Ohira Y, Ishine S, Tabata I, Kurata H, Wakatsuki T, Sugawara S, Yasui W, Tanaka H, Kuroda Y
Department of Physiology and Biomechanics, National Institute of Fitness and Sports, Kanoya, Japan.
Jpn J Physiol. 1994;44(4):391-402. doi: 10.2170/jjphysiol.44.391.
The effects of high-energy phosphate contents in muscles on glucose tolerance and glucose uptake into tissues were studied in rats and mice. Enhanced glucose tolerance associated with depleted high-energy phosphates and elevated glycogen content in muscles and liver was observed in animals fed creatine analogue beta-guanidinopropionic acid (beta-GPA). Distribution of infused 2-[1-14C]deoxy-D-glucose in tissues especially in the soleus muscle, kidney, and brain was greater in mice fed beta-GPA than controls. The glucose uptake was decreased when the contents of ATP and glycogen were normalized following creatine supplementation. Plasma insulin in animals at rest was lower and its concentration after intraperitoneal glucose infusion tended to be less in animals fed beta-GPA than controls (p > 0.05), although the pattern of insulin response to glucose loading was similar to the control. The daily voluntary activity in beta-GPA fed mice was also less than controls. These results suggest that improved glucose tolerance is not related to elevated insulin concentration and/or decreased glycogen following exercise. Such improvement may be due to an increased mitochondrial energy metabolism caused by depletion of high-energy phosphates.
在大鼠和小鼠中研究了肌肉中高能磷酸盐含量对葡萄糖耐量及组织摄取葡萄糖的影响。在喂食肌酸类似物β-胍基丙酸（β-GPA）的动物中，观察到葡萄糖耐量增强，同时肌肉和肝脏中的高能磷酸盐耗竭，糖原含量升高。喂食β-GPA的小鼠组织中，尤其是比目鱼肌、肾脏和大脑中注入的2-[1-14C]脱氧-D-葡萄糖的分布比对照组更大。补充肌酸后，当ATP和糖原含量恢复正常时，葡萄糖摄取减少。喂食β-GPA的动物静息时血浆胰岛素水平较低，腹腔注射葡萄糖后其浓度趋于低于对照组（p>0.05），尽管胰岛素对葡萄糖负荷的反应模式与对照组相似。喂食β-GPA的小鼠每日自主活动量也低于对照组。这些结果表明，葡萄糖耐量的改善与运动后胰岛素浓度升高和/或糖原减少无关。这种改善可能是由于高能磷酸盐耗竭导致线粒体能量代谢增加所致。
