Metabolite changes in individual rat muscle fibers during stimulation.
Metabolite changes in individual rat muscle fibers during stimulation.
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刺激过程中大鼠肌纤维的代谢变化。
DOI：
10.1152/ajpcell.1982.242.3.c218
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发表时间：
1982
期刊：
影响因子：
--
通讯作者：
Lowry,OH
中科院分区：
文献类型：
--
作者：
Hintz,CS;Chi,MM;Fell,RD;Ivy,JL;Kaiser,KK;Lowry,CV;Lowry,OH
大鼠跖肌和比目鱼肌在体内强烈刺激1和15分钟，冷冻夹持，并冷冻干燥，和个别纤维被解剖自由。根据乳酸脱氢酶和苹果酸脱氢酶将纤维分为四组，分别分析ATP、P-肌酸、糖原、葡萄糖、葡萄糖-6-磷酸（葡萄糖-6-P）、乳酸、柠檬酸和苹果酸。还分析了一些纤维的果糖1，6-磷酸，总腺苷酸和总肌酸。虽然作为一个整体，每组在控制成分和对刺激的反应方面表现出显着且通常很大的差异，但单个纤维的变化足以从一个极端到另一个极端产生几乎连续的代谢物水平谱。这些数据表明，在控制状态下，最慢的抽搐纤维是最活跃的。刺激1分钟导致所有组中ATP的小幅增加，“快白色”纤维中P-肌酸的大幅减少，其余纤维中P-肌酸的适度减少。刺激15分钟后，快速白色纤维失去了60%的初始ATP和97%的初始P-肌酸，而在其他类型的纤维，这些化合物进行了进一步的变化不大。代谢物的变化与刺激也最大的快白色纤维。葡萄糖-6-P上升15倍，在1分钟，然后下降到低于控制15分钟时，糖原已耗尽;乳酸上升2至6倍以上，比其他类型。所有组中的葡萄糖在15分钟时升高至与血浆平衡相容的水平。
Rat plantaris and soleus muscles were stimulated intensely in vivo for 1 and 15 min, freeze-clamped, and freeze-dried, and individual fibers were dissected free. Fibers, assigned to four groups on the basis of lactate dehydrogenase and malate dehydrogenase, were each separately analyzed for ATP, P-creatine, glycogen, glucose, glucose-6-phosphate (glucose-6-P), lactate, citrate, and malate. Some fibers were also analyzed for fructose 1,6-phosphate, total adenylate and total creatine. Although each group as a whole showed significant and often large differences in control composition and response to stimulation, individual fibers varied enough to create an almost continuous spectrum of metabolite levels from one extreme to the other. The data suggest that the slowest twitch fibers were the most active in the control state. Stimulation for 1 min caused a small increase in ATP in all groups with a large decrease in P-creatine in "fast white" fibers and a modest decrease in the rest. After 15-min stimulation, fast white fibers had lost 60% of initial ATP and 97% of initial P-creatine, whereas in other fiber types these compounds underwent little further change. Metabolite changes with stimulation were also greatest in fast white fibers. Glucose-6-P rose 15-fold in 1 min, then fell to below control by 15 min when glycogen had been exhausted; lactate rose two to six times more than in other types. Glucose rose in all groups to levels at 15 min, compatible with equilibrium with blood plasma.