CORRECTION OF SEPARATE LINKS OF SEROTONIN METABOLISM UNDER EXPERIMENTAL TYPE 2 DIABETES

Abstract

It was investigated the joint effect of nicotinamide, acetyl-L-carnitine and α-lipoic acid on the separate links of serotonin metabolism and NAD levels in the brain of rats  with experimental type 2 diabetes mellitus. The development of diabetes lead to insulin resistance, increased blood glucose and glycated haemoglobin levels at 1.8  and 2 times respectively. The content of NAD in brain of rats was decreased by 44% as compared to control. Diabetes evoked the decrease of tryptophan and serotonin  levels in the blood by  40% and 45%, and in the brain by 62% and 53% respectively. The joint administration of these compounds caused reduction of glucose  and glycated haemoglobin levels at 1.4 and 1.7 times respectively compared to rats under type 2 diabetes. Normalization of serotonin level in blood and its  increase in brain by 46%, elevation  of tryptophan content in blood and brain by 51% and 47% respectively compared to rats under type 2 diabetes were also established. Tryptophan hydroxylase activity in diabetic brain was increased by 20% and was partially decreased after the joint administration nicotinamide, acetyl-L- carnitine and α-lipoic acid. Thus, the joint administration of these compounds may be useful for correction of functional alterations of key links of serotonin  metabolism in brain under type 2 diabetes mellitus.