大鼠创伤性脑损伤后胰岛素抵抗与伤后高血糖的相关分析

目的 探讨大鼠创伤性脑损伤后血糖、血清胰岛素及胰岛素敏感性的变化规律,验证机体是否发生胰岛素抵抗现象.方法 采用大鼠自由落体脑损伤模型(Feeney's model),分别在伤前1/2 h及伤后6、12、24、48、72、120 h测定轻、中、重型脑损伤动物的血糖和血清胰岛素值.运用正常血糖-高血胰岛素钳夹技术,检测大鼠重型创伤性脑损伤6、24、48、72 h后BG60-120、GIR60-120、胰岛素敏感性指数(ISI)等3个反映胰岛素敏感性的指标.结果 中、重型创伤性脑损伤后大鼠血糖含量升高的同时血清胰岛素水平升高,大鼠重型创伤性脑损伤6、24、48、72 h后BG60-120显著地升高,GIR60-120、ISI显著地降低.重型脑损伤组大鼠伤后血糖与相应时间段血清胰岛素值呈现正相关,与相应时间段BG60-120呈现正相关,与相应时间段GIR60-120、ISI呈现负相关.结论 在重型创伤性脑损伤急性期,大鼠血糖和血清胰岛素水平均显著地升高,高水平的胰岛素未能起到相应的降低血糖的作用,机体产生胰岛素抵抗现象.

Correlation analysis of increased blood glucose and insulin resistance after traumatic brain injury in rats

Objective To study the pattern of the alterations of blood glucose,insulin and insulin sensitivity after traumatic brain injury in rats,and verify the occurrence of insulin resistance after the injury.Methods Based on Feeney's model of brain injury,the blood glucose and insulin concentration of the dogs measured 30 min before and at 6,12,24,48,72 and 120 h after injury.BG60-120,GIR60-120,and insulin sensitivity index(ISI)reflecting the insulin sensitivity were measured at 6,24,48,and 72 hours following severe traumatic brain injury using euglycemic-hyperinsulinemic clamp.Results Both the blood glucose and insulin concentration increased markedly in rats following moderate and severe brain injury.BG60-120 increased markedly,and GIR60-120 and ISI decreased significantly 6,24,48,and 72 h after severe brain trauma as compared with those of the sham operation group.Blood glucose concentration of rats following severe injury was positively correlated with insulin concentration and BG60-120 at the corresponding time points,but negatively with GIR60-120 and ISI.Conclusion Both the blood glucose and insulin concentration increase markedly in rats following severe brain injury.Increased blood glucose even in the presence of high-level insulin is due to acute insulin resistance occurring after traumatic brain injury.