The Effect of Rosiglitazone on Gluose Metabolism and Insulin Sensitivity in Non Obese Type 2 Diabetic Rat Models

Abstract

Background: In Korea, most of type 2 diabetic patients are non obese. We made non obese type 2 diabetic rat models, which were characterized by insulin resistance and insulin secretion defect. Our study aimed to investigate the effect of rosiglitazone on glucose metabolism and insulin sensitivity in non obese type 2 diabetic rat models. Furthermore, we may estimate the effect of rosiglitazone treatment in non obese type 2 diabetic patients in Korea. Methods: 20 male newborn (12 hours old) Sprague-Dawley rats were made diabetes by streptozotocin (75 mg/kg, intraperitoneal injection). At 16 weeks old, diabetes were confirmed by intraperitoneal glucose tolerance test (IPGTT, 30% D/W, 2 kg/kg). After that, diabetic groups were divided into two groups. One group was fed on normal chow and rosiglitazone (3 mg/kg/day) and the other group was fed on normal chow for eight weeks. At the age of 24 weeks, we measured body weight (BW), plasma glucose, insulin, C-peptide levels. And we performed IPGTT and insulin tolerance test (ITT) in two groups. Thereafter, we determined the insulin content of pancreas and epididymal fat weight. Results: Body weight was significantly higher in rosiglitazone group than control group. On IPGTT, plasma glucose, insulin and C-peptide levels were not significantly different between two groups. But, on insulin tolerance test, Kitt (%/min) values of rosiglitazone group were significantly higher than control group (2.7 vs. 1.8). The insulin content of pancreas and epididymal fat weight was not different between two groups. Conclusion: These results suggested that rosiglitazone improved insulin sensitivity in non obese type 2 diabetes rat models independent of glucose level. (J Kor Diabetes Assoc 31:319~325, 2007)