Mimran A, Casellas D
Pflugers Arch. 1979 Nov;382(3):233-40. doi: 10.1007/BF00583707.
The influence of microsphere size upon the estimation of cardiac output (CO), renal blood flow (RBF) and its cortical distribution (ICBFD) was evaluated by simultaneous injection of 8.5 +/- 0.8 micrometer (SD) and 12.7 +/- 1.7 micrometer (SD) spheres in control conditions and after hemorrhagic hypotension (HH rats). The values of CO and RBF were unaffected whilst the ratio of flow to outer and inner halves of cortex (OCF/ICF) was 32% higher with 12.7 micrometer than with 8.5 micrometer spheres in both groups. Microscopic analysis of cleared kidneys slices confirmed that large spheres were more concentrated in outermost and less concentrated in innermost glomeruli than small spheres. In addition, the ratio of sphere number per outermost to that per innermost glomerulus (fs/fjm), and approximation of glomerular blood flow distribution was 1.74 and 1.76 with large spheres and 0.98 and 1.06 with small spheres in control and HH rats respectively. It is concluded that the artifact due to sphere size was not minimized in low flow conditions (HH rats) and that 8.5 micrometer spheres may be a more realistic marker of glomerular blood flow distribution in the rat than 12.7 micrometer spheres.
通过在对照条件下以及失血性低血压（HH大鼠）后同时注射直径为8.5±0.8微米（标准差）和12.7±1.7微米（标准差）的微球，评估微球大小对心输出量（CO）、肾血流量（RBF）及其皮质分布（ICBF D）估计的影响。在两组中，CO和RBF的值均未受影响，而直径12.7微米微球组皮质外半区与内半区的血流比值（OCF/ICF）比直径8.5微米微球组高32%。对清除后的肾脏切片进行显微镜分析证实，大微球在最外层肾小球中更集中，而在最内层肾小球中浓度较低。此外，在对照大鼠和HH大鼠中，大微球最外层与最内层肾小球的微球数量比值（fs/fjm）以及肾小球血流分布的近似值分别为1.74和1.76，而小微球分别为0.98和1.06。得出的结论是，在低流量条件下（HH大鼠），由于微球大小导致的假象并未最小化，并且与12.7微米微球相比，8.5微米微球可能是大鼠肾小球血流分布更真实的标志物。
