西格列汀对db/db糖尿病小鼠坐骨神经传导速度的影响

Effects of Sitagliptin on Motor Nerve Conduction Velocity of Sciatic Nerve in db/db Mice

目的探讨西格列汀对db/db糖尿病小鼠坐骨神经传导速度的影响。方法将60只12周龄的db/db小鼠随机分为3组:西格列汀组、二甲双胍组、db/db组,各20只,分别给予8周西格列汀、二甲双胍、安慰剂灌胃治疗。另选取20只同周龄、同窝出生的db/m非糖尿病小鼠(对照组)。治疗8周后行腹腔葡萄糖耐量试验(IPGTT),治疗前后分别测定4组小鼠的坐骨神经传导速度。结果与db/db组比较,西格列汀和二甲双胍组治疗8周后空腹血糖显著下降(P<0.05),而西格列汀组与二甲双胍组比较差异无统计学意义(P>0.05)。糖负荷120 min后西格列汀和二甲双胍组小鼠葡萄糖曲线下面积和胰岛素曲线下面积均显著低于db/db组(P<0.05),但两组间差异无统计学意义(P>0.05)。西格列汀组小鼠治疗后坐骨神经传导速度显著高于db/db组和二甲双胍组(P<0.05),而二甲双胍组与db/db组比较差异无统计学意义(P>0.05)。结论西格列汀降低血糖的同时能提高坐骨神经传导速度,其作用独立于降糖作用。

Objective To investigate the effects of sitagliptin on motor nerve conduction velocity（MNCV） of sciatic nerve in db/db mice.Methods Sixty db/db mice of 12-week-old were randomized into three groups（20 each） and were administered with sitagliptin 10 mg·kg-1·d-1,metformin 150 mg·kg-1·d-1,or placebo.Another 20 age-matched nondiabetic littermates db/m mice were treated with placebo and defined as the control group.Intraperitoneal glucose tolerance test（IPGTT） was carried out after 8 weeks of treatment.Motor nerve conduction velocity of sciatic nerve was determined both before and after the treatment.Results After 8 weeks of treatment,levels of fasting plasma glucose significantly decreased in the sitagliptin and the metformin group compared with the db/db control group（P0.05）,with no significant differences between the first two groups（P0.05）.Area under the curve for both glucose and insulin 120 minutes after glucose load were lower in the sitagliptin and the metformin group compared with the db/db control group（P0.05）,with no significant differences between the first two groups（P0.05）.The liptin group showed a higher MNCV than both db/db and metformin groups（P0.05）,whereas no significant difference were found between the db/db control and the metformin groups（P0.05）.Conclusion Sitagliptin might be able to improve MNCV effectively in db/db mice,which was independent of the concurrent glucose lowering effect.