The importance of the creatine kinase reactionthe concept of metabolic capacitance
作者:
H. SWEENEY,
期刊:
Medicine and Science in Sports and Exercise
(OVID Available online 1994)
卷期:
Volume 26,
issue 1
页码: 30-36
ISSN:0195-9131
年代: 1994
出版商: OVID
关键词: CREATINE PHOSPHATE;CREATINE KINASE;MUSCLE ENERGETICS;MUSCLE METABOLISM;MITOCHONDRIA
数据来源: OVID
摘要:
The creatine kinase reaction is traditionally viewed as providing an energy reserve in muscle. However, the physiological importance of this reaction (and the analogous invertebrate reaction catalyzed by arginine kinase) is better understood when viewed as providing metabolic capacitance. This capacitance allows reduction of peak rates of ATP synthesis in cells that alternate between periods of high and low energy consumption. Furthermore, the capacitance allows repayment of energy “debt” that is incurred during periods of high energy demand to occur during periods of low rates of energy consumption. The creatine kinase reaction provides facilitated diffusion of ATP and ADP, which leads to spatial buffering in addition to temporal buffering. Data are presented which suggest that the existence of the creatine kinase reaction allows muscle cells to maintain reduced mitochondrial volume, support larger diameter fibers, and express faster isoforms of myosin. These data lead to speculation that there may be a coupling in the expression of metabolic and contractile proteins.
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