不同时间脂肪乳输注对大鼠葡萄糖输注率的影响

目的观察不同时间脂肪乳输注使血浆游离脂肪酸（FFA）升高对大鼠葡萄糖输注率（GIR）的影响。方法分别给大鼠输注脂肪乳2、5、7和48 h,行高胰岛素-正血糖钳夹试验评价葡萄糖输注率,测定血浆葡萄糖、FFA。结果与生理盐水输注组比较,2 h脂肪乳输注使血浆FFA升高了2倍（P〈0.01）,GIR下降27%（P〈0.05）,脂肪乳输注5 h GIR降低了52%（P〈0.01）,7 h GIR降低56%（P〈0.01）,输注48 h脂肪乳GIR降低58%（P〈0.01）,5 h组7、h组及48 h脂肪乳输注组间GIR差异没有统计学意义。结论大鼠输注脂肪乳使FFA浓度达到基础值的3倍左右,可复制出脂毒性胰岛素抵抗的模型,而且胰岛素抵抗达到一定程度后保持恒定。

Effect of Intravenous Intralipid Infusion on Glucose Infusion Rate at Different Times in Rats

Objective To investigate the effect of intravenous intralipid infusion elevating the plasma free fatty acids （FFA） level at different times on glucose infusion rate in rats. Methods Intralipid ＋ heparin （IH） and saline （SAL） were intravenously infused for 2 h, 5 h, 7 h, and 48 h, respectively. Insulin sensitivity was assessed with glucose infusion rate （G/R） and determined by hyperinsulinemic-euglucemic clamp method. The levels of plasma glucose and FFA were measured. Results Compared with the SAL group, the plasma FFA level was elevated by 2 times （ P 〈 0.01 ） in group IH at 2 h, while GIR decreased 27% （ P 〈 0.05） at 2 h, decreased 52% at 5 h （ P 〈 0.01 ）, decreased 56% at 7 h （ P 〈 0.01 ）, and decreased 58 % at 48 h （ P 〈 0.01 ）, however there was no significant difference between the GIR values at 5 h, 7 h and 48 h. Conclusion A rat model of insulin resistance mediated by lipotoxicity has been successfully established by intravenous intralipid infusion, when the plasma FFA concentration reaches 3 times of the basic level and still maintaining such a high level for a longer time period.