奥曲肽对链脲佐菌素诱发糖尿病大鼠胰岛功能的影响

Effect of Octreotide on the Pancreatic Islet Function in Diabetic Rats Induced by Streptozotocin

目的探讨奥曲肽对糖尿病大鼠胰岛功能的影响。方法选用雄性SD大鼠32只,腹腔注射链脲佐菌素(STZ)建立糖尿病大鼠模型。分4组(每组8只),分别予奥曲肽(DA组)、胰岛素(DI组)、奥曲肽加胰岛素(DAI组)、生理盐水(DC组)治疗4周。另8只同龄SD大鼠一次性腹腔注射相应剂量的柠檬酸钠缓冲液,作为正常对照(NC)组。分别测定治疗前后空腹及糖耐量2 h血糖、血浆胰高血糖素、胰岛素和C肽。结果治疗前,糖尿病各组血浆胰高血糖素较NC组显著升高、血浆胰岛素和C肽显著降低(均P<0.001)。治疗后,DA组和DAI组的2 h血糖均较治疗前显著下降(P<0.01或<0.001);DAI组的2 h血糖均比DA组和DI组明显降低(均P<0.05)。DA组和DAI组的空腹及2 h血浆胰高血糖素均较治疗前明显下降(P<0.05或<0.01)。DA组的空腹及2 h血浆C肽明显高于DC组(P<0.001或<0.05)。胰岛素结果类似于C肽。结论奥曲肽可降低STZ诱导的糖尿病大鼠的餐后高血糖和高胰高血糖素水平,改善胰岛A细胞功能;并可使"B细胞休息",保护胰岛B细胞。

Objective To investigate the effect of octreotide on the pancreatic islet function in diabetic rats. Methods There were 40 male Sparagne-Dawley （SD） rats altogether. Thirty-two rats were turned into diabetic rats by being injecting intraperitoneally streptozotocin （STZ）, and then were divided into four groups（ 8 ones in each group） ： treated by octreotide （group DA）, insulin （group DI ）, octreotide and insulin（group DAI） and physiological saline（group DC）. Other 8 healthy SD rats were injected intraperitoneally sodium citrate buffer as the control group （group NC ）. Plasma concentration of blood glu- cose, glucagon, insulin and C-peptide were measured at fasting and 2 hours after oral glucose tolerance test respectively before and 4 weeks after the treatment. Results Compared with group NC, before the treatment blood glucose and glucogan in the 4 groups of diabetic rats increased significantly, while insulin and C-peptide decreased significantly（ all P 〈0. 001 ）. After treatment, 2 h-blood glucose （2 h BG） of group DA and group DAI decreased significantly compared with that before treatment （ P 〈 0.01 or 〈 0.001 ） ; 2 h BG of group DAI decreased compared with that in the group DA and group DI （ both P 〈 0.05 ） ; Fast- ing glucagon and 2 h-gulcagon in the group DA and group DAI decreased significantly （P 〈 0.05 or 〈 0.01 ） ; Fasting C-peptide and 2h-C-peptide of group DA increased significantly than those in the group DC （P 〈 0. 001 or 〈 0.05 ）. The results of insulin were similar to C-peptide. Conclusion Octreotide can decrease the high postprandial level of blood glucose and glucagon the diabetic rats induced by STZ. The reason is probably that Octreotide can improve the function of A cells in the islet and thus protect the function of B cells in the islet by inducing ＂B cell rest＂.