Effects of electrical stimulation as a new method of treating diabetes on animal models: Review

Abstract

Diabetes is a group of metabolic diseases characterized by hyperglycemia resulting from defects in insulin secretion, insulin action, or both. It is proven that electrical stimulation could accelerate wound or fracture healing and also decreases pain. Because of numerous benefits on cell function, it is assumed that electrical stimulation can have positive effect on diabetes. Aim of this article is to summarize results of different studies which analyzed effect of electrical stimulation on most important parameters of diabetes mellitus in animal models. Unilateral electrical stimulation of dorsal motor nucleus of the vagus nerve resulted in rapid rise in plasma insulin levels >200%, and stimulation of the nucleus tractus solitarius, also produced 50% increase in insulinemia, in Wistar rats. Mild electrical stimulation (MES) combined with heath shock treatment (HS), significantly decreased fasting blood glucose and insulin levels, and improved insulin sensitivity in C57BL/6J, db/db mice as well as in KKAy mice. Peripheral electrical stimulation (PES) increased hepatic glucose output during the basal state in insulin-resistant Wistar-Han rats. PES improved tissue sensitivity to insulin, improved suppression of hepatic glucose production, and significantly elevated rate of glycogenesis compared with controls. Hepatic electrical stimulation was effective in reducing blood glucose by 27-31%, in Sprague-Dawley rats, streptozocin induced diabetic rats and Fa/Fa diabetic fatty rats. The present studies indicate that electrical stimulation treatment of very short duration is very potent to stimulate glucose uptake and improve insulin sensitivity. Electrical stimulation may directly affect major insulin target tissues or leading to secondary effects in other tissues. Low intensity current showed no observable adverse effects, but electrical conductance in cells should be measured. Electrical stimulation has very positive impact on diabetes in animal models, so it should be subject of further examinations for human use.