Stearns S B, Tepperman H M, Tepperman J
J Lipid Res. 1979 Jul;20(5):654-62.
Several aspects of lipid metabolism in the soleus and diaphragm muscles of streptozotocin-diabetic and control rats were investigated. The triglyceride content of both muscles was elevated in the diabetic state and the presence of increased intracellular lipid was confirmed by electron microscopy. In vitro glucose and palmitate oxidation studies showed that both types of muscle from the diabetic animals metabolized more fat than did the soleus and diaphragm from control rats. While isoproterenol alone produced a significant lipolytic response in both the soleus and diaphragm from control and diabetic animals, there was no difference in the percent increase in fatty acids released from muscles of diabetic rats compared to controls. However, the absolute difference was greater when the diaphragms were compared. Muscles from experimental and control animals showed a marked reduction in the amount of free fatty acids released in response to insulin. In addition, in the presence of the hormone, both the absolute and percent isoproterenol-stimulated increases in fatty acids were significantly greater for both diaphragm and soleus muscles from diabetic rats. The effects of insulin, isoproterenol, and the combination of these two hormones on the amount of glycerol released into the incubation medium were similar to those found on free fatty acid release. The results of these experiments show that there is an apparent increase in fat utilization in skeletal muscle of diabetic rats. Furthermore, measurements of triglyceride concentration and the enhanced response to isoproterenol stimulation in the muscles from these animals suggests that they may have an increased capacity for mobilization of intracellular lipids. Finally, in the diabetic state, both the soleus and diaphragm appear to demonstrate an increased response to the antilipolytic effect of insulin as measured by the decreased amount of fatty acid released into the incubation medium, the percent change also being significant for the soleus muscle.-Stearns, S. B., H. M. Tepperman, and J. Tepperman. Studies on the utilization and mobilization of lipid in skeletal muscles from streptozotocin-diabetic and control rats.
研究了链脲佐菌素诱导的糖尿病大鼠和对照大鼠比目鱼肌与膈肌脂质代谢的几个方面。糖尿病状态下，两种肌肉的甘油三酯含量均升高，并且通过电子显微镜证实细胞内脂质增加。体外葡萄糖和棕榈酸氧化研究表明，糖尿病动物的这两种类型的肌肉比对照大鼠的比目鱼肌和膈肌代谢更多的脂肪。虽然单独使用异丙肾上腺素在对照和糖尿病动物的比目鱼肌和膈肌中均产生显著的脂解反应，但与对照相比，糖尿病大鼠肌肉释放的脂肪酸增加百分比没有差异。然而，当比较膈肌时，绝对差异更大。实验动物和对照动物的肌肉对胰岛素刺激释放的游离脂肪酸量均显著减少。此外，在激素存在的情况下，糖尿病大鼠的膈肌和比目鱼肌对异丙肾上腺素刺激的脂肪酸增加的绝对值和百分比均显著更高。胰岛素、异丙肾上腺素以及这两种激素的组合对释放到孵育培养基中的甘油量的影响与游离脂肪酸释放的影响相似。这些实验结果表明，糖尿病大鼠骨骼肌中的脂肪利用率明显增加。此外，这些动物肌肉中甘油三酯浓度的测量以及对异丙肾上腺素刺激的增强反应表明，它们动员细胞内脂质的能力可能增强。最后，在糖尿病状态下，通过释放到孵育培养基中的脂肪酸量减少来衡量，比目鱼肌和膈肌似乎对胰岛素的抗脂解作用反应增强，比目鱼肌的百分比变化也很显著。——斯特恩斯，S. B.，H. M. 特珀曼，和 J. 特珀曼。链脲佐菌素诱导的糖尿病大鼠和对照大鼠骨骼肌中脂质利用与动员的研究
