静脉输注胰淀素对大鼠胰岛激素分泌及血糖的影响

Effect of amylin on secretion of insulin and glucagon in SD rat

目的观察外源性胰淀素对高脂饲养的SD大鼠胰岛素分泌第一时相胰高血糖素和胰岛素分泌的影响。方法32只8周龄雄性SD大鼠随机分为常规饲养组(CC组)、高脂饲养组(CF组)、高脂饲养低剂量胰淀素组(AmyL组)、高脂饲养高剂量胰淀素组(AmyH组)。饲养28周后进行静脉葡萄糖耐量试验(IVGTT),分别于静脉注射葡萄糖后0、3、5、10min留取动脉血检测胰岛素及胰高血糖素水平,并同时测定血糖。AmyL组和AmyH组大鼠IVGTT前50min开始以410pmol.kg-1.min-1及610pmol.kg-1.min-1的速度泵入胰淀素溶液。结果AmyH组胰高血糖素水平显著低于CF组(P<0.01);AmyL组及AmyH组大鼠胰岛素水平均显著低于CF组(P<0.05,P<0.01);AmyL组及AmyH组血糖均高于CF组(P<0.05)。结论胰淀素在一定浓度范围可抑制胰高血糖素的异常分泌,但同时降低胰岛素分泌,且此作用强于抑制胰高血糖素的作用,造成血糖升高,提示胰淀素对血糖的影响可能与其对胰岛素及胰高血糖素分泌抑制之间的平衡有关。

Objective To observe the effect of amylin infusion on secretion of insulin and glueagon in first phase in SD rats. Methods Thirty two normal SD rats were randomly divided into 4 groups： normal group （group CC）, high-fat diet feeding group （group CF）, high fat diet feeding and low close amylin group （group AmyL） , high fat diet feeding and high dose amylin group（ group AmyH ）. Twenty eight weeks later, the intravenous glucose tolerance test（IVGTT） was conducted. Blood samples were collected at 0, 3, 5, 10 minutes after dextrose injection, and the levels of glucose, insulin and glucagon were measured. Fifty minutes before starting IVGTF, amylin was infused with pump at 410 pmol · kg^-1· min^-1 and 610 pmol · kg^-1 · min^-1 to rats in group AmyL and group AmyH respectively. Results Glueagon level in group AmyH was significant lower than that in group CF（P 〈0. 01 ）. Insulin levels in group AmyL and AmyH were lower than that in group CF（P 〈 0.05, P 〈 0.01 ）. Glucose level in group AmyL and group AmyH was higher than that in group CF（ P 〈 0.05）. Conclusion Amylin infusion inhibited the secrtion of glucagon, and it increased blood glucose due to the inhibition of insulin secretion. The effect of amylin on blood glucose may be dependent on the balance between the change of insulin secretion and glueagon secretion during amylin infusion.