Cardinal Trevor R, Hoying James B
Physiological Sciences Program, University of Arizona, Tucson, Arizona, 85724, USA.
Vascul Pharmacol. 2007 Jul;47(1):48-56. doi: 10.1016/j.vph.2007.04.002. Epub 2007 Apr 19.
The goal of this study was to develop a modified fluorescent microsphere-based approach for measuring resting and hyperemic blood flows in individual mouse skeletal muscles. Absolute resting blood flow in the left gracilis posterior was 1.04+/-0.12 ml x min(-1).g(-1), while functional hyperemia following muscle activity was 5.94+/-1.33 ml x min(-1) x g(-1). Measuring absolute blood flow requires sampling arterial blood that serves as a flow-rate and concentration reference to the fluorescent microsphere (FMS) content in the tissue-of-interest for calculating the flow value. Because sampling arterial blood can impair cardiovascular function in the mouse, we also modified our FMS approach to determine relative blood flows in the left gracilis posterior by using the contralateral muscle as our reference in blood flow calculations. Absolute and relative hyperemia measurements detect similar increases in blood flow - 521.93+/-216.76% and 555.24+/-213.82%, respectively. However, sampling arterial blood during absolute blood flow measurements significantly decreased mean arterial pressure from the beginning to the end of our experiments, from 102.7+/-2.18 to 75.5+/-9.71 mm Hg. This decrease was not seen when measuring relative blood flows. This approach provides critical advantages over contemporary blood flow measurement approaches by allowing blood flow measurements in small and non-superficial tissues.
本研究的目的是开发一种基于荧光微球的改良方法，用于测量单个小鼠骨骼肌的静息和充血血流量。左侧股薄肌后部的绝对静息血流量为1.04±0.12 ml·min⁻¹·g⁻¹，而肌肉活动后的功能性充血为5.94±1.33 ml·min⁻¹·g⁻¹。测量绝对血流量需要采集动脉血，作为感兴趣组织中荧光微球（FMS）含量的流速和浓度参考，以计算流量值。由于采集动脉血会损害小鼠的心血管功能，我们还对FMS方法进行了改良，在血流量计算中使用对侧肌肉作为参考，以确定左侧股薄肌后部的相对血流量。绝对和相对充血测量分别检测到血流量相似的增加——分别为521.93±216.76%和555.24±213.82%。然而，在绝对血流量测量过程中采集动脉血，从实验开始到结束，平均动脉压显著降低，从102.7±2.18降至75.5±9.71 mmHg。在测量相对血流量时未观察到这种下降。该方法相对于当代血流量测量方法具有关键优势，能够在小型和非浅表组织中进行血流量测量。
