Postmortem diffusion of autoradiographic blood flow tracers.
Postmortem diffusion of autoradiographic blood flow tracers.
复制标题
放射自显影血流示踪剂的死后扩散。
DOI：
10.1016/s0006-8993(99)01854-5
复制
发表时间：
1999
期刊：
影响因子：
2.9
通讯作者：
Chen,J
中科院分区：
文献类型：
--
作者：
Greenberg,JH;LoBrutto,C;Lombard,KM;Chen,J
在正常和病理生理条件下，以及在功能激活过程中，大脑中的血流的异质性，激发了兴趣，在使用放射自显影作为一种技术，用于测量局部脑血流。[14C碘安替比林是局部脑血流放射自显影测量中最常用的示踪剂，因为它是惰性的、非挥发性的，并且容易通过血脑屏障扩散。然而，如果动物被处死和组织被冷冻之间的持续时间变得可观，则在脑组织中自由扩散的能力可能导致显著的误差，从而导致示踪剂的显著死后扩散。使用体外技术，[14 C]碘安替比林在脑组织中的体扩散系数（2.1×10− 6cm 2/s）被测量。在麻醉大鼠中，用[14 C]碘安替比林测量脑血流量。在放射性示踪剂输注结束时，使用由两个快速旋转的不锈钢刀片组成的装置冷冻捕获大脑，所述不锈钢刀片被旋转驱动穿过头部，在处死后几百毫秒冷冻组织。这些脑的放射自显影显示出血流的显著异质性。计算机模拟示踪剂扩散对这些放射自显影的影响显示显着退化的图像突出非常快速的死后冷冻的重要性。
The heterogeneity of blood flow in the brain under normo- and pathophysiological conditions, as well as during functional activation, has stimulated an interest in the use of autoradiography as a technique for the measurement of local cerebral blood flow. [14C ]iodoantipyrine is the most prevalent tracer for the autoradiographic measurement of local cerebral blood flow since it is inert, nonvolatile, and is readily diffusible through the blood–brain barrier. The ability to diffuse freely in cerebral tissue, however, can lead to significant errors if the time duration between when the animal is sacrificed and when the tissue is frozen becomes appreciable, leading to significant postmortem diffusion of the tracer. Using an in vitro technique, the bulk diffusion coefficient for [14C ]iodoantipyrine was measured in brain tissue (2.1×10−6cm2/s). Cerebral blood flow was measured with [14C ]iodoantipyrine in anesthetized rats. At the end of the radiotracer infusion, the brain was freeze-captured using a device consisting of two rapidly spinning stainless steel blades that were pneumatically driven through the head, freezing the tissue several hundred milliseconds following sacrifice. Autoradiograms from these brains exhibit considerable heterogeneity in blood flow. Computer simulations of the effect of tracer diffusion on these autoradiograms show significant degradation of the images highlighting the importance of very rapid postmortem freezing.