Andersen K S, Skjaerven R, Lekven J
Acta Physiol Scand. 1985 Apr;123(4):373-81. doi: 10.1111/j.1748-1716.1985.tb07603.x.
Distribution of radiolabelled microspheres is widely utilized for determination of regional blood flow in experimental myocardial infarction studies. The purpose of this investigation was evaluation of the microsphere method during 1 h of regional ischaemia. Special attention was focused upon loss of preocclusion microspheres from ischaemic myocardium; mechanisms for loss and blood flow distribution in non-ischaemic left ventricle. Microspheres (15 micron) were injected into the left atrium in nine pentobarbital anaesthetized cats prior to coronary artery occlusion and again after 1 h of occlusion. Preocclusion blood flow estimates were lower in ischaemic compared with non-ischaemic myocardium (1.36 vs. 1.62 cm3 X min-1 X g-1, P = 0.002), corresponding to 16% apparent loss. In endocardial ischaemic tissue, development of oedema could account for the loss. In epicardial ischaemic tissue, oedema was not present and loss was therefore due to migration of microspheres. Epicardial loss increased in proportion to restoration of left ventricular contractility. There was no evidence for significant microsphere loss through lymphatic pathways. In non-ischaemic left ventricular tissue, myocardial blood flow was evenly distributed from apex to base, and also between endocardial and epicardial layers. This study quantitates an important limitation to measurements of local blood flow in ischaemic myocardium by radiolabelled microspheres.
放射性标记微球的分布广泛应用于实验性心肌梗死研究中区域血流的测定。本研究的目的是评估局部缺血1小时期间的微球法。特别关注缺血心肌中闭塞前微球的丢失；非缺血性左心室中微球丢失的机制和血流分布。在9只戊巴比妥麻醉的猫冠状动脉闭塞前和闭塞1小时后，将微球（15微米）注入左心房。与非缺血心肌相比，缺血心肌闭塞前的血流估计值较低（1.36对1.62 cm3×min-1×g-1，P = 0.002），相当于16%的明显丢失。在心内膜缺血组织中，水肿的发展可解释微球的丢失。在心外膜缺血组织中，不存在水肿，因此微球的丢失是由于微球的迁移。心外膜微球丢失与左心室收缩力的恢复成比例增加。没有证据表明微球通过淋巴途径有明显丢失。在非缺血性左心室组织中，心肌血流从心尖到心底均匀分布，在心内膜和心外膜层之间也均匀分布。本研究定量了放射性标记微球测量缺血心肌局部血流的一个重要局限性。
