GK糖尿病大鼠生物学特性观察

目的了解2型糖尿病模型GK大鼠生长曲线、主要脏器重量、糖代谢等生物学特性，评价GK大鼠葡萄糖刺激的胰岛素分泌能力。方法采用51只雄性GK大鼠及15只年龄性别匹配的Wistar大鼠作为研究对象。测定13周龄GK、Wistar大鼠空腹血糖、23周龄GK大鼠空腹及随机血糖。随访GK及Wistar大鼠生长曲线，34～46周龄期间血糖、糖化血红蛋白。46周龄时行腹腔葡萄糖耐量实验（IPGTT），计算相关参数评价β细胞葡萄糖刺激的胰岛素分泌能力；之后处死大鼠，脏器称重。比较GK及Wistar大鼠间上述各指标差异。结果13周龄GK大鼠空腹血糖4．74±0．41mmol／L，对照Wistar大鼠1．85±0．44mmol／L（P〈0．001）。23周龄GK大鼠空腹血糖7．88±1．96mmol／L，随机血糖9．91±3．52～13．46±4．13mmol／L。7～20及34～45周龄期间GK大鼠体重高于对照Wistar大鼠（P〈0．05），46周龄时无显著性差异。34～45周龄期间GK大鼠空腹血糖、进食后血糖、HbAlc均高于对照Wistar大鼠（P〈0．05）。IPGTT曲线下面积分析示GK大鼠胰岛素曲线下面积（AUCi）、葡萄糖曲线下面积（AUCg）高于对照Wistar大鼠，胰岛素与葡萄糖曲线下面积比值（AUCi／AUCg）低于对照Wistar大鼠，差异均有显著性（P〈0．05）。GK大鼠肾脏重量高于对照Wistar大鼠（P〈0．05），余主要脏器重量差异无显著性。结论GK大鼠空腹血糖、进食后血糖、HbAlc水平升高，葡萄糖刺激的胰岛素分泌能力（GSIS）减退，葡萄糖刺激后胰岛素分泌早期相消失，晚期相代偿性增加，具有2型糖尿病特点；体重、血糖等生物学特性稳定。

Observation of Biological Characteristics of GK Rat --a New Model of Type 2 Diabetes

Objective This study was aimed to obtain a profile knowledge of biological characteristics of GK rat including growth curve, weight of major organs, and glucose metabolism status. Glucose stimulated insulin secretion ability of GK rat was also evaluated. Methods Fifty one male GK rats and fifteen age- and sex-matched Wistar rats were studied. Fasting blood glucose was measured when GK and Wistar rats were 13-week old. Fasting and random blood glucose levels of 23-week old GK rats were determined. The growth curves were followed up, and fasting and postprandial blood glucose and glycosylated haemoglobin Alc levels were also followed up from 34-week old onto 45-week old. An intraperitoneal glucose tolerance test （IPGTT） was performed when the rats were 46-week old. Areas under the curves were analyzed to assess the glucose stimulated insulin secretion ability. Weight of main major organs was recorded after the rats were sacrificed. The differences of those parameters between GK and Wistar rats were compared. Results Fasting blood glucose of 13-week old GK rats was 4.74 ± 0.41 mmol/L （ mean ± S. D. ）, and that of Wistar rats was 1.85 ± 0.44 mmol/L （ P 〈 0.001 ） . Fasting blood glucose of 23-week old GK rats was 7.88 ± 1.96 mmol/L,and random blood glucose levels were within a range of 9.91 ± 3.52 mmol/L to 13.46 ± 4.13 mmol/ L. The body weights of GK rats were heavier than age- and sex-matched Wistar rats from 7 - 20 and 34 - 45-week old （ P 〈 0.05） ,but were s3imilar at the age of 46-week, During the follow-up period from 34-week old to 45-week old, GK rats had significantly higher levels of blood glucose （both fasting and postprandial） and HbAlc than those in control Wistar rats. Blood glucose levels of GK rats on 0, 15,30,60,120, 180 minutes after glucose load, respectively, during IPGTT test were significantly higher than those of control Wistar rats. The areas under the curves of serum insulin levels （AUCi） and blood glucose levels （AUCg） were significantly higher in GK rats