Mamedova Liaman K, Shneyvays Vladimir, Katz Abram, Shainberg Asher
Gonda (Goldshmied) Medical Diagnostic Research Center, Faculty of Life Sciences, Bar-Ilan University, Ramat Gan, Israel.
Mol Cell Biochem. 2003 Aug;250(1-2):11-9. doi: 10.1023/a:1024980710799.
A model to study glycogen supercompensation (the significant increase in glycogen content above basal level) in primary rat skeletal muscle culture was established. Glycogen was completely depleted in differentiated myotubes by 2 h of electrical stimulation or exposure to hypoxia during incubation in medium devoid of glucose. Thereafter, cells were incubated in medium containing glucose, and glycogen supercompensation was clearly observed in treated myotubes after 72 h. Peak glycogen levels were obtained after 120 h, averaging 2.5 and 4 fold above control values in the stimulated- and hypoxia-treated cells, respectively. Glycogen synthase activity increased and phosphorylase activity decreased continuously during 120 h of recovery in the treated cells. Rates of 2-deoxyglucose uptake were significantly elevated in the treated cells at 96 and 120 h, averaging 1.4-2 fold above control values. Glycogenin content increased slightly in the treated cells after 48 h (1.2 fold vs. control) and then increased considerably, achieving peak values after 120 h (2 fold vs. control). The results demonstrate two phases of glycogen supercompensation: the first phase depends primarily on activation of glycogen synthase and inactivation of phosphorylase; the second phase includes increases in glucose uptake and glycogenin level.
建立了一个在原代大鼠骨骼肌培养物中研究糖原超补偿（糖原含量显著高于基础水平的增加）的模型。在不含葡萄糖的培养基中孵育期间，通过2小时的电刺激或暴露于缺氧环境，分化的肌管中的糖原完全耗尽。此后，将细胞在含葡萄糖的培养基中孵育，72小时后在处理过的肌管中明显观察到糖原超补偿。120小时后达到糖原峰值水平，在电刺激和缺氧处理的细胞中分别平均比对照值高2.5倍和4倍。在处理过的细胞恢复的120小时内，糖原合酶活性持续增加，磷酸化酶活性持续降低。在96小时和120小时时，处理过的细胞中2-脱氧葡萄糖摄取率显著升高，平均比对照值高1.4 - 2倍。处理过的细胞在48小时后糖原素含量略有增加（相对于对照为1.2倍），然后大幅增加，在120小时后达到峰值（相对于对照为2倍）。结果表明糖原超补偿有两个阶段：第一阶段主要取决于糖原合酶的激活和磷酸化酶的失活；第二阶段包括葡萄糖摄取和糖原素水平的增加。
