TNFα对正常昆明小鼠骨骼肌和肝脏葡萄糖摄取的影响

The Effects of TNFα on Glucose-uptake by the Skeletal Muscles and Liver with or without Insulin-Stimulation in Mice

目的观察肿瘤坏死因子α(TNFα)对正常昆明小鼠骨骼肌和肝脏葡萄糖摄取的影响。方法80只昆明小鼠随机分为高剂量连续注射组(TH组,n=20)、TNFα低剂量连续注射组(TL组,n=20)、TNFα高剂量一次注射组(T1组,n=20)和正常对照组(C组,n=20),以3H标记的2脱氧葡萄糖(2-DG)为示踪剂,观察各组非胰岛素刺激(基础)和胰岛素刺激的离体骨骼肌和肝脏葡萄糖摄取量的变化。结果1)正常昆明小鼠肝脏基础葡萄糖摄取量明显高于骨骼肌葡萄糖摄取量(P<0.01),肝脏胰岛素刺激的葡萄糖摄取量变化值明显低于骨骼肌葡萄糖摄取量变化值(P<0.01)。2)TH组和TL组骨骼肌和肝脏基础葡萄糖摄取量均明显高于C组(P<0.01),且TH组明显高于TL组(P<0.01)。3)TH组和TL组骨骼肌和肝脏胰岛素刺激的葡萄糖摄取量均明显低于C组(P<0.01),且TH组明显低于TL组(P<0.01)。4)T1组骨骼肌和肝脏无论基础还是胰岛素刺激的葡萄糖摄取量均与C组差异无显著性(P>0.05)。结论1)正常动物肝脏和骨骼肌葡萄糖摄取方式不同,骨骼肌葡萄糖摄取受胰岛素调控比肝脏强。2)TNFα抑制组织胰岛素刺激的葡萄糖摄取,但促进组织基础葡萄糖摄取。3)TNFα对组织葡萄糖摄取的影响,呈剂量和时间依赖性。

Objective To study the effects of TNFa on glucose uptake by skeletal muscles and liver with or without insulin stimulation in mice .Methods 80 Kunming mice were randomly divided into 4 groups： the TH group （TNFa high dose group, n = 20）, the TL group （TNFa low-dose group, n = 20）, the T1 group （High dose of TNFa, but administered only once, n = 20） and the C group （control group, n = 20）. The levels of glucose uptake by muscles and liver with or without insulin stimulation in all groups were assayed by 3 H-2-DG labeling. Results 1 ） The level of glucose uptake by liver without insulin stimulation was significantly higher than that of muscles in control mice （ P 〈 0.01 ）, but the changes of glucose uptake by liver stimulated by insulin were significantly lower than that by muscles in control mice （ P 〈 0.01 ）. 2） The levels of glucose uptake by muscles and liver without insulin stimulation in TH and TL groups were significantly higher than that in C group （P 〈 0.01 ）, and the level of TH group was significantly higher than that of TL group （ P 〈 0.01 ）. 3） The levels of glucose uptake by muscles and liver with insulin stimulation in TH and TL groups were significantly lower than that in C group （ P 〈 0.01 ） ,and the level of TH group was significantly lower than that of TL group （ P 〈 0.01 ）. 4） There was no significant difference of glucose uptake by muscles and liver with or without insulin stimulation between the T1 and C groups （ P 〉 0.05）. Conclusion 1 ） In normal mice, the glucose uptake by liver is differently controlled from that of muscles. The glucose uptake by muscles is more strongly controlled by insulin stimulation than that by liver. 2） TNFα can suppress the glucose uptake by muscles and liver with insulin stimulation, but enhance the tissue basic glucose uptake. 3） The effects of TNFct on glucose uptake by muscles and liver act in a dose- and time-dependent manner.