Red blood cell velocity and oxygen tension measurement in cerebral microvessels by double-wavelength photoexcitation
Red blood cell velocity and oxygen tension measurement in cerebral microvessels by double-wavelength photoexcitation
复制标题
DOI：
10.1152/japplphysiol.00764.2003
复制
发表时间：
2004-04-01
影响因子：
3.3
通讯作者：
Minamitani, H
中科院分区：
文献类型：
--
作者：
Tsukada, K;Sekizuka, E;Minamitani, H
由于如果不测量脑微血管中的血流动力学和氧浓度，就无法分析大脑皮层微循环的调节，因此我们开发了一种荧光和磷光系统，用于以高空间分辨率无创、连续地估计脑微循环中的红细胞速度和氧张力。使用荧光异硫氰酸盐标记的红细胞来可视化红细胞分布，并使用 Pd-内消旋四-(4-羧基苯基)-卟啉磷光的氧猝灭来测量氧张力，从而能够同时测量血流速度和氧张力。我们研究了空间分辨率以及穿过目标微血管并激发其下方组织中的氧探针染料的激发激光如何影响测量精度。将激发光聚焦到微容器中可以稳定每个空间分辨率下的磷光寿命；此外，它还大大减少了脑组织的磷光。涉及急性失血性休克的动物实验表明，小静脉流速和氧张力的变化与平均动脉压的变化同步，证明了我们的系统的可行性。我们的系统利用荧光和磷光之间的发光和波长的差异来测量脑微循环中的红细胞速度和氧浓度，使得可以轻松地同时获取有关脑微循环分布和氧张力的信息。
Because the regulation of microcirculation in the cerebral cortex cannot be analyzed without measuring the blood flow dynamics and oxygen concentration in cerebral microvessels, we developed a fluorescence and phosphorescence system for estimating red blood cell velocity and oxygen tension in cerebral microcirculation noninvasively and continuously with high spatial resolution. Using red blood cells labeled with fluorescent isothiocyanate to visualize red cell distribution and using the oxygen quenching of Pd-meso-tetra-(4-carboxyphenyl)-porphyrin phosphorescence to measure oxygen tension enabled simultaneous measurement of blood velocity and oxygen tension. We examined how the measurement accuracy was affected by the spatial resolution and by the excitation laser light passing through the targeted microvessel and exciting the oxygen probe dye in the tissue beneath it. Focusing the excitation light into the microvessel stabilized the phosphorescence lifetime at each spatial resolution; moreover, it greatly reduced phosphorescence from the brain tissue. Animal experiments involving acute hemorrhagic shock demonstrated the feasibility of our system by showing that the changes in venular velocity and oxygen tension are synchronized to the change in mean arterial pressure. Our system measures the red cell velocity and oxygen concentration in the cerebral microcirculation by using the differences in luminescence and wavelength between fluorescence and phosphorescence, making it possible to easily acquire information about cerebral microcirculatory distribution and oxygen tension simultaneously.