Toth A, Pal M, Tischler M E, Johnson P C
Department of Physiology, University of Arizona, Tucson 85724, USA.
Am J Physiol. 1996 Jun;270(6 Pt 2):H1933-9. doi: 10.1152/ajpheart.1996.270.6.H1933.
The purpose of this study was to determine whether there are local regions in resting skeletal muscle in which the oxygen delivery is insufficient to support oxidative metabolism. This hypothesis was tested by stopping the blood supply to the exteriorized cat sartorius muscle for 5 min while monitoring NADH fluorescence in localized tissue areas 15-25 microns in diameter. A rise in fluorescence was taken to indicate a shift to anaerobic metabolism. Tissue sites in the arteriolar and venular regions of the capillary network were selected for study. After flow stoppage, fluorescence did not change for an average of 48 +/- 22 (SD) s and then rose over a period of 61 +/- 27 s to an average value 55 +/- 19% above control for arteriolar and venular sites combined. Fluorescence began to rise within 5 s of flow stasis in only 1 of 61 sites and within 10 s in 2 sites. There was no difference in the time course or magnitude of fluorescence changes at arteriolar and venular sites. The data indicate that in resting skeletal muscle, oxygen supply appears sufficient to support oxidative metabolism in over 95% of the tissue.
本研究的目的是确定在静息骨骼肌中是否存在局部区域，其氧气供应不足以支持氧化代谢。通过在监测直径为15 - 25微米的局部组织区域中NADH荧光的同时，将外部化的猫缝匠肌的血液供应中断5分钟，来检验这一假设。荧光增强被视为向无氧代谢的转变。选择毛细血管网的小动脉和小静脉区域的组织部位进行研究。血流停止后，荧光平均在48 +/- 22（标准差）秒内没有变化，然后在61 +/- 27秒的时间内上升，小动脉和小静脉部位合并后的平均值比对照高出55 +/- 19%。在61个部位中，只有1个部位的荧光在血流停滞后5秒内开始上升，2个部位在10秒内开始上升。小动脉和小静脉部位荧光变化的时间进程或幅度没有差异。数据表明，在静息骨骼肌中，超过95%的组织中氧气供应似乎足以支持氧化代谢。
