Gutmann F D, Murthy V S, Wojciechowski M T, Wurm R M, Edzards R A
Circ Shock. 1987;21(3):185-95.
We evaluated the time-course of regional platelet sequestration, following a bolus dose of endotoxin in anesthetized dogs. Autologous indium 111 labeled platelets, representing less than 1% of the circulating platelets, were injected 35-60 min prior to administering endotoxin intravenously to dogs. A gamma camera was used to monitor the distribution of these platelets within the thorax and abdomen. Alterations in the circulating blood platelet count paralleled the changes in blood radioactivity, enabling us to use external imaging to evaluate platelet kinetics. Marked hypotension and thrombocytopenia occurred within 6 min after administering endotoxin. The platelet pool in the lungs peaked at 9 min and was temporally related to the decrease in circulating platelet count, hypotension and increase in liver size. Translocation of platelets from the lungs to the circulating platelet pool occurred during the subsequent hour with sequestration occurring in the liver and possibly other organs. During this phase there was a recovery in platelet count to 35% of baseline levels but without significant recovery in mean arterial pressure. Based on these results we propose that endotoxin-induced thrombocytopenia results from pulmonary and hepatic sequestration of platelets, but that sequestration of platelets in the lungs is only transient. The mechanism and significance of subsequent translocation of platelets from the lungs to other sites, particularly the liver and the circulating platelet pool, remain to be investigated.
我们评估了麻醉犬静脉注射大剂量内毒素后局部血小板滞留的时间进程。在给犬静脉注射内毒素前35 - 60分钟，注射了占循环血小板不到1%的自体铟111标记血小板。使用γ相机监测这些血小板在胸腹部的分布。循环血小板计数的变化与血液放射性的变化平行，这使我们能够利用外部成像来评估血小板动力学。注射内毒素后6分钟内出现明显低血压和血小板减少。肺内血小板池在9分钟时达到峰值，且在时间上与循环血小板计数减少、低血压及肝脏肿大增加相关。随后一小时内，血小板从肺向循环血小板池转移，同时血小板在肝脏及可能的其他器官中滞留。在此阶段，血小板计数恢复至基线水平的35%，但平均动脉压无明显恢复。基于这些结果，我们提出内毒素诱导的血小板减少是由于血小板在肺和肝脏的滞留所致，但血小板在肺内的滞留只是短暂的。血小板随后从肺向其他部位，特别是肝脏和循环血小板池转移的机制及意义仍有待研究。
