Chronic stimulation of mammalian muscle: changes in metabolite concentrations in individual fibers.
Chronic stimulation of mammalian muscle: changes in metabolite concentrations in individual fibers.
复制标题
哺乳动物肌肉的慢性刺激：单个纤维中代谢物浓度的变化。
DOI：
10.1152/ajpcell.1988.255.4.c543
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发表时间：
1988
期刊：
影响因子：
--
通讯作者：
Lowry,OH
中科院分区：
文献类型：
--
作者：
Henriksson,J;Salmons,S;Chi,MY;Hintz,CS;Lowry,OH
Single fibers were analyzed from rabbit fast-twitch tibialis anterior muscles freeze-clamped during continuous stimulation at 10 Hz for up to 8 wk. ATP declined after 1 wk to a stable level approximately 30% below controls. Phosphocreatine decreased earlier and to a greater extent (approximately 50%). Glycogen varied considerably among stimulated fibers and decreased on average approximately 75% by 8 wk. Glucose, lactate, citrate, and malate had changed little in the first 30 h and then increased four-, two-, four-, and sevenfold, respectively, over the next 5 wk. Glucose 6-phosphate showed the most unexpected behavior: with an overall upward trend, it descended to extremely low values (10% of control) after approximately 1 wk of stimulation. As long as high- and low-oxidative fibers were present, the former showed slightly higher levels of ATP, lactate, and malate; other metabolites did not differ in a consistent way. These unexpected observations, which differ strikingly from data for acute stimulation, shed light on adaptations that enable a chronically stimulated muscle to sustain a continuous high level of ATP utilization.
