of these changes with the NAD-nicotinamide derivative. The study was conducted on a model of streptotrozectinic diabetes mellitus (single administration of streptozotocin in a dose of 60 mg per 1 kg of body weight). Four weeks after induction of diabetes, nicotinamide (100 mg per 1 kg body weight) was injected. The level of glucose was determined by the Accu-chek (Roshe Diagnostics, Switzerland) glucose meter. The content of NAD and NADH was determined in the non-protein extracts. The statistical analysis was carried out using the Microsoft Excel statistical analysis program. The difference between the indicators was considered statistically significant (p<0.05). The NAD level was reduced by 31%, the NAD/NADN ratio was 32%. The dependence of the ratio of NADP/NADPN in conditions of hyperglycemia of diabetes mellitus with clinical manifestations of diabetic nephropathy is determined. A decrease in the ratio of NADP/NADPN to 38% in the rat kidney in the cortical layer was detected. The introduction of nicotinamide normalized the reduced content of NAD diabetic rats. These results provide perspectives for further research in which nicotinamide can be used as a renal protector.