Mossberg K A, Mommessin J I, Taegtmeyer H
Department of Medicine, University of Texas Health Science Center, Houston.
Metabolism. 1993 Dec;42(12):1609-16. doi: 10.1016/0026-0495(93)90158-k.
The goal of the present study was to examine the time course of skeletal muscle glucose uptake and changes in intracellular metabolites occurring with the onset of in situ stimulation, and to assess the effect of a prior period of contractions on subsequent contraction-induced increases in glucose uptake. Hindlimb muscle in anesthetized rabbits was studied noninvasively using the positron-emitting glucose analog 18F-2-fluoro-deoxy-D-glucose (FDG). Fractional rates of FDG phosphorylation were measured on a minute-to-minute basis during rest, 3.5 minutes of priming exercise (PE), 15 or 30 minutes of PE recovery, and a subsequent 15-minute period of contractions. Muscles were electrically stimulated at 2 Hz, and force production was held constant during the contraction period(s). FDG uptake did not differ from control values either during PE or during 60 minutes of recovery from PE. In response to 15 minutes of contractions, muscle stimulated without PE demonstrated increased FDG uptake, but only after a delay of 5.0 +/- 0.7 minutes. Muscle with PE but rested 15 minutes had increased FDG uptake with a delay of 0.5 +/- 0.2 minutes, and muscle with PE but rested 30 minutes had increased FDG uptake after a delay of 8.0 +/- 0.9 minutes (P < .01 all groups). All groups reached similar levels of FDG uptake by the end of 15 minutes of contractions. Both groups with PE had control levels of adenosine triphosphate (ATP), phosphocreatine (PCr), and glucose-6-phosphate (G6P) after PE recovery, but glycogen level was lower than the control value (P < .05).(ABSTRACT TRUNCATED AT 250 WORDS)
本研究的目的是检查骨骼肌葡萄糖摄取的时间进程以及原位刺激开始时细胞内代谢物的变化，并评估前期收缩对随后收缩诱导的葡萄糖摄取增加的影响。使用正电子发射葡萄糖类似物18F-2-氟-脱氧-D-葡萄糖（FDG）对麻醉兔的后肢肌肉进行无创研究。在静息、3.5分钟的预运动（PE）、15或30分钟的PE恢复以及随后15分钟的收缩期间，每分钟测量FDG磷酸化分数率。以2Hz的频率对肌肉进行电刺激，在收缩期力的产生保持恒定。在PE期间或从PE恢复的60分钟内，FDG摄取与对照值无差异。在15分钟收缩期，未进行PE刺激的肌肉在延迟5.0±0.7分钟后FDG摄取增加。进行PE但休息15分钟的肌肉在延迟0.5±0.2分钟后FDG摄取增加，进行PE但休息30分钟的肌肉在延迟8.0±0.9分钟后FDG摄取增加（所有组P<0.01）。在15分钟收缩期末，所有组的FDG摄取达到相似水平。两组进行PE的肌肉在PE恢复后三磷酸腺苷（ATP）、磷酸肌酸（PCr）和葡萄糖-6-磷酸（G6P）水平与对照值相同，但糖原水平低于对照值（P<0.05）。（摘要截断于250字）
