Gehr P, Brain J D, Bloom S B, Valberg P A
Nature. 1983;302(5906):336-8. doi: 10.1038/302336a0.
Previous studies have used magnetic particles to estimate the viscosity of cell cytoplasm in vitro 1-4. Here we describe how magnetic Fe2O3 particles can be used to estimate non-invasively the motion of organelles in hepatic macrophages in intact animals. We report that when these particles are injected intravenously (i.v.), most are phagocytosed by hepatic macrophages (Fig. 1)5. When an external magnetic field is applied to the rabbit, these particles become magnetized and aligned. After removal of the field, the particles collectively produce a remanent magnetic field which can be measured at the body surface. This field decreases with time due to particle rotation (relaxation) 6,7. As the particles are contained in phagosomes or secondary lysosomes, we conclude that motions of these organelles are responsible for the particle rotation and relaxation.
先前的研究已利用磁性颗粒在体外估算细胞质的黏度1-4。在此，我们描述了磁性Fe2O3颗粒如何用于在完整动物体内非侵入性地估算肝巨噬细胞内细胞器的运动。我们报告称，当将这些颗粒静脉内（i.v.）注射时，大多数会被肝巨噬细胞吞噬（图1）5。当对兔子施加外部磁场时，这些颗粒会被磁化并排列。去除磁场后，这些颗粒共同产生一个可在体表测量的剩余磁场。由于颗粒旋转（弛豫）6,7，该磁场会随时间减弱。由于颗粒包含在吞噬体或次级溶酶体中，我们得出结论，这些细胞器的运动是颗粒旋转和弛豫的原因。
