Effects of Blood Pressure and Blood Viscosity on Fluorescein Transit Time in the Cerebral Microcirculation in the Mouse
Effects of Blood Pressure and Blood Viscosity on Fluorescein Transit Time in the Cerebral Microcirculation in the Mouse
复制标题
血压和血液粘度对小鼠脑微循环荧光素渡越时间的影响
作者：
W. Rosenblum
通过分析以40帧/秒拍摄的电影，在小鼠中测量黄绿素从软脑膜小动脉到软脑膜小静脉的通过时间。血压升高缩短了通过时间。血液粘度增加延长了通过时间。通过使动物红细胞增多或通过输注高分子量葡聚糖来增加粘度。使用两种不同的葡聚糖。具有较高分子量（500，000）的一种比具有较低分子量（250，000）的一种产生更高的粘度和更长的过渡时间。尽管在体外应用的生理相关剪切速率范围内，红细胞增多症中的全血粘度超过了右旋糖酐处理小鼠的全血粘度，但这些右旋糖酐产生的通过时间延长等于或大于在红细胞增多症动物中观察到的通过时间延长。旋转粘度计。结果表明，血液粘度的增加导致血浆速度的降低，并且通过提高血细胞比容所带来的粘度增量可能不如通过提高血浆粘度所带来的粘度增量有效。
Fluorescein transit time from pial arterioles to pial venules was measured in the mouse by analyzing motion pictures taken at 40 frames/sec. Increased blood pressure reduced the transit time. Increased blood viscosity lengthened the transit time. Viscosity was increased by rendering the animals polycythemic, or by infusions of high molecular weight dextran. Two different dextrans were used. The one with the higher molecular weight (500,000) produced a higher viscosity and a more prolonged transit time than the one with the lower molecular weight (250,000). These dextrans produced a prolongation of the transit time equal to that, or greater than that, observed in the polycythemic animals, even though whole blood viscosity in polycythemia exceeded that of the dextran treated mice over a wide range of physiologically pertinent shear rates applied in vitro in a rotational viscometer. Results indicate that increases of blood viscosity produce decreases in the velocity of the plasma, and that viscosity increments brought about by raising the hematocrit, may be less effective than viscosity increments brought about by raising the viscosity of the plasma.