壳聚糖胰岛素微球在糖尿病大鼠中的降糖作用研究

Hypoglycemic Effect of Chitosan-microcapsulated Insulin on the Blood Glucose Level of Streptozotocin-diabetic Wistar Rats

我们观察了壳聚糖为载体的胰岛素微球的口服制剂对链脲菌素致糖尿病大鼠的降血糖作用。用扫描电镜观察正常大鼠管饲壳聚糖胰岛素微球后 1、2、3、7d微球在大鼠体内的分布。 18只链脲佐菌素致糖尿病大鼠被随机分成 3组 :壳聚糖胰岛素微球管饲组 (12 0 U/kg,n=6 ) ;诺和灵中效胰岛素皮下注射组 (2 4U/kg,n=6 ) ,空白对照组 (管饲等容积的蒸馏水 ,n=6 )。另有 5只正常大鼠作为正常对照组 (管饲等容积的蒸馏水 ,n=5 )。分别测定 4组大鼠用药前后的血糖值 ,并做组间分析比较。结果表明 :(1)壳聚糖胰岛素微球能通过大鼠的小肠吸收 ,并靶向分布于小肠、肝、脾等器官。 (2 )壳聚糖胰岛素微球管饲组在管饲微球后第 1天 ,糖尿病大鼠的血糖从 2 4.7± 3.2mm ol/L 下降至 16 .9± 5 .5 mm ol/L,第 2天降至最低 12 .1± 5 .7m mol/L,第 3天开始逐渐回升至用药前水平 ,血糖最大下降幅度为 5 0 .2 %。诺和灵中效胰岛素皮下注射组注射胰岛素后 ,糖尿病大鼠的血糖从 2 5 .2± 3.8m mol/L下降至 10 .4± 5 .2 mm ol/L,第 2天开始逐渐回升至用药前水平 ,血糖最大下降幅度为 5 8.7%。两组下降幅度比较无统计学差异 (P>0 .0 5 )。而空白对照组和正常对照组大鼠的血糖无明显变化 ,但它们分别和前两组比较 ,具有统计学差异

This study was conducted to observe the hypoglycemic effect of chitosan-microcapsulated insulin (insulin-microspheres) on blood glucose (BG), in diabetic rats by gavage. Using the scanning electron microscope, we observed the shape and distribution of insulin-microspheres in the tissues of liver, spleen, and small intestine of normal rats after gavage. The following groups of rats were studied; normal control rats (NC, n=5); streptozotocin (STZ)-inducing diabetic control rats(DC, n=6); STZ-diabetic rats treated with insulin-microsphere [120u/kg] by gavage (DF, n=6); STZ-diabetic rats treated with subcutaneous insulin injection [24u NPH/kg] (DT, n=6). Blood glucose was measured at 0 [similar to] 7 days after the treatments. The insulin-microspheres was found in small intestine, liver and spleen at 1,2,3 and 7 days. In DF group, the average blood glucose level decreased significantly from 24.7±3. 2mmol/L to 16.9±5. 5mmol/L during the first day of treatment and reached the lowest level (12.1±5.7mmol/L) on the second day. From the third day on, the BG gradually elevated to the level before treatment; the maximum decrease of blood glucose level was 50.2%. In DT group, the average blood glucose level decreased from 25.2±3.8mmol/L to 10.4±5.2mmol/L during the first day of treatment and then went up gradually from the 2nd day on; the maximum decrease of glucose level was 58.7%. No significant difference was seen in maximum decrease between the two groups. These data demonstrate that oral chitosan-microcapsulated insulin has the antihyperglycemic effect on the blood glucose level of streptozotocin-diabetic rats.