Improvement in glucose tolerance as a result of enhanced insulin sensitivity during electroacupuncture in spontaneously diabetic Goto-Kakizaki rats

We studied whether electroacupuncture (EA) applied on the abdomen improved glucose tolerance in the Goto-Kakizaki (GK) rat, a genetic model of type 2 diabetes mellitus. Male GK rats and nondiabetic Wistar rats were studied under pentobarbital anesthesia. Blood samples were drawn from the ventral tail artery during the fasting stage and after a glucose load (0.5 g/kg). Electroacupuncture (15 Hz, 10 mA) was performed for 90 minutes during both the fasting and intravenous glucose tolerance test (IVGTT) periods. A hyperinsulinemic euglycemic clamp was also carried out to assess glucose uptake during EA. A significant decrease in fasting blood glucose and an increase in plasma insulin levels were observed during the fasting period in GK rats treated with EA. Blood glucose levels after glucose load were also significantly lower in GK rats treated with EA compared with controls. The homeostasis model assessment index during IVGTT indicated an improvement in insulin sensitivity in GK rats treated with EA, whereas glucose infusion rate during hyperinsulinemic clamp was increased significantly during EA. The present study demonstrated that EA improved hyperglycemia in the fasting stage with a marked increase in plasma insulin levels. Electroacupuncture also restored impaired glucose tolerance during an IVGTT in GK rats by enhancing insulin sensitivity.