Ma J, Ma Z, Wang J, Milne R W, Xu D, Davey A K, Evans A M
Sansom Institute, School of Pharmacy and Medical Science, University of South Australia, Adelaide, Australia.
Diabetes Obes Metab. 2007 Jul;9(4):597-9. doi: 10.1111/j.1463-1326.2006.00630.x.
The aim of this study was to test the effect of isosteviol on blood glucose and insulin levels during the intravenous glucose tolerance test (IVGTT) in Wistar and Zucker diabetic fatty (ZDF) rats.
ZDF rats were divided into a control and three isosteviol treatment (1, 5 and 10 mg/kg) groups. Wistar rats were divided into a control group and an isosteviol treatment group (10 mg/kg). The rats were fasted for 12 h prior to infusion of isosteviol and glucose (1.0 g/kg). Blood samples were taken at 0, 5, 15, 30, 60, 90 and 120 min after the injection of glucose. Glucose concentrations were determined by the glucose oxidase method, and plasma insulin was analysed by radioimmunoassay. The area under the curve (AUC) of the net change in plasma glucose concentration was used to compare the isosteviol treatment and control groups.
In ZDF rats, isosteviol at 5 and 10 mg/kg caused a significant (p < 0.05) reduction in the AUC of glucose during the IVGTT. However, isosteviol did not increase plasma insulin concentrations in ZDF rats. In Wistar rats, isosteviol did not significantly affect plasma glucose or insulin levels during the IVGTT.
Isosteviol exerts an antihyperglycaemic effect during IVGTT in ZDF rats but not in Wistar rats. Isosteviol has no significant effect on plasma insulin concentrations. The glucose-lowering effect of isosteviol may be due to changes in the sensitivity of peripheral tissues to insulin.
本研究旨在检测异甜菊醇对Wistar大鼠和Zucker糖尿病肥胖（ZDF）大鼠静脉葡萄糖耐量试验（IVGTT）期间血糖和胰岛素水平的影响。
将ZDF大鼠分为对照组和三个异甜菊醇治疗组（1、5和10mg/kg）。将Wistar大鼠分为对照组和异甜菊醇治疗组（10mg/kg）。在输注异甜菊醇和葡萄糖（1.0g/kg）之前，大鼠禁食12小时。在注射葡萄糖后的0、5、15、30、60、90和120分钟采集血样。采用葡萄糖氧化酶法测定葡萄糖浓度，采用放射免疫分析法分析血浆胰岛素。用血浆葡萄糖浓度净变化的曲线下面积（AUC）比较异甜菊醇治疗组和对照组。
在ZDF大鼠中，5和10mg/kg的异甜菊醇在IVGTT期间使葡萄糖的AUC显著降低（p<0.05）。然而，异甜菊醇并未增加ZDF大鼠的血浆胰岛素浓度。在Wistar大鼠中，异甜菊醇在IVGTT期间对血浆葡萄糖或胰岛素水平无显著影响。
异甜菊醇在ZDF大鼠的IVGTT期间发挥降糖作用，但在Wistar大鼠中未发挥此作用。异甜菊醇对血浆胰岛素浓度无显著影响。异甜菊醇的降糖作用可能归因于外周组织对胰岛素敏感性的变化。
