Sullivan S M, Johnson P C
Am J Physiol. 1981 Oct;241(4):H547-56. doi: 10.1152/ajpheart.1981.241.4.H547.
The effect of O2 on arteriolar internal diameter, dual-slit velocity, and volume flow was studied by intravital microscopy in isolated autoperfused cat sartorius muscle. The muscle surface was covered with silicone oil, and gas mixtures containing 0, 5, 10, or 20% O2 in N2 were introduced over the muscle. When the O2 concentration was increased from 0 to 10%, arteriolar diameter, dual-slit velocity, and volume flow decreased on the average by 11 +/- 4, 30 +/- 29, and 37 +/- 13%, respectively. Under 20% O2, these parameters decrease by an additional 9 +/- 5, 29 +/- 10, and 30 +/- 14%, respectively. Percentage reduction in the diameter of large and small arterioles located at the same depth in the muscle were not significantly different. Conversely, the fall in volume flow was significantly greater in small arterioles. The lesser flow decrease in large vessels may reflect the fact that large vessels also feed deep muscle layers where the change in tissue O2 tension (PO2) is less. Our results do not support the hypothesis that small arterioles are intrinsically more sensitive to changes in tissue PO2.
通过活体显微镜观察法，在分离的自体灌注猫缝匠肌中研究了氧气对小动脉内径、双缝速度和容积流量的影响。肌肉表面覆盖有硅油，并将氮气中分别含有0%、5%、10%或20%氧气的混合气体通入肌肉上方。当氧气浓度从0%增加到10%时，小动脉直径、双缝速度和容积流量平均分别下降11±4%、30±29%和37±13%。在20%氧气条件下，这些参数分别再下降9±5%、29±10%和30±14%。位于肌肉同一深度的大、小动脉直径减少的百分比无显著差异。相反，小动脉中容积流量的下降明显更大。大血管中流量下降较小可能反映了这样一个事实，即大血管也为深部肌肉层供血，而深部肌肉层中组织氧张力（PO2）的变化较小。我们的结果不支持小动脉对组织PO2变化本质上更敏感这一假说。
